Microwave Limb Sounder

Contact: Michelle Santee

Basic Information Chlorine monoxide (ClO) is the dominant form of reactive chlorine in the stratosphere and is thus the principal agent for chlorine-catalyzed destruction of stratospheric ozone. The primary source of stratospheric chlorine is chlorofluorocarbons, or CFCs, chemical compounds composed of chlorine, fluorine, and carbon that are emitted by human activities at the surface. After they reach the upper stratosphere (primarily by upwelling in the tropics), the CFCs are broken down by high-energy UV radiation, liberating chlorine. Away from the polar regions, most of the chlorine released from CFCs resides in relatively benign reservoir species such as ClONO2 and HCl that do not directly destroy ozone. In the winter polar regions, however, heterogeneous chemical reactions on the surfaces of polar stratospheric clouds convert chlorine to highly reactive forms. Enhanced levels of ClO are a signal that ozone destruction is taking place.

The ClO Molecule

(map from 2005d250)

ClO Information from the Spectroscopy Database Product Information Line Listing

v3.3 ClO Vertical Averaging Kernel
colored lines are individual kernels; thick dashed line is full width at half maximum, thick solid is integrated kernel value

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Publications related to the MLS ClO data product

2011

1. de Laat, A.T.J., "The 2010 Antarctic ozone hole: Observed reduction in ozone destruction by minor sudden stratospheric warmings", vol 10.1038/srep00038, num 1, pgs. 38, 2011. Preprint
2. Feng, W., "Modelling the effect of denitrification on polar ozone depletion for Arctic winter 2004/2005", num 11, 2011. Preprint
3. Manney, G.L., "Unprecedented Arctic ozone loss in 2011", vol doi:10.1038/nature10556, num 478, 2011. Preprint
4. Nedoluha, G.E., "Ground-based measurements of ClO from Mauna Kea and intercomparisons with Aura and UARS MLS", vol doi:10.1029/2010JD014732, num 116, 2011. Reprint Preprint
5. Pumphrey, H.C., "Microwave Limb Sounder observations of biomass-burning products from the Australian bush fires of February 2009", vol doi:10.5194/acp-11-6285-2011, num 11, pgs. 2, 2011. Reprint Preprint
6. Santee, M.L., "Trace gas evolution in the lowermost stratosphere from Aura Microwave Limb Sounder measurements", vol 10.1029/2011JD015590, num 116, 2011. Preprint

2010

1. Kuttippurath, J., "Spatial, temporal, and vertical variability of polar stratospheric ozone loss in the Arctic winters 2004/2005-2009/2010", vol doi:10.5194/acp-10-9915-2010, num 10, 2010. Reprint Preprint
2. Santee, M.L., "Constraining the chlorine monoxide (ClO) / chlorine peroxide (ClOOCl) equilibrium constant from Aura Microwave Limb Sounder measurements of nighttime ClO", vol doi:10.1073/pnas.0912659107, num 107, pgs. 15, 2010. Reprint Preprint

2009

1. Kuttippurath, J., "Ozone depletion in the Arctic winter 2007-2008", vol doi:10.1080/01431160902821965, num 30, pgs. 15-16, 2009. Reprint Preprint

2008

1. Manson, A.H., "Regional stratospheric warmings in the Pacific-Western Canada (PWC) sector during winter 2004/2005: implications for temperatures, winds, chemical constituents and the characterization of the Polar vortex", num 26, 2008. Preprint
2. McConnell, J.C., "Stratospheric Ozone Chemistry", vol doi:10.3137/ao.460104, num 46, pgs. No. 1, 2008. Reprint Preprint
3. Santee, M.L., "A study of stratospheric chlorine partitioning based on new", vol doi:10.1029/2007JD009057, num 113, 2008. Reprint Preprint
4. Santee, M.L., "Validation of the Aura Microwave Limb Sounder ClO Measurements", vol doi:10.1029/2007JD008762, num 113, 2008. Reprint Preprint

2007

1. Connor, B.J., "Comparison of ClO measurements from the Aura Microwave Limb Sounder to ground-based microwave measurements at Scott Base, Antarctica, in spring 2005", vol doi:10.1029/2007JD008792, num 112, 2007. Preprint
2. Kovalenko, L.J., "Observed and Modeled HOCl Profiles in the Midlatitude Stratosphere: Implication for Ozone Loss", vol doi:10.1029/2007GL031100, num 34, 2007. Reprint Preprint

2006

1. Barret, B., "Intercomparisons of Trace Gas Profiles from the Odin/SMR and Aura/MLS Limb Sounders", vol doi:10.1029/2006JD007305, num 111, 2006. Reprint Preprint
2. Cofield, R.E., "Design and field-of-view calibration of 114-660 GHz optics of the Earth Observing System Microwave Limb Sounder", num 44, pgs. no. 5, 2006. Preprint
3. Schoeberl, M.R., "Chemical Observations of a Polar Vortex Intrusion", vol doi:10.1029/2006JD007134, num 111, 2006. Reprint Preprint

2005

1. Santee, M.L., "Polar processing and development of the 2004 Antarctic ozone hole: First results from Aura MLS", vol doi:10.1029/2005GL022582, num 32, 2005. Preprint

2003

1. Rex, M., "On the unexplained stratospheric ozone losses during cold Arctic Januaries", vol doi:10.1029/2002GL016008, num 30, 2003. Reprint Preprint
2. Santee, M.L., "Variations and climatology of ClO in the polar lower stratosphere from UARS MLS measurements", vol doi:10.1029/2002JD003335, num 108, pgs. D15, 2003. Preprint

2002

1. Danilin, M.Y., "Comparison of ER-2 aircraft and POAM-III, MLS, and SAGE II satellite measurements during SOLVE using traditional correlative analysis and trajectory hunting techniques", vol doi:10.1029/2002JD000781, num 107, pgs. D5, 2002. Reprint Preprint

2001

1. Drouin, B.J., "Further investigations of the ClO rotational spectrum", num 207, 2001. Preprint
2. Huang, F.T., "Synoptic estimates of chemically active species and other diurnally varying parameters in the stratosphere, derived from measurements from the Upper Atmosphere Research Satellite (UARS)", num 106, pgs. D2, 2001. Preprint
3. Wu, J., "Comparisons between measurements and models of Antarctic ozone loss", num 106, pgs. D3, 2001. Preprint

2000

1. Danilin, M.Y., "Trajectory hunting: A case study of rapid chlorine activation in December 1992 as seen by UARS", num 105, pgs. D3, 2000. Preprint
2. Feist, D.G., "Validation of stratospheric ClO from the Millimeter-wave Atmospheric Sounder (MAS)", num 105, pgs. D7, 2000. Preprint
3. Froidevaux, L., "Variations in the free chlorine content of the stratosphere (1991-1997): Anthropogenic, volcanic, and methane influences", num 105, pgs. D4, 2000. Preprint
4. Massie, S.T., "Chlorine activation during the 1995-1996 Arctic winter", num 105, pgs. D6, 2000. Preprint
5. Ricaud, P., "Temporal evolution of chlorine monoxide in the middle stratosphere", num 105, pgs. D4, 2000. Preprint
6. Santee, M.L., "UARS Microwave Limb Sounder Observations of Denitrification and Ozone Loss in the 2000 Arctic Late Winter", num 27, 2000. Preprint
7. van den Broek, M W.P., "Model study of stratospheric chlorine activation and ozone loss during 1996/1997 winter", num 105, pgs. D23, 2000. Reprint Preprint

1999

1. Khattatov, B.V., "Assimilation of photochemically active species and a case analysis of UARS data", num 104, pgs. D15, 1999. Reprint Preprint
2. Randel, W.J., "Space-time patterns of trends in stratospheric constituents derived from UARS measurements", num 104, pgs. D3, 1999. Preprint
3. Solomon, S., "Stratospheric ozone depletion: A review of concepts and history", num 37, 1999. Preprint
4. Stachnik, R.A., "Measurements of chlorine partitioning in the winter Arctic stratosphere", num 26, 1999. Preprint

1998

1. Dessler, A.E., "Selected science highlights from the first 5 years of the Upper Atmosphere Research Satellite (UARS) program", num 36, 1998. Reprint Preprint
2. Khosravi, R., "Significant Reduction in Stratospheric Ozone Deficit using a 3-D Model Constrained with UARS Data", num 103, pgs. D13, 1998. Reprint Preprint
3. Ricaud, P., "Stratosphere over Dumont d'Urville, Antarctica, in winter 1992", num 103, pgs. D11, 1998. Preprint
4. Searle, K.R., "The impact of spatial averaging on calculated polar ozone loss: 1. Model experiments", num 103, pgs. D19, 1998. Reprint Preprint
5. Siskind, D.E., "Implications of upper stratospheric trace constituent changes observed by HALOE for O₃ and ClO from 1992 to 1995", num 25, 1998. Preprint

1997

1. Engel, A., "Partitioning Between Chlorine Reservoir Species Deduced from Observations in the Arctic Winter Stratosphere", num 27, 1997. Preprint
2. Lutman, E.R., "Three dimensional studies of the 1991/92 Northern Hemisphere winter using domain-filling trajectories with chemistry", num 102, pgs. D1, 1997. Preprint
3. Osterman, G.B., "Balloon-borne measurements of stratospheric radicals and their precursors: Implications for the production and loss of ozone", num 24, 1997. Preprint
4. Santee, M.L., "MLS observations of ClO and HNO₃ in the 1996-97 Arctic polar vortex", num 24, 1997. Preprint
5. Yudin, V.A., "A UARS study of lower stratospheric polar processing in the early stages of northern and southern winters", num 102, pgs. D15, 1997. Preprint

1996

1. Aellig, C.P., "Latitudinal distribution of upper stratospheric ClO as derived from space borne microwave spectroscopy", num 23, 1996. Preprint
2. Chance, K., "Simultaneous measurements of stratospheric HO_x, NO_x and Cl_x: Comparsion with a photochemical model", num 101, pgs. D4, 1996. Preprint
3. Chipperfield, M.P., "Analyses of UARS data in the southern polar vortex in September 1992 using a chemical transport model", num 101, pgs. D13, 1996. Reprint Preprint
4. Dessler, A.E., "A test of the partitioning between ClO and ClONO₂ using simultaneous UARS measurements of ClO, NO₂ and ClONO₂", num 101, pgs. D7, 1996. Preprint
5. Dessler, A.E., "UARS measurements of ClO and NO₂ at 40 and 46 km and implications for the 'ozone deficit'", num 23, 1996. Preprint
6. Jucks, K.W., "Ozone Production and loss rate measurements in the middle stratosphere", num 101, pgs. D22, 1996. Preprint
7. Santee, M.L., "Chlorine deactivation in the lower stratospheric polar regions during late winter: Results from UARS", num 101, pgs. D13, 1996. Preprint
8. Santee, M.L., "Polar vortex conditions during the 1995-96 Arctic winter: MLS ClO and HNO₃", num 23, 1996. Preprint
9. Schoeberl, M.R., "The development of the Antarctic ozone hole", num 101, pgs. D15, 1996. Preprint
10. Waters, J.W., "Validation of UARS Microwave Limb Sounder ClO measurements", num 101, pgs. D6, 1996. Preprint

1995

1. Crewell, S., "Comparison of ClO measurements made by airborne and spaceborne microwave radiometers in the Arctic winter stratosphere 1993", num 22, 1995. Preprint
2. Dessler, A.E., "Correlated observations of HCl and ClONO₂ from UARS and implications for stratospheric chlorine partitioning", num 22, 1995. Preprint
3. Douglass, A.R., "Interhemispheric differences in springtime production of HCl and ClONO₂ in the polar vortices", num 100, pgs. D7, 1995. Preprint
4. Eckman, R.S., "Stratospheric trace constituents simulated by a three-dimensional general circulation model: Comparison with UARS data", num 100, pgs. D7, 1995. Preprint
5. Fahey, D.W., "Polar Ozone", num 1994, pgs. ch.4, 1995.
6. Geller, M.A., "UARS PSC, ClONO₂, HCl, and ClO measurements in early winter: Additional verification of the paradigm for chlorine activation", num 22, 1995. Preprint
7. Johnson, D.G., "Estimating the abundance of ClO from simultaneous remote sensing measurements of stratospheric HO_x, NO_x and Cl_x", num 22, 1995. Preprint
8. Manney, G.L., "Evidence for arctic ozone depletion in late February and early March 1994", num 22, 1995. Preprint
9. Pyle, J.A., "Early modelling results from the SESAME and ASHOE campaigns", num 100, 1995.
10. Ricaud, P.D., "Polar stratospheric clouds as deduced from MLS and CLAES measurements", num 22, 1995. Preprint
11. Santee, M.L., "Interhemispheric differences in polar stratospheric HNO3, H2O, ClO and O3", num 267, 1995. Preprint
12. Waters, J.W., "UARS MLS observations of lower stratospheric ClO in the 1992-93 and 1993-94 arctic winter vortices", num 22, 1995. Preprint

1994

1. Bell, W., "Column measurements of stratospheric trace species over Are, Sweden in the winter of 1991-1992", num 21, 1994. Preprint
2. Lefevre, F., "Chemistry of the 1991-1992 stratospheric winter: Three-dimensional model simulations", num 99, pgs. D4, 1994. Preprint
3. Manney, G.L., "Chemical depletion of ozone in the Arctic lower stratosphere during winter 1992-93", num 370, 1994. Preprint
4. Oh, J.J., "Pressure broadening of ClO by N2 and O2 near 204 and 649 GHz and new frequency measurements between 632 and 725 GHz", num 54, 1994.

1993

1. Chipperfield, M., "Satellite maps ozone destroyer", num 362, 1993. Preprint
2. Douglass, A., "A 3D simulation of the early winter distribution of reactive chlorine in the north polar vortex", num 20, 1993. Reprint Preprint
3. Geller, M.A., "3-D transport-chemistry studies of the stratosphere using satellite data together with data assimilation", 1993.
4. Schoeberl, M.R., "MLS ClO observations and arctic polar vortex temperatures", num 20, 1993. Reprint Preprint
5. Waters, J.W., "Lower stratospheric ClO and O₃ in the 1992 southern hemisphere winter", num 20, 1993. Reprint Preprint
6. Waters, J.W., "Stratospheric ClO and ozone from the Microwave Limb Sounder on the Upper Atmosphere Research Satellite", num 362, 1993. Preprint
7. Waters, J.W., "The chlorine threat to stratospheric ozone", num LVI, 1993.

1992

1. Stachnik, R.A., "Submillimeterwave heterodyne measurements of stratospheric ClO, HCl, O₃, and HO₂: First results", num 19, 1992. Reprint Preprint

1988

1. Waters, J.W., "ClO and O3 stratospheric profiles: Balloon microwave measurements", num 15, 1988. Reprint Preprint

1981

1. Pickett, H.M., "Pressure broadening of ClO by nitrogen", num 86, 1981. Reprint Preprint
2. Waters, J.W., "Chlorine monoxide radical, ozone, and hydrogen peroxide: Stratospheric measurements by microwave limb sounding", num 214, 1981. Preprint

1979

1. Waters, J.W., "Aircraft search for millimeter wavelength emission by stratospheric ClO", num 84, 1979. Reprint Preprint