Environmental Lapse Rate for High‐Resolution Land Surface Downscaling: An Application to ERA5
Abstract In this study we derive the environmental lapse rate (ELR) from vertical profiles of temperature in the lower troposphere, applying it to downscale air temperature of the new European Centre For Medium‐Range Weather Forecasts (ECMWF) reanalysis ERA5, which replaces ERA‐Interim (ERAI). We fo...
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2020-05-01
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Online Access: | https://doi.org/10.1029/2019EA000984 |
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doaj-9201b0155fa5438aa56b06ee9566d8da2020-11-25T03:14:48ZengAmerican Geophysical Union (AGU)Earth and Space Science2333-50842020-05-0175n/an/a10.1029/2019EA000984Environmental Lapse Rate for High‐Resolution Land Surface Downscaling: An Application to ERA5Emanuel Dutra0Joaquín Muñoz‐Sabater1Souhail Boussetta2Takuya Komori3Shoji Hirahara4Gianpaolo Balsamo5Instituto Dom Luiz (IDL), Faculdade de Ciências Universidade de Lisboa Lisbon PortugalEuropean Centre for Medium‐Range Weather Forecasts Reading UKEuropean Centre for Medium‐Range Weather Forecasts Reading UKGlobal Environment and Marine Department Japan Meteorological Agency Tokyo JapanGlobal Environment and Marine Department Japan Meteorological Agency Tokyo JapanEuropean Centre for Medium‐Range Weather Forecasts Reading UKAbstract In this study we derive the environmental lapse rate (ELR) from vertical profiles of temperature in the lower troposphere, applying it to downscale air temperature of the new European Centre For Medium‐Range Weather Forecasts (ECMWF) reanalysis ERA5, which replaces ERA‐Interim (ERAI). We focus over the western U.S. region, a data‐rich area with observations of daily maximum and minimum temperature (Global Historical Climatology Network) and snow depth and soil temperature. Observations indicate an ELR of −4.5 K·km−1 in the region, lower than the commonly used −6.5 K·km−1. ERA5 ELR agrees with the observational estimates, with some overestimation in winter and limitations in the diurnal variability. The elevation correction of ERA5 temperature using different ELR showed the benefits of deriving ELR fields from ERA5 vertical profiles, when compared with a constant ELR. Simulations with the ECMWF land surface model, at 9‐km resolution, driven by ERA5 using different ELR corrections showed the added value of the methodology, but the impact of different ELR corrections is limited. However, the validity of the downscaling method in reducing temperature to station altitude suggests that there is sufficient generality for application at kilometer and subkilometer resolutions. By comparing the estimated representativity errors of observations with reanalysis, the improvements from ERAI to ERA5 are mainly visible in the random component of the error. Large systematic biases remain, which require further attention from the modeling and data assimilation, and limit the potential benefits of ELR corrections.https://doi.org/10.1029/2019EA000984land surfacedownscalingreanalysislapse rate |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Emanuel Dutra Joaquín Muñoz‐Sabater Souhail Boussetta Takuya Komori Shoji Hirahara Gianpaolo Balsamo |
spellingShingle |
Emanuel Dutra Joaquín Muñoz‐Sabater Souhail Boussetta Takuya Komori Shoji Hirahara Gianpaolo Balsamo Environmental Lapse Rate for High‐Resolution Land Surface Downscaling: An Application to ERA5 Earth and Space Science land surface downscaling reanalysis lapse rate |
author_facet |
Emanuel Dutra Joaquín Muñoz‐Sabater Souhail Boussetta Takuya Komori Shoji Hirahara Gianpaolo Balsamo |
author_sort |
Emanuel Dutra |
title |
Environmental Lapse Rate for High‐Resolution Land Surface Downscaling: An Application to ERA5 |
title_short |
Environmental Lapse Rate for High‐Resolution Land Surface Downscaling: An Application to ERA5 |
title_full |
Environmental Lapse Rate for High‐Resolution Land Surface Downscaling: An Application to ERA5 |
title_fullStr |
Environmental Lapse Rate for High‐Resolution Land Surface Downscaling: An Application to ERA5 |
title_full_unstemmed |
Environmental Lapse Rate for High‐Resolution Land Surface Downscaling: An Application to ERA5 |
title_sort |
environmental lapse rate for high‐resolution land surface downscaling: an application to era5 |
publisher |
American Geophysical Union (AGU) |
series |
Earth and Space Science |
issn |
2333-5084 |
publishDate |
2020-05-01 |
description |
Abstract In this study we derive the environmental lapse rate (ELR) from vertical profiles of temperature in the lower troposphere, applying it to downscale air temperature of the new European Centre For Medium‐Range Weather Forecasts (ECMWF) reanalysis ERA5, which replaces ERA‐Interim (ERAI). We focus over the western U.S. region, a data‐rich area with observations of daily maximum and minimum temperature (Global Historical Climatology Network) and snow depth and soil temperature. Observations indicate an ELR of −4.5 K·km−1 in the region, lower than the commonly used −6.5 K·km−1. ERA5 ELR agrees with the observational estimates, with some overestimation in winter and limitations in the diurnal variability. The elevation correction of ERA5 temperature using different ELR showed the benefits of deriving ELR fields from ERA5 vertical profiles, when compared with a constant ELR. Simulations with the ECMWF land surface model, at 9‐km resolution, driven by ERA5 using different ELR corrections showed the added value of the methodology, but the impact of different ELR corrections is limited. However, the validity of the downscaling method in reducing temperature to station altitude suggests that there is sufficient generality for application at kilometer and subkilometer resolutions. By comparing the estimated representativity errors of observations with reanalysis, the improvements from ERAI to ERA5 are mainly visible in the random component of the error. Large systematic biases remain, which require further attention from the modeling and data assimilation, and limit the potential benefits of ELR corrections. |
topic |
land surface downscaling reanalysis lapse rate |
url |
https://doi.org/10.1029/2019EA000984 |
work_keys_str_mv |
AT emanueldutra environmentallapserateforhighresolutionlandsurfacedownscalinganapplicationtoera5 AT joaquinmunozsabater environmentallapserateforhighresolutionlandsurfacedownscalinganapplicationtoera5 AT souhailboussetta environmentallapserateforhighresolutionlandsurfacedownscalinganapplicationtoera5 AT takuyakomori environmentallapserateforhighresolutionlandsurfacedownscalinganapplicationtoera5 AT shojihirahara environmentallapserateforhighresolutionlandsurfacedownscalinganapplicationtoera5 AT gianpaolobalsamo environmentallapserateforhighresolutionlandsurfacedownscalinganapplicationtoera5 |
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