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J. Kar

Publications and source records attributed to J. Kar.

4 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS2018

Swelling of Transported Smoke from Savanna Fires over the Southeast Atlantic Ocean

We use the recently released Cloud Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) Version 4.1 (V4) lidar data to study the smoke plumes transported from Southern African biomass burning areas. Significant improvements in the CALIPSO V4 Level 1 calibration and V4 Level 2 algorithms lead to a better representation of their optical properties, with the aerosol subtype improvements being particularly relevant to smoke over this area. For the first time, we show evidence of smoke particles increasing in size, as demonstrated by their particulate color ratios, as they are transported over the South Atlantic Ocean from the source regions over Southern Africa. We hypothesize that this is due to hygroscopic swelling of the smoke particles and is reflected in the higher relative humidity in the middle troposphere for profiles with smoke. This finding may have implications for radiative forcing estimates over this area and is also relevant to the ORACLES field mission.

J. Kar↗
NASA NTRSDate not supplied

Mapping Modeled Aerosol Species to Measured Lidar Ratios for the MIRA Project

Overarching goal: Create Climatological Lidar Ratio Maps for CALIPSO - Since CALIPSO is an elastic backscatter lidar, it is necessary to select a priori aerosol lidar ratios prior to computing extinction profiles. - Presently, the CALIPSO lidar ratio selection process uses a single lidar ratio for each of the 7 CALIPSO aerosol types in the troposphere. - Consequently, regional and seasonal variability of the lidar ratio is very limited in the present CALIPSO algorithm. - Here, we describe an approach for creating new climatological lidar ratio maps for each of the CALIPSO aerosol types using MODIS-CALIPSO constrained retrievals and global model simulations. - The purpose is to eventually replace the seven single-valued lidar ratios for the CALIPSO types with latitude- and longitude-dependent maps for each of the seven types.

G. L. Schuster↗