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Spatial representativeness of ground-based solar radiation measurements

The validation of gridded surface solar radiation (SSR) data often relies on the comparison with ground-based in situ measurements. This poses the question on how representative a point measurement is for a larger-scale surrounding. We use high-resolution (0.03 degrees) SSR data from the Satellite Application Facility on Climate Monitoring (CM SAF) to study the subgrid spatial variability in all-sky SSR over Europe and the spatial representativeness of 143 surface sites with homogeneous records for their site-centered larger surroundings varying in size from 0.25 degrees to 3 degrees, as well as with respect to a given standard grid of 1 degrees resolution. These analyses are done on a climatological annual and monthly mean basis over the period 2001-2005. The spatial variability of the CM SAF data set itself agrees very well with surface measurements in Europe, justifying its use for the present study. The annual mean subgrid variability in the 1 degrees standard grid over European land is on average 1.6% (2.4 W m(-2)), with maximum of up to 10% in Northern Spain. The annual mean representation error of point values at 143 surface sites with respect to their 1 degrees surrounding is on average 2% (3 W m(-2)). For larger surroundings of 3 degrees, the representation error increases to 3% (4.8 W m(-2)). The monthly mean representation error at the surface sites with respect to the 1 degrees standard grid is on average 3.7% (4 W m(-2)). This error is reduced when site-specific correction factors are applied or when multiple sites are available in the same grid cell, i.e., three more sites reduce the error by 50%

This study is funded by the Swiss National Science Foundation grant 200021 135395 ("Towards an improved understanding of the Global Energy Balance: Absorption of solar radiation"). A. Sanchez-Lorenzo was supported by a postdoctoral fellowship from the government of Catalonia (2011 BP-B) and the project NUCLIERSOL (CGL2010-18546)

© Journal of Geophysical Research: Atmospheres, 2013, vol. 118, núm. 15, p. 8585-8597

American Geophysical Union (AGU)

Author: Hakuba, M. Z.
Folini, Doris
Sánchez Lorenzo, Arturo
Wild, Martin
Date: 2013
Abstract: The validation of gridded surface solar radiation (SSR) data often relies on the comparison with ground-based in situ measurements. This poses the question on how representative a point measurement is for a larger-scale surrounding. We use high-resolution (0.03 degrees) SSR data from the Satellite Application Facility on Climate Monitoring (CM SAF) to study the subgrid spatial variability in all-sky SSR over Europe and the spatial representativeness of 143 surface sites with homogeneous records for their site-centered larger surroundings varying in size from 0.25 degrees to 3 degrees, as well as with respect to a given standard grid of 1 degrees resolution. These analyses are done on a climatological annual and monthly mean basis over the period 2001-2005. The spatial variability of the CM SAF data set itself agrees very well with surface measurements in Europe, justifying its use for the present study. The annual mean subgrid variability in the 1 degrees standard grid over European land is on average 1.6% (2.4 W m(-2)), with maximum of up to 10% in Northern Spain. The annual mean representation error of point values at 143 surface sites with respect to their 1 degrees surrounding is on average 2% (3 W m(-2)). For larger surroundings of 3 degrees, the representation error increases to 3% (4.8 W m(-2)). The monthly mean representation error at the surface sites with respect to the 1 degrees standard grid is on average 3.7% (4 W m(-2)). This error is reduced when site-specific correction factors are applied or when multiple sites are available in the same grid cell, i.e., three more sites reduce the error by 50%
This study is funded by the Swiss National Science Foundation grant 200021 135395 ("Towards an improved understanding of the Global Energy Balance: Absorption of solar radiation"). A. Sanchez-Lorenzo was supported by a postdoctoral fellowship from the government of Catalonia (2011 BP-B) and the project NUCLIERSOL (CGL2010-18546)
Format: application/pdf
ISSN: 2169-897X (versió paper)
2169-8996 (versió electrònica)
Document access: http://hdl.handle.net/10256/11930
Language: eng
Publisher: American Geophysical Union (AGU)
Collection: MICINN/PN 2011-2013/CGL2010-18546
Reproducció digital del document publicat a: http://dx.doi.org/10.1002/jgrd.50673
Articles publicats (D-F)
Is part of: © Journal of Geophysical Research: Atmospheres, 2013, vol. 118, núm. 15, p. 8585-8597
Rights: Tots els drets reservats
Subject: Radiació solar
Solar radiation
Climatologia
Climatology
Title: Spatial representativeness of ground-based solar radiation measurements
Type: info:eu-repo/semantics/article
Repository: DUGiDocs

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