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Increase in upper tropospheric and lower stratospheric aerosol levels and its potential connection with Asian pollution

Vernier, J. -P.; Fairlie, T. D.; Natarajan, M.; Wienhold, F. G.; Bian, J.; Martinsson, Bengt LU ; Crumeyrolle, S.; Thomason, L. W. and Bedka, K. M. (2015) In Journal of Geophysical Research: Atmospheres 120(4). p.1608-1619
Abstract
Satellite observations have shown that the Asian Summer Monsoon strongly influences the upper troposphere and lower stratosphere (UTLS) aerosol morphology through its role in the formation of the Asian Tropopause Aerosol Layer (ATAL). Stratospheric Aerosol and Gas Experiment II solar occultation and Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) lidar observations show that summertime UTLS Aerosol Optical Depth (AOD) between 13 and 18 km over Asia has increased by three times since the late 1990s. Here we present the first in situ balloon measurements of aerosol backscatter in the UTLS from Western China, which confirm high aerosol levels observed by CALIPSO since 2006. Aircraft in situ measurements suggest... (More)
Satellite observations have shown that the Asian Summer Monsoon strongly influences the upper troposphere and lower stratosphere (UTLS) aerosol morphology through its role in the formation of the Asian Tropopause Aerosol Layer (ATAL). Stratospheric Aerosol and Gas Experiment II solar occultation and Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) lidar observations show that summertime UTLS Aerosol Optical Depth (AOD) between 13 and 18 km over Asia has increased by three times since the late 1990s. Here we present the first in situ balloon measurements of aerosol backscatter in the UTLS from Western China, which confirm high aerosol levels observed by CALIPSO since 2006. Aircraft in situ measurements suggest that aerosols at lower altitudes of the ATAL are largely composed of carbonaceous and sulfate materials (carbon/sulfur elemental ratio ranging from 2 to 10). Back trajectory analysis from Cloud-Aerosol Lidar with Orthogonal Polarization observations indicates that deep convection over the Indian subcontinent supplies the ATAL through the transport of pollution into the UTLS. Time series of deep convection occurrence, carbon monoxide, aerosol, temperature, and relative humidity suggest that secondary aerosol formation and growth in a cold, moist convective environment could play an important role in the formation of ATAL. Finally, radiative calculations show that the ATAL layer has exerted a short-term regional forcing at the top of the atmosphere of -0.1 W/m(2) in the past 18 years. (Less)
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author
organization
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type
Contribution to journal
publication status
published
subject
in
Journal of Geophysical Research: Atmospheres
volume
120
issue
4
pages
1608 - 1619
publisher
Wiley-Blackwell
external identifiers
  • pmid:26691186
  • wos:000351182400023
  • scopus:84925096685
ISSN
2169-8996
DOI
10.1002/2014JD022372
language
English
LU publication?
yes
id
f24d18ca-5dc6-42bd-a0c8-28f8350c57d3 (old id 5293802)
date added to LUP
2015-04-24 15:31:38
date last changed
2017-10-22 03:08:38
@article{f24d18ca-5dc6-42bd-a0c8-28f8350c57d3,
  abstract     = {Satellite observations have shown that the Asian Summer Monsoon strongly influences the upper troposphere and lower stratosphere (UTLS) aerosol morphology through its role in the formation of the Asian Tropopause Aerosol Layer (ATAL). Stratospheric Aerosol and Gas Experiment II solar occultation and Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) lidar observations show that summertime UTLS Aerosol Optical Depth (AOD) between 13 and 18 km over Asia has increased by three times since the late 1990s. Here we present the first in situ balloon measurements of aerosol backscatter in the UTLS from Western China, which confirm high aerosol levels observed by CALIPSO since 2006. Aircraft in situ measurements suggest that aerosols at lower altitudes of the ATAL are largely composed of carbonaceous and sulfate materials (carbon/sulfur elemental ratio ranging from 2 to 10). Back trajectory analysis from Cloud-Aerosol Lidar with Orthogonal Polarization observations indicates that deep convection over the Indian subcontinent supplies the ATAL through the transport of pollution into the UTLS. Time series of deep convection occurrence, carbon monoxide, aerosol, temperature, and relative humidity suggest that secondary aerosol formation and growth in a cold, moist convective environment could play an important role in the formation of ATAL. Finally, radiative calculations show that the ATAL layer has exerted a short-term regional forcing at the top of the atmosphere of -0.1 W/m(2) in the past 18 years.},
  author       = {Vernier, J. -P. and Fairlie, T. D. and Natarajan, M. and Wienhold, F. G. and Bian, J. and Martinsson, Bengt and Crumeyrolle, S. and Thomason, L. W. and Bedka, K. M.},
  issn         = {2169-8996},
  language     = {eng},
  number       = {4},
  pages        = {1608--1619},
  publisher    = {Wiley-Blackwell},
  series       = {Journal of Geophysical Research: Atmospheres},
  title        = {Increase in upper tropospheric and lower stratospheric aerosol levels and its potential connection with Asian pollution},
  url          = {http://dx.doi.org/10.1002/2014JD022372},
  volume       = {120},
  year         = {2015},
}