Physically-based atmospheric correction of optical Earth Observation satellite data is used to accurately derive surface biogeophysical parameters free from the atmospheric influence. While water vapor or surface pressure can be univocally characterized, the compensation of aerosol radiometric effects relies on assumptions and parametric approximations of their properties. To determine the vali...

Aerosols are prevalent in the atmosphere where they can serve as cloud condensation nuclei (CCN). Here we report on new CCN measurements to characterize the temperature dependence of CCN activity for single component organic aerosol and secondary organic aerosol from the reaction of α-pinene and O(3) generated in the laboratory. For compounds with a weak dependence of water activity on temperat...

Multi AXis Differential Optical Absorption Spectroscopy (MAX-DOAS) observations of the oxygen dimer O4 are presented which can serve as a new method for the determination of atmospheric aerosol properties. 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, the nov...

The recent observation of ultrafine aerosol particles in cirrus clouds has raised the question whether aerosol formation within cirrus clouds is possible, and if so, what mechanisms are involved. We have developed an aerosol parcel model of neutral and charged H2SO4/H2O aerosol processes, including nucleation from the gas phase and loss onto cirrus ice particles. Laboratory thermodynamic data f...

The composition and physical properties of aged atmospheric aerosol were characterized at a remote sampling site on the northern coast of Crete, Greece during the Finokalia Aerosol Measurement Experiment in May 2008 (FAME-2008). A reduced Dry-Ambient Aerosol Size Spectrometer (DAASS) was deployed to measure the aerosol water content and volumetric growth factor of fine particulate matter. The p...

LEXFOAM is an explosive foam developed from two non-explosive components to replace C-4 or TNT in humanitarian demining. This paper discusses a recent break through in packaging, the properties of newly developed LEXFOAM and improvement in delivery based on deficiencies noted in field testing. The Hand-held delivery system consists of two disposable aerosol cans. A large aerosol can contains 50...

[1] Aerosol absorption of sunlight, in particular by black carbon soot and dark organic material produced from incomplete combustion of fossil fuel and from vegetation fires, is emerging as a key component of climate forcing. However, global characterization of black carbon emissions, distribution and absorption of sunlight cannot be determined within a factor of 5. Here we propose that the oce...

[1] Aerosol particles modify the transfer of solar radiation in the atmosphere. To quantify this impact, the composition and the size distribution of the aerosol have to be known. In this study, simulations with a comprehensive model system including meteorological processes, gas phase chemistry, and aerosol dynamics and chemistry were carried out to investigate the impact of aerosol particles ...

Assimilation of the Moderate Resolution Imaging Spectroradiometer (MODIS) total aerosol optical depth (AOD) retrieval products (at 550 nm wavelength) from both Terra and Aqua satellites have been developed within the National Centers for Environmental Prediction (NCEP) Gridpoint Statistical Interpolation (GSI) three-dimensional variational (3DVAR) data assimilation system. This newly developed ...

The effect of a cloud layer on top-of-atmosphere (TOA) aerosol radiative forcing is examined by means of a one-dimensional vertical column simulation. To span the range between nonabsorbing and strongly absorbing particles, (NH4)2SO4 and soot aerosols are considered individually and in internal and external mixtures. For a cloud layer embedded within an aerosol layer it is shown that direct aer...