Open AccessComparison of modeled backscatter using measured aerosol microphysics with focused CW lidar data over Pacific
Author(s) -
Srivastava Vandana,
Clarke Antony D.,
Jarzembski Maurice A.,
Rothermel Jeffry
Publication year - 1997
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/97jd00604
Subject(s) - aerosol , backscatter (email) , intertropical convergence zone , lidar , environmental science , troposphere , atmospheric sciences , remote sensing , meteorology , geology , precipitation , geography , telecommunications , computer science , wireless
During NASA's GLObal Backscatter Experiment (GLOBE) II flight mission over the Pacific Ocean in May‐June 1990, extensive aerosol backscatter data sets from two continuous wave, focused CO 2 Doppler lidars and an aerosol microphysics data set from a laser optical particle counter (LOPC) were obtained. Changes in aerosol loading in various air masses with associated changes in chemical composition, from sulfuric acid and sulfates to dustlike crustal material, significantly affected aerosol backscatter, causing variation of about 3 to 4 orders of magnitude. Some of the significant backscatter features encountered in different air masses were the low backscatter in subtropical air with even lower values in the tropics near the Intertropical Convergence Zone (ITCZ), highly variable backscatter in the ITCZ, mid‐tropospheric aerosol backscatter background mode, and high backscatter in an Asian dust plume off the Japanese coast. Differences in aerosol composition and backscatter for northern and southern hemisphere also were observed. Using the LOPC measurements of physical and chemical aerosol properties, we determined the complex refractive index from three different aerosol mixture models to calculate backscatter. These values provided a well‐defined envelope of modeled backscatter for various atmospheric conditions, giving good agreement with the lidar data over a horizontal sampling of ∼18,000 km in the mid‐troposphere.