Open AccessApril 1998 Asian dust event: A southern California perspective
Author(s) -
Tratt David M.,
Frouin Robert J.,
Westphal Douglas L.
Publication year - 2001
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 - 10.1029/2000jd900758
Subject(s) - lidar , troposphere , asian dust , backscatter (email) , environmental science , atmospheric sciences , aerosol , albedo (alchemy) , single scattering albedo , effective radius , opacity , plume , geology , meteorology , remote sensing , geography , physics , optics , art , telecommunications , quantum mechanics , galaxy , performance art , computer science , wireless , art history
In late April 1998 an extreme Asian dust episode reached the U.S. western seaboard. This event was observed by several in situ and remote sensing atmospheric measurement stations. Dramatic reductions in boundary layer visibility were recorded and the resultant peak backscatter coefficients exceeded prevailing upper tropospheric background conditions by at least 2 orders of magnitude. An analysis of this event is given using lidar vertical backscatter profilometry, concurrent Sun photometer opacity data, and transport modeling. At San Nicolas Island the measured and modeled aerosol optical thickness at 500 nm increased dramatically from 0.15 on April 25 to 0.52 on April 26–27. Volume size distribution on April 27 exhibited a prominent coarse mode at 1–2 μm radius, and single‐scattering albedo was observed to increase from 0.90 in the blue to 0.93 in the near infrared. Concurrent lidar observations tracked the evolution of the plume vertical structure, which consisted of up to three well‐defined layers distributed throughout the free troposphere.