Nkiaka, E., Nawaz, N.R. and Lovett, J.C. (2017) Evaluating global reanalysis precipitation datasets with rain gauge measurements in the Sudano-Sahel region: case study of the Logone catchment, Lake Chad Basin. Meteorological Applications, 24 (1). pp. 9-18. ISSN 1350-4827
Abstract
Africa has a paucity of long term reliable meteorological ground station data and reanalysis products are used to provide the climate estimations that are important for climate change projections. In this paper monthly observed precipitation records in the Logone catchment of the Lake Chad Basin are used to evaluate the performance of two global reanalysis products: the Climate Forecasting System Reanalysis (CFSR) and ERA Interim datasets.
The two reanalysis products reproduced the monthly, annual and decadal cycle of precipitation and variability relatively accurately albeit with some discrepancies. The catchment rainfall gradient was also well captured by the two products. There are good correlations between the reanalysis and rain gauge datasets although significant deviations exist, especially for CFSR. Both reanalysis products overestimated rainfall in 68% of the rain gauge stations. ERA Interim produced the lowest bias and mean absolute error with average values of 2% and 6.5 mm month−1 respectively compared to 15% and 34 mm month−1 for the CFSR. However, both reanalysis products systematically underestimated annual rainfall in the catchment during the period 1997–2002 for ERA Interim and 1998–2000 for CFSR. This research demonstrates that evaluating reanalysis products in remote areas like the Logone catchment enables users to identify artefacts inherent in reanalysis datasets. This will facilitate improvements in certain aspects of the reanalysis forecast model physics and parameterization to improve reanalysis dataset quality.
This study concludes that the application of each reanalysis product in the catchment will depend on the purpose for which it is to be used and the spatial scale required.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2016 Royal Meteorological Society. This is an author-produced version of a paper subsequently published in Meteorological Applications. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | CFSR; ERA Interim; rain gauge; reanalysis; Sudano‐Sahel region; Logone catchment; Lake Chad Basin |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Social Sciences (Sheffield) > Department of Geography (Sheffield) |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 04 Sep 2020 16:14 |
Last Modified: | 04 Sep 2020 16:14 |
Status: | Published |
Publisher: | Wiley |
Refereed: | Yes |
Identification Number: | 10.1002/met.1600 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:165144 |