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Record Details

Record 24 of 5535
Temporal Decrease in Upper Atmospheric Chlorine
External Online Source: hdl:2014/40388
doi:10.1029/2006GL027600
Author and Affiliation:
Froidevaux, L.(Jet Propulsion Lab., California Inst. of Tech., Pasadena, CA, United States)
Livesey, N. J.(Jet Propulsion Lab., California Inst. of Tech., Pasadena, CA, United States)
Read, W. G.(Jet Propulsion Lab., California Inst. of Tech., Pasadena, CA, United States)
Salawitch, R. J.(Jet Propulsion Lab., California Inst. of Tech., Pasadena, CA, United States)
Waters, J. W.(Jet Propulsion Lab., California Inst. of Tech., Pasadena, CA, United States)
Drouin, B.(Jet Propulsion Lab., California Inst. of Tech., Pasadena, CA, United States)
MacKenzie, I. A.(Edinburgh Univ., School of GeoSciences, United Kingdom)
Pumphrey, H. C.(Edinburgh Univ., School of GeoSciences, United Kingdom)
Bernath, P.(Waterloo Univ., Dept.of Chemistry, Ontario, Canada)
Boone, C.(Waterloo Univ., Dept.of Chemistry, Ontario, Canada) Show more authors
Abstract: We report a steady decrease in the upper stratospheric and lower mesospheric abundances of hydrogen chloride (HCl) from August 2004 through January 2006, as measured by the Microwave Limb Sounder (MLS) aboard the Aura satellite. For 60(deg)S to 60(deg)N zonal means, the average yearly change in the 0.7 to 0.1 hPa (approx.50 to 65 km) region is -27 +/- 3 pptv/year, or -0.78 +/- 0.08 percent/year. This is consistent with surface abundance decrease rates (about 6 to 7 years earlier) in chlorine source gases. The MLS data confirm that international agreements to reduce global emissions of ozone-depleting industrial gases are leading to global decreases in the total gaseous chlorine burden. Tracking stratospheric HCl variations on a seasonal basis is now possible with MLS data. Inferred stratospheric total chlorine (CITOT) has a value of 3.60 ppbv at the beginning of 2006, with a (2-sigma) accuracy estimate of 7%; the stratospheric chlorine loading has decreased by about 43 pptv in the 18-month period studied here. We discuss the MLS HCl measurements in the context of other satellite-based HCl data, as well as expectations from surface chlorine data. A mean age of air of approx. 5.5 years and an age spectrum width of 2 years or less provide a fairly good fit to the ensemble of measurements.
Publication Date: Dec 14, 2006
Document ID:
20070032967
(Acquired Nov 14, 2007)
Subject Category: CHEMISTRY AND MATERIALS (GENERAL)
Document Type: Journal Article
Publication Information: Geophysical Research Letters (ISSN 0094-8276); Volume 33
Publisher Information: American Geophysical Union, Washington, DC, United States
Financial Sponsor: Jet Propulsion Lab., California Inst. of Tech.; Pasadena, CA, United States
Canadian Space Agency; Ottawa, Ontario, Canada
Natural Sciences and Engineering Research Council; Ottawa, Ontario, Canada
Organization Source: Jet Propulsion Lab., California Inst. of Tech.; Pasadena, CA, United States
Description: 5p; In English; Original contains color illustrations
Distribution Limits: Unclassified; Publicly available; Unlimited
Rights: Copyright
NASA Terms: UPPER ATMOSPHERE; STRATOSPHERE; MESOSPHERE; HYDROGEN CHLORIDES; ABUNDANCE; MICROWAVE SOUNDING; ACCURACY; OZONE; CHLORINE
Other Descriptors: ATMOSPHERIC COMPOSITION; CHLORINE; OZONE
Availability Source: Other Sources
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