Recent studies revealed layers of enhanced aerosol scattering in the upper troposphere and lower stratosphere over Asia (Asian Tropopause Aerosol Layer (ATAL)) and North America (North American Tropospheric Aerosol Layer (NATAL)). We use a sectional aerosol model (Community Aerosol and Radiation Model for Atmospheres (CARMA)) coupled with the Community Earth System Model version 1 (CESM1) to ex...

[1] Multi AXis Differential Optical Absorption Spectroscopy (MAX-DOAS) observations of the oxygen dimer O4 which can serve as a new method for the determination of atmospheric aerosol properties are presented. Like established methods, e.g., Sun radiometer and LIDAR measurements, MAX-DOAS O4 observations determine optical properties of aerosol under atmospheric conditions (not dried). However, ...

We estimate the extent of upper tropospheric aerosol layers (UT ALs) surrounding mesoscale convective systems (MCSs) and explore the relationships between UT AL extent and the morphology, location, and developmental stage of collocated MCSs in the tropics. Our analysis is based on satellite data collected over equatorial Africa, South Asia, and the Amazon basin between June 2006 and June 2008. ...

The significance of aerosols in the climate system has been emphasized in many recent studies. However current quantification of aerosol forcing on climate has large uncertainties (IPCC, 2001). To fully understand the complex effect of aerosols requires an intensive measurement and analysis strategy. The emissions of natural and anthropogenic aerosols have been increasing in the past two decade...

Light scattering measurements from a searchlight beam were carried out in New Mexico to determine the aerosol properties of the atmosphere. Although data were acquired to an altitude of about 70 km, the results show the aerosol attenuation parameters to be significant to about 35 km. The expression for the aerosol attenuation coefficient is derived based on the field geometry in conjunction wit...

Scientific understanding of aerosol-cloud interactions can profit from an analysis of the transition regions between pure aerosol and pure clouds as detected in satellite data. This study identifies and evaluates pixels in this region by analysing the residual areas of aerosol and cloud products from the Moderate Resolution Imaging Radiometer (MODIS) satellite sensor. These pixels are expected ...

The heterogeneous oxidation of organic aerosol by hydroxyl radicals (OH) can proceed through two general pathways: functionalization, in which oxygen functional groups are added to the carbon skeleton, and fragmentation, in which carbon-carbon bonds are broken, producing higher volatility, lower molecular weight products. An ongoing challenge is to develop a quantitative molecular description o...

An algorithm for linear estimation of aerosol bulk properties such as particle volume, effective radius and complex refractive index from multiwavelength lidar measurements is presented. The approach uses the fact that the total aerosol concentration can well be approximated as a linear combination of aerosol characteristics measured by multiwavelength lidar. Therefore, the aerosol concentratio...

[1] The main uncertainty in anthropogenic forcing of the Earth’s climate stems from pollution aerosols, particularly their ‘‘indirect effect’’ whereby aerosols modify cloud properties. We develop a new methodology to derive a measurement-based estimate using almost exclusively information from an Earth radiation budget instrument (CERES) and a radiometer (MODIS). We derive a statistical relatio...