Monday, September 21, 2020, 12:00PM - 1:00PM
Glacial lessons on tropical climate change: The importance of the Indian and Atlantic oceans
The Pacific Ocean is generally expected to play a key role in the response of the tropics to greenhouse warming. The importance of the Atlantic and Indian oceans remains unclear due to inconsistent model predictions and conflictive interpretations of paleoclimate records. Combining models and paleoclimate records we have identified a series of mechanisms whereby these oceans could play a key role in past and future changes. A coupled ocean-atmosphere feedback amplified glacial changes in the Indian Ocean, resulting in oceanographic conditions akin to the Pacific Ocean – including a previously unknown mode of variability akin to the Pacific El Nino. Analysis of hydroclimate changes during Heinrich Stadial 1 – a past interval when the Atlantic Meridional Overturning Circulation nearly collapsed – reveals a key role for the tropical North Atlantic communicating the influence of high latitude cooling to the global tropics. Both mechanisms are likely to operate under greenhouse warming, although they are not active in every model. The paleoclimate evidence increases our confidence in models simulating them, thus improving our ability to predict future changes.
Graduate students are invited to meet with Dr. DiNezio on Zoom after the talk. See the grad student channel on Teams for more info!
We will also have an informal coffee half-hour immediately before the seminar, if you'd like to socialize with your fellow INSTAARS. We'll use the same zoom link as for the seminar.