Please join us Thursday, February 9, 2023, for our Winter Seminar Series with our guest speaker: Daniel Whitt.  

EARTH SYSTEM SCIENCE
SEMINAR SERIES
12:00-1:20pm
Mccullough Building Room 115

Daniel Whitt, Research Scientist
Earth Science Division, NASA Ames Research Center

“How slowing ocean circulation drives down North Atlantic Ocean biological productivity in global warming”

It is a high priority for Earth system science to understand the impacts of global warming on ocean biological productivity, which is responsible for half of global carbon fixation and fuels marine food webs from plankton to fish. Earth system models currently project modest reductions in global ocean productivity, but each of these global projections is a highly uncertain sum of strong regional changes of both signs. Thus, it is necessary to study the susceptible regions individually, the most susceptible of which may be the Subarctic Atlantic where high productivity declines by as much as 50% in high-emissions scenarios. In this talk, I aim to elucidate the role of the circulation in the bottom-up control of productivity in the changing Subarctic Atlantic Ocean, from the basin scale to the submesoscale (<10 km). I will advance the hypothesis that productivity in the Subarctic Atlantic is especially susceptible to global warming due to its susceptibility to the slowing North Atlantic nutrient stream, which supplies nutrients from the low-latitude thermocline to the surface in the Subarctic and slows in conjunction with the Atlantic meridional overturning circulation. While the results indicate ways to evaluate and possibly reduce uncertainty in model projections, the uncertainties in the multi-scale response of the basin-scale overturning circulation to emissions impose a lower bound on the uncertainties in the regional biological response to emissions in the Subarctic Atlantic.

Bio

Since 2021, Dan has been a research scientist and interdisciplinary oceanographer in the Biospheric Science Branch of the Earth Science Division at NASA Ames. He uses observations, high-end computing, and theory to understand and model the ocean, including its physics, biogeochemistry, and ecology as well as its role in the changing Earth system. Previously, he spent 4 years as a Project Scientist at the National Center for Atmospheric Research and 2 years as an NSF international postdoctoral fellow at the University of Cambridge. He received his PhD in Environmental Earth System Science from Stanford in 2015.

Websites

Danielwhitt.github.io

https://www.nasa.gov/centers/ames/earthscience/members/biosphericsciencebranch/daniel_whitt_bio