Air Pollution, Aerosols and Clouds in the Climate System

It is widely know that dust is essentially non-spherical and hence radiative transfer calculations treating dust as a spherical particle are not adequate. A recent laboratory based study on dust particles by Jingmin Li and Kazuo Osada is very interesting. This article appeared in GRL this month. They study the preferential setting of elongated mineral dust collected from snow in a high mountain in Japan. The positions of particles' centers of gravity and folding centers are analyzed using a scanning electron microscopy and optical microscopy. Their results suggest that a preferential orientation exists for particles settling heavy side down (as expected) but what is interesting is the analysis of results from Ginoux's model wherein they apply this preferential orientation information and show that : " away from the source regions, dust particles are essentially spherical, which considerably simplify the calculation of settling velocity in transport and of radiative trans...

Its time for aerosol scientists to gear up for the upcoming Glory Mission that has a fantastic passive sensor for monitoring aerosols from space with unmatched retrieval accuracies of 0.02 over ocean and 0.04 over land! This article on the Glory Mission appeared in BAMS in the May 2007 edition, volume 88, number 5. It has a very detailed description of the science objectives, the instruments on Glory, measurement objectives, the data products from these instruments, associated uncertainties and validation plans. Glory is basically a part of the A-Train constellation of satellites. It is scheduled to be launched in 2008 and will carry two independent instruments : 1) The Total Irradiance Monitor (TIM) 2) The Aerosol Polarimetry Sensor (APS) The main purpose of the Glory mission is to help address the challenge of reducing uncertainty in adequately contraining climate sensitivity. Glory is intented to specifically meet the following four scientific objectives : " • improve the quant...