Numerical Simulation of Surface Energy and Water Balances over a Semiarid Grassland Ecosystem in the West African Savanna
To understand surface energy exchange processes over the semiarid regions in West Africa, numerical simulations of surface energy and water balances were carried out using a one-dimensional multilayer atmosphere-SOil-VEGetation (SOLVEG) model for selected days of the dry and rainy seasons over a sav...
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| Format: | Article |
| Language: | English |
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Wiley
2017-01-01
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| Series: | Advances in Meteorology |
| Online Access: | http://dx.doi.org/10.1155/2017/6258180 |
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| author | Emmanuel Quansah Genki Katata Matthias Mauder Thompson Annor Leonard K. Amekudzi Jan Bliefernicht Dominikus Heinzeller Ahmed A. Balogun Harald Kunstmann |
| author_facet | Emmanuel Quansah Genki Katata Matthias Mauder Thompson Annor Leonard K. Amekudzi Jan Bliefernicht Dominikus Heinzeller Ahmed A. Balogun Harald Kunstmann |
| author_sort | Emmanuel Quansah |
| collection | DOAJ |
| description | To understand surface energy exchange processes over the semiarid regions in West Africa, numerical simulations of surface energy and water balances were carried out using a one-dimensional multilayer atmosphere-SOil-VEGetation (SOLVEG) model for selected days of the dry and rainy seasons over a savanna grassland ecosystem in Sumbrungu in the Upper East region of Ghana. The measured Bowen ratio was used to partition the residual energy into the observed sensible heat flux (H) and latent heat flux (LE) in order to investigate the impact of the surface energy closure on model performance. The results showed that the model overall reproduced the diurnal changes in the observed energy fluxes, especially the net radiation (Rn), compared to half-hourly eddy covariance flux measurements, for the study periods. The performance measure in terms of the correlation coefficient (R), centred root mean square error (RMSE), and normalized standard deviation (σ) between the simulated H and LE and their corresponding uncorrected observed values ranged between R = 0.63–0.99 and 0.83–0.94, RMSE = 0.88–1.25 and 0.88–1.92, and σ = 0.95–2.23 and 0.13–2.82 for the dry and rainy periods respectively, indicating a moderate to good model performance. The partitioning of H and LE by SOLVEG was generally in agreement with the observations during the dry period but showed clear discrepancies during the rainy period, particularly after rainfall events. Further sensitivity tests over longer simulation periods (e.g., 1 year) are required to improve model performance and to investigate seasonal exchanges of surface energy fluxes over the West African Savanna ecosystems in more details. |
| format | Article |
| id | doaj-art-9d1d3217428b47beb77b400aa2f09a9b |
| institution | Kabale University |
| issn | 1687-9309 1687-9317 |
| language | English |
| publishDate | 2017-01-01 |
| publisher | Wiley |
| record_format | Article |
| series | Advances in Meteorology |
| spelling | doaj-art-9d1d3217428b47beb77b400aa2f09a9b2025-02-03T01:31:52ZengWileyAdvances in Meteorology1687-93091687-93172017-01-01201710.1155/2017/62581806258180Numerical Simulation of Surface Energy and Water Balances over a Semiarid Grassland Ecosystem in the West African SavannaEmmanuel Quansah0Genki Katata1Matthias Mauder2Thompson Annor3Leonard K. Amekudzi4Jan Bliefernicht5Dominikus Heinzeller6Ahmed A. Balogun7Harald Kunstmann8Meteorology and Climate Science Unit, Department of Physics, Kwame Nkrumah University of Science and Technology, Kumasi, GhanaJapan Atomic Energy Agency, Ibaraki, JapanInstitute of Meteorology and Climate Research, Karlsruhe Institute of Technology, Garmisch-Partenkirchen, GermanyMeteorology and Climate Science Unit, Department of Physics, Kwame Nkrumah University of Science and Technology, Kumasi, GhanaMeteorology and Climate Science Unit, Department of Physics, Kwame Nkrumah University of Science and Technology, Kumasi, GhanaChair for Regional Climate and Hydrology, University of Augsburg, Augsburg, GermanyInstitute of Meteorology and Climate Research, Karlsruhe Institute of Technology, Garmisch-Partenkirchen, GermanyDepartment of Meteorology and Climate Science, Federal University of Technology, Akure, NigeriaInstitute of Meteorology and Climate Research, Karlsruhe Institute of Technology, Garmisch-Partenkirchen, GermanyTo understand surface energy exchange processes over the semiarid regions in West Africa, numerical simulations of surface energy and water balances were carried out using a one-dimensional multilayer atmosphere-SOil-VEGetation (SOLVEG) model for selected days of the dry and rainy seasons over a savanna grassland ecosystem in Sumbrungu in the Upper East region of Ghana. The measured Bowen ratio was used to partition the residual energy into the observed sensible heat flux (H) and latent heat flux (LE) in order to investigate the impact of the surface energy closure on model performance. The results showed that the model overall reproduced the diurnal changes in the observed energy fluxes, especially the net radiation (Rn), compared to half-hourly eddy covariance flux measurements, for the study periods. The performance measure in terms of the correlation coefficient (R), centred root mean square error (RMSE), and normalized standard deviation (σ) between the simulated H and LE and their corresponding uncorrected observed values ranged between R = 0.63–0.99 and 0.83–0.94, RMSE = 0.88–1.25 and 0.88–1.92, and σ = 0.95–2.23 and 0.13–2.82 for the dry and rainy periods respectively, indicating a moderate to good model performance. The partitioning of H and LE by SOLVEG was generally in agreement with the observations during the dry period but showed clear discrepancies during the rainy period, particularly after rainfall events. Further sensitivity tests over longer simulation periods (e.g., 1 year) are required to improve model performance and to investigate seasonal exchanges of surface energy fluxes over the West African Savanna ecosystems in more details.http://dx.doi.org/10.1155/2017/6258180 |
| spellingShingle | Emmanuel Quansah Genki Katata Matthias Mauder Thompson Annor Leonard K. Amekudzi Jan Bliefernicht Dominikus Heinzeller Ahmed A. Balogun Harald Kunstmann Numerical Simulation of Surface Energy and Water Balances over a Semiarid Grassland Ecosystem in the West African Savanna Advances in Meteorology |
| title | Numerical Simulation of Surface Energy and Water Balances over a Semiarid Grassland Ecosystem in the West African Savanna |
| title_full | Numerical Simulation of Surface Energy and Water Balances over a Semiarid Grassland Ecosystem in the West African Savanna |
| title_fullStr | Numerical Simulation of Surface Energy and Water Balances over a Semiarid Grassland Ecosystem in the West African Savanna |
| title_full_unstemmed | Numerical Simulation of Surface Energy and Water Balances over a Semiarid Grassland Ecosystem in the West African Savanna |
| title_short | Numerical Simulation of Surface Energy and Water Balances over a Semiarid Grassland Ecosystem in the West African Savanna |
| title_sort | numerical simulation of surface energy and water balances over a semiarid grassland ecosystem in the west african savanna |
| url | http://dx.doi.org/10.1155/2017/6258180 |
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