A global view of aerosols from merged transport models, satellite, and ground observations

Abstract

[1] Growing recognition of the importance of natural and anthropogenic aerosols in climate research led to numerous efforts to obtain information on aerosols based on model simulations, satellite remote sensing, and ground observations. This study describes an approach to combine information from independent sources that complement each other in their capabilities to achieve a global characterization of monthly mean clear-sky daytime aerosol optical depth. The following sources of information have been used: simulations from the Global Ozone Chemistry Aerosol Radiation and Transport (GOCART) model; retrievals from the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument on the Terra satellite; and measurements from the Aerosol Robotic Network (AERONET). Leading empirical orthogonal functions (EOFs) are used to represent the significant variation signals from model and satellite results; the EOFs are fitted to the ground observations to propagate the AERONET information at a global scale. The methodology is implemented with a 2-year time record when collocated data from all three sources are available.

Impacts of Aerosol Shortwave Radiation Absorption on the Dynamics of an Idealized Convective Atmospheric Boundary Layer

“…Depending on the amount and nature of aerosols, the effects on the convective atmospheric boundary-layer (CBL) evolution, structure and thermodynamics may differ significantly (Forster et al 2007). More specifically, the CBL's heat budget and the surface fluxes are modified when radiation is scattered or absorbed, thus allowing less radiation to reach the surface (Charlson et al 1992;Jacobson 1998;Raga et al 2001;Yu et al 2002;Liu et al 2005;Li et al 2007;Johnson et al 2008;Malavelle et al 2011). Extending previous studies, we address here the response of the CBL, driven by surface and entrainment fluxes, to aerosol heat absorption.…”

“…The impact of aerosols on the vertical structure of the CBL has been investigated by means of various methodologies: satellite data (Kaufman et al 2002), observations made in experimental campaigns (Angevine et al 1998;Johnson et al 2008;Masson et al 2008), numerical modelling (Cuijpers and Holtslag 1998;Yu et al 2002) and combinations of these techniques (Liu et al 2005;Wong et al 2012). A process study on how aerosol heating by SW-absorbing aerosols influences the turbulent fluxes, surface forcing, vertical structure and heat budget of the CBL is still lacking, however.…”

Aerosol microphysics modules in the framework of the ECHAM5 climate model – intercomparison under stratospheric conditions

“…be simplified. The aerosol distribution in aerosol modules is described in most cases using the bulk approach (Liao and Seinfeld, 2005;Liu et al, 2005;Reddy et al, 2005;, modal approach (Ghan et al, 2001;Wilson et al, 2001;Herzog et al, 2004;Vignati et al, 2004;Lauer et al, 2005;Stier et al, 2005), and sectional approach (Weisenstein et al, 1997;Jacobson, 2001;Timmreck, 2001;Rodriguez and Dabdub, 2004;Spracklen et al, 2005;Hommel, 2008;Kokkola et al, 2008). In the bulk approach, only the aerosol mass is prognostic.…”

SALSA – a Sectional Aerosol module for Large Scale Applications

“…Because of the computational demands, sectional approaches have often neglected one or more major aerosol types and assumed an internal mixture between the simulated components (Jacobson, 2001;Rodriguez and Dabdub, 2004;Spracklen et al, 2005, e.g.). Another way of tackling this problem is to apply the sectional approach for some of the aerosol sizes and to treat the rest of the aerosol sizes using either modal or bulk mass based approach (Liao and Seinfeld, 2005;Liu et al, 2005;Reddy et al, 2005). Nevertheless, in the approaches by Liao and Seinfeld (2005) and Reddy et al (2005) the sectional, modal and bulk aerosol components are completely non-interacting.…”