INSTAAR Noon Seminar-Abstracts

Selected Abstracts
INSTAAR Noon Seminars

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20 Feb. Chris Jenkins, INSTAAR
"Google and Wordnet methods applied to sediment/rock/soil vocabularies."

Complex vocabularies are a big problem in the Earth Sciences. And they stand in the way of modern science directions like multidisciplinary research, widescale data integration, and crossing the model-data divide. Google/Wordnet computational linguistics can produce accurate software 'crosswalks' through the semantic mazes. Then those formal, shallow and dogmatic 'Ontologies' that we have all sat through lectures on, might become a thing of the past.

13 Feb. Chuck Kutscher, National Renewable Energy Laboratory.
"CSP: The other solar electric technology."

Most people are familiar with photovoltaic modules, which convert sunlight directly into electricity. But there is another form of solar electricity that has re-emerged in recent years: concentrating solar power, or CSP. CSP systems concentrate sunlight to achieve the high temperatures needed to run thermodynamic power cycles of the type used in conventional power plants. Because these systems can incorporate relatively inexpensive thermal storage, they can provide electricity during times when the solar resource is low and can help to enable the large penetration of variable renewable technologies into the electric grid. The talk will describe this technology and present some of the research underway at NREL to improve its efficiency and lower its costs.

06 Feb. Brad Udall, CU-NOAA Western Water Assessment.
"Lessons in water management from Australia for the Colorado River Basin."

The Murray Darling Basin in Australia bears many geographic and climatic similarities to the Colorado River Basin but Australian water management is remarkably different from that utilized in the United States. Since the early 1990s Australia has pursued a broad national agenda of water reform which includes full cost pricing, sufficient water for the environment, water conservation, irrigation infrastructure improvements, and clear delineation of roles and responsibilities of different water institutions among other reforms. A series of substantial changes to commonwealth and state law has resulted from these major initiatives. This reform effort was capped by groundbreaking commonwealth legislation in 2007 and 2008 that to large extent federalized the operation of the nation’s largest river system, the Murray-Darling. A new basin wide authority, the MDBA, was created to manage the river via the concept of sustainable diversion limits (SDLs) to be promulgated through additional federal legislation. The October 2010 initial plan for these SDLs suggested cuts in use of up to 40% in the basin and was met with widespread opposition by irrigators. Subsequently, top leadership in the MDBA resigned, a number of parliamentary inquiries were begun, and the entire process has been delayed. How did Australia get to its current position with respect to water reform, and what is the likely outcome of the current delay? How has water management evolved in Australia over the last 20 years? What lessons exist for the Western United States and especially the Colorado River Basin?

Science plays an increasingly important role in our society to help explain the natural world around us and inside us. Greater understanding can feed the engines for enviro-socio-economic advances. As we use ever more complex tools to produce more accurate models and more robust findings, the very intricacies of our discipline and the language of our science can alienate us from the very audience who could most benefit from the insight that our science provides.

There are numerous advantages to sharing science with the public, from increasing global awareness about earth systems to greasing the skids with existing and potential funders. But successfully accomplishing this task has become a science in and of itself. During this talk we will examine the role of cutting-edge science in society and what has proven effective or ineffective for reaching out with information to given populations. We can no longer avoid the most pressing question, “Does awareness result in action”? We will discuss simple methods to better reach target audiences presenting specific initiatives to provide both the public and policy makers with empowerment and information for wise decision-making.

23 Jan. Mark Serreze, National Snow and Ice Data Center (NSIDC).
"Lessons learned in communicating the science of Climate Change."

Nowhere on the planet are emerging signals of global climate change more visible than in the Arctic. The Arctic is warming faster than the rest of the planet, with thawing permafrost, replacement of barren, windswept tundra by shrub vegetation, accelerated coastal erosion, and, most striking of all, a quickly shrinking sea ice cover. The National Snow and Ice Data Center (NSIDC) has assumed a strong role in communicating the science of Arctic change to the public. Through experiences gained in responding to interview requests from the media, a growing web presence including our popular “Arctic Sea Ice News and Analysis”, trial, error, and occasional embarrassment, NSIDC scientists and staff have learned many valuable lessons. The most important of these are: 1) NSIDC’s credibility lies in its role as an honest broker of data and information. While the line separating science communication and advocacy may be grey, we must always be aware that it exists; 2) Effective communication places equal emphasis on scientific accuracy and accessibility to a wide audience; 3) Quickly acknowledge errors and accept responsibility for them; 4) Accept that data, information and the reputation of NSIDC scientists will sometimes be misused, but that making data and information freely available is more effective than trying to restrict access; 5) Vigilantly monitor how our data are represented and discussed in media and blogs, and try and set the record straight when necessary. This talk examines lessons learned from reporting recent significant events, for example, the record-setting sea ice minimum of 2007, public responses to a satellite sensor failure that led to erroneous depictions of sea ice extent, tactics of climate “skeptics,” and incorrect attribution of scientifically inaccurate statements to NSIDC. What have we learned, and how are we using these lessons to improve how NSIDC communicates climate science?

28 Nov. Patty Limerick, Center of the American West.
"A ditch in time: Denver, the West, and water."

Tracing the origins and growth of the Denver Water Department, the book, A Ditch in Time: The City, the West, and Water (to be published in the Fall of 2012) places this case study in the big picture of regional, national, and even international history. Written with humor and in a style aimed at demystifying the arcane workings of water law and policy, this book raises questions of consequence about the uneasy relationship between democracy and conservation, the complex relationship among cities, suburbs, and rural areas, the crucial role of engineering in shaping the West, the unexpectedly entrancing workings of governmental agencies and bureaucracies, and the varying roles of contention and cooperation, litigation and negotiation in the control of the West's water. In the presentation at INSTAAR, Limerick will provide a lightning-paced review of Denver Water’s history and then harvest lessons that have bearing on the work of environmental scientists: the impacts of diversions on watersheds and the quest for a baseline to calibrate disturbance; the relationship between headwaters counties and downstream users; and the stance of water utilities toward climate change studies, a positioning that that often steers clear of the politicized tangles in which so many other public agencies and organizations are now bogged.

14 Nov. Bill Denig, NOAA, NGDC.
"Space weather and nighttime lights of the world."

The auroral borealis is a beautiful and awe-inspiring manifestation of solar-terrestrial interactions which is often described in terms of Space Weather. During this talk I will discuss various aspects and impacts of space weather starting within the context of auroral emissions in the near-earth space environment and then working outwards into the terrestrial magnetosphere, interplanetary space and finally the sun. For over 50 years, NOAA has provided space weather services and the Solar & Terrestrial Physics division within the National Geophysical Data Center (NGDC) has been responsible for stewarding the Nation’s operational space weather data. One aspect of this has been monitoring aurora from space using sensitive while light imagers on polar-orbiting satellites. These data have also been used to provide stunning views of the darkened earth in the form of the famous “Nightime Lights of the World”. While beautiful in and of themselves, these nighttime images of the earth are primarily used by NOAA to monitor national economic prosperity, population migrations over time, and infrastructure impacts of natural and manmade disasters. This noontime seminar will provide a general overview of space weather and of the associated uses of nighttime lights earth imagery.

07 Nov. James R. McGoodwin, INSTAAR Research Affiliate
"The world's fisheries: Yesterday, today, and tomorrow."

Yesterday's prime concerns in ocean fisheries were underscored by catastrophic declines and changed access regimes prescribed by the new Law of the Sea in 1982. From these phenomena a robust interest in fishing communities arose which explored the implications of various property institutions, as well as the roles fishing communities might play in management. The tendency to conceptualize fisheries as regions with certain marine species moved toward conceptualizing them as ecosystems, prompting new concerns about the impact of fishing practices, fish stocks that straddle national boundaries, and sustainable fishing practices. And at the same time that management regimes increasingly limited entry and facilitated the commodification of fisheries resources, more holistic thinking about fisheries governance emerged. Now new challenges are emerging which may become the prime concerns in the near future --climatic and ecological change, the further extension of aquaculture into the oceans and seas, and ever more engineering of the planet's last great wild domain.

31 Oct. Piotr Wolski, University of Botswana.
"Climatic, hydrological and geomorphological changes in the Okavango Delta of Botswana."

The Okavango Delta is a large, pristine flood-pulsed wetland system located in northern Botswana, Africa, that has been recognized as a Ramsar site, a wetland of international importance. This talk will focus on how hydrological variability in the Okavango Delta is shaped by interactions between natural climatic variability, anthropogenic climate change, and endogenous transformation of the wetland. Statistical analyses, climate and hydrological modelling are used to show that a) in the long-term the system is driven by multidecadal periodicity in rainfall, possibly related to global climatic processes represented by the Pacific Decadal Oscillation, b) anthropogenic climate change actually moderates rather than causes the high flood conditions observed in the recent years and c) the entire system is subject to gradual redistribution of water, independent of the overall wetness of the system. Implications of these for management of the system under sustainable use imperative will be discussed.

24 Oct. Jim Balog, Extreme Ice Survey, INSTAAR affiliate.
"From ice to fire to forests: A year in the life of the Extreme Ice Survey."

Having started out monitoring retreating glaciers in various regions of the world, the EIS team has been employing it's methodology to document other changes to our planet. In the last two years we have monitored beetle kill in the Rocky Mountain region and the effects of the Fourmile Canyon fire. We photographed the aftermath of the Gulf oil spill, and are observing atmospheric dust in the four corners region. In this lecture, we will present some of images we have obtained and discuss the techniques the Survey is using.

17 Oct. Stephen G. Osborn, California Polytechnic University, Pomona.
"Hydraulic fracturing - Environmental perspective."

Hydraulic fracturing and directional drilling technologies have significantly expanded natural gas production from organic-rich shale formations in the US and worldwide. A lack of published scientific data on the potential for environmental and health impacts has precluded a thorough assessment of risks. This talk will discuss potential environmental impacts to shallow groundwater associated with intensive natural gas extraction from the Marcellus organic-rich shale in northeast Pennsylvania. Recent research (Osborn et al., 2011) noted higher methane concentrations (17 times higher on average) in areas with active natural gas extraction when compared to areas without extraction (non-active). Additionally, the dissolved gas geochemistry in active extraction areas was distinctly different and characteristic of a deep-seated organic matter source when compared to non-active extraction areas that had dissolved gas characteristic of mixed or biogenic origin. Importantly, there was no evidence in this study for contamination of shallow groundwater by hydraulic fracturing fluids based on major elemental analyses and some isotopic constituents (oxygen, hydrogen, carbon, boron, and 226Radium) when compared to historic groundwater analyses from the region and between active and non-active extraction areas. More published research is necessary to understand the mechanisms of fluid flow and assess health effects of natural gas (Jackson et al, 2011). This research could improve the public confidence, and ensure a sustainable future for both natural gas extraction and groundwater resources.

10 Oct. Will Fleckenstein, Colorado School of Mines.
"Shale drilling and hydraulic fracturing."
Location change for this talk only
RL-1 Room 269 (RL-1 is just west of ARC/ RL-3)

The combination of horizontal drilling and hydraulic fracturing has led to a resurgence in oil and gas drilling in many parts of the United States, with many other countries actively watching the American experience with this technology. This talk discusses what horizontal drilling and multi-stage hydraulic fracturing are and what are the technical issues that are involved with the technology.

03 Oct. Moe Tabrizi, CU Boulder Facilities Management.
"Sustainability and the new Geosciences building."

Tabrizi will discuss campus sustainability initiatives and results. He will be covering CU's focus and payback on design and constructing green and sustainable buildings. In addition, he will discuss energy and water conservation in CU's research labs and the overall campus energy and water consumption and trends. This will be a good time to discuss sustainability and the new Geosciences Building.

26 Sep. Gifford Miller, INSTAAR.
"The end of the Ice Age; Modeling the disappearance of the Barnes Ice Cap."

The Laurentide Ice Sheet covered most of Canada & NE USA ~20 ka, but began to retreat in earnest by 16 ka. Most of the Northern Hemisphere thought the ice age was over by 10 ka, but at that time most of the Eastern Canadian Arctic was still under the ice sheet. The waning ice sheet continued to retract to the NE through the early and middle Holocene, until by 3 ka, its only remnant was the Barnes Ice Cap, resting on the high plateau of Baffin Island. By then, orbital changes had reduced summer insolation sufficiently that the Barnes Ice Cap stabilized, leaving it the only true remnant of the great ice sheet. For the next 3000 years the ice cap changed very little. However, an increasing body of evidence suggests that over the past 60 years the Barnes Ice Cap has transitioned from an equilibrium state to one of melt at all elevations. Under the current regime, even with no additional warming, it is inevitable that the ice cap will eventually disappear. Unlike other ice caps in the Canadian Arctic, the Barnes Ice Cap rests on a gently undulating, tilted plateau, without large outlet glaciers, or a marine terminus. This makes it a straightforward numerical modeling target. New geospatial technologies, including multi-year lidar altimetry and differential gps surveys, define the rate of ice cap thinning. Lidar altimetry, ice-penetrating radar, 2011 stereo imagery, and georeferenced topomaps will allow development of a sub-ice bedrock DEM and ice-surface DEMs for 1961 and 2011 that provide secure modeling targets. Given the inevitability of the ice cap’s demise, we can ask how frequently have past interglacials been warm enough to produce complete deglaciation. That answer, it appears, is not very often. Cosmogenic radionuclide inventories in rocks immediately adjacent to the ice cap suggest that the Barnes Ice Cap almost never disappeared during past interglaciations, reinforcing the unusual nature of the ice cap’s pending disappearance during a summer insolation minimum.

19 Sep. Natalie Mladenov, INSTAAR.
"Atmospheric deposition as a source of carbon and nutrients to barren soils of Niwot Ridge, CO."

Alpine environments are often thought of as remote areas unaffected by direct human influence. However, there is much evidence that atmospheric deposition of pollutants, dust, nutrients, and other aerosols, both inorganic and organic, influences alpine areas. For example, aeolian transport delivers P, Ca, and other nutrients to oligotrophic alpine lakes and has been shown to have a fertilizing effect on phytoplankton in these systems. More recently, atmospheric deposition of organic carbon was found to have an important influence on dissolved organic matter (DOM) concentrations and optical properties in clear, alpine lakes globally. The potential for atmospheric deposition of nutrients and DOM to also influence terrestrial biogeochemical processes is a central question for our research in the barren alpine regions of Green Lake Valley, Niwot Ridge, CO. To assess this influence, we evaluated concentrations and loadings of organic and inorganic species in snow and in National Atmospheric Deposition Program (NADP) and NWT-LTER deposition collectors at Niwot Ridge.

Wet deposition was found to be a seasonally variable source of dissolved organic carbon (DOC), depositing roughly 1500 kg C to the Green Lake 4 (GL4) watershed. This input of DOC was equivalent to over 80% of the carbon yield from the watershed. Wet deposition loadings of nitrogen and phosphorus were also substantial compared to the yield of these constituents. Dry deposition represents another extremely important input of DOC, nitrogen, and phosphorus and appears to be the main input of calcium to the GL4 watershed.

Given that atmospheric DOM inputs are substantial, a key question now is whether this C source is labile and involved in microbial and biogeochemical processes in these barren soils. Characterization of DOM quality in wet and dry deposition by fluorescence and absorbance spectroscopy showed that in summer months, high concentrations of amino acid-like fluorescence were associated with large numbers of pollen and other bioaerosols. Further, the optical properties of DOM in atmospheric deposition reflect intense photobleaching of DOM, which may enhance its bioavailability.

12 Sep. G. Robert Brakenridge, INSTAAR.
"Core-collapse supernovae and the Younger Dryas/terminal Rancholabrean extinctions."

Early predictions that some supernovae release large quantities of prompt high energy photons are now corroborated by optical identification of core-collapse supernovae associated with extragalactic gamma bursts and x-ray flashes. Given in-galaxy supernova frequency and recurrence statistics, significant Earth-incident events during the past several million years very likely occurred. Such nearby events should have affected terrestrial surface solar UV, the Earth’s climate, and its ecology. The Younger Dryas Stadial, commencing at ~12,900 calendar yr BP, began with sharply cooler temperatures in the Earth’s northern hemisphere, regional drought, paleoecological evidence compatible with increased UV, and abrupt increases in cosmogenic 14C and 10Be in ice and marine cores. In North America,stratigraphic and faunal sequences indicate that a major pulse of mammalian extinctions began very close to 12,830 calendar yr BP and was sudden. A 10 s beamed gamma burst within 2 kpc of the Earth causes spallation and catalytic reactions depleting 35–50% O3, and producing excess NOx species (which favor cooling and drought), 14C and 10Be. An un-beamed, 10^50 erg hard photon impulse at ~250 pc distance produces similar terrestrial atmospheric effects, with recovery times measured in several 10^2 yr. A well-characterized massive star supernova, the unusually close Vela event(d = 250 ± 30 pc; total energy of 1–2 x 10^51 erg; age constrained from remnant nebula shock velocities considerations at ~13,000–16,000 yr) may have initiated the Younger Dryas climate change, and caused the "Rancholabrean" faunal extinctions.

25 Apr. Peter van der Beek, Université Joseph Fourier, Grenoble..
"Erosion rates and relief development in the Western European Alps in response to late Quaternary climate change."

The Ecrins-Pelvoux massif (French Western Alps) was extensively glaciated during Quaternary glaciations, leading to a ~100 % increase in relief through glacial valley carving and leaving a strong imprint on the morphology of the massif¹. Here, I aim to address the efficiency of erosion processes in relief evolution in response to deglaciation of the massif 15-17 ka ago. Denudation rates inferred from in-situ produced 10Be concentrations in stream sediments, obtained from 12 catchments throughout the Ecrins-Pelvoux massif, correlate with mean catchment elevation in the absence of significant relationships with other morphometric parameters². We have proposed² that present-day (millennial-timescale) denudation of Ecrins-Pelvoux massif is climatically driven through increasing efficiency of frost-controlled processes with elevation, providing a mechanistic link for the inferred feedback between uplift, elevation and denudation rates observed in the European Alps^{3, 4}.

However, cosmogenic isotope measurements in stream sediments do not allow distinguishing the intrinsic spatial variability of denudation within a catchment. Therefore, we have sought to verify our previous conclusions on a smaller scale within a single catchment, from exhaustive measurements of 10Be concentrations carried by different sources feeding the high-altitude sediment routing system, in order to develop a 10Be budget at the catchment scale. 10Be concentration measurements at a single catchment scale suggest the processes within a catchment to be more complex than our initial interpretation based on catchment-wide erosion rates on the massif scale. In particular, the roles of attrition of scree material, transient storage of scree deposits on slopes leading to non-steady state conditions on Holocene timescales, and strongly localised glacial and fluvial erosion need to be taken into account.

References
1. van der Beek, P. & Bourbon, P. A quantification of the glacial imprint on relief development in the French Western Alps. Geomorphology 97, 52-72 (2008).
2. Delunel, R., van der Beek, P. A., Carcaillet, J., Bourlès, D. L. & Valla, P. G. Frost-cracking control on catchment denudation rates: Insights from in situ produced 10Be concentrations in stream sediments (Ecrins-Pelvoux massif, French Western Alps). Earth Planet. Sci. Lett. 293, 72-83 (2010).
3. Wittmann, H., von Blanckenburg, F., Kruesmann, T., Norton, K. P. & Kubik, P. W. The relation between rock uplift and denudation from cosmogenic nuclides in river sediment in the Central Alps of Switzerland. J. Geophys. Res. 112, F04010, doi:10.1029/2006JF000729 (2007).
4. Champagnac, J.-D. et al. Erosion-driven uplift of the modern Central Alps. Tectonophysics 474, 236-249 (2009).

18 Apr. Brian Ebel, U.S. Geological Survey.
"Thoughts in a dry land: Post-fire hydrology of Fourmile Canyon, CO."

The Fourmile Canyon Fire burned from 6 Sept. 2010 until containment on 13 Sept. 2010, spreading over 2,500 hectares. With 167 homes burned, the Fourmile Canyon fire was the costliest in Colorado history in terms of property damage. Over 300 homes remain in the burned area, leaving many people potentially in the path of floods and debris flows. Immediately after the fire, we established a study site at the southern edge of the fire near Sugarloaf Mountain to examine the hydrologic conditions and response to rainfall. Measurements collected at the site include soil-water content, matric potential, air and soil temperature, relative humidity, wind speed, barometric pressure, and incoming solar radiation. We will discuss the (i) observed hyper-dry conditions present in burned soils, (ii) measured changes in soil physical and hydraulic properties that impact surface and subsurface water fluxes, and (iii) hydrologic and geomorphologic process differences after the fire. We will also cover ongoing and future efforts aimed at understanding flood potential, nutrient fluxes, and water quality issues.

11 Apr. Walt Meier, National Snow and Ice Data Center.
"Climate change in the fast lane: Science, data, and communication of Arctic sea ice observations."

Arctic sea ice is one of most dramatic indicators of change in the global climate system over the past three decades, with reductions in summer ice extent of over 30% and coinciding thinning of the ice cover. It appears that the Arctic will likely experience near ice-free conditions during summer within the next 30 to 40 years. The impacts of such a change will be widespread, both within and outside of the Arctic, and will affect climate, wildlife, and human activities. As a result, sea ice data has been widely used by scientists, policymakers, military planners, educators, media, and the general public. This talk will review historical and recent observations of sea ice change, evolving issues with sea ice data, and lessons learned from interacting with the public about NSIDC’s sea ice data.

04 Apr. Tad Pfeffer, INSTAAR
"Finding the weaknesses in 21st Century sea level forecasts."

Meaningful projections of sea level rise – forecasts of sufficient accuracy that engineers and planners can design adaptations within acceptable cost limits – are ideally delivered as probability distribution functions, with the probability of occurrence of any given total sea level rise expressed as a distribution in which the most likely sea level rise (or most likely range of sea level rise) is identified as well as information on outliers or ‘worst-case’ scenarios. Sea level rise projections will thus ideally be delivered not as simple time series but as sequences of probability distribution functions defined for certain times in the future.

Observations of the components of present-day sea level rise are incomplete, and even today we cannot say exactly how rapidly sea level is rising or what the sources of sea level rise are. Our knowledge of the basic physics governing critical sea level rise processes, most notably the potential dynamic behavior of land-based ice, is also incomplete, and numerical models of glacier and ice sheet response to climate forcing have not progressed to the point where robust simulations of land ice contributions to sea level will be operational in the near future. One option for short-term projection is extrapolation using present-day loss rates and rates of change, with the principal emphasis on evaluating the growth of uncertainty during the extrapolation, and on generating distributions of uncertainty. I review the use of this technique in publications over the past 6 years, its potential as a primary tool for sea level forecasts in the near-term future, and the primary weaknesses of this approach.

28 Mar. Astrid Ogilvie, INSTAAR.
"Past and present environmental and social impacts of volcanic eruptions in Iceland"

This presentation will focus on effects of the recent 2010 eruption of Eyjafjallajökull, and also on the Laki fissure or Skaftáreldar (the “Skaftá fires”) eruption, which occurred in 1783-84. The Eyjafjallajökull eruption was fairly minor but caused havoc to air traffic during brief periods in April and May of 2010. The Laki fissure eruption lasted from June 1783 until February 1784 and was one of the largest fissure eruptions in historical times. The eruption had a catastrophic effect in Iceland. The grass, the basic food supply for the grazing livestock, became polluted and fluorine poisoned. Within a year of the eruption, 53% of the cattle, 80% of the sheep and 77% of the horses died. It is estimated that the total death toll in Iceland represented about 22% of the population or about 10,000 people. The effects went far beyond Iceland. The fine ash and volcanic dust that rained down on Iceland were also reported elsewhere, e.g. in the Faeroe Islands, Scotland, Denmark, Norway, northern Germany and France. The dry fog associated with the eruption which was observed in many parts of Europe, also seems to have been witnessed in areas as far apart as Labrador, Newfoundland, Asia Minor and possibly China. The Eyjafjallajökull eruption had serious but not lasting effects for those living in the vicinity of the volcano.

The extent of Arctic sea ice has been shrinking rapidly over the past few decades, and concurrent acceleration of erosion is now occurring along the Arctic coast. This both brings coastal infrastructure into harm’s way and promotes a complex response of the adjacent landscape to global change. We here quantify the effects of declining sea ice extent on coastal erosion rates along a 75-km stretch of permafrost coast along the Beaufort Sea, Alaska, where present-day erosion rates are ~14 m yr-1. Observations suggest thermal erosion controls the notching of the base of the 3-5m tall bluffs and subsequent bluff failure. We used a modified iceberg-melting algorithm to further investigate the erosion process.

To look at long-term changes we model the interaction between the nearshore sea ice concentration, the location of the sea ice margin, and the fetch-limited, shallow water wave field, since these parameters ultimately control both sea surface temperatures and the height to which these waters can bathe the frozen bluffs. Thirty years of satellite passive microwave data reveal that the nearshore open water season lengthened ~54 days over 1979-2009. Given these time series, we modeled daily wave heights during the open water season for each year. This “annual wave exposure” increased by 250% during 1979-2009. Ultimately, we aim to couple and employ these models to explore changes in coastal retreat rates for various climate change scenarios that include further increase in the duration of sea-ice free conditions, warming ocean temperatures, and changes in storm frequencies.

07 Mar. Bryan Shuman, Geology and Geophysics, University of Wyoming.
"From causes to impacts of Holocene moisture variation in mid-latitude North America."

Monotonic changes in global climate controls during the Holocene need to be reconciled with evidence of rapid ecological changes and potentially swift cultural transitions. One potential explanation may be that monotonic external forcing can generate different directions and rates of response in the various components of the Earth system, which then interact to produce non-monotonic climate changes and attendant impacts. Here, we demonstrate that ecologically- and culturally-important hydroclimatic variability in mid-latitude North America over the past 12,000 years was driven by direct responses to orbital change in combination with atmosphere-ocean responses to orbitally-initiated but abrupt collapses of 1) the Laurentide Ice Sheet by 8.2 ka and 2) the African monsoon by 5.5 ka. Time series of these factors predict 84-96% of the variance in replicated, quantitative lake-level histories from the United States, and thus provide a framework for interpreting the hierarchy of dynamics underlying correlated cultural and ecological changes, including abrupt human population and plant species declines.

28 Feb. Greg Tucker, CIRES, Univ. of Co., Dept. of Geological Sciences.
"Geomorphic and climatic significance of bedrock scarps on normal-fault footwalls."

The existence of well-preserved Holocene bedrock fault scarps along active normal faults in the Mediterranean region and elsewhere suggests a dramatic reduction in rates of rock weathering and erosion that correlates with the transition from glacial to interglacial climate. We test and quantify this interpretation using a case study in the Italian Central Apennines. Holocene rates are derived from measurements of weathering-pit depth along the Magnola scarp, where previous cosmogenic 36Cl analyses constrain exposure history. To estimate the average hillslope erosion rate over ~105 years, we introduce a simple geometric model of normal-fault footwall slope evolution. The model predicts that the gradient of a weathering-limited footwall hillslope is set by fault dip angle and by the ratio of slip rate to erosion rate; if either slip or erosion rate is known, the other can be derived. Applying this model to the Magnola fault yields an estimated average weathering rate on the order of 0.2-0.4 mm/yr, more than 10x higher than either the Holocene scarp weathering rate or modern regional limestone weathering rates. A numerical model of footwall growth and erosion, in which erosion rate tracks the oxygen-isotope curve, reproduces the main features of hillslope and scarp morphology and suggests that the hillslope erosion rate has varied by about a factor of 30 over the past one to two glacial cycles. We conclude that preservation of carbonate fault scarps reflects strong climatic control on rock breakdown by frost cracking.

21 Feb. Reed Maxwell, Colorado School of Mines.
"The groundwater-land-surface-atmosphere connection: Using coupled model simulations to diagnose interactions between the subsurface, land-energy fluxes and the lower atmosphere."

Complete models of the hydrologic cycle have gained recent attention as research has shown interdependence between the coupled land and energy balance of the subsurface, land surface and lower-atmosphere. Here the coupling strategy behind “groundwater to atmospheric models” is discussed and examples of such models are presented. A number of examples are then used to demonstrate the improvement in important physical processes afforded by these coupled models. These examples include the role of groundwater on the land energy budget, spatial patterns of land energy fluxes created by complicated subsurface heterogeneity and the interdependence of human management practices (such as pumping and irrigation) and climate change on hydrologic and land energy cycles. As energy fluxes are an important component of land-atmosphere interactions, different formulations for water stress on transpiration will also be presented. These formulations provide differing degrees of interaction between deep roots and the free water table in addition to different mechanisms to moderate transpiration based on water limitations. Finally, thoughts on the path forward for modeling the hydrologic cycle will be presented.

14 Feb. Jon Landvik, Norwegian Univ. of Life Sciences, Dept. of Plant and Environmental Sciences, Norway.
"The last Svalbard/Barents Sea Ice Sheet – from ice margin reconstructions to ice sheet dynamics."

For several decades the history of the last Svalbard/Barents Sea Ice Sheet has been the subject to large scientific controversies. These differences settled in the late 1990’s with a general acceptance of a Barents Sea ice sheet, which was confluent with the Fennoscandian Ice Sheet to the south, extending to the continental shelf break in the west and north, but only inundated the northwestern most part of Russia, and left the Kara Sea ice free. This was a two-dimensional model of ice sheet extent.

The focus on the Barents ice sheet waned for a while. However, during the last decade, we have added new methods, like exposure age dating and high-resolution sea floor mapping to our toolbox, as well as an improved glaciological understanding of ice sheet behavior. An important area of research has been the interplay between the ice sheets and the adjacent ocean. Thus, new research questions have been asked and “old” areas of ice sheet research have been revisited.

New research shows that the dynamics of the ice sheet was much more dynamic than previously assumed. Fjords and troughs represented conduits for high-flux ice streams feeding the ocean, whereas inter-fjord areas experienced a limited ice flux leaving a contrasting sedimentary record. However, both areas are dominated by the geological signatures left during the last decay of the ice sheet. Thus, the complex behavior of past ice sheets in both space and time challenges our established understanding past ice sheet/ocean interaction.

07 Feb. Marika Holland, National Center for Atmospheric Research.
"Sea ice predictability in a rapidly changing Arctic environment."

Seasonal predictions of Arctic sea ice have typically been based on statistical regression models or on results from ensemble ice model forecasts driven by historical atmospheric forcing. However, in the rapidly changing Arctic environment, the predictability characteristics of summer ice cover could undergo important transformations. Here global coupled climate model simulations are used to assess the changing role of predictors for end of summer Arctic ice cover.

Additional model experiments are run to investigate the inherent predictability of Arctic sea ice conditions on seasonal to interannual timescales. The role of preconditioning of the ice cover versus intrinsic variations in determining sea ice conditions is examined using ensemble experiments initialized in January with identical ice-ocean-terrestrial conditions. Three sets of initial conditions are employed to determine the role of changing climate conditions for sea ice predictability characteristics. Finally, the sources of uncertainty for predictability on longer (decadal-century) timescales is discussed.

31 Jan. Nikki Lovenduski, INSTAAR.
"Recent changes in Southern Ocean biogeochemistry."

The Southern Ocean plays a critical role in global climate, absorbing a substantial fraction of anthropogenic CO2 from the atmosphere and controlling the global oceanic distribution of nutrients and carbon. The cold upwelling waters in the Southern Ocean are characterized by low carbonate ion concentrations, making this region particularly vulnerable to acidification in a changing climate. Over the past few decades, increased wind stress and CO2 uptake have altered both the physical circulation and carbon chemistry of the region, and the future is likely to be characterized by further changes.

In this talk, output from an ocean physical-biogeochemical-ecological model will be probed to better understand the response of the Southern Ocean to climate variability and change.

24 Jan. Miriam Duhnforth, INSTAAR.
"Glacial and sedimentary processes in alpine landscapes: Case studies from Yosemite National Park, CA, and the Colorado Front Range."

Advances and retreats of alpine glaciers over glacial-interglacial cycles have strongly influenced the evolution of alpine landscapes and have led to variations in the patterns and rates of sediment erosion and transport. I will present case studies from Yosemite National Park and the Colorado Front Range to show how glaciers erode the landscape and to demonstrate the variability of sediment transport outside of the glacial footprint through time.

In Yosemite National Park, differences in the degree of fracture spacing control the efficiency of glacial erosion processes during glacial times. The broader the fracture spacing, the lower are the rates at which a glacier can erode blocks from its bed. We suggest that the lack of cracking in some of the plutons of Yosemite National Park makes subglacial less efficient than elsewhere, leading to Yosemite’s characteristic landscape with its smoothly polished bedrock surfaces and granitic domes.

The amount of glacial erosion dictates how much sediment is fed into the fluvial system at the glacier terminus. In the Boulder Creek watershed the timing of glacier retreat appears to influence the pattern of sediment transport and deposition. Absolute dates from terraces in Boulder Canyon and from terraces along the Colorado Front Range suggest that sediment aggradation and lateral planation of surfaces were dominating during glacial times and during the transition from glacial to interglacial climate conditions when sediment supply is high. During deep interglacial conditions, however, the lack of sediment supply from the mountain watersheds led to the incision of Boulder Canyon and the High Plains. The presence of multiple levels of gravel-capped terraces in Boulder Canyon and immediately adjacent to the Colorado Front Range most likely represents a direct evidence for the influence of glacial-interglacial climate variations on the incision history in this area.

06 Dec. Diane McKnight, INSTAAR
"The McMurdo Dry Valleys, Antarctica: Climate change reconnects terrestrial and aquatic ecosystems."

The McMurdo Dry Valleys of Antarctica is comprised of alpine and termianl glaceirs, large expanses of patterned ground, and permanently ice-covered lakes in the valley floors, which are linked by glacial meltwater streams that flow during the austral summer. Many streams have thriving cyanobacterial mats that are freeze-dried through the winter and begin photosynthesis with the onset of flow. As part of the McMurdo Dry Valleys Long-Term Ecological research project, we have studied the responses of soil, lake and stream ecosystems through a sustained cooling period that has been driven by atmospheric changes associated with the ozone hole. This cooling period has been interrupted by two warm summers that created "flood events" in the valleys. We studied the stream ecosystem response in a formerly abandoned channel, which was experimentally reactivated by a flow diversion in 1994 and in a stream that only flows during the rare flood events. We found that the mats where flow is typically low with episodic periods of high flows typically have diatom communities that are dominated by species of two aerophilic genera, many of which are endemic. Further, by comparing the abundance of invertebrates and diatoms in the cyanobacterial mats and sediments during cold (low flow) and warm (high flow) summers, we found that during the cold summer invertebrates were less abundant in the mats than in the underlying sediments, while during the warm summer this pattern was reveresed. These findings suggest that the optimal habitat for invertebrates in mats and sediments is partially driven by stream hydrology. This limitation on potential grazers (which are important nutrient transformers) during low flow may account for the accumulation of algal biomass and subsequent nutrient immobilization in the mats over many summers.

01 Dec. Lynne Cherry, INSTAAR visiting Scholar.
"Lunchtime talk, movie screening and book signing by Lynne Cherry."

Lynne Cherry, illustrator and well known as a environmental children's book author, is presently a visiting Scholar at INSTAAR. She will give a talk illustrated with numerous movies, and show how successful science outreach can be.

Cherry is the author/illustrator of over 30 environmental children's books including The Great Kapok Tree, A River Ran Wild, and How We Know What We Know About Our Changing Climate: Scientists and Kids Explore Global Warming.

Lynn is interested in hearing about your science to possibly incorporate into kids books. She will sign children books as well (so a good opportunity to score some holiday gifts!)

29 Nov. John Hoffecker, INSTAAR.
"Changing climate and human settlement at Cape Espenberg, Northwest Alaska."

Groups of former houses and associated features are spread across ten beach ridges near the tip of Cape Espenberg (northern Seward Peninsula), representing at least 700 years of Iñupiat settlement. During the second phase (2010) of a three-year interdisciplinary project, houses were excavated on three ridges dating collectively to roughly AD 1300–1800. Core samples were taken from ponds and bogs to construct a local record of past climate change. The excavated houses are small, but yielded a wealth of artifacts and faunal remains, which will be used to address questions concerning social and economic change in the context of changing climates in the Kotzebue Sound region. Among the artifacts of particular interest recovered this year are a piece of slat armor and a copper needle (both from a house recently dated to AD 1600–1700). A major issue is the role of whaling in the economy of the inhabitants of Cape Espenberg; whale bones are found on the ridges and in the houses, but their interpretation is problematic.

15 Nov. Eve-Lyn S. Hinckley, INSTAAR.
"Investigation of hydrological flows and the fate of nitrogen deposition using 15N tracer studies in the Boulder Creek Critical Zone Observatory."

Increased deposition of reactive nitrogen (Nr) to the Colorado Front Range has changed ecosystem stoichiometry, microbial transformation rates, and aquatic community structure over the last decade. While several studies have examined N loading to the alpine zone, little attention has focused on lower elevations, including subalpine and montane zones. To understand Nr impacts in these areas, we instrumented plots along a north-south cross-section in a forested montane catchment that is part of the Boulder Creek Critical Zone Observatory. We applied 15N-nitrate and lithium bromide tracers during spring snowmelt and a simulated summer rain event, the two major hydrologic events mobilizing N in these systems. Following each application, we measured tracer constituents in solution waters, as well as N isotopic composition and concentrations in soils, vegetation, and microbial pools in order to 1) determine the residence time, export pathways, and biological uptake of deposited N, and 2) develop an understanding of the seasonal hydrologic forcing and soil profile characteristics that determine the annual N budget. Our data show that source dynamics (e.g., variation in snowpack melting) control N movement through the soil profile during snowmelt; preliminary data suggest that the majority of all tracers moved out of snow-covered north-facing slope plots over the course of 40 days, versus during a two-day melt event in the south-facing slope plots. In contrast, local soil properties (e.g., texture and structure) exert control during rainfall events; N retention on the south-facing slope was greater than on the north-facing slope by a factor of six, leading to more N uptake by vegetation and microbial pools. Our results lend insights that are important for understanding catchment-scale timing of N transport to streams and the role of mid-elevation forests in metabolizing deposited N within the larger landscape context, from alpine to plains.

08 Nov. Christina Tague, University of California, Santa Barbara.
"Eco-hydrologic responses of mountain forested watersheds to climate warming: interactions among snowmelt, soil/geology and vegetation water use."

At regional scales, spatial variation in eco-hydrologic processes is a complex function of geology, soil, topography, climate and vegetation patterns. Understanding how these different controls vary and interact remains a key challenge for climate change impact assessment. In snow-dominated mountain environments, there is growing evidence that reduced snow accumulation and earlier melt is already occurring and is an important driver of summer streamflow and ecosystem responses. Modelling these responses requires estimation not only of the spatial pattern of melt response to warming, but also of vegetation water use. For both vegetation water use and streamflow responses, soil and subsurface storage mediates system sensitivity to changes in water inputs relative to available energy. We use a coupled process-based model of ecosystem hydrologic and carbon cycling, RHESSys, to demonstrate that soil moisture drainage and storage characteristics exert a significant control on how forest water use, carbon cycling and mortality respond to earlier snowmelt. We focus our modeling scenarios on sites with measurements of streamflow, and vegetation growth that can be used to evaluate model performance. We then use the model to show how projected changes in terrestrial ecosystem responses alter streamflow regimes and may have important implications for aquatic and human communities.

These modeling studies provide an expanded perspective on landscape-level sensitivities to climate warming, and can provide guidance for the strategic design of data assimilation and monitoring strategies.

01 Nov. Sagy Cohen, INSTAAR.
"The mARM4D soil-landscape evolution model, modeling framework and selected case studies."

Soil, through its various properties, is a key factor in the hydrological, geomorphic and biogeochemical cycles. Quantifying its spatio-temporal dynamics is therefore imperative for deciphering past and predicting future trends in terrestrial, aquatic and atmospheric systems. However, explicit quantification of soil is challenging as soil is a complex and dynamic substance, constantly evolving in response to changing environmental conditions. Field-based description of soil properties by sampling and analysis is extremely limited in both its spatial extrapolation and temporal interpretation. At the same time numerical modeling of soil has mainly focused on in situ description of various pedogenesis processes (mainly chemical). In recent years there is an increasing effort toward mechanistic modeling of soil in the context of landscape processes. These so called soil-landscape models are an important advance in soil modeling but so far limited in their ability to explicitly simulate the soil-landscape interaction, largely due to computational constraints.

The mARM4D model is a spatially and temporally explicit soil-landscape evolution model. To achieve computational efficiency the model is based on a novel mathematical algorithm that express the processes physics with multi-dimensional transition matrices. This allows for detailed description of soil properties (e.g. 10’s of grading size-classes), spatial domain (10,000’s of pixels with 10’s soil-profile layers) and temporal change (millions of iterations). At its current configuration mARM4D simulate the soil-landscape interaction as a function of (1) selective fluvial sediment transport, (2) diffusive sediment transport, (3) Aeolian deposition and (4) physical weathering of bedrock and soil particles. Additional processes (e.g. translocation, chemical weathering) are gradually introduced to the modeling framework.

(1) The affect of various soil production and soil weathering functions (exponential decline with depth, the “humped”, constant and age-dependent) on soil profile morphology and surface soil-grading;

(3) Comparison between diffusive and fluvial soil-transport processes at a semi-arid field-site.

25 Oct. Megan Otu, INSTAAR.
"The effect of climate on the formation of sediments in a tropical meteorite crater lake."

There is a tremendous need to understand climate patterns over West Africa, a region devastated by frequent and prolonged drought. There are few meteorological or environmental records in existence for West Africa, however sediment records from Lake Bosomtwe, Ghana may be a prime candidate in understanding regional climate trends. Lake Bosomtwe is a tropical crater lake formed one million years ago by a meteorite impact. The lake is known to act like a rain gauge, where lake levels are controlled by the delivery of precipitation relative to rates of evaporation. In 2004, the International Continental Scientific Drilling Program recovered the complete 1 million year sediment record for paleoclimatic reconstructions, yet, there has been little study of the present day climate patterns in relation to the limnology and sedimentation patterns in the basin. This presentation will examine recent meteorological data, water column profiles, sediment trap samples and short gravity cores from Lake Bosomtwe, with particular attention to the organic matter δ13C and δ15N. Res

ults show that seasonal mixing patterns significantly alter annual primary production and delivery of organic matter to the sediments.

18 Oct. Hari Rajaram, Civil, Environmental, and Architectural Engineering.
"Modeling fracture dissolution and early evolution of karst systems."

I will present results from many years of research attempting to simulate the morphological imprint of karst and cave systems using coupled models of flow, reactive solute transport, dissolution and heat transport in fractures. Specifically, our efforts were targeted towards developing models that can reproduce the morphology of two types of cave systems - branchwork caves that evolve along bedding planes in meteoric karst systems; and mazework caves that are speculated to evolve in hypogene environments, driven to some extent by the retrograde solubility of calcite.

Our simulations show that the critical processes involved in the development of branchwork patterns are (i) competition between dissolution fingers during the laminar flow stage, followed by breakthrough of a single finger; and (ii) a tendency for sub-dominant fingers to converge on to the dominant finger, leading to a river network-like branchwork pattern. The mazework patterns in hypogene systems are a little harder to reproduce, because the mazes are in fact three-dimensional, and 3D simulations in fracture networks are not yet within our reach (also we ran out of funding). However, we show that two-dimensional maze-like structures can be generated in single fault or fracture planes (with close to vertical inclination), and result largely from the role of buoyant convection rolls.

These simulations were performed without the use of parallel computation, employing state-of-the-art sparse matrix solvers on single-processor machines.

11 Oct. Chris Jenkins, INSTAAR.
"Earth scientist: You have a parameter problem."

INSTAAR probably produces scientific data for hundreds of parameters each week. The Ocean Drilling Program has data for over 100,000 parameters. This is a great problem for scientists to navigate through, especially if they are from another science and want to be inter-disciplinary - to work at a boundary. The expertise and vocabulary needed to find data in the Parameter maze effectively locks out researchers from adjacent fields.

A new project at INSTAAR is exploring database, linked data, visual interactive, and semantic tools to rationalize this situation, and to open our data to (i) new technologies, (ii) curiosity at large, (iii) new generations of scientists. This talk will address these issues in geophysics, biogeochemistry, sediments, and will show some new approaches that draw inspiration from commerce, actually.

04 Oct. Carol Finn, US Geological Survey.
"Aerogeophysical mapping of sub ice geology in Antarctica: From Precambrian tectonics to Cenozoic climate change."

Antarctica is a key element in Earth’s geodynamic and climatic systems, yet we lack fundamental geologic and geophysical data from the deep interior of this vast continent. Coastal exposures record the 3500 million-year history of a continent that participated in the formation and breakup of two supercontinents, Rodinia and Gondwana. East Antarctica occupied the center of both supercontinents and may represent ~15% of Earth’s Precambrian crust. Despite the central role that Antarctica has played in shaping the present global environment, basic, first-order parameters such as bedrock elevation, lithology, structure, age, tectonic history and ice volume remain poorly known over large portions of the continent. Given the extensive ice cover, airborne geophysical data, constrained by field-based geologic mapping, ground-based geophysics, and petrologic, geochemical and geochronological analysis of outcrop and drill-hole samples, is the best way to define the origin and evolution of broad areas of the Antarctic lithosphere. This talk will focus on geophysical mapping of sub ice geology and discuss links between the geology and the ice sheet.

27 Sep. Diana Nemergut, INSTAAR.
"Is everything everywhere? An examination of bacterial biogeography."

Bacteria control major nutrient cycles and directly influence plant, animal, and human health. However, we know relatively little about the forces shaping their large-scale ecological ranges. I will discuss a meta-analysis of patterns in the distribution of individual bacterial taxa at multiple levels of phylogenetic resolution within and between Earth’s major habitat types. This analysis suggests that while macro-scale habitats structure bacterial distribution to some degree, most bacteria are confined to single assemblages. In addition, the most cosmopolitan taxa are also the most abundant in individual assemblages. One possible explanation for these patterns is that bacteria are subject to dispersal limitations. Thus, I will also discuss an experiment designed to test the age-old “everything is everywhere but the environment selects” hypothesis. Patterns of bacterial community succession were examined in jars containing heterotrophic media separated by either short (~1m) or long (>1 km) distances, where environmental factors including shading, temperature and precipitation were held constant. Initial beta diversity (i.e., the difference between communities) was low but it increased over time as communities shifted from those dominated by Bacillus to more diverse, move even communities. Geography affected the distribution of rare taxa but not abundant organisms. Together, these results support similarities between the biogeography of macroorganisms and microbes and suggest that bacteria may also experience dispersal limitations that are related to their local abundance.

20 Sep. Andrew Ashton, Woods Hole Oceanographic Institution.
"How do waves shape deltas?"

The mark of ocean waves on the depositional pattern of river deltas tends to be clear, creating characteristic landforms such as beach ridges or even downdrift-extending spits. Many wave-dominated deltas, however, exhibit plan-view asymmetry including the formation of discrete breaks in shoreline orientation and the development of spits and migrating shoreline sandwaves along the downdrift flank. A numerical model of plan-view shoreline evolution demonstrates how the angle distribution of incoming waves can have a first-order effect delta evolution, leading to asymmetrical development observed in nature. Furthermore, because the shape of a wave-influenced delta arises as a feedback between the sediment delivery rate of the river and alongshore sediment transport, the actual littoral transport of sediment away from a river mouth will typically be less than the maximum potential sediment transport for a given wave climate. The characteristics of both incoming wave and direction can be used to provide a measure to estimate whether a delta would be fluvially or littorally dominated.

13 Sep. Daniel Muhs, US Geological Survey.
"Sea level during the last interglacial period in southern Florida: Implications for the history of the Greenland and West Antarctic ice sheets."

As a future warm-climate analog, much attention has been directed to studies of the last interglacial period or marine isotope stage (MIS) 5.5, which occurred ~120,000 years ago. Nevertheless, there are still uncertainties with respect to its duration, warmth and magnitude of sea level rise. Here we present new data from tectonically stable peninsular Florida and the Florida Keys that provide estimates of the timing and magnitude of sea-level rise during the last interglacial period. The last interglacial high sea stand in southern Florida is recorded by the Key Largo Limestone, a fossil reef complex, and the Miami Limestone, an oolitic marine sediment. Thirty-five new, high-precision, uranium-series ages of fossil corals from the Key Largo Limestone indicate that sea level was significantly above present for at least 9,000 years during the last interglacial period, and possibly longer. Ooids from the Miami Limestone show open-system histories with respect to U-series dating, but show a clear linear trend towards an age of ~120 ka, correlating this unit with the last interglacial corals of the Key Largo Limestone. Elevation measurements of both the Key Largo Limestone and the Miami Limestone indicate that local (relative) sea level was at least 6.6 m, and possibly as much as 8.5 higher than present during the last interglacial period. A sea-level rise of this magnitude, if it reflects global sea level, would require complete loss of either the Greenland or West Antarctic ice sheets, or some combination of loss from both. Should a sea-level rise of comparable magnitude occur in a future warm climate, many of the world’s coastal cities would be inundated, including all those of southern Florida.

30 Aug. Suzanne Anderson, INSTAAR & Geography.
"Highlights from the Boulder Creek Critical Zone Observatory."

The Boulder Creek Critical Zone Observatory (CZO) was established in 2007 to study how interactions between weathering and erosion shape near surface environments. The Front Range, which Boulder Creek drains, provides an ideal laboratory for this exploration, with glacially-scoured headwaters, a middle zone that has evolved without significant perturbations since the end of the Laramide Orogeny (ca. 50 Ma), and regions impacted by baselevel lowering and canyon cutting over the last ~5 Ma. Much of our research effort has focused on Gordon Gulch, in the middle zone post-Laramide Rocky Mountain surface. The east-west trending valley shows marked contrasts between its south-facing and north-facing slopes in vegetation, snow cover, soil temperatures, moisture delivery, and weathering of the underlying rock. These aspect differences, however, are not seen strongly in the microbial populations in the soils. We are using the aspect “experiment” in Gordon Gulch to help develop models of weathering and hydrology.

03 May Jim Balog, Photographer, Extreme Ice Survey
"Extreme Ice Survey: Three years of arctic & alpine glacier time-lapse."

Art meets science in this stunning look at our changing planet. Internationally acclaimed photographer, adventurer and naturalist James Balog, extensively published in National Geographic and other international media, takes us on an inspiring quest to document spectacular arctic and alpine glaciers.

Braving treacherous conditions—crevasses, rockslides, avalanches, temperatures down to -40 F., and frigid river crossings—his Extreme Ice Survey team brings back to civilization extraordinary documentation of how quickly the ice is vanishing.

These fast-changing glacial landscapes are the canary in the coal mine, the most tangible, visible evidence of climate change anywhere in the world today. Building on his early career training as an earth scientist and mountaineer, James is uniquely qualified to make an informative presentation mixing astounding scientific facts with otherworldly beauty.
This is a passionate story of devotion, commitment and creativity. But it goes even further: it alters our perception of what it means to be human at this historic moment of geologic time.

26 Apr. Leilani Arthurs CU Boulder Geological Sciences,.
"The science of geoscience education."

Geoscience Education Research (GER) is an emerging interdisciplinary field. It is largely aimed at understanding how students think and learn about the earth sciences and at directly applying these findings in programmatic and curricular ways. For example findings about student thinking are applied to (i) develop and use assessment instruments to measure both student learning gains and student attitudes about the geosciences and to (ii) design and evaluate instructional interventions that facilitate improved student learning. Three broad categories of student alternative conceptions and cognitive models dealing with rocks, density and convection, and groundwater will be presented. Current challenges and directions within the field of GER will also be discussed.

12 Apr. Ross Edwards, Desert Research Institute.
"Late Holocene variability in soot deposition to Antarctica."

Fire emissions of black carbon (soot) in the Southern Hemisphere (SH) are dominated by dry season burning in savannas of Southern Africa, Northern and Central Australia and the grasslands of South America. These emissions perturb the SH radiation budget, atmospheric chemistry and the hydrologic cycle. Transported in the atmosphere on a hemispheric scale, soot from these fires is deposited onto the Antarctic ice cap, preserving a history of SH fire emissions. We will present high temporal resolution soot ice core records from West Antarctica, South Pole and East Antarctica, which reveal large scale changes in SH soot over the past ~ 2400 years.

05 Apr. Laurel Hartley, Department of Integrative Biology, University of Colorado Denver.
"Effects of disease and global change factors on role of prairie dogs (Cynomys ludovicianus) as ecosystem engineers in Colorado."

Prairie dogs are an iconic species in the American west. Through their burrowing and grazing, they alter plant community composition, nutrient cycling rates, and provide habitat for other grassland animal species. Introduced plague, caused by Yersinia pestis, exotic plant species, urbanization, nitrogen deposition, and warmer and longer growing seasons could influence the role of prairie dogs as keystone species and ecosystem engineers in Colorado. The first part of this talk will present research results suggesting that introduced plague is altering the spatial characteristics of prairie dog colonies on the shortgrass steppe such that colonies no longer persist on the landscape for decades as they did prior to introduction of plague. On the Pawnee National Grassland, approximately 98% of colonies experience a plague epizootic within 15 years of continuous activity, nearly half remain inactive for at least 5 years following an epizootic, and less than half attain their pre-plague area within 10 years of an epizootic. The second part of this talk will focus on research results showing that plague epizootics mediate the role of prairie dogs in shaping plant communities and nutrient cycling. The effects of prairie dogs on vegetation and nutrient cycling increase with colony age, but few colonies persist more than 15 years because of plague. The effects of prairie dogs on vegetation and nutrient cycling also decrease quickly after a colony is extirpated by plague. The final part of this talk will focus on recent pilot data and proposed research related to the role of prairie dogs in shaping urban plant communities. In urban areas, high densities of prairie dogs, legacy effects from agriculture and other soil disturbances, propagule pressure from non-native plant species, and climate-mediated changes to potential vegetation may all interact with prairie dog grazing and burrowing to produce novel plant communities.

29 Mar. Anne Jennings, INSTAAR.
"LGM-to-Present Greenland Ice Sheet history in the Disko and Umanak systems of West Greenland."

Recent observations suggest that the Greenland Ice Sheet (GIS) may have entered a state of rapidly increasing negative mass balance, which is a major concern, because the GIS stores enough fresh water to raise global sea level by c. 6.5 m. An understanding of the longer-term Late Quaternary-Holocene history of the GIS and its ice streams, and the ice sheet response to past climate would facilitate modeling of its response to future climate warming. Until recently, the late Quaternary and Holocene history of the GIS and its behavior during past warm climate intervals have been limited to studies of the ice-free land areas between the present-day ice sheet margin and the ocean, leaving the history of the 200 km wide shelf areas beyond the present day coast open to question. Marine geophysical and sediment core studies are beginning to make significant contributions to the knowledge of the glacial history, providing constraints on the Last Glacial Maximum extent of the GIS, the timing of deglaciation, and continuous records of the environmental and paleoceanographic conditions from deglaciation through the Holocene. This talk will present the first results from JR175, a geophysical and coring expedition to the Disko and Umanak systems of Western Greenland in late summer of 2009 on the British Antarctic Survey research ship, RRS James Clark Ross. Results of multibeam swath bathymetry, radiocarbon dating, and sediment cores from the trough-mouth fans on the contintental slope which were active during the LGM, along the shelf troughs that once served as ice-stream conduits, to the modern calving margin of the GIS will be shown (along with some nice photos!).

15 Mar. Scott Peckham, INSTAAR.
"Plug-and-play modeling with CSDMS components is way cool."

The Community Surface Dynamics Modeling System (CSDMS) is an NSF-funded project that is helping a diverse community of surface dynamics modelers and model users to work together toward common goals. A community of almost 400 CSDMS members has contributed numerous open-source models and process modules which are now available from the CSDMS website. However, CSDMS has also established a set of procedures and protocols that can enable these contributed models to work together as plug-and-play components within an integrated modeling system. The CSDMS approach to this problem has been to build upon and combine an existing set of advanced software tools from the high-performance computing (HPC) community. This includes the standards and tools of the Common Component Architecture (CCA, www.cca-forum.org), the netCDF file format and the VisIt tool for visualization.

CSDMS is nearing the end of its third year and now has many working examples of plug-and-play modeling available in its new CSDMS Modeling Tool. The entire system is based on the concept of components, which may be multi-process models or "submodels" of just a particular physical process (e.g. infiltration). Components are designed to encapsulate key functionality and to retrieve the input they need from other components through linking. They may be written to use a single processor or multiple processors and they communicate through an advanced framework that supports high-performance scientific computing. They may also be written in any of several different programming languages.

While components can be used outside of a graphical environment, using them from within the CSDMS Modeling Tool means that each has its own HTML help pages and its own tabbed dialog for changing input. The main advantage of the system is that users can easily replace one process component or model with another that offers similar functionality, without recompiling. This opens up exciting possibilities in terms of both scientific research and education. It allows researchers to rapidly compare different approaches and algorithms with regard to speed, efficiency, accuracy, numerical scheme or scalability. Similarly, it allows students to compare results from simpler models to those from more complex or complete models. The purpose of this talk is to demonstrate the CSDMS system with several examples.

08 Mar. Jonathan Friedman, USGS.
"Inherited latitudinal variation in cold hardiness of native and introduced trees: climate change implications."

Phenological shifts such as earlier flowering time have provided some of the clearest evidence of biological effects of climate change, and models relating phenology to temperature, photoperiod, etc., can be used to predict future responses of biota to changing climate. However, in wild populations some of the variation in phenology over space and time is a consequence of genetic variation. Correctly modeling the response to climate change requires distinguishing the effects of genetic variation from those of climate. We used a common garden consisting of paired collections of native and introduced riparian trees sampled along a latitudinal gradient to explore the genetic component of latitudinal phenological variation. The garden in Fort Collins, Colorado (latitude 40.6°N), included 681 native plains cottonwood (Populus deltoides subsp. monilifera) and introduced saltcedar (Tamarix ramosissima, T. chinensis and hybrids) collected from 15 sites ranging from Texas to Montana. In the common garden both species showed latitudinal variation in fall, but not spring, leaf phenology, demonstrating that the latitudinal gradient in fall phenology observed in the field reflects both genetic and climatic variation, while the latitudinal gradient in spring phenology observed in the field reflects climatic variation alone. In contrast, cold hardiness showed strong genetic variation in both fall and spring for both species. The latitudinal variation in fall phenology and cold hardiness of saltcedar appears to have evolved through hybridization and natural selection in the 150 years since introduction. Observed shifts in phenology and distribution of native and invasive species include the effects of both global change and evolution.

01 Mar. Craig Lee, INSTAAR.
"Ice patch archaeology in the mid-latitude Rocky Mountains: Five years of tough prospects and amazing discoveries."

As the Earth’s climate warms, archeological and paleontological materials are being discovered in areas of melting perennial snow and ice. Although artifacts have been found in association with glaciers, in North America they have primarily been discovered in association with relatively static snow banks, or “ice patches.” Archaeological discoveries demonstrate some ice patches attracted animals and their human predators. The stable ice in these features retards decay and has kept otherwise perishable materials suspended in virtually unaltered states for millennia. Once released from this protective environment, arrested taphonomic processes resume and organic artifacts rapidly decompose. Discoveries in the mid-latitude Rocky Mountains include a complete atl atl dart foreshaft, dart and arrow shaft fragments, chipped stone tools and processed animal remains. The discoveries offer important insights into alpine paleoecology and the use of high elevation environments by humans. Ice patch archaeology is a nascent field in North America. This talk will review progress made in the last five years to identify and survey prospective locations in the greater Yellowstone area and the Rocky Mountains of Colorado as well as review of the state of ice patch archaeology from a global perspective.

22 Feb. Tad Pfeffer, INSTAAR Fellow and Professor, Department of Civil, Environmental, and Architectural Engineering.
"Realistic and useful predictions of sea level in the next 100 years."

Prediction of future sea level rise ranks as one of the most urgent, specific, and publicly visible tasks facing the climatological, oceanographic, and glaciological research communities. Published research on sea level rise to date tends to focus on understanding physical processes, on end-point predictions (e.g. sea level rise by 2100, ultimate sea level rise under future equilibrium conditions, etc), and on outlier events (e.g. collapse of the West Antarctic Ice Sheet). Policy makers and planners, on the other hand, need information on near-term rates (e.g. estimated sea level rise decade-by-decade) qualified by uncertainties. Predictions in the near-term require careful incorporation of all sources of sea level rise, including those sources which may be second-order effects in the long-term but which dominate initially. These predictions require that some conclusions be drawn about processes which at present are poorly understood (e.g. iceberg calving) and also require data which are incomplete at this time (e.g. comprehensive mass balance assessments of glaciers and ice caps exclusive of the two ice sheets). The qualified prediction of sea level rise on multiple time scales thus has aspects of an applied science or engineering problem, whereas the current model of funding for this research is one of basic science. This disparity complicates timely progress toward usable results.

15 Feb. David Anderson, NOAA Paleoclimatology & INSTAAR.
"Ocean acidification and marine biogeochemical cycles"

Thirty percent of the carbon produced by man has entered the ocean where it lowers the pH and reduces the saturation with respect to calcium carbonate, the skeletal material of organisms ranging from plankton to corals. Negative effects on organisms have been forecast, however the calcification response varies among organisms and experiments. Effects observed in paleo proxies in response to changing saturation are consistent with reduced calcification, however no paleo changes equal the magnitude of change forecast by the end of the century. Dramatic changes appear inevitable for the ocean, beginning with the biological response and later including the dissolution of sedimentary calcium carbonate (shells and reefs). The ultimate fate of much of the anthropogenic carbon dioxide is neutralization by dissolving sedimentary calcium carbonate, returning the concentration of carbon dioxide in the atmosphere close to original levels over thousands of years.

08 Feb. Mark Serreze, Director of NSIDC and Professor of Geography, CU Boulder.
"The Arctic's uncertain future."

Nowhere on the planet are emerging signals of climate change more visible than in the Arctic. There is increasing recognition that these changes will have impacts extending well beyond the Arctic region itself. This includes responses of atmospheric circulation patterns to reduced ice extent, and release of carbon dioxide and methane to the atmosphere as terrestrial and sub sea permafrost warms and thaws. As sea ice retreats, the Arctic also becomes more accessible to shipping and extraction of oil and natural gas reserves under the Arctic coastal seas. Projections of how Arctic conditions will evolve through the 21st century, which in turn bear on the wider impacts of Arctic change, are fraught with uncertainty. Simulations with the current generation of coupled global climate models with the A1B emissions scenario project that the Arctic Ocean will become essentially ice free in late summer as early as 2030 to as late as 2100 and beyond. While a growing number of studies modeling studies indicate that loss of the ice cover will have significant impacts on atmospheric circulation beyond the Arctic, there is no consensus regarding even the basic structure of expected changes. Projected when and to what degree the Arctic becomes a net carbon source to the atmosphere is confounded by, among other things, the large range in projected warming rates, which in turn reflects the strength of Arctic feedbacks linked to changes in snow and sea ice cover.

01 Feb. Henry Gholz, NSF BIO/DEB.
"Support for ecological research by NSF - musings of a Program Officer on long-term leave..."

NSF currently supports over 60% of research in "environmental biology" at U.S. universities and research institutions. This is due to the agency's unique mission and structure that focuses entirely on external support for fundamental (or basic) research - science not tied to the usual Federal agency mission. However, Congressional and Executive expectations that NSF do more to support climate change research have introduced a major dynamic into programs across the Foundation that is only now just playing out in recent Dear Colleague Letters and announcements of opportunity. At the same time, research questions related to the environmental sciences, including ecology, continue to expand in scope, demanding more interdisciplinary approaches and new ways to synthesize exisiting data. Finally, new "distributed observatories" promise a new paradigm for environmental science in the future. How might this play out and how should universities - and their faculties and students - respond to changes at NSF? Potential discussion topics may range from what the new announcements represent, to how synthetic thinking can be better taught, to how PIs might best approach NSF proposal writing.

25 Jan. Lesleigh Anderson, INSTAAR & USGS.
"Upper Colorado snowpack variations during the last 10,000 years: a decade-to-century reconstruction from lake-carbonate d18O."

Seasonal snowpack is the primary source of the Upper Colorado River, a watershed that provides critical water resources to 7 states. Management of this resource has relied on ~50-years of instrumental measurements that reflect a relatively limited range of climatic variability. Presented here are two ~10,000-year oxygen isotope (d18O) records from the sedimentary carbonate of alpine lakes (>3000 m a.s.l.) in northwest Colorado. The two continuous d18O-stratigraphies have unprecedented decade-to-century scale temporal resolution compared with previous paleoclimatic records from this region and provide important new detail for better understanding recent hydroclimatic extremes and range of variability. Bison Lake, 3255 m a.s.l., has lake-water d18O sensitivity to variations in inflow which is annually dominated by snowpack depth. Nearby Yellow Lake, 3140 m a.s.l., has lake-water d18O sensitivity to summer evaporation which is closely linked to summer temperatures. The sedimentary d18O data record past lake-water d18O and indicate that during the early to middle Holocene there was a considerably reduced snowpack, warmer/drier summers, and possibly a more 18O-enriched moisture source to the region, a likely reflection of the influence of seasonal solar insolation trends on regional synoptic climate patterns. After ~3500 Cal yr BP, a series of abrupt negative excursions in Bison-d18O indicate amplified seasonality and unprecedented increases in snowpack depth that correspond with the increasing influence of ENSO on western North America. Similar patterns continue through the last millennia, when Bison-d18O indicate sustained maximum snowpack corresponding with variable and/or intensified ENSO, which culminate during the late 19th century. The influence of natural external and internal climate forcing mechanisms evident in these new Holocene records emphasizes that climate model based future projections of Upper Colorado water availability include an accurate ability to simulate the tropical Pacific’s response to anthropogenic climate forcing.

19 Jan. G. Robert Brakenridge, Visiting Scientist, Community Surface Dynamics Modeling System (CSDMS), University of Colorado. Director, Dartmouth Flood Observatory, Dartmouth College.
"Predicting and managing the effects of extreme floods using orbital remote sensing."

Present and planned Earth-observing orbital sensors provide observations useful for directly measuring the surface water component of the Earth's hydrologic cycle, including flooding. This capability can be more fully utilized for scientific as well as societal needs. Our work is structured in order that, as research is conducted, some practical applications are immediately realized. The seminar will describe how existing sensor data streams can be transformed into river discharge measurements, how calibrated time series of global watershed runoff, mid-2002 to present, can thereby be produced, how the two MODIS sensors and the upcoming VIIRS sensor can also be used in satellite-based surface water surveillance and recording systems, to survey flood inundation extent, and, finally, how as we develop this technology, digital map and GIS data sets of flood inundation are being made immediately available to government ministries, relief agencies, and the general public. If such inundation extent information is then accessible via an organized archive, these data, concerning past flood events, can be integrated with the at-a-site discharge measurements in order to translate mapped flood extents into future flood hazard prediction.

Selected Abstracts INSTAAR Noon Seminars

Selected Abstracts
INSTAAR Noon Seminars