Orographic biases in IMERG precipitation estimates in the Ebro River basin (Spain): The effects of rain gauge density and altitude
A gridded precipitation dataset derived from the high-density rain gauge network of the Ebro River Basin Authority is used to evaluate the performance of Integrated Multi-satellitE Retrievals for GPM (IMERG) level-3 estimates. Although aggregated values compare well, several differences are found be...
| Autores: | , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2020 |
| País: | España |
| Institución: | Universidad de Castilla-La Mancha |
| Repositorio: | RUIdeRA. Repositorio Institucional de la UCLM |
| OAI Identifier: | oai:ruidera.uclm.es:10578/33856 |
| Acceso en línea: | https://www.sciencedirect.com/science/article/pii/S0169809520300399?via%3Dihub https://hdl.handle.net/10578/33856 |
| Access Level: | acceso abierto |
| Palabra clave: | IMERG Precipitation Rain gauges Satellite observations Surface observations |
| Sumario: | A gridded precipitation dataset derived from the high-density rain gauge network of the Ebro River Basin Authority is used to evaluate the performance of Integrated Multi-satellitE Retrievals for GPM (IMERG) level-3 estimates. Although aggregated values compare well, several differences are found between climate regions. The research investigates the role of orography and gauge density on IMERG performance. There are important discrepancies over un-instrumented areas in the Pyrenees (R2 = 0.31) but the correlation dramatically increases (R2 > 0.71) when at least one rain gauge is available for calibration, even in complex, high-altitude terrain (>1500 m). IMERG overestimates precipitation at both lower altitudes (<500 m), especially in summer and autumn because of convective activity, and mid-altitudes (600–1200 m) in the northwestern study area, where weather is dominated by the advection of wet maritime air masses. The main conclusion is that IMERG performance strongly depends on altitude and the precipitation regime. IMERG is nonetheless a suitable alternative to gridded gauge-derived only products for hydrologic operations, especially in areas with a sparse rain gauge network. |
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