Sorry, you need to enable JavaScript to visit this website.

The impact of deep convection on the West African summer monsoon climate: A regional climate model sensitivity study

TitoloThe impact of deep convection on the West African summer monsoon climate: A regional climate model sensitivity study
Tipo di pubblicazioneArticolo su Rivista peer-reviewed
Anno di Pubblicazione2011
AutoriSylla, M.B., Giorgi F., Ruti P.M., Calmanti Sandro, and Dell'Aquila Alessandro
RivistaQuarterly Journal of the Royal Meteorological Society
Volume137
Paginazione1417-1430
ISSN00359009
Parole chiaveAfrican easterly jet, African easterly waves, atmospheric convection, atmospheric moisture, Atmospheric thermodynamics, baroclinic motion, climate modeling, Climate models, Computer simulation, Deep convection scheme, easterly wave, intertropical convergence zone, jet flow, monsoon, Natural convection, orographic effect, potential vorticity, Regional climate, Regional climate models, Sensitivity analysis, summer, wave propagation, West Africa, West African Monsoon
Abstract

The role of the representation of deep convection on key elements of the West African summer monsoon climate is addressed using the Regional Climate Model RegCM3. Two simulations in which a scheme of deep convection is activated and then turned off are performed and intercompared. Results show that the presence of deep convective heating along the intertropical convergence zone sustains increased lower-level baroclinicity favoring intensification of the jet core and leading to a more realistic African easterly jet. In addition, although the isentropic potential vorticity (IPV) is lower when the convection scheme is switched off, African easterly waves (AEWs) are still generated and propagate westwards but they dissipate around the west coast. Substantial differences between the two simulations occur mainly at the 6- to 9-day time-scale over land, when much weaker activity is simulated in the absence of convection. This indicates that orographic friction and low-level large-scale moisture convergence, generating high values of latent heat and IPV, may play the dominant role in the genesis and growth of AEWs and that deep convection acts to strengthen the overall wave activity and to favor their west coast development. © 2011 Royal Meteorological Society.

Note

cited By 30

URLhttps://www.scopus.com/inward/record.uri?eid=2-s2.0-80052519324&doi=10.1002%2fqj.853&partnerID=40&md5=b242f3f8035a048df94571e6a6e58ca1
DOI10.1002/qj.853
Citation KeySylla20111417