학술논문

Sources of interannual yield variability in JULES-crop and implications for forcing with seasonal weather forecasts.
Document Type
Article
Source
Geoscientific Model Development Discussions. 2015, Vol. 8 Issue 6, p4599-4621. 23p.
Subject
*CROP yields
*LONG-range weather forecasting
*CLIMATE change
*FORCING (Plants)
*METEOROLOGICAL precipitation
*ATMOSPHERIC temperature
Language
ISSN
1991-9611
Abstract
JULES-crop is a parametrisation of crops in the Joint UK Land Environment Simulator (JULES). We investigate the sources of the interannual variability in the modelled maize yield, using global runs driven by reanalysis data, with a view to understanding the impact of various approximations in the driving data and initialisation. The standard forcing dataset for JULES consists of a combination of meteorological variables describing precipitation, radiation, temperature, pressure, specific humidity and wind, at subdaily time resolution. We find that the main characteristics of the modelled yield can be reproduced with a subset of these variables and using daily forcing, with inter nal disaggregation to the model timestep. This has implications in particular for the use of the model with seasonal forcing data, which may not have been provided at subdaily resolution for all required driving variables. We also investigate the effect on annual yield of initialising the model with climatology on the sowing date. This approximation has the potential to considerably simplify the use of the model with seasonal forecasts, since obtaining observations or reanalysis output for all the initialisation variables required by JULES for the start date of the seasonal forecast would present significant practical challenges. [ABSTRACT FROM AUTHOR]