The Impact of Parameterized Convection on the Simulation of Crop Processes

Global climate and weather models are a key tool for the prediction of future crop productivity, but they all rely on parameterizations of atmospheric convection, which often produce significant biases in rainfall characteristics over the tropics. The authors evaluate the impact of these biases by d...

Full description

Bibliographic Details
Main Authors: García Carreras, L., Challinor, Andrew J., Parkes BJ, Birch, C.E., Nicklin KJ, Parker DJ
Format: Journal Article
Language:Inglés
Published: American Meteorological Society 2015
Subjects:
Online Access:https://hdl.handle.net/10568/76570
_version_ 1855520296407138304
author García Carreras, L.
Challinor, Andrew J.
Parkes BJ
Birch, C.E.
Nicklin KJ
Parker DJ
author_browse Birch, C.E.
Challinor, Andrew J.
García Carreras, L.
Nicklin KJ
Parker DJ
Parkes BJ
author_facet García Carreras, L.
Challinor, Andrew J.
Parkes BJ
Birch, C.E.
Nicklin KJ
Parker DJ
author_sort García Carreras, L.
collection Repository of Agricultural Research Outputs (CGSpace)
description Global climate and weather models are a key tool for the prediction of future crop productivity, but they all rely on parameterizations of atmospheric convection, which often produce significant biases in rainfall characteristics over the tropics. The authors evaluate the impact of these biases by driving the General Large Area Model for annual crops (GLAM) with regional-scale atmospheric simulations of one cropping season over West Africa at different resolutions, with and without a parameterization of convection, and compare these with a GLAM run driven by observations. The parameterization of convection produces too light and frequent rainfall throughout the domain, as compared with the short, localized, high-intensity events in the observations and in the convection-permitting runs. Persistent light rain increases surface evaporation, and much heavier rainfall is required to trigger planting. Planting is therefore delayed in the runs with parameterized convection and occurs at a seasonally cooler time, altering the environmental conditions experienced by the crops. Even at high resolutions, runs driven by parameterized convection underpredict the small-scale variability in yields produced by realistic rainfall patterns. Correcting the distribution of rainfall frequencies and intensities before use in crop models will improve the process-based representation of the crop life cycle, increasing confidence in the predictions of crop yield. The rainfall biases described here are a common feature of parameterizations of convection, and therefore the crop-model errors described are likely to occur when using any global weather or climate model, thus remaining hidden when using climate-model intercomparisons to evaluate uncertainty.
format Journal Article
id CGSpace76570
institution CGIAR Consortium
language Inglés
publishDate 2015
publishDateRange 2015
publishDateSort 2015
publisher American Meteorological Society
publisherStr American Meteorological Society
record_format dspace
spelling CGSpace765702024-10-17T10:13:27Z The Impact of Parameterized Convection on the Simulation of Crop Processes García Carreras, L. Challinor, Andrew J. Parkes BJ Birch, C.E. Nicklin KJ Parker DJ climate change agriculture food security climate prediction convective parameterization model errors Global climate and weather models are a key tool for the prediction of future crop productivity, but they all rely on parameterizations of atmospheric convection, which often produce significant biases in rainfall characteristics over the tropics. The authors evaluate the impact of these biases by driving the General Large Area Model for annual crops (GLAM) with regional-scale atmospheric simulations of one cropping season over West Africa at different resolutions, with and without a parameterization of convection, and compare these with a GLAM run driven by observations. The parameterization of convection produces too light and frequent rainfall throughout the domain, as compared with the short, localized, high-intensity events in the observations and in the convection-permitting runs. Persistent light rain increases surface evaporation, and much heavier rainfall is required to trigger planting. Planting is therefore delayed in the runs with parameterized convection and occurs at a seasonally cooler time, altering the environmental conditions experienced by the crops. Even at high resolutions, runs driven by parameterized convection underpredict the small-scale variability in yields produced by realistic rainfall patterns. Correcting the distribution of rainfall frequencies and intensities before use in crop models will improve the process-based representation of the crop life cycle, increasing confidence in the predictions of crop yield. The rainfall biases described here are a common feature of parameterizations of convection, and therefore the crop-model errors described are likely to occur when using any global weather or climate model, thus remaining hidden when using climate-model intercomparisons to evaluate uncertainty. 2015-06-01 2016-08-25T11:51:03Z 2016-08-25T11:51:03Z Journal Article https://hdl.handle.net/10568/76570 en Open Access American Meteorological Society Garcia-Carreras L, Challinor AJ, Parkes BJ, Birch CE, Nicklin KJ, Parker DJ. 2015. The Impact of Parameterized Convection on the Simulation of Crop Processes. Journal of Applied Meteorology and Climatology 54:1283–1296.
spellingShingle climate change
agriculture
food security
climate prediction
convective parameterization
model errors
García Carreras, L.
Challinor, Andrew J.
Parkes BJ
Birch, C.E.
Nicklin KJ
Parker DJ
The Impact of Parameterized Convection on the Simulation of Crop Processes
title The Impact of Parameterized Convection on the Simulation of Crop Processes
title_full The Impact of Parameterized Convection on the Simulation of Crop Processes
title_fullStr The Impact of Parameterized Convection on the Simulation of Crop Processes
title_full_unstemmed The Impact of Parameterized Convection on the Simulation of Crop Processes
title_short The Impact of Parameterized Convection on the Simulation of Crop Processes
title_sort impact of parameterized convection on the simulation of crop processes
topic climate change
agriculture
food security
climate prediction
convective parameterization
model errors
url https://hdl.handle.net/10568/76570
work_keys_str_mv AT garciacarrerasl theimpactofparameterizedconvectiononthesimulationofcropprocesses
AT challinorandrewj theimpactofparameterizedconvectiononthesimulationofcropprocesses
AT parkesbj theimpactofparameterizedconvectiononthesimulationofcropprocesses
AT birchce theimpactofparameterizedconvectiononthesimulationofcropprocesses
AT nicklinkj theimpactofparameterizedconvectiononthesimulationofcropprocesses
AT parkerdj theimpactofparameterizedconvectiononthesimulationofcropprocesses
AT garciacarrerasl impactofparameterizedconvectiononthesimulationofcropprocesses
AT challinorandrewj impactofparameterizedconvectiononthesimulationofcropprocesses
AT parkesbj impactofparameterizedconvectiononthesimulationofcropprocesses
AT birchce impactofparameterizedconvectiononthesimulationofcropprocesses
AT nicklinkj impactofparameterizedconvectiononthesimulationofcropprocesses
AT parkerdj impactofparameterizedconvectiononthesimulationofcropprocesses