Comparison of 850-hPa relative humidity between ERA-40 and NCEP/NCAR re-analyses: detection of suspicious data in ERA-40

• Published in: Atmospheric Science Letters
• Main Authors: Ben Daoud, Aurélien, Sauquet, Eric, Lang, Michel, Obled, Charles, Bontron, Guillaume
• Other Authors: Hydrologie-Hydraulique (UR HHLY), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Laboratoire d'étude des transferts en hydrologie et environnement (LTHE), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS), Compagnie Nationale du Rhône (CNR)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2009
• Subjects: relative humidity; re-analyses; ERA-40; NCEP/NCAR; western Europe; radio sounding; anomalous values; [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces; environment; [SDE.MCG]Environmental Sciences/Global Changes; North Atlantic
• Online Access: https://insu.hal.science/insu-00411903; https://doi.org/10.1002/asl.208

[Departement_IRSTEA]Eaux [TR1_IRSTEA]ARCEAU International audience An exploratory study is performed on the 850-hPa relative humidity data (RH850) extracted from the Re-Analysis Project (ERA-40) and National Centers for Environmental Prediction (NCEP)/National Center for Atmospheric Research (NCAR) re-analyses covering a domain centred on western Europe (60°W-60°E, 15°N-75°N). The largest deviations between the two data archives are observed over the North Atlantic Ocean. In addition, unrealistic values of RH850 are detected in the ERA-40 re-analysis at resolutions of both 2.5° and 1.125°. There is no strong correlation between RH850 provided by ERA-40 and observations from radio sounding stations, thus ruling out a straightforward correction of the detected anomalous values. Copyright © 2009 Royal Meteorological Society