Elevation correction of ERA-Interim temperature data in complex terrain

摘要

Air temperature controls a large variety of environmental processes, and isan essential input parameter for land surface models, for example in hydrology,ecology and climatology. However, meteorological networks, which can providethe necessary information, are commonly sparse in complex terrains,especially in high mountainous regions. In order to provide temperature datain an adequate temporal and spatial resolution for local scale applicationsa new elevation correction method has been developed that is able todownscale 3-hourly ERA-Interim temperature data. The scheme is based onmodel internal vertical lapse rates derived from different ERA-Interimpressure levels and has been validated for twelve meteorological stations inthe German and Swiss Alps. The method was also compared with two otherstatistical, lapse rate based correction approaches. The results indicatethat the use of model internal ERA-Interim lapse rates can significantlyimprove the downscaling performance when compared to the standard procedureof using fixed lapse rates.