Collaborative Research: P2C2--Interrogating the Free Troposphere during the Last Deglaciation

William Marsh Rice University, Houston TX

Investigators

Abstract

This project aims to provide the first global-scale constraints on temperature and dynamics of the free- troposphere- which comprises altitudes ranging from about 2 - 18 km. Specifically, the researcher will use new isotopic measurements and 3 Dimensional (3D) global modeling to reconstruct and interpret high-altitude atmospheric temperature and circulation changes during the last deglaciation (18,000 to 8,000 years before present). This project will use an emerging tracer from ice-core records to generate a paleo-temperature record that will reveal the state of the troposphere and its interaction with the stratosphere across the most recent major climate transition in Earth history. Research goals include constraining the thermal evolution of the free troposphere during a time period that includes several episodes of abrupt climate change; testing modeled free-troposphere responses to orbital and greenhouse-gas forcing; and testing stratosphere-to- troposphere exchange dynamics across major climate transitions. This combined measurement-modeling study will constrain the paleoclimate at altitude during the most recent major episode of global change, when circulation patterns shifted under different climatic boundary conditions. The potential Broader Impacts include developing a new temperature record of the free troposphere during the last deglaciation. The application of a new isotopic tracer to investigate the dynamics of stratosphere-troposphere exchange is potentially transformative for paleoclimate research. Other broader impacts include participation of the researchers in STEM outreach events as part of their ongoing activities, including participation in the department’s annual Earth Day at Rice University with the Girl Scouts. The project will train one undergraduate and two graduate students, and support two early career researchers. 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.