Modelling sea salt aerosol and its direct and indirect effects on climate

[摘要] A size-dependent sea salt aerosol parameterization was developedbased on the piecewise log-normal approximation (PLA) for aerosol sizedistributions. Results of this parameterization from simulations with aglobal climate model produce good agreementwith observations at the surface and for vertically-integratedvolume size distributions. The global and annual mean of the sea saltburden is 10.1 mg m⁻². The direct radiative forcing is calculated to be −1.52 and −0.60 W m⁻²for clear sky and all sky, respectively. Thefirst indirect radiative forcing is about twice as large as the direct forcingfor all-sky (−1.34 W m⁻²). The results also show that the totalindirect forcing of sea salt is −2.9 W m⁻² if climatic feedbacksare taken into account. The sensitivity of theforcings to changes in the burdens and sizes of sea salt particles wasalso investigated based on additional simulations with a different sea saltsource function.

[学科分类] 大气科学