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Evaluating the Sensitivity of Agricultural Model Performance to Different Climate Inputs: Supplemental MaterialProjections of future food production necessarily rely on models, which must themselves be validated through historical assessments comparing modeled and observed yields. Reliable historical validation requires both accurate agricultural models and accurate climate inputs. Problems with either may compromise the validation exercise. Previous studies have compared the effects of different climate inputs on agricultural projections but either incompletely or without a ground truth of observed yields that would allow distinguishing errors due to climate inputs from those intrinsic to the crop model. This study is a systematic evaluation of the reliability of a widely used crop model for simulating U.S. maize yields when driven by multiple observational data products. The parallelized Decision Support System for Agrotechnology Transfer (pDSSAT) is driven with climate inputs from multiple sources reanalysis, reanalysis that is bias corrected with observed climate, and a control dataset and compared with observed historical yields. The simulations show that model output is more accurate when driven by any observation-based precipitation product than when driven by non-bias-corrected reanalysis. The simulations also suggest, in contrast to previous studies, that biased precipitation distribution is significant for yields only in arid regions. Some issues persist for all choices of climate inputs: crop yields appear to be oversensitive to precipitation fluctuations but under sensitive to floods and heat waves. These results suggest that the most important issue for agricultural projections may be not climate inputs but structural limitations in the crop models themselves.
Document ID
20160003527
Document Type
Reprint (Version printed in journal)
Authors
Glotter, Michael J. (Chicago Univ. Chicago, IL, United States)
Ruane, Alex C. (NASA Goddard Inst. for Space Studies New York, NY United States)
Moyer, Elisabeth J. (Chicago Univ. Chicago, IL, United States)
Elliott, Joshua W. (Chicago Univ. Chicago, IL, United States)
Date Acquired
March 17, 2016
Publication Date
November 13, 2015
Publication Information
Publication: Journal of Applied Meteorology and Climatology
Volume: 55
Issue: 3
Subject Category
Earth Resources and Remote Sensing
Meteorology and Climatology
Report/Patent Number
GSFC-E-DAA-TN30449
Funding Number(s)
WBS: WBS 509496.02.08.04.24
Distribution Limits
Public
Copyright
Other
Keywords
simulation
climate
bias
physical exercise
farm crops
agriculture
histories