Central Objectives:
First objective is the quantification of the absorption capacity of atmospheric aerosols in terms of the imaginary component of the refractive index. This information is critically important to convert the attenuated backscatter measured by Calipso to total extinction. The second objective is the use of nadir-only Calipso observations of aerosol layer height, MODIS derived optical depth, and AIRS measured brightness temperature, to extend the Calipso nadir-only information to off-nadir viewing configurations.
Method:
The first objective will be accomplished by using the near-simultaneous measurements of aerosol vertical distribution by Calipso, and backscattered radiances in the near UV by the Aura-OMI sensor. These observables will be used in a retrieval scheme to derive the imaginary refractive index and the single scattering albedo of aerosols.
The second objective will be carried out by developing a functional relationship between aerosol layer height (Calipso) aerosol optical depth (MODIS) and brightness temperature difference betweem two AIRS thermal IR channels. Using this relationship, aerosol layer heights can be obtained at all locations where simultaneous MODIS and AIRS observations are available.
Significance:
This proposal contributes to enhance the science value of the CALIPSO aerosol products, by providing specific information on aerosol optical properties. In addition, the proposal seeks to take advantage of synergic A-train measurements to derive the altitude of aerosol layer height. This information is needed for validation of chemical transport as well as general circulation models, and for improved accuracy of radiative forcing studies.
