April 5, 2016

Category: News

The winner of the Montgomery Prize for best oral presentation at the GeoDaze 2016 symposium was Luke Parsons for “Spatial consistency of temperature and precipitation scaling in CMIP5 models.” The symposium, a student-run showcase of graduate and undergraduate research in the earth sciences, was held at the University of Arizona from March 31 – April 2. In addition to receiving a $2000 cash prize, Parsons will be invited to present his talk to our Tucson staff.

Luke is not only a PhD candidate at the UA Department of Geosciences but also an NSF graduate research fellow. He is currently studying the potential for future drought in monsoon regions using climate models and sediment cores from lakes.

M&A has supported GeoDaze for many years in an effort to promote excellence in research and communication in the geosciences. We also award a Montgomery Prize at another UA symposium — El Dia del Agua — sponsored by the Department of Hydrology & Water Resources.

Abstract: Spatial consistency of temperature and precipitation scaling in CMIP5 models

Accurate assessments of future climate and climate impacts require realistic simulation of decadal- to centennial-scale temperature and precipitation variability, and yet there is no clear consensus regarding the nature of this variability across the globe. We use NCAR CESM Last Millennium Ensemble, CMIP5 Last Millennium, and CMIP5 pre-industrial Control simulations to study the magnitude and spatial consistency of surface temperature and precipitation spectral scaling. We compare patterns of temperature and precipitation scaling within different runs of one model (CESM) and across modeling agencies (CMIP5 experiments). We find that among different runs and models, surface temperature scales relatively consistently across the globe, especially over most of the high latitude oceans. However, precipitation scaling is much less consistent, even within different runs of one model, except over isolated patches of high latitude oceans and the tropical Pacific. Precipitation and temperature scaling over high latitudes (60°N-70°N, 60°S-70°S) and the tropics (0°-10°N) tend to agree in CMIP5 models, but the magnitude of scaling is quite different. Importantly, volcanic forcing significantly reddens the temperature spectrum, especially over the tropical Pacific, but has little effect on precipitation.

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