We welcome new group member and PhD candidate, Qinghuan Zhang
August 30, 2017. We welcome Qinghuan Zhang to the Mountain Hydrology Group. Qinghuan, a PhD student in Geography focusing on hydrology and water resources. She studies streamflow partioning and hydrologic modeling in mountainous watersheds.
RSE paper applies GRACE Groundwater Drought Index (GGDI) over CA Central Valley capturing drought delays unique to groundwater drought
August 17, 2017. Remote Sensing of Environment paper quantitatively presents "an approach to evaluate groundwater drought occurrence based on observations from NASA's Gravity Recovery and Climate Experiment (GRACE) satellite mis- sion. Normalized GRACE-derived groundwater storage deviations are shown to quantify groundwater storage deficits during the GRACE record, which we define as the GRACE Groundwater Drought Index (GGDI)."
A warm welcome to new group member and PhD candidate Kehan Yang
August 14, 2017. Kehan has just arrived from the Institute of Remote Sensing and Digital Earth at the Chinese Academy of Sciences in Beijing where she earned a masters degree in Cartography and Geography Information System Science. Her masters thesis is titled, Monitoring lake area dynamics on the endorheic Tibetan Plateau based on multi-source satellite data.
Mtn Hydro Group joins 1000 other commuters at tube to work day on Boulder Creek
July 14, 2017. According to the Daily Camera, "About 1,000 tubers [were] ... on Boulder Creek as Tube to Work Day celebrated its 10th year today with by far the largest commute in the event's history. When Jeff Kagan and Andy Gruel took to Boulder Creek in 2008 for the inaugural Tube to Work Day, it was just the two of them. In 2017, so many people showed up that tubers had to wait in line and flash wristbands, as if Boulder Creek was the area's newest amusement park ride."
Paper just out quantifying the sensitivity of snowpack in Mediterranean climate mountain areas
July 4, 2017. In this study we quantified the sensitivity of snow to climate warming in selected mountain sites having a Mediterranean climate, including the Pyrenees in Spain and Andorra, the Sierra Nevada in Spain and California (USA), the Atlas in Morocco, and the Andes in Chile. Meteorological observations from high elevations were used to simulate the snow energy and mass balance (SEMB) and calculate its sensitivity to climate. Very different climate sensitivities were evident amongst the various sites. For example, reductions of 9%–19% and 6–28 days in the mean snow water equivalent (SWE) and snow duration, respectively, were found per °C increase.
Video short showing a great application of Terrestrial Laser Scanning (TLS) to study mountain snow hydrology on Niwot Ridge
July 1, 2017. Adrian Harpold partnered with Keith Williams at UNAVCO, Inc. to perform the survey at the National Science Foundation funded Boulder Creek, CO Critical Zone Observatory (CZO) site. A Terrestrial Laser Scanning (TLS) system was used to characterize the forest structure at sites where intensive under-canopy snowpack monitoring is occurring and airborne laser scanning (ALS) has also been employed. Combining the technologies allowed a better estimate of forest structure and snowpack energy balance. Ultimately, this type of information can be employed to increase the effectiveness of land surface models in forested and complex terrain. For more information visit Adrian's paper here or the UNAVCO Highlight page here.
Just published paper by group members highlights a socio-hydro case study of water stress in the Naryn River Basin, Kyrgyzstan
June 22, 2017. Alice Hill and Alana Wilson's new paper in the journal Water and covered in Glacier Hub's front page press release discusses how water vulnerabilities in Central Asia are affected by a complex combination of climate-sensitive water sources, trans-boundary political tensions, infrastructure deficiencies and a lack of water management organization from community to federal levels. This study aims to clarify the drivers of water stress across the 440 km Naryn River basin, headwater stem to the Syr Darya and the disappearing North Aral Sea.
CU Boulder scientists on skis gather snowpack data in spring
June 12, 2017. Each spring, a team of researchers from CU Boulder heads to a glacier where the city of Boulder gets its drinking water and measures the depth of snowpack. The data are used to help forecast water supplies and estimate wildfire danger for the coming year. The survey helps maintain an unbroken record of environmental data to measure climate change. http://www.colorado.edu/mrs/
Paper just out in Water Resources Research spotlighting our snow aridity index to predict forest productivity affected by bark beetle disturbance
May 29, 2017. John Knowles, Leanne Lestak and Noah Molotch just published a paper comparing our snow aridity index (SAI) and snow water equivalent (SWE) to predict forest productivity. The SAI explained more variability than SWE. Multiple sources of remotely sensed and ground based information were used to evaluate the spatiotemporal variability of snowpack accumulation, potential evapotranspiration (PET), and Normalized Difference Vegetation Index (NDVI) throughout the Southern Rocky Mountain ecoregion, USA. Relationships between these variables were used to establish baseline values of expected forest productivity given water and energy inputs
New group paper published in Environmental Research Letters about topoclimate effects on conifer growth
May 23, 2017. David Barnard, Holly Barnard and Noah Molotch's paper published online today looks at the topoclimate effects on growing season length and montane conifer growth. Spatial variability in the topoclimate-driven linkage between forest phenology and tree growth in complex terrain is poorly understood, limiting our understanding of how ecosystems function as a whole. To characterize the influence of topoclimate on phenology and growth, we determined the start, end, and length of the growing season (GSstart, GSend, and GSL, respectively) using the correlation between transpiration and evaporative demand, measured with sapflow.
A warm welcome to 3 new group members
April 14, 2017. We welcome 3 new members to the Mountain Hydrology Group. Alice Hill, a PhD student in Geography who specializes in snow dominated water resource vulnerabilities in a changing climate; Alana Wilson, a graduate student in Geography who is studying climate change, water resources and the cryosphere; and Adam Wlostowski, a Postdoctoral Scholar whose interests lie at the intersection of hydrology, biogeochemistry, geology, and climatology.
Nature paper just published finds counterintuitive observations of slower snowmelt in a warmer world
March 3, 2017. The lead author, Keith Musselman, a Mountain Hydrology Group alumni states in the Nature paper, "There is general consensus that projected warming will cause earlier snowmelt, but how snowmelt rates will respond to climate change is poorly known. We present snowpack observations from western North America illustrating that shallower snowpack melts earlier, and at lower rates, than deeper, later-lying snow-cover." In a Daily Camera article Noah Molotch, Mountain Hydrology Group director, "described Musselman's finding as particularly interesting as it shows a paradigm shift on how scientists perceive mountain snow sensitivity and how it's affected by climate."
NASA Earth Observatory press release highlights Mtn Hydro group near real time SWE data
March 2, 2017. According to the press release written by Michael Carlowicz, "Snowpack on the Sierra Nevada provides one-third of the water consumed by California citizens, farmers, and businesses each year. For the first time in at least five years, there should be more than enough of it. According to the California Department of Water Resources (DWR), the water stored as snow in the Sierra Nevada range was 185 percent of the long-term average for the beginning of March. One year ago, it was 83 percent of the norm. According to the latest measurements from 98 ground-based stations, the average snow-water equivalent in the mountains was 45.5 inches as of March 1, 2017."
Group members are participating in new NASA SnowEx campaign
February 21, 2017. According to Dan Elliott at the Denver AP News, "Instrument-laden aircraft are surveying the Colorado high country this month as scientists search for better ways to measure how much water is locked up in the world's mountain snows — water that sustains a substantial share of the global population. A NASA-led experiment called SnowEx is using five aircraft to test 10 sensors that might one day be used to monitor snow from satellites. The goal: Find the ideal combination to overcome multiple obstacles, including how to analyze snow hidden beneath forest canopies."
KCBS news radio interviews Mountain Hydrology Group director, Noah Molotch
January 26, 2017. Discussions about water supply/management/storage/runoff, early snow melt, flood control, long-term drought, climate change, atmospheric rivers and wildlife habitat management.
Recent storms recouped 37 percent of California’s five-year snow-water deficit
January 24, 2017. The recent "atmospheric river" weather pattern that pummeled California with storms from late December to late January may have recouped 37 percent of the state's five-year snow-water deficit, according to new research led by members of the INSTAAR Mountain Hydrology Group at CWEST. Using NASA satellite data, computer models, and ground-based snow sensors, researchers at CU Boulder’s Center for Water Earth Science and Technology (CWEST) estimate that the recent storms deposited roughly 17.5 million acre feet of water during the month of January.
Latest paper shows high-mountain haze due to increasing wildfires in the west
January 9, 2017. Bruce Finley wrote in the Denver Post yesterday, "The climate shift favoring droughts and more wildfires in the Western United States is leading to hazier days with reduced visibility in the high country, especially wilderness areas, where visitors seek endless blue skies."
Mountain Hydrology Group members will be at AGU in San Francisco next week
December 7, 2016. Mountain Hydrology group members will be converging on San Francisco next week for the annual American Geophysical Union (AGU) Fall meeting. Have a look at the INSTAAR Mountain Hydrology schedule to see how to connect with group members.
“With the satellite data you get a much more comprehensive perspective … You can then use that to translate to how much spring runoff we might expect.”
November 22, 2016. Work that the Mountain Hydrology group is doing using remote sensing to assess snowpack in western mountains is featured in the magazine Western Water in this article, The view from above: The promise of remote sensing. In the article the writer, Gary Pitzer, covers water science and the use of various forms of remote sensing technology to monitor, analyze, and better understand water in the West.
We welcome Oliver Wigmore as a post doctoral researcher to the Mountain Hydrology Group
October 17, 2016. Oliver Wigmore just completed a Ph.D. at the Ohio State University Department of Geography and Byrd Polar and Climate Research Center. His research interests are primarily centered around the cryosphere, mountain hydrology and water resources, with an additional focus on the development and deployment of unmanned aerial systems (UAS) and remote sensing. His dissertation titled, Assessing Variability in Pro-glacial Soil Moisture: Integrating UAV’s, Satellites and Field Hydrology in the Peruvian Andes, examines the role of soil moisture storage within the hydrologic budget of the Cordillera Blanca, Peru. His work at CU will integrate UAS datasets with field measurements to improve our understanding of dynamic ecohydrologic connections and spatiotemporal variability in the Boulder Creek watershed. He is working with Noah Molotch at the CU Earth Lab and the INSTAAR Mountain Hydrology Group. For more information visit his personal webpage.
Groundbreaking real-time SWE modeling improves snowpack information
October 14, 2016. Details are in our latest paper, Real-time estimation of snow water equivalent in the Upper Colorado River Basin using MODIS-based SWE Reconstructions and SNOTEL data. Changes in climate necessitate improved snowpack information to better represent anomalous distributions of snow water equivalent (SWE) and improve water resource management. We estimate the spatial distribution of SWE for the Upper Colorado River basin weekly from January to June 2001–2012 in quasireal-time. Given that previous works using SWE reconstructions were limited to retrospective analyses by necessity, the work presented here represents an important contribution in that it extends SWE reconstructions to real-time applications and illustrates that doing so significantly improves the accuracy of SWE estimates.
New paper uses contact spectroscopy to solve measurement gap of seasonally-changing snow grain size
September 28, 2016. The paper, Measuring spatiotemporal variation in snow optical grain size under a subalpine forest canopy using contact spectroscopy is available from the Water Resources Research journal. The distribution of forest cover exerts strong controls on the spatiotemporal distribution of snow accumulation and snowmelt. The physical processes that govern these controls are poorly understood given a lack of detailed measurements of snow states. In this study, we address one of many measurement gaps by using contact spectroscopy to measure snow optical grain size at high spatial resolution in trenches dug between tree boles in a subalpine forest.
Kate Hale joins the Mountain Hydrology Team as an MA student
August 19, 2016. Kate will be pursuing research in snow and ice hydrology, interests originating from her upbringing in the "Frozen Tundra" of Green Bay, WI, years spent paddling Canadian arctic rivers and a B.S. in Environmental Biology from Georgetown University. Noah Molotch will be Kate's primary mentor. Kate is excited to be further integrating her love for the natural world into her academic career.
Streamflow decreases and forest uptake of atmospheric carbon dioxide are driven by earlier snowmelt
August 3, 2016. Two companion papers published today by Mountain Hydrology Group members in Geophysical Research Letters determine the effects of earlier snowmelt in the Colorado Rocky Mountains. The Barnhart, et al. paper Snowmelt Rate Dictates Streamflow and the Winchell, et al. paper Earlier snowmelt reduces atmospheric carbon uptake in midlatitude subalpine forests demonstrate the consequences of a warming climate on streamflow (Barnhart) and carbon uptake by forests (Winchell). The papers have been recognized by joint press releases at the National Science Foundation and the University of Colorado, follow the press release links to view additional content, including interviews, photos, and insights by scientists.
Ryan Webb joins the Mountain Hydrology Group for a postdoctoral fellowship
July 1, 2016. The Mountain Hydrology group welcomes Ryan Webb who just completed a Ph.D. in snow and vadose zone hydrology at Colorado State University. Ryan is an NSF Postdoctoral Fellow and will be mentored by Noah Molotch and Mark Williams here at INSTAAR along with Dr. Stefan Finsterle of Lawrence Berkeley National Labs. The title of his postdoctoral research project is New approaches to address scaling issues for lateral flow of water in a layered snow pack.
Taylor Winchell defends his master's thesis
May 10, 2016. Today Taylor Scott Winchell successfully defended his master's thesis Changing Snowpack Dynamics: Phase Predictions and Forest Implications which was submitted to the Faculty of the Graduate School of the University of Colorado in partial fulfillment of the requirement for the degree of Masters of Science at the Department of Civil, Environmental, and Architectural Engineering.
Noah Molotch speaks to The Desert Sun, "... how are we going to manage the infrastructure that is not adapted to the new regime ..."
April 14, 2016. A very interesting and comprehensive analysis of climate change and snow in the western U.S. Losing snow in a changing climate: What global warming means for our water supplies. Story by Ian James and photographs by Jay Calderon, The Desert Sun, April 14, 2016.
Colorado and Utah Scientists Study Colorado Mountain Streamflow in a Warming Climate
April 12, 2016. In snow-dominated mountain regions, a warming climate is expected to alter two drivers of hydrology: (1) decrease the fraction of precipitation falling as snow; and (2) increase surface energy available to drive evapotranspiration. This study uses a novel integrated modeling approach to explicitly separate energy budget increases via warming from precipitation phase transitions from snow to rain in two mountain headwaters transects of the central Rocky Mountains.
John Knowles Joins the Mountain Hydrology Group as postdoctoral researcher
September 11, 2016. We welcome John Knowles as a new postdoctoral researcher in our group. John received his PhD from the University of Colorado in 2015 and his research during that time was broadly focused on the exchange of water vapor and carbon dioxide between Earth's surface and the atmosphere using eddy covariance, chamber, gradient method, and isotopic techniques. During his tenure with the Mountain Hydrology Group, he's looking forward to incorporating Geographical Information Systems (GIS) and remote sensing techniques into his research program at the nexus of hydrological, biological, and atmospheric processes. In his free time, John also enjoys skiing, cooking, gardening, and spending time with his family.
March 12, 2015. A bark beetle epidemic across western North America isn’t just leaving ugly grey spots among green mountain vistas. A recently published study adds to the evidence that it’s changing the way water moves across the landscape and eventually into people’s homes.
Alumna Danielle Perrot Begins Position at the City of Greeley Water Dept.
September 15, 2014. Congratulations to Danielle Perrot who is now a Water Resource Analyst at the City of Greeley Water and Sewer Department in Greeley, Colorado. She will be using biogeochemistry to do decreed water accounting which is required for the administration of our water supply here in Colorado.
Adrian Harpold Accepts Professorship at U of Nevada, Reno
September 15, 2014. Congratulations to Adrian Harpold on his new assistant professor position in the Department of Natural Resources and Environmental Science at the University of Nevada, Reno. His research program utilizes existing observation networks and new field observations to improve the ecohydrological process underpinnings of Earth systems models. His diverse interests and background have led to investigations of runoff generation mechanisms via hydrological tracers and models, as well as the partitioning of water to its various stores and fluxes.
Taylor Winchell Joins the Mountain Hydrology Group as a masters candidate
August 13, 2014. We welcome Taylor Wincell who just finished his bachelor of science degree in the Environmental Fluid Mechanics and Hydrology Program at the University of California, Berkley. His research focused on understanding the feedback interactions between vegetation and water. He will be working on a masters degree in the Civil, Environmental and Architectural Engineering department here at CU with Noah Molotch as his primary advisor.
Keith Jennings Joins the Mountain Hydrology Group as a doctoral candidate
August 13, 2014. Welcome to Keith Jennings who just finished his master of science degree in the Water Resources Graduate Program at Oregon State University. He will be working on a PhD at the Geography department here at CU with Noah Molotch as his primary advisor. His master's thesis was titled, Precipitation-snowmelt timing and snowmelt augmentation of large peak flow events, western Cascades, Oregon.
Dominik Schneider Wins 3 Year NASA Fellowship
May 28, 2014. Congratulations to Dominik Schneider for winning a NASA Earth and Space Science Fellowship which will provide him with full support for the next three years. His project will use satellite observations, models, and ground measurements to estimate snow water equivalent in the Colorado River Basin. The data sets will provide water managers throughout the river basin with real time snowpack information which will improve water resource decision making
Brooke Stamper Joins the Mountain Hydrology Group as an undergraduate researcher
February 3, 2014. Brooke Stamper is a senior at the University of Colorado at Boulder. She will be working with Adrian Harpold this semester studying spatio-temporal variability in soil moisture. The photo of Brooke Stamper on the right was taken at the New Mexico field site.
Study Finds Climate Link to Atmospheric-River Storms
November 12, 2013. A new NASA-led study of atmospheric-river storms from the Pacific Ocean may help scientists better predict major winter snowfalls that hit West Coast mountains and lead to heavy spring runoff and sometimes flooding. Atmospheric rivers -- short-lived wind tunnels that carry water vapor from the tropical oceans to mid-latitude land areas -- are prolific producers of rain and snow on California's Sierra Nevada mountains. The finding, published in the journal Water Resources Research, has major implications for water management in the West, where Sierra runoff is used for drinking water, agriculture and hydropower.
Enhancing Estimates of Water Supplies and Seasonal Availability
October 29, 2013. The reconstructed Sierra Nevada, California snow water equivalent (SWE) product and interactions with the California Department of Water Resources forecasters were featured in NASA's Earth Science Applied Sciences Program 2012 annual report. "An Applied Sciences project is working with the California Department of Water Resources (CDWR) to assess applications of MODIS snow cover data to improve water supply forecasting. Estimating the amount of water stored in snow (snow water equivalent, or SWE) helps inform seasonal water availability. Typically, hydrologists measure mountain SWE at middle elevation locations using snow pillows, which are large bladders that measure the weight of the overlying snowpack. Such measures provide detailed information at point locations."
Important study about SNOTEL spatial representativeness published in Hydrological Processes paper
July 18, 2013. The spatial distribution of snow water equivalent (SWE) is a key variable in many regional-scale land surface models. Currently, the assimilation of point-scale snow sensor data into these models is commonly performed without consideration of the spatial representativeness of the point data with respect to the model grid-scale SWE. (Paper can be found in Hydrological Processes, DOI: 10.1002/hyp.9355, 2013)
Niwot LTER researchers using satellite to study snowpack in the Rockies
July 2, 2013. A group of researchers at the Niwot Ridge (NWT) Long Term Ecological Research (LTER) program are using an innovative new research approach to evaluate snowpack conditions across the Rocky Mountain region. Led by Noah Molotch, the group is employing remote-sensing from satellites and automated depth sensors at various elevations on Niwot Ridge to measure the snowpack to augment the existing snow measurement network now used by water managers.
New paper examines turbulent fluxes in an energy balance snowmelt model in Niwot Ridge forests
April 3, 2013. Turbulent fluxes of sensible and latent heat are important processes in the surface energy balance that drives snowmelt. Modeling these fluxes in a forested environment is complicated because of the canopy effects on the wind field. This paper presents and tests a turbulent flux model developed to represent these processes in an energy balance snowmelt model. (Paper can be found in Water Resources Research, doi:10.1002/wrcr.20073, 2013)
Molotch presents at the Center for Science & Technology Policy Research series
March 7, 2013. Noah Moloch presented "Ecohydrological Vulnerability to Changes in Climate and Land Use in the Rocky Mountains". The talk was designed for non-hydrologists and was delivered like a 101 course covering the group's latest snow hydrology research and related water issues in the Rocky Mountain region.
Harpold paper highlighted in EOS Research Spotlight
January 8, 2013. The freshwater supplies of the American West rely, for the most part, on snow. The Colorado River, the Rio Grande, and other rivers in the intermountain west—bounded by the Sierra Nevada and Cascade mountains to the west and the Rockies to the east—are the main sources of water for one of the driest parts of the continent, and their flows are predominantly fed by the spring- time melt of snow accumulated over the winter. (Paper can be found in Water Resources Research, doi:10.1029/2012WR011949, 2012)
Paper documents new spectral snowpack profiler probe
November 7, 2012. We present a portable spectral profiler probe to measure snow grain size stratigraphy in mountain snowpack at up to 5 mm vertical resolution, without the need for snow pit excavation. The probe infers grain size using near-infrared reflectance spectroscopy by inserting into the snowpack an optical package consisting of a light source and fiber optic receiver, which views the snow laterally and sends the collected reflected light to a spectrometer at the surface.
Leah Meromy defends her master's thesis
October 30th, 2012. Leah Meromy, a student at the University of Colorado at Boulder Geography Department and Hydrologic Sciences graduate program successfully defended her master's thesis. Her advisors are Noah Molotch (chair), Mark Williams, and Peter Blanken. The title of her thesis is "Subalpine snowpack-climate manipulation and modeling experiment at Niwot Ridge, CO and Valles Caldera National Preserve, NM".
Danielle Perrot defends her master's thesis
October 11th, 2012. Danielle Perrot, a student at the University of Colorado at Boulder Geography Department and Hydrologic Sciences graduate program successfully defended her master's thesis. Her advisors are Noah Molotch (chair), Mark Williams, and Suzanne Anderson. The title of her thesis is "Nitrate export response to spatially distributed snowmelt in alpine catchments".
Western snow is mother nature's drip irrigation system
September 28th, 2012. Live interview on the Weather Channel. "Effectively what we've measured is the greeness or how the forest conducts photosynthesis each spring and summer period and we've related that to the amount of snow we get each winter preceeding that. We are looking at mother nature's drip irrigation system, which starts with the snowpack in the western United States, snow melt is providing water to the forest throughout the growing season."
Blended observations and models of snow water equivalent for water resource applications
September 27, 2012. Talk presented at the remote sensing workshop in San Diego sponsored by the Environmental Defense Fund, the Water Education Foundation, and the California Water Foundation. The workshop focused on highlighting water management needs for which remote sensing could add capacity or efficiency. The workshop was attended by water managers, technical experts, and academics.
CU-led mountain forest study shows vulnerability to climate change
September 10th, 2012. A new University of Colorado Boulder-led study that ties forest “greenness” in the western United States to fluctuating year-to-year snowpack indicates mid-elevation mountain ecosystems are most sensitive to rising temperatures and changes in precipitation and snowmelt.
Keith Musselman publishes paper on the influence of canopy and solar irradiance on snowmelt rates
August 15, 2012. Sub-canopy snow ablation rates were measured for three years at forested research plots in the Sierra Nevada, California with a network of 24 automated snow depth sensors and monthly snow density surveys.
Adrian Harpold joins Mountain Hydrology Group as a postdoctorate fellow
August 1, 2012. Adrian is pursuing an NSF Earth Sciences Postdoctoral Fellowship to improve our understanding of snow-vegetation interactions in land surface models. He jointly works with Noah Molotch at INSTAAR and David Gochis at NCAR. This work will focus on sites within the Boulder Creek CZO, but also include work in the Southern Sierra CZO and Jemez River Basin-Santa Catalina Mountains CZO.