We propose the combined analysis of suborbital and satellite measurements of aerosol in conjunction with mesoscale aerosol transport modeling to investigate the vertical structure of aerosol radiative effects. The proposed work will study the information content of a combination of CALIPSO lidar backscatter data with data derived by other A-Train aerosol sensors with the following particular goals:
- Investigating the information content gained by combining lidar-derived aerosol backscatter profiles (CALIPSO), aerosol optical depth (MODIS and POLDER), aerosol absorption optical depth (OMI) and aerosol depolarization (POLDER and CALIPSO) to determine the vertical structure of aerosol radiative properties and effects,
- Investigating the information content gained by combining lidar-derived aerosol backscatter profiles (CALIPSO), aerosol optical depth (MODIS and POLDER), aerosol absorption optical depth (OMI) and aerosol depolarization (POLDER and CALIPSO) to determine the vertical structure of aerosol radiative properties and effects,
- Studying lidar backscatter data (e.g., color ratios) in the immediate vicinity of clouds to elucidate aerosol indirect effects and the separation of aerosol and cloud signals in the passive remote sensing instruments within the A-Train.
n the first task of the work proposed here, we intend to use suborbital airborne lidar and sunphotometer data recently collected in INTEX-A as a test-bed to develop techniques to derive aerosol radiative properties. We intend to transfer these techniques to the space-borne sensors CALIPSO and MODIS and study the additional information gained by incorporating data on aerosol absorption, depolarization and aerosol-induced flux changes from OMI, POLDER and CERES, respectively. We will then study the feasibility of estimating aerosol fine-mode fraction and plan to derive a new product, the vertical profile of solar direct aerosol-induced radiative flux change, to be archived with the CALIPSO data set. This task is directly aimed at answering Earth Science Enterprise (ESE) Strategic Question 2: How well do EOS sensors measure the magnitude and spatial distribution of primary forcings of the Earth system?
Aided by the CALIPSO-derived information on the vertical structure of aerosol optical properties, the second focus of our work will be the improved modeling of aerosol transport and radiative effects with a mesoscale transport model. We expect that detailed information on the injection height of biomass burning aerosol along with the assimilation of CALIPSO derived profiles of aerosol backscatter will improve the aerosol transport model beyond what the assimilation of clear-sky MODIS AOD or radiances could achieve. In addition to being responsive to ESE strategic question 1 on the Earth's natural variability and question 2 on the distribution of climate forcings, this task will specifically address questions posed by the Earth-Sun System Division's (ESSD) focus area on atmospheric composition, namely those regarding the formation, properties, and transport of aerosols in the Earth's troposphere.
In the third part of our work we plan to make use of the vertically-resolved aerosol data (e.g., the lidar color ratio) from CALIPSO in the vicinity of clouds to gain further insights into aerosol-cloud separation techniques and aerosol-induced modifications of cloud properties, hence the aerosol indirect forcing of climate. We plan to make the results of our work available to both the CloudSat and CALIPSO science teams with the primary intent of joining the CALIPSO science team.
By combining the team at BAERI/NASA Ames Research Center and the group led by Prof. Christopher at UAH, we have assembled a team of collaborators highly capable of investigating the three research objectives outlined above. Our combined experience in suborbital lidar and sunphotometer data analysis, aerosol modeling, and interpretation and assimilation of aerosol data from satellite sensors makes the team uniquely qualified to carry out the work proposed here.
