TY - JOUR
T1 - Estimating daily solar radiation in the Argentine Pampas
AU - Podestá, Guillermo P.
AU - Núñez, Liliana
AU - Villanueva, Carlos A.
AU - Skansi, María A.
N1 - Funding Information:
This work was supported by a planning grant from the Biocomplexity in the Environment initiative of the National Science Foundation, and funds awarded by NOAA’s Office of Global Programs, Climate and Societal Interactions Program.
PY - 2004/5/20
Y1 - 2004/5/20
N2 - Solar radiation is an important input to crop growth models used for risk management and assessment purposes. Methods are explored to estimate daily solar radiation in the Argentine Pampas, one of the most important agricultural areas in the world. Two scenarios are considered: (i) sunshine duration data are available for a given location, or (ii) only daily temperature (minimum and maximum) and precipitation records exist. If sunshine duration data are available, an association between this quantity and atmospheric transmissivity yields daily radiation estimates with a root mean square error (RMSE) of 1.5MJm-2 per day. Without sunshine duration records, daily temperature and precipitation can be used to estimate atmospheric transmittance and then compute daily radiation values. A model linking predictors that are proxies of cloudiness and atmospheric humidity to atmospheric transmittance was fitted using Generalized Additive Models (GAMs), a modern statistical technique that does not assume any a priori functional forms for the association between predictors and predictand. The errors in radiation estimates using temperature and precipitation are larger (RMSE of 3.2MJm-2 per day) than those derived from sunshine duration, but they are comparable to results for other locations and methods. Most importantly, daily radiation estimates have small bias and the errors show no systematic patterns with season or other variables.
AB - Solar radiation is an important input to crop growth models used for risk management and assessment purposes. Methods are explored to estimate daily solar radiation in the Argentine Pampas, one of the most important agricultural areas in the world. Two scenarios are considered: (i) sunshine duration data are available for a given location, or (ii) only daily temperature (minimum and maximum) and precipitation records exist. If sunshine duration data are available, an association between this quantity and atmospheric transmissivity yields daily radiation estimates with a root mean square error (RMSE) of 1.5MJm-2 per day. Without sunshine duration records, daily temperature and precipitation can be used to estimate atmospheric transmittance and then compute daily radiation values. A model linking predictors that are proxies of cloudiness and atmospheric humidity to atmospheric transmittance was fitted using Generalized Additive Models (GAMs), a modern statistical technique that does not assume any a priori functional forms for the association between predictors and predictand. The errors in radiation estimates using temperature and precipitation are larger (RMSE of 3.2MJm-2 per day) than those derived from sunshine duration, but they are comparable to results for other locations and methods. Most importantly, daily radiation estimates have small bias and the errors show no systematic patterns with season or other variables.
KW - Angström-Prescott equation
KW - Diurnal temperature range
KW - Generalized Additive Models
KW - Solar radiation
KW - Transmissivity
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U2 - 10.1016/j.agrformet.2003.11.002
DO - 10.1016/j.agrformet.2003.11.002
M3 - Article
AN - SCOPUS:16544371757
VL - 123
SP - 41
EP - 53
JO - Agricultural and Forest Meteorology
JF - Agricultural and Forest Meteorology
SN - 0168-1923
IS - 1-2
ER -