Research: Graduate Student Profile

 

Snapshots...

Christy Field
Climate and Atmospheric Science, NASA/GISS

M.A., Earth and Environmental Sciences, Columbia University, 2005.
B.A., English, Cornell University, 1996.

"Doing graduate work at Columbia has been a fantastic experience in practically every respect. I love working with my advisors and am continually impressed by their willingness to discuss research tactics and answer questions. DEES consistently recruits top-quality students whose variety of interests are a great source of new ideas and who are constantly creating new ways to enrich the grad school experience. The department does an amazing job of staying on top of the numerous administrative hurdles associated with student life – which is hugely valuable to anyone trying to get research done, help teach classes, and juggle all the other tasks of graduate school. This combined with all the rich collection of resources and facilities that Columbia provides makes me feel lucky to be a student here."

Production and Climate-related Impacts on Beryllium-10 in Ice Cores

In order to understand contemporary climate change, it is necessary to quantify natural forcings – particularly solar variability, the most significant natural forcing on centennial timescales. Changes in solar irradiance are positively linked with changes in solar magnetic activity, which controls Earth's exposure to cosmic rays. Collisions between cosmic rays and Earth's atmosphere produce "cosmogenic isotopes" such as ¹⁰Be. The resulting anti-correlation between ¹⁰Be production and solar output is the basis of ¹⁰Be’s potential use as a proxy for solar activity.

Once produced, ¹⁰Be attaches primarily to sulfate aerosols, which are deposited at the Earth's surface by both wind- and precipitation-related processes. Beryllium-10 concentrations can be measured in polar ice core records, potentially providing long-term records of solar activity. A complicating factor is the possibility that climatic effects may confound solar signals in the ¹⁰Be record. If ¹⁰Be is to be unambiguously used to infer solar variation, we need a way to account for the effects of climate as they appear in the ice-core record. My research involves using climate models to examine how production- and climate-related changes impact 10Be, with the goal of better understanding how accurately ¹⁰Be can be used as a proxy for solar activity.

Advisors: Gavin Schmidt , David Rind, and Sidney Hemming.