# Presentation: 403537

## Analysis of Aerosol Transport & Extinction Using Models and Space Lidar

- Welton et al., 2006: *Eos Trans. AGU*, **87**, A31F-08.

- 2.  Model Helps to Determine Aerosol Type
-      (needed to retrieve extinction from lidar)

- 4. GLAS Aerosol Extinction Profiles
-      (drives aerosol climate forcing)

- 1. GLAS Layer Heights

- Aerosols are generated and transported using the GEOS-4 model. Profiles of modeled aerosol mixtures are compared with GLAS layer heights. GEOS-4 aerosols help constrain the retrieval of extinction derived from GLAS by assigning correct aerosol type. In turn, GLAS layer heights will help constrain modeled aerosol transport.

- Dust, pollution, and other aerosol loading cause a high degree of uncertainty in global climate change prediction. For the first time, aerosol heights from satellite backscatter lidar are merged with global aerosol models to provide vertical knowledge of aerosol type and extinction needed to understand transport and forcing.

- GLAS Satellite Lidar Profiles off West Africa:  10/4/2003   21:34:40 UTC

- GEOS-4 Aerosol Mixtures

**Notes:**
Name: Ellsworth J. Welton (NASA/GSFC)
E-mail:  Ellsworth.J.Welton@nasa.gov
Phone number:  301-614-6279
Literature reference(s): Welton, E. J., S. P. Palm, D. L. Hlavka, J. D. Spinhirne, P. R. Colarco, A. da Silva, D. L. Westphal, J. S. Reid, Satellite Lidar and Aerosol Transport Model Synergism: Improved GLAS Aerosol Products. Eos Trans. AGU, 87, Fall Meeting Suppl., Abstract A31F-08, 2006.
Technical description of image(s): Top figure shows attenuated backscatter profiles from GLAS (level 1 data) over the tropical Atlantic. Elevated aerosol layer is shown above marine boundary layer in the south to height of ~4 km. Strong scattering layers from surface to ~5km in the northern portion of the track. The next figure (below) shows GLAS aerosol and cloud heights (level 2). Blue indicates cloud, red the boundary layer top, and yellow are elevated aerosol layers. The next figure (below) displays aerosol mixtures from the GEOS-4 model along the same track as GLAS. The aerosol mixtures were developed using a new aerosol scene classification algorithm developed for this study. Aerosol mixtures are color coded using the colorbar at the right of the slide. The scene classifier is used to produce a final aerosol mixture for the boundary layer (BL) and free troposphere (FT), which are required inputs to generate profiles of extinction and optical depth from GLAS. The bottom figure shows final extinction profiles. 
Data sources: Satellite lidar data are from the GLAS sensor onboard the ICESat spacecraft. Modeled products are from the NASA Goddard Earth Observing System general circulation model and data assimilation system (GEOS-4).
Relationship to future science, missions, and major reports such as the Decadal Survey: This process is being used to reprocess GLAS data for the version 30 release. The GLAS data files will contain the GEOS-4 derived aerosol mixtures, and this will be the first merged satellite lidar/model data set ever generated. We are expanding this effort to apply to CALIPSO and the A-train. We will compare 3D aerosol scene classification using CALIPSO and MODIS with the GEOS-4 aerosol classifier in the context of providing an initial verification of the 3D GEOS-4 aerosol products. The HQ sponsored mission study for the Aerosol, Cloud, and Ecology (ACE) mission in the Decadal Survey was recently completed. A key topic of discussion was the ideal sampling strategy for future aerosol/cloud lidar. This effort is helping to lay the ground work for modeling based sampling studies because it is the first foray into global model assimilation of satellite lidar. In addition, the ACE mission requires input on the current ability to determine aerosol type using CALIPSO and A-train like sensors in order to determine future needs.