Simulation of crop yields using ERA-40: Limits to skill and nonstationarity in weather-yield relationships

Challinor, A. J., Wheeler, T. R., Slingo, J. M., Craufurd, P. Q. and Grimes, D. I. F. (2005) Simulation of crop yields using ERA-40: Limits to skill and nonstationarity in weather-yield relationships. Journal of Applied Meteorology, 44 (4). pp. 516-531. ISSN 0894-8763 doi: 10.1175/JAM2212.1

Abstract/Summary

Reanalysis data provide an excellent test bed for impacts prediction systems. because they represent an upper limit on the skill of climate models. Indian groundnut (Arachis hypogaea L.) yields have been simulated using the General Large-Area Model (GLAM) for annual crops and the European Centre for Medium-Range Weather Forecasts (ECMWF) 40-yr reanalysis (ERA-40). The ability of ERA-40 to represent the Indian summer monsoon has been examined. The ability of GLAM. when driven with daily ERA-40 data, to model both observed yields and observed relationships between subseasonal weather and yield has been assessed. Mean yields "were simulated well across much of India. Correlations between observed and modeled yields, where these are significant. are comparable to correlations between observed yields and ERA-40 rainfall. Uncertainties due to the input planting window, crop duration, and weather data have been examined. A reduction in the root-mean-square error of simulated yields was achieved by applying bias correction techniques to the precipitation. The stability of the relationship between weather and yield over time has been examined. Weather-yield correlations vary on decadal time scales. and this has direct implications for the accuracy of yield simulations. Analysis of the skewness of both detrended yields and precipitation suggest that nonclimatic factors are partly responsible for this nonstationarity. Evidence from other studies, including data on cereal and pulse yields, indicates that this result is not particular to groundnut yield. The detection and modeling of nonstationary weather-yield relationships emerges from this study as an important part of the process of understanding and predicting the impacts of climate variability and change on crop yields.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/8391
Item Type	Article
Refereed	Yes
Divisions	Science > School of Mathematical, Physical and Computational Sciences > Department of Meteorology Life Sciences > School of Agriculture, Policy and Development
Uncontrolled Keywords	CLIMATE-CHANGE SCENARIOS, 3-DIMENSIONAL ATMOSPHERIC SIMULATIONS, SEASONAL PLANT-GROWTH, ASIAN SUMMER MONSOON, FOODGRAIN PRODUCTION, FORECASTING SYSTEM, DATA ASSIMILATION, INDIAN MONSOON, PART I, VARIABILITY
Publisher	American Meteorological Society
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