Process Oriented evaluation of the oversea AROME configuration: focus on the representation of cloud organisation

• Published in: Quarterly Journal of the Royal Meteorological Society
• Main Authors: Beucher, Florent, Couvreux, Fleur, Bouniol, Dominique, Faure, Ghislain, Favot, Florence, Dauhut, Thibaut, Ayet, Alex
• Other Authors: Centre national de recherches météorologiques (CNRM), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), GIPSA - Signal Images Physique (GIPSA-SIGMAPHY), GIPSA Pôle Sciences des Données (GIPSA-PSD), Grenoble Images Parole Signal Automatique (GIPSA-lab), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA)-Grenoble Images Parole Signal Automatique (GIPSA-lab), Université Grenoble Alpes (UGA), Climat, Environnement, Couplages et Incertitudes Toulouse (CECI), Institut national des sciences de l'Univers (INSU - CNRS)-Centre Européen de Recherche et de Formation Avancée en Calcul Scientifique - CERFACS (CERFACS)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2022
• Subjects: shallow convection; cloud resolving model; cloud -organisation; evaluation; North Atlantic Trades; [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; North Atlantic
• Online Access: https://hal.science/hal-03869111; https://hal.science/hal-03869111/document; https://hal.science/hal-03869111/file/QJ-21-0344.R2_accepted.pdf; https://doi.org/10.1002/qj.4354

International audience This study evaluates the ability of the French convection-permitting model AROME-OM to represent shallow cumulus and their main organisations forboreal winter conditions in the North Atlantic trades. It uses a set of three winter seasons (January–February, 2018–2020) of high-resolution (1.3 and 2.5 km) simulations over the Caribbean domain (9.7–22.9◦ N, 75.3–51.7◦ W). The model is assessed against soundings at Grantley Adams Airport and remote-sensing observations at a site located on the east coast of Barbados which is representative of downwind trade regimes. The thermodynamic environment of the model fits the observations overall but the boundary layer is slightly too deep, resulting in a weak cold and dry bias. Both model and observations clearly exhibit (a) a double peak of cloud fraction, a first peak near the cloud base and a second one near the cloud top and (b) a larger variance in cloudiness near the top of the deepest cumuli, at around 2 km, with a higher sensitivity to the environment. We then take advantage of the EUREC4 A field campaign which took place in January–February 2020 to assess the ability of the model to reproduce the four main mesoscale patterns and to characterize the air masses in which they develop. All the observations confirm the capacity of the model to predict the different mesoscale organizations and their associated environment.