Pollution in the Upper Troposphere

Tibet Provides Passage for Chemicals to Reach the Stratosphere Date: 09 May 2006 NASA and university researchers have found that thunderstorms over Tibet provide a main pathway for water vapor and chemicals to travel from the lower atmosphere, where human activity directly affects atmospheric composition, into the stratosphere, where the protective ozone layer resides. +Read More
MLS Weekly UT Maps Now On-Line Date: 27 March 2006 Global maps of weekly-average MLS measurements of upper tropospheric cloud ice, relative humidity with respect to ice, water vapor, CO, O3 and temperature are now available from the MLS web site data page. Included for comparison are maps for the same period of GEOS-CHEM model (driven by GMAO GEOS-4 meteorological data) near-real-time output for CO and O3, and GMAO GEOS-4 first look output for water vapor. Maps are currently available for MLS v01.51 and v01.52 data at 100, 147, and 215 hPa pressure surfaces. These plots are available at: http://mls.jpl.nasa.gov/data/gallery.php
Convective outflow of South Asian pollution: A global CTM simulation compared with EOS MLS observations Date: 28 July 2005 A global 3-D chemical transport model is used to analyze observations of carbon monoxide (CO) and upper tropospheric clouds from the EOS Microwave Limb Sounder (MLS). MLS observations during 25 August-6 September 2004 reveal elevated CO and dense high clouds in the upper troposphere over the Tibetan plateau and southwest China, collocating with the upper level Tibetan anticyclone. Model simulations indicate the transport of boundary layer pollution by Asian summer monsoon (ASM) convection and orographic lifting to the upper troposphere over South Asia, where simulated distributions of CO resemble MLS observations. Model results also show elevated aerosols in the anticyclone region. Analysis of model simulated CO and aerosols indicate that the Tibetan anticyclone could 'trap' anthropogenic emissions lifted from northeast India and southwest China. These aerosols may be responsible for the formation of some of the dense high clouds. +Read More
Carbon monoxide measured by the EOS Microwave Limb Sounder on Aura: First results Date: 28 July 2005 Atmospheric carbon monoxide (CO) is measured by the EOS Microwave Limb Sounder (MLS) on NASA's recently-launched Aura satellite. Descent has been observed in the 2004-2005 Northern Hemisphere winter polar mesosphere and upper stratosphere. During August and September 2004 enhanced CO was observed in the upper troposphere over India and Tibet. The MLS CO measurements are described and the radiance signal due to the enhanced CO in the upper troposphere is demonstrated. +Read more

MLS-related publications concerning pollution in the upper troposphere

2008

1. Barret, B., P. Ricaud, C. Mari, J-L. Attie, N. Bousserez, B. Josse, E. Le Flochmoen, N.J. Livesey, S. Massart, A. Piacentini, B. Sauvage, V. Thouret, J-P. Cammas, "Transport pathways of CO in the African upper troposphere during the monsoon season: a study based upon the assimilation of spaceborne observations", vol 8, pgs. 2863-2902, 2008. Reprint

2007

1. Park, M., W.J. Randel, A. Gettleman, S.T. Massie, J.H. Jiang, "Transport above the Asian summer monsoon anticyclone inferred from Aura MLS tracers", vol 112, pgs. D16309, 2007. Reprint
2. Jiang, J.H., N.J. Livesey, H. Su, L. Neary, J.C. McConnell, N.A. Richards, "Connecting surface emissions, convective uplifting, and long-range transport of carbon monoxide in the upper-troposphere: New observations from the Aura Microwave Limb Sounder", vol 34, pgs. L18812, 2007. Reprint

2005

1. Filipiak, M.J., R.S. Harwood, J.H. Jiang, Q. Li, N.J. Livesey, G.L. Manney, W.G. Read, M.J. Schwartz, J.W. Waters, D.L. Wu, "Carbon Monoxide Measured by the EOS Microwave Limb Sounder on Aura: First Results", vol 32, pgs. L14825, 2005. Reprint Summary