Influence of the boundary layer height on the global air-sea surface fluxes
2009 (English)In: Climate Dynamics, ISSN 0930-7575, E-ISSN 1432-0894, Vol. 33, no 1, 33-44 p.Article in journal (Refereed) Published
Results from large-eddy simulations and field measurements have previously shown that the velocity field is influenced by the boundary layer height, z (i) , during close to neutral, slightly unstable, atmospheric stratification. During such conditions the non-dimensional wind profile, phi (m) , has been found to be a function of both z/L and z (i) /L. At constant z/L, phi (m) decreases with decreasing boundary layer height. Since phi (m) is directly related to the parameterizations of the air-sea surface fluxes, these results will have an influence when calculating the surface fluxes in weather and climate models. The global impact of this was estimated using re-analysis data from 1979 to 2001 and bulk parameterizations. The results show that the sum of the global latent and sensible mean heat fluxes increase by 0.77 W m(-2) or about 1% and the mean surface stress increase by 1.4 mN m(-2) or 1.8% when including the effects of the boundary layer height in the parameterizations. However, some regions show a larger response. The greatest impact is found over the tropical oceans between 30A degrees S and 30A degrees N. In this region the boundary layer height influences the non-dimensional wind profile during extended periods of time. In the mid Indian Ocean this results in an increase of the mean annual heat fluxes by 2.0 W m(-2) and an increase of the mean annual surface stress by 2.6 mN m(-2).
Place, publisher, year, edition, pages
2009. Vol. 33, no 1, 33-44 p.
Boundary layer height, ERA-40, Latent heat flux, Momentum flux, Sensible heat flux
Earth and Related Environmental Sciences
IdentifiersURN: urn:nbn:se:uu:diva-111328DOI: 10.1007/s00382-008-0411-9ISI: 000266266500003OAI: oai:DiVA.org:uu-111328DiVA: diva2:280499