Collaborative Research: Identifying Model Biases in Poleward Heat Transport--Atmosphere-Ocean Partitioning, Trends over the Historical Period and Sub-Seasonal Variability

University Of California-Santa Cruz, Santa Cruz CA

Investigators

Abstract

Winds in the atmosphere and currents in the ocean move heat from the equator to the pole thereby moderating temperatures over Earth’s surface. In the absence of poleward heat transport, the tropics would be uninhabitably warm and sea ice would cover nearly half the planet. Future changes in poleward heat transport rely on coupled (atmosphere/ocean) climate model simulations and have substantial impacts on the spatial structure of projected temperature changes. This project will evaluate if state-of-the-art climate models adequately represent key physical processes responsible for poleward heat transport. Research will be pursued through a model-observation comparison of poleward heat transport at three observable timescales. First, at climatological (long-term averages) timescales the partitioning of poleward heat transport between the atmosphere and ocean will be compared in models and observations. Second, the model simulated long-term trends in poleward heat transport over the last 40 years will be compared to the observational record. Last, the investigators will assess if climate models adequately represent the daily variability of atmospheric heat transport responsible for heat waves. The project will serve a platform for training undergraduate and graduate students and involve outreach activities at local venues. The project will improve the physics of climate models by identifying model biases in the processes responsible for the global scale movement of heat through the climate system at observable timescales. These same physical processes in climate models govern future long-term temperature change and variability with substantial human impact. Additionally, the atmospheric motions that move energy through the climate system also move moisture and, thus, the project results will also improve future predictions of rain and snowfall changes. Lastly, the project directly addresses if models adequately represent the atmospheric processes responsible for heat waves. Identifying model biases in the underlying causes of heatwaves will lead to improved predictions of regional heatwave intensity changes in a warming world. In addition to training undergraduate and graduate students, the investigators will perform public outreach on project-related science concepts to engender enthusiasm amongst younger generations and raise awareness of climate research among the general public. This project is jointly funded by the Climate and Large-Scale Dynamics Program and Division of Atmospheric and Geospace Sciences to support projects that increase research capabilities, capacity and infrastructure at a wide variety of institution types, as outlined in the GEO EMBRACE DCL. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.