The MLS ClO Product

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

v2.2 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

2008

1. Santee, M.L., A. Lambert, W.G. Read, N.J. Livesey, G.L. Manney, R.E. Cofield, D.T. Cuddy, W.H. Daffer, B.J. Drouin, L. Froidevaux, R.A. Fuller, R.F. Jarnot, B.W. Knosp, V.S. Perun, W.V. Snyder, P.C. Stek, R.P. Thurstans, P.A. Wagner, J.W. Waters, B. Connor, J. Urban, D. Murtagh, P. Ricaud, B. Barrett, A. Kleinboehl, J. Kuttippurath, H. Kullmann, M. von Hobe, G.C. Toon, R.A. Stachnik, "Validation of the Aura Microwave Limb Sounder ClO Measurements", vol 113, pgs. D15S22, 2008. Reprint
2. Santee, M.L., I.A. MacKenzie, G.L. Manney, M.P. Chipperfield, P.F. Bernath, K.A. Walker, C.D. Boone, L. Froidevaux, N.J. Livesey, J.W. Waters, "A study of stratospheric chlorine partitioning based on new", vol 113, pgs. D12307, 2008. Reprint
3. McConnell, J.C., J.J. Jin, "Stratospheric Ozone Chemistry", vol 46, num No. 1, pgs. 69-92, 2008. Reprint

2007

1. Kovalenko, L.J., K.W. Jucks, R.J. Salawitch, G.C. Toon, J-F. Blavier, D.G. Johnson, , N.J. Livesey, J.J. Margitan, H.M. Pickett, M.L. Santee, B. Sen, R.A. Stachnik, J.W. Waters, "Observed and Modeled HOCl Profiles in the Midlatitude Stratosphere: Implication for Ozone Loss", vol 34, pgs. L19801, 2007. Reprint
2. Connor, B.J., T. Mooney, J. Barrett, P. Solomon, A. Parrish, M. Santee, "Comparison of ClO measurements from the Aura Microwave Limb Sounder to ground-based microwave measurements at Scott Base, Antarctica, in spring 2005", vol 112, pgs. D24S42, 2007. Reprint

2006

1. Cofield, R.E., P.C. Stek, "Design and field-of-view calibration of 114-660 GHz optics of the Earth Observing System Microwave Limb Sounder", vol 44, num no. 5, pgs. 1166-1181, 2006. Reprint
2. Barret, B., P. Ricaud, M.L. Santee, J-L. Attie, J. Urban, E. Le Flochmoen, G. Berthet, D. Murtagh, P. Eriksson, A. Jones, J. de La Noe, E. Dupuy, L. Froidevaux, N.J. Livesey, J.W. Waters, M.J. Filipiak, "Intercomparisons of Trace Gas Profiles from the Odin/SMR and Aura/MLS Limb Sounders", vol 111, pgs. D21302, 2006. Reprint
3. Schoeberl, M.R., S.R. Kawa, A.R. Douglass, T.J. McGee, E.V. Browell, J.W. Waters, N.J. Livesey, W.G. Read, L. Froidevaux, M.L. Santee, H.C. Pumphrey, L.R. Lait, L. Twigg, "Chemical Observations of a Polar Vortex Intrusion", vol 111, pgs. D20306, 2006. Reprint

2005

1. Santee, M.L., G.L. Manney, N.J. Livesey, L. Froidevaux, H.C. Pumphrey, W.G. Read, M.J. Schwartz, J.W. Waters, "Polar processing and development of the 2004 Antarctic ozone hole: First results from Aura MLS", vol 32, pgs. L12817, 2005. Reprint Summary

2003

1. Rex, M., R.J. Salawitch, M.L. Santee, J.W. Waters, K. Hoppel, R. Bevilacqua, "On the unexplained stratospheric ozone losses during cold Arctic Januaries", vol 30, pgs. 1008, 2003. Reprint Summary
2. Santee, M.L., G.L. Manney, J.W. Waters, N.J. Livesey, "Variations and climatology of ClO in the polar lower stratosphere from UARS MLS measurements", vol 108, num D15, pgs. 4454, 2003. Reprint Summary

2002

1. Danilin, M.Y., M K.W. Ko, R.M. Bevilacqua, L.V. Lyjak, L. Froidevaux, M.L. Santee, J.M. Zawodny, K.W. Hoppel, E.C. Richard, J.R. Spackman, E.M. Weinstock, R.L. Herman, K.A. McKinney, P.O. Wennberg, F.L. Eisele, R.M. Stimpfle, C.J. Scott, J.W. Elkins, T.V. Bui, "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 107, num D5, pgs. 8315, 2002. Reprint Summary

2001

1. Drouin, B.J., C.E. Miller, E.A. Cohen, G. Wagner, M. Birk, "Further investigations of the ClO rotational spectrum", vol 207, pgs. 4-9, 2001. Reprint
2. Huang, F.T., C.A. Reber, "Synoptic estimates of chemically active species and other diurnally varying parameters in the stratosphere, derived from measurements from the Upper Atmosphere Research Satellite (UARS)", vol 106, num D2, pgs. 1655-1667, 2001. Reprint
3. Wu, J., A.E. Dessler, "Comparisons between measurements and models of Antarctic ozone loss", vol 106, num D3, pgs. 3195-3201, 2001. Reprint

2000

1. Danilin, M.Y., M.L. Santee, J.M. Rodriguez, M K.W. Ko, J.M. Mergenthaler, J.B. Kumer, A. Tabazadeh, N.J. Livesey, "Trajectory hunting: A case study of rapid chlorine activation in December 1992 as seen by UARS", vol 105, num D3, pgs. 4003-4018, 2000. Reprint
2. Feist, D.G., C.P. Aellig, N. Kampfer, P.M. Solomon, J.W. Barrett, S. Zoonematkermani, P. Hartogh, C. Jarchow, J.W. Waters, "Validation of stratospheric ClO from the Millimeter-wave Atmospheric Sounder (MAS)", vol 105, num D7, pgs. 9053-9062, 2000. Reprint
3. Froidevaux, L., J.W. Waters, W.G. Read, P.S. Connell, D.E. Kinnison, J.M. Russell, "Variations in the free chlorine content of the stratosphere (1991-1997): Anthropogenic, volcanic, and methane influences", vol 105, num D4, pgs. 4471-4481, 2000. Reprint
4. Massie, S.T., X.X. Tie, G.P. Brasseur, R.M. Bevilacqua, M.D. Fromm, M.L. Santee, "Chlorine activation during the 1995-1996 Arctic winter", vol 105, num D6, pgs. 7111-7131, 2000. Reprint
5. Ricaud, P., M.P. Chipperfield, J.W. Waters, J.M. Russell, A.E. Roche, "Temporal evolution of chlorine monoxide in the middle stratosphere", vol 105, num D4, pgs. 4459-4469, 2000. Reprint
6. Santee, M.L., G.L. Manney, N.J. Livesey, J.W. Waters, "UARS Microwave Limb Sounder Observations of Denitrification and Ozone Loss in the 2000 Arctic Late Winter", vol 27, pgs. 3213-3216, 2000. Reprint
7. van den Broek, M W.P., A. Bregman, J. Lelieveld, "Model study of stratospheric chlorine activation and ozone loss during 1996/1997 winter", vol 105, num D23, pgs. 28,961-29,977, 2000. Reprint

1999

1. Khattatov, B.V., J.C. Gille, L.V. Lyjak, G.P. Brasseur, V.L. Dvortsov, A.E. Roche, J.W. Waters, "Assimilation of photochemically active species and a case analysis of UARS data", vol 104, num D15, pgs. 18,715-18,737, 1999. Reprint
2. Randel, W.J., F. Wu, J.M. Russell, J. Waters, "Space-time patterns of trends in stratospheric constituents derived from UARS measurements", vol 104, num D3, pgs. 3711-3727, 1999. Reprint
3. Solomon, S., "Stratospheric ozone depletion: A review of concepts and history", vol 37, pgs. 275-316, 1999. Reprint
4. Stachnik, R.A., R.J. Salawitch, A. Engel, U. Schmidt, "Measurements of chlorine partitioning in the winter Arctic stratosphere", vol 26, pgs. 3093-3096, 1999. Reprint

1998

1. Dessler, A.E., M.D. Burrage, J-U. Groos, J.R. Holton, J.L. Lean, S.T. Massie, M.R. Schoeberl, A.R. Douglass, C.H. Jackman, "Selected science highlights from the first 5 years of the Upper Atmosphere Research Satellite (UARS) program", vol 36, pgs. 183-210, 1998. Reprint
2. Khosravi, R., G.P. Brasseur, A. Smith, D.W. Rusch, J.W. Waters, J.M. Russell III, "Significant Reduction in Stratospheric Ozone Deficit using a 3-D Model Constrained with UARS Data", vol 103, num D13, pgs. 16,203-16,219, 1998. Reprint
3. Ricaud, P., E. Monnier, F. Goutail, J-P. Pommereau, C. David, S. Godin, L. Froidevaux, J.W. Waters, J. Mergenthaler, A.E. Roche, H. Pumphrey, M.P. Chipperfield, "Stratosphere over Dumont d'Urville, Antarctica, in winter 1992", vol 103, num D11, pgs. 13,267-13,284, 1998. Reprint
4. Searle, K.R., M.P. Chipperfield, S. Bekki, J.A. Pyle, "The impact of spatial averaging on calculated polar ozone loss: 1. Model experiments", vol 103, num D19, pgs. 25,397-25,408, 1998. Reprint
5. Siskind, D.E., L. Froidevaux, J.M. Russell, J. Lean, "Implications of upper stratospheric trace constituent changes observed by HALOE for O₃ and ClO from 1992 to 1995", vol 25, pgs. 3513-3516, 1998. Reprint

1997

1. Engel, A., U. Schmidt, R.A. Stachnik, "Partitioning Between Chlorine Reservoir Species Deduced from Observations in the Arctic Winter Stratosphere", vol 27, pgs. 107-126, 1997. Reprint
2. Lutman, E.R., J.A. Pyle, M.P. Chipperfield, D.J. Lary, I. Kilbane-Dawe, J.W. Waters, N. Larsen, "Three dimensional studies of the 1991/92 Northern Hemisphere winter using domain-filling trajectories with chemistry", vol 102, num D1, pgs. 1479-1488, 1997. Reprint
3. Osterman, G.B., R.J. Salawitch, B. Sen, G.C. Toon, R.A. Stachnik, H.M. Pickett, J.J. Margitan, J-F. Blavier, D.B. Peterson, "Balloon-borne measurements of stratospheric radicals and their precursors: Implications for the production and loss of ozone", vol 24, pgs. 1107-1110, 1997. Reprint
4. Santee, M.L., G.L. Manney, L. Froidevaux, R.W. Zurek, J.W. Waters, "MLS observations of ClO and HNO₃ in the 1996-97 Arctic polar vortex", vol 24, pgs. 2713-2716, 1997. Reprint
5. Yudin, V.A., M.A. Geller, B.V. Khattatov, A.R. Douglass, M.C. Cerniglia, J.W. Waters, L.S. Elson, A.E. Roche, J.M. Russell, "A UARS study of lower stratospheric polar processing in the early stages of northern and southern winters", vol 102, num D15, pgs. 19,137-19,148, 1997. Reprint

1996

1. Aellig, C.P., N. Kampfer, C. Rudin, R.M. Bevilacqua, W. Degenhardt, P. Hartogh, C. Jarchow, K. Kunzi, J.J. Olivero, C. Croskey, J.W. Waters, H.A. Michelsen, "Latitudinal distribution of upper stratospheric ClO as derived from space borne microwave spectroscopy", vol 23, pgs. 2321-2324, 1996. Reprint
2. Chance, K., W.A. Traub, D.G. Johnson, K.W. Jucks, P. Ciarpallini, R.A. Stachnik, R.J. Salawitch, H.A. Michelsen, "Simultaneous measurements of stratospheric HO_x, NO_x and Cl_x: Comparsion with a photochemical model", vol 101, num D4, pgs. 9031-9043, 1996. Reprint
3. Chipperfield, M.P., M.L. Santee, L. Froidevaux, G.L. Manney, W.G. Read, J.W. Waters, A.E. Roche, J.M. Russell III, "Analyses of UARS data in the southern polar vortex in September 1992 using a chemical transport model", vol 101, num D13, pgs. 18,861-18,881, 1996. Reprint
4. Dessler, A.E., S.R. Kawa, D.B. Considine, J.W. Waters, L. Froidevaux, J.B. Kumer, "UARS measurements of ClO and NO₂ at 40 and 46 km and implications for the 'ozone deficit'", vol 23, pgs. 339-342, 1996. Reprint
5. Dessler, A.E., S.R. Kawa, A. Douglass, D.B. Considine, J.B. Kumer, A.E. Roche, J.W. Waters, J.M. Russell, J.C. Gille, "A test of the partitioning between ClO and ClONO₂ using simultaneous UARS measurements of ClO, NO₂ and ClONO₂", vol 101, num D7, pgs. 12,515-12,521, 1996. Reprint
6. Jucks, K.W., D.G. Johnson, K.V. Chance, W.A. Traub, R.J. Salawitch, R.A. Stachnik, "Ozone Production and loss rate measurements in the middle stratosphere", vol 101, num D22, pgs. 28,785-28,792, 1996. Reprint
7. Santee, M.L., L. Froidevaux, G.L. Manney, W.G. Read, J.W. Waters, M.P. Chipperfield, A.E. Roche, J.B. Kumer, J.L. Mergenthaler, J.M. Russell, "Chlorine deactivation in the lower stratospheric polar regions during late winter: Results from UARS", vol 101, num D13, pgs. 18,835-18,859, 1996. Reprint
8. Santee, M.L., G.L. Manney, W.G. Read, L. Froidevaux, J.W. Waters, "Polar vortex conditions during the 1995-96 Arctic winter: MLS ClO and HNO₃", vol 23, pgs. 3207-3210, 1996. Reprint
9. Schoeberl, M.R., A.R. Douglass, S.R. Kawa, A.E. Dessler, P.A. Newman, R.S. Stolarski, A.E. Roche, J.W. Waters, J.M. Russell, "The development of the Antarctic ozone hole", vol 101, num D15, pgs. 20,909-20,924, 1996. Reprint
10. Waters, J.W., W.G. Read, L. Froidevaux, T.A. Lungu, V.S. Perun, R.A. Stachnik, R.F. Jarnot, R.E. Cofield, E.F. Fishbein, D.A. Flower, J.R. Burke, J.C. Hardy, L.L. Nakamura, B.P. Ridenoure, Z. Shippony, R.P. Thurstans, L.M. Avallone, D.W. Toohey, R.L. de Zafra, D.T. Shindell, "Validation of UARS Microwave Limb Sounder ClO measurements", vol 101, num D6, pgs. 10,091-10,127, 1996. Reprint

1995

1. Crewell, S., R. Fabian, K. Kunzi, H. Nett, T. Wehr, W. Read, J. Waters, "Comparison of ClO measurements made by airborne and spaceborne microwave radiometers in the Arctic winter stratosphere 1993", vol 22, pgs. 1489-1492, 1995. Reprint
2. Dessler, A.E., D.B. Considine, G.A. Morris, M.R. Schoeberl, A.E. Roche, J. Mergenthaler, J.M. Russell, J.W. Waters, J. Gille, G.K. Yue, "Correlated observations of HCl and ClONO₂ from UARS and implications for stratospheric chlorine partitioning", vol 22, pgs. 1721-1724, 1995. Reprint
3. Douglass, A.R., M.R. Schoeberl, R.S. Stolarski, J.W. Waters, J.M. Russell, A.E. Roche, "Interhemispheric differences in springtime production of HCl and ClONO₂ in the polar vortices", vol 100, num D7, pgs. 13,967-13,978, 1995. Reprint
4. Eckman, R.S., W.L. Grose, R.E. Turner, W.T. Blackshear, J.M. Russell, L. Froidevaux, J.W. Waters, J.B. Kumer, A.E. Roche, "Stratospheric trace constituents simulated by a three-dimensional general circulation model: Comparison with UARS data", vol 100, num D7, pgs. 13,951-13,966, 1995. Reprint
5. Fahey, D.W., G. Braathen, D. Cariolle, Y. Kondo, W.A. Matthews, M.J. Molina, J.A. Pyle, R.B. Rood, J.M. Russell, U. Schmidt, D.W. Toohey, J.W. Waters, C.R. Webster, S.C. Wofsy, "Polar Ozone", vol 1994, num ch.4, 1995.
6. Geller, M.A., V. Yudin, A.R. Douglass, J.W. Waters, L.S. Elson, A.E. Roche, J.M. Russell, "UARS PSC, ClONO₂, HCl, and ClO measurements in early winter: Additional verification of the paradigm for chlorine activation", vol 22, pgs. 2937-2940, 1995. Reprint
7. Johnson, D.G., W. Traub, K. Chance, K. Jucks, R.A. Stachnik, "Estimating the abundance of ClO from simultaneous remote sensing measurements of stratospheric HO_x, NO_x and Cl_x", vol 22, pgs. 1869-1871, 1995. Reprint
8. Manney, G.L., R.W. Zurek, L. Froidevaux, J.W. Waters, "Evidence for arctic ozone depletion in late February and early March 1994", vol 22, pgs. 2941-2944, 1995. Reprint
9. Pyle, J.A., M.P. Chipperfield, I. Kilbane-Dawe, A.M. Lee, R.M. Stimpfle, D. Kohn, W. Renger, J.W. Waters, "Early modelling results from the SESAME and ASHOE campaigns", vol 100, pgs. 371-387, 1995.
10. Ricaud, P.D., E.S. Carr, R.S. Harwood, W.A. Lahoz, L. Froidevaux, W.G. Read, J.W. Waters, J.L. Mergenthaler, J.B. Kumer, A.E. Roche, G.E. Peckham, "Polar stratospheric clouds as deduced from MLS and CLAES measurements", vol 22, pgs. 2033-2036, 1995. Reprint
11. Santee, M.L., W.G. Read, J.W. Waters, L. Froidevaux, G.L. Manney, D.A. Flower, R.F. Jarnot, R.S. Harwood, G.E. Peckham, "Interhemispheric differences in polar stratospheric HNO3, H2O, ClO and O3", vol 267, pgs. 849-852, 1995. Reprint
12. Waters, J.W., G.L. Manney, W.G. Read, L. Froidevaux, D.A. Flower, R.F. Jarnot, "UARS MLS observations of lower stratospheric ClO in the 1992-93 and 1993-94 arctic winter vortices", vol 22, pgs. 823-826, 1995. Reprint

1994

1. Bell, W., N.A. Martin, T.D. Gardiner, N.R. Swann, P.T. Woods, P.F. Fogal, J.W. Waters, "Column measurements of stratospheric trace species over Are, Sweden in the winter of 1991-1992", vol 21, pgs. 1347-1350, 1994. Reprint
2. Lefevre, F., G.P. Brasseur, I. Folkins, A.K. Smith, P. Simon, "Chemistry of the 1991-1992 stratospheric winter: Three-dimensional model simulations", vol 99, num D4, pgs. 8183-8195, 1994. Reprint
3. Manney, G.L., L. Froidevaux, J.W. Waters, R.W. Zurek, W.G. Read, L.S. Elson, J.B. Kumer, J.L. Mergenthaler, A.E. Roche, A. O'Neill, R.S. Harwood, I. MacKenzie, R. Swinbank, "Chemical depletion of ozone in the Arctic lower stratosphere during winter 1992-93", vol 370, pgs. 429-434, 1994. Reprint
4. Oh, J.J., E.A. Cohen, "Pressure broadening of ClO by N2 and O2 near 204 and 649 GHz and new frequency measurements between 632 and 725 GHz", vol 54, pgs. 151-156, 1994.

1993

1. Chipperfield, M., "Satellite maps ozone destroyer", vol 362, pgs. 592-593, 1993. Reprint
2. Douglass, A., R. Rood, J. Waters, L. Froidevaux, W. Read, L. Elson, M. Geller, Y. Chi, M. Cerniglia, S. Steenrod, "A 3D simulation of the early winter distribution of reactive chlorine in the north polar vortex", vol 20, pgs. 1271-1274, 1993. Reprint
3. Geller, M.A., Y. Chi, R.B. Rood, A.R. Douglass, D.R. Allen, M. Cerniglia, J.W. Waters, "3-D transport-chemistry studies of the stratosphere using satellite data together with data assimilation", 1993.
4. Schoeberl, M.R., R.S. Stolarski, A.R. Douglass, P.A. Newman, L.R. Lait, J.W. Waters, L. Froidevaux, W.G. Read, "MLS ClO observations and arctic polar vortex temperatures", vol 20, pgs. 2861-2864, 1993. Reprint
5. Waters, J.W., L. Froidevaux, W.G. Read, G.L. Manney, L.S. Elson, D.A. Flower, R.F. Jarnot, R.S. Harwood, "Stratospheric ClO and ozone from the Microwave Limb Sounder on the Upper Atmosphere Research Satellite", vol 362, pgs. 597-602, 1993. Reprint
6. Waters, J.W., L. Froidevaux, G.L. Manney, W.G. Read, L.S. Elson, "Lower stratospheric ClO and O₃ in the 1992 southern hemisphere winter", vol 20, pgs. 1219-1222, 1993. Reprint
7. Waters, J.W., "The chlorine threat to stratospheric ozone", vol LVI, pgs. 2-13, 1993.

1992

1. Stachnik, R.A., J.C. Hardy, J.A. Tarsala, J.W. Waters, N.R. Erickson, "Submillimeterwave heterodyne measurements of stratospheric ClO, HCl, O₃, and HO₂: First results", vol 19, pgs. 1931-1934, 1992. Reprint

1988

1. Waters, J.W., R.A. Stachnik, J.C. Hardy, R.F. Jarnot, "ClO and O3 stratospheric profiles: Balloon microwave measurements", vol 15, pgs. 780-783, 1988. Reprint

1981

1. Pickett, H.M., D.E. Brinza, E.A. Cohen, "Pressure broadening of ClO by nitrogen", vol 86, pgs. 7279-7282, 1981. Reprint
2. Waters, J.W., J.C. Hardy, R.F. Jarnot, H.M. Pickett, "Chlorine monoxide radical, ozone, and hydrogen peroxide: Stratospheric measurements by microwave limb sounding", vol 214, pgs. 61-64, 1981. Reprint

1979

1. Waters, J.W., J.J. Gustincic, R.K. Kakar, H.K. Roscoe, P.N. Swanson, T.G. Phillips, T. DeGraauw, A.R. Kerr, R.J. Mattauch, "Aircraft search for millimeter wavelength emission by stratospheric ClO", vol 84, pgs. 7034-7040, 1979. Reprint

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