What Drives the Intensification of Mesoscale Convective Systems over the West African Sahel under Climate Change
Rory G. J. Fitzpatrick,Rory G. J. Fitzpatrick,Douglas J. Parker,John H. Marsham,David P. Rowell,Françoise Guichard,Christopher M. Taylor,Kerry H. Cook,Edward K. Vizy,Lawrence S. Jackson,Declan L. Finney,J. A. Crook,Rachel Stratton,Simon Tucker +13 more
TLDR
In this paper, the authors used the first convection-permitting simulations of African climate change to understand how changes in thermodynamics and storm dynamics affect future extreme Sahelian rainfall.Abstract:
Extreme rainfall is expected to increase under climate change, carrying potential socioeconomic risks. However, the magnitude of increase is uncertain. Over recent decades, extreme storms over the West African Sahel have increased in frequency, with increased vertical wind shear shown to be a cause. Drier midlevels, stronger cold pools, and increased storm organization have also been observed. Global models do not capture the potential effects of lower- to midtropospheric wind shear or cold pools on storm organization since they parameterize convection. Here we use the first convection-permitting simulations of African climate change to understand how changes in thermodynamics and storm dynamics affect future extreme Sahelian rainfall. The model, which simulates warming associated with representative concentration pathway 8.5 (RCP8.5) until the end of the twenty-first century, projects a 28% increase of the extreme rain rate of MCSs. The Sahel moisture change on average follows Clausius–Clapeyron scaling, but has regional heterogeneity. Rain rates scale with the product of time-of-storm total column water (TCW) and in-storm vertical velocity. Additionally, prestorm wind shear and convective available potential energy both modulate in-storm vertical velocity. Although wind shear affects cloud-top temperatures within our model, it has no direct correlation with precipitation rates. In our model, projected future increase in TCW is the primary explanation for increased rain rates. Finally, although colder cold pools are modeled in the future climate, we see no significant change in near-surface winds, highlighting avenues for future research on convection-permitting modeling of storm dynamics.read more
Citations
More filters
The role of moist convection in the West African monsoon
John H. Marsham,Cathryn E. Birch,Douglas J. Parker,Peter Knippertz,N. S. Dixon,Luis Garcia-Carreras,Grenville M. S. Lister +6 more
TL;DR: In this paper, the authors compare multiday continental-scale simulations of the WAM that explicitly resolve moist convection with simulations which parameterize convection, showing that more realistic explicit convection gives greater latent and radiative heating farther north, with latent heating later in the day.
Journal ArticleDOI
The formation, character and changing nature of mesoscale convective systems
TL;DR: In this paper, the authors synthesize current knowledge on mesoscale convective system formation, climatological characteristics, hazardous weather, predictive capacity and projected changes with anthropogenic warming.
Journal ArticleDOI
Convection-permitting modeling with regional climate models: Latest developments and next steps
Philippe Lucas-Picher,Daniel Argüeso,Erwan Brisson,Yves Tramblay,Peter Berg,Aude Lemonsu,Sven Kotlarski,Cécile Caillaud +7 more
The role of precipitation in controlling the transition from stratocumulus to cumulus clouds in a northern hemisphere cold-air outbreak
Steven J. Abel,Ian A. Boutle,Kirk Waite,Stuart Fox,Philip R. A. Brown,Richard Cotton,Gary Lloyd,Thomas Choularton,Keith Bower +8 more
TL;DR: In this paper, the boundary layer and cloud properties in an overcast mixed-phase stratocumulus cloud layer and across the transition to more broken open-cellular convection are examined.
Journal ArticleDOI
Extreme precipitation in the tropics is closely associated with long-lived convective systems
Rémy Roca,Thomas Fiolleau +1 more
TL;DR: In this paper, the authors present an analysis of satellite-derived observations of daily accumulated precipitation and of the characteristics of convective systems throughout the tropics to investigate the relationship between the organization of mesoscale convective system and extreme precipitation in the Tropics.
References
More filters
Journal ArticleDOI
Daily High-Resolution-Blended Analyses for Sea Surface Temperature
Richard W. Reynolds,Thomas M. Smith,Chunying Liu,Dudley B. Chelton,Kenneth S. Casey,Michael G. Schlax +5 more
TL;DR: In this paper, two new high-resolution sea surface temperature (SST) analysis products have been developed using optimum interpolation (OI), which have a spatial grid resolution of 0.25° and a temporal resolution of 1 day.
Journal ArticleDOI
A Theory for Strong, Long-Lived Squall Lines
TL;DR: In this article, the mechanics of long-lived, line-oriented, precipitating cumulus convection (squall lines) using two-and three-dimensional numerical models of moist convection are studied.
Journal ArticleDOI
Mesoscale convective systems
TL;DR: The largest convective clouds are mesoscale convective systems, which account for a large portion of Earth's cloud cover and precipitation, and the patterns of wind and weather associated with mesoscales are important local phenomena that often must be forecast on short timescales.
Journal ArticleDOI
A scheme for predicting layer clouds and their water content in a general circulation model
TL;DR: In this paper, a cloud water variable has been included in the Meteorological Office atmospheric general circulation model, which is generated by a scheme which assumes a distribution of thermodynamic and water content variables about their grid-box-mean values.
Journal ArticleDOI
The Met Office Unified Model Global Atmosphere 7.0/7.1 and JULES Global Land 7.0 configurations
David N. Walters,Anthony J. Baran,Anthony J. Baran,Ian A. Boutle,M. E. Brooks,Paul Earnshaw,John M. Edwards,Kalli Furtado,Peter Hill,Adrian Lock,James Manners,Cyril J. Morcrette,Jane Mulcahy,Claudio Sanchez,Chris Smith,Rachel Stratton,Warren Tennant,Lorenzo Tomassini,Kwinten Van Weverberg,Simon Vosper,Martin Willett,J. Browse,Andrew C. Bushell,Kenneth S. Carslaw,Mohit Dalvi,Richard Essery,Nicola Gedney,Steven C. Hardiman,Ben Johnson,Colin E. Johnson,Andrew Jones,Colin Jones,Graham Mann,Sean Milton,Heather Rumbold,Alistair Sellar,Masashi Ujiie,Michael Whitall,Keith D. Williams,M. Zerroukat +39 more
TL;DR: The Global Atmosphere 3.0 (GA3.0) as mentioned in this paper is a configuration of the Met Office Unified Model (MetUM) developed for use across climate research and weather prediction activities.