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Michelle Santee

Photo of Michelle Santee


4800 Oak Grove Drive
M/S 183-701

Pasadena, CA 91109





Member of:

Stratosphere And Upper Troposphere

Group Supervisor


  • B.S. Mechanical and Aerospace Engineering, Cornell University (1982)
  • M.S. Aerospace Engineering, University of Texas at Austin (1984)
  • M.S. Planetary Science, California Institute of Technology (1989)
  • Ph.D. Planetary Science, California Institute of Technology (1993)

Professional Experience

  • Jet Propulsion Laboratory
    • Supervisor, Stratosphere and Upper Troposphere Group (2014-present)
    • Manager, Earth Atmospheric Science Section (2009-2014)
    • Supervisor, Microwave Atmospheric Science Group (2006-2009)
    • Research Scientist/Principal Scientist/Senior Research Scientist (1994-present)

Research Interests

  • Processes controlling trace gas distributions in the upper troposphere / lower stratosphere (UTLS), such as volcanic injections, convective (including pyro-convective) transport of boundary-layer pollutants, and stratosphere-troposphere exchange
  • The impact of the summer monsoons on UTLS composition
  • Lower stratospheric polar processes such as chlorine activation and deactivation, polar stratospheric cloud formation, denitrification and dehydration, and chemical ozone loss 
  • Stratospheric and mesospheric effects of solar energetic particle precipitation

Selected Publications

  1. Millán, L.F., M.L. Santee, A. Lambert, N.J. Livesey, F. Werner, M.J. Schwartz, H.C. Pumphrey, G.L. Manney, Y. Wang, H. Su, L. Wu, W.G. Read, and L. Froidevaux, The Hunga Tonga-Hunga Ha’apai hydration of the stratosphere, Geophys. Res. Lett., 49, e2022GL099381, doi:10.1029/2022GL099381, 2022.
  2. Pan, L., D. Kinnison, Q. Liang, M. Chin, M.L. Santee, J. Flemming, W. Smith, S. Honomichl, J. Bresch, L.R. Lait, Y. Zhu, S. Tilmes, P. Colarco, J. Warner, A. Vuvan, C. Clerbaux, E. Atlas, P. Newman, T. Thornberry, W. Randel, and O.B. Toon, A Multi-Model Investigation of Asian Summer Monsoon UTLS Transport over the Western Pacific, J. Geophys. Res. Atmos., 127, 2022.
  3. Konopka, P., M. Tao, F. Ploeger, D.F. Hurst, M.L. Santee, J.S. Wright, and M. Riese, Stratospheric moistening after 2000, Geophys. Res. Lett., 49, e2021GL097609, doi:10.1029/2021GL097609, 2022.
  4. Manney, G.L., A.H. Butler, Z.D. Lawrence, K. Wargan, and M.L. Santee, What’s in a name? On the use and significance of the term “polar vortex”, Geophys. Res. Lett., 49, e2021GL097617, doi:10.1029/2021GL097617, 2022.
  5. Manney, G.L., L.F. Millán, M.L. Santee, K. Wargan, A. Lambert, J.L. Neu, F. Werner, Z.D. Lawrence, M.J. Schwartz, N.J. Livesey, W.G. Read, Signatures of anomalous transport in the 2019/2020 Arctic stratospheric polar vortex, J. Geophys. Res. Atmos., 127, e2022JD037407, doi:10.1029/2022JD037407, 2022.
  6. Mironova, I., M. Sinnhuber, G. Bazilevskaya, M. Clilverd, B. Funke, V. Makhmutov, E. Rozanov, M.L. Santee, T. Sukhodolov, and T. Ulich, Exceptional middle latitude electron precipitation detected by balloon observations, Atmos. Chem. Phys., 22, 6703–6716, doi:10.5194/acp-22-6703-2022, 2022.
  7. Santee, M.L., A. Lambert, G.L. Manney, N.J. Livesey, L. Froidevaux, J.L. Neu, M.J. Schwartz, L.F. Millán, F. Werner, W.G. Read, M. Park, R.A. Fuller, and B.M. Ward, Prolonged and Pervasive Perturbations in the Composition of the Southern Hemisphere Midlatitude Lower Stratosphere From the Australian New Year’s Fires, Geophys. Res. Lett., 49, e2021GL096270, doi:10.1029/2021GL096270, 2022.
  8. Dhomse, S.S., M.P. Chipperfield, W. Feng, R. Hossaini, G.W. Mann, M.L. Santee, and M. Weber, A single-peak-structured solar cycle signal in stratospheric ozone based on Microwave Limb Sounder observations and model simulations, Atmos. Chem. Phys., 22, 903–916, doi:10.5194/acp-22-903-2022, 2022.
  9. Froidevaux, L., D.E. Kinnison, M.L. Santee, L.F. Millán, N.J. Livesey, W.G. Read, C.G. Bardeen, J.J. Orlando, and R.A. Fuller, Upper stratospheric ClO and HOCl trends (2005–2020): Aura Microwave Limb Sounder and model results, Atmos. Chem. Phys., 22, 4779–4799, doi:/10.5194/acp-22-4779-2022, 2022.
  10. Feng, W., S.S. Dhomse, C. Arosio, M. Weber, J.P. Burrows, M.L. Santee, and M.P. Chipperfield, Arctic ozone depletion in 2019/20: Roles of chemistry, dynamics and the Montreal Protocol, Geophys. Res. Lett., 48, e2020GL091911, doi:10.1029/2020GL091911, 2021.
  11. Livesey, N.J., W.G. Read, L. Froidevaux, A. Lambert, M.L. Santee, M.J. Schwartz, L.F. Millán, R.F. Jarnot, P.A. Wagner, D. Hurst, K.A. Walker, P.E. Sheese, and G.E. Nedoluha, Investigation and amelioration of long-term instrumental drifts in water vapor and nitrous oxide measurements from the Aura Microwave Limb Sounder (MLS) and their implications for studies of variability and trends, Atmos. Chem. Phys., 21, 15409–15430, doi:10.5194/acp-21-15409-2021, 2021.
  12. Manney, G.L., M.L. Santee, Z.D. Lawrence, K. Wargan, M.J. Schwartz, A Moments View of Climatology and Variability of the Asian Summer Monsoon Anticyclone, J. Clim., 34, 7821–7841, doi:10.1175/JCLI-D-20-0729.1, 2021.
  13. Park, M., H.M. Worden, B. Gaubert, S. Tilmes, L.K. Emmons, M.L. Santee, L. Froidevaux, D.E. Kinnison, and C.D. Boone, Fate of pollution emitted during the 2015 Indonesian Fire Season, J. Geophys. Res. Atmos., 126, e2020JD033474, doi:10.1029/2020JD033474, 2021.
  14. Pumphrey, H.C., M.J. Schwartz, M.L. Santee, G.P. Kablick, M.D. Fromm, and N.J. Livesey, Stratospheric pollution from Canadian forest fires, Atmos. Chem. Phys., 21, 16645–16659, doi:10.5194/acp-21-16645-2021, 2021.
  15. Werner, F., N.J. Livesey, M.J. Schwartz, W.G. Read, M.L. Santee, and G. Wind, Improved cloud detection for the Aura Microwave Limb Sounder (MLS): training an artificial neural network on colocated MLS and Aqua MODIS data, Atmos. Meas. Tech., 14, 7749–7773, doi:10.5194/amt-14-7749-2021, 2021.
  16. Manney, G.L., N.J. Livesey, M.L. Santee, L. Froidevaux, A. Lambert, Z.D Lawrence, L.F Millán, J.L. Neu, W.G. Read, M.J. Schwartz, and R.A. Fuller, Record-low Arctic stratospheric ozone in 2020: MLS observations of chemical processes and comparisons with previous extreme winters, Geophys. Res. Lett., 47, e2020GL089063, doi:10.1029/2020GL089063, 2020.
  17. Schwartz, M.J., M.L. Santee, H.C. Pumphrey, G.L. Manney, A. Lambert, N.J. Livesey, L. Millán, J.L. Neu, W.G. Read, and F. Werner, Australian New Year’s pyroCb impact on stratospheric composition, Geophys. Res. Lett., 47, e2020GL090831, doi:10.1002/2020GL090831, 2020.
  18. Werner, F., M.J. Schwartz, N.J. Livesey, W.J. Read, and M.L. Santee, Extreme outliers in lower stratospheric water vapor over North America observed by MLS: Relation to overshooting convection diagnosed from colocated Aqua-MODIS data, Geophys. Res. Lett., 47, e2020GL090131, doi:10.1002/2020GL090131, 2020.
  19. Diallo, M., P. Konopka, M.L. Santee, R. Müller, M. Tao, K.A. Walker, B. Legras, M. Riese, M. Ern, and F. Ploeger, Structural changes in the shallow and transition branch of the Brewer-Dobson circulation induced by El Niño, Atmos. Chem. Phys., 19, 425-446, doi:10.5194/acp-19-425-2019, 2019.
  20. Johansson, S., M.L. Santee, J.-U. Grooß, M. Höpfner, M. Braun, F. Friedl-Vallon, F. Khosrawi, O. Kirner, E. Kretschmer, H. Oelhaf, J. Orphal, B.-M. Sinnhuber, I. Tritscher, J. Ungermann, K.A. Walker, and W. Woiwode, Unusual chlorine partitioning in the 2015/16 Arctic winter lowermost stratosphere: Observations and simulations, Atmos. Chem. Phys., 8311-8338, doi:10.5194/acp-19-8311-2019, 2019.
  21. Chipperfield, M.P., S. Dhomse, R. Hossaini, W. Feng, M.L. Santee, M. Weber, J.P. Burrows, J.D. Wild, D. Layola, M. Coldewey-Egbers, On the Cause of Recent Variations in Lower Stratospheric Ozone, Geophys. Res. Lett., 45, 5718-5726, doi:10.1029/2018GL078071, 2018.
  22. Diallo, M., M. Riese, T. Birner, P. Konopka, R. Müller, M.I. Hegglin, M.L. Santee, M. Baldwin, B. Legras, and F. Ploeger, Response of stratospheric water vapor and ozone to the unusual timing of El Niño and the QBO disruption in 2015-2016, Atmos. Chem. Phys., 18, 13055-13073, doi:10.5194/acp-18-13055-2018, 2018.
  23. Millán, L., N.J. Livesey, ,M.L. Santee, T. von Clarmann, Characterizing sampling and quality screening biases in infrared and microwave limb sounding, Atmos. Chem. Phys., 18, 4187-4199, doi:10.5194/acp-18-4187-2018, 2018.
  24. Yan, X., P. Konopka, F. Ploeger, M. Tao, R. Müller, M.L. Santee, J. Bian, and M. Riese, El Niño Southern Oscillation influence on the Asian summer monsoon anticyclone, Atmos. Chem. Phys., 18, 8079-8096, doi:10.5194/acp-18-8079-2018, 2018.
  25. Lambert, A. and M.L. Santee, Accuracy and precision of lower stratospheric polar reanalysis temperatures evaluated from A-Train CALIOP and MLS, COSMIC GPS RO, and the equilibrium thermodynamics of super-cooled ternary solutions and ice clouds, Atmos. Chem. Phys., doi:10.5194/acp-18-1945-2018, 1945-1975, 2018.
  26. M.L. Santee, G.L. Manney, N.J. Livesey, M.J. Schwartz, J.L. Neu, and W.G. Read, A comprehensive overview of the climatological composition of the Asian summer monsoon anticyclone based on 10 years of Aura Microwave Limb Sounder measurements, J. Geophys. Res. Atmos., 122, 5491-5514, doi:10.1002/2016JD026408, 2017.
  27. Manney, G.L., M.I. Hegglin, Z.D. Lawrence, K. Wargan, L.F. Millan, M.J. Schwartz, M.L. Santee, A. Lambert, S. Pawson, B.W. Knosp, R.A. Fuller, and W.H. Daffer, Reanalysis comparisons of upper tropospheric-lower stratospheric jets and multiple tropopauses, Atmos. Chem. Phys., 17, doi:10.5194/acp-17-11541-2017, 11541-11566, 2017.
  28. Lambert, A., M.L. Santee, and N.J. Livesey, Interannual variations of early winter Antarctic polar stratospheric cloud formation and nitric acid observed by CALIOP and MLS, Atmos. Chem. Phys., 16, 15,219-15,246, doi:10.5194/acp-16-15219-2016, 2016.
  29. Millan, L., N.J. Livesey, M.L. Santee, J.L. Neu, G.L. Manney, and R.A. Fuller, Case studies of the impact of orbital sampling on stratospheric trend detection and derivation of tropical vertical velocities: Solar occultation versus limb emission sounding, Atmos. Chem. Phys., 16, doi:10.5194/acp-16-11521-2016, 11,521-11,534, 2016.
  30. Nedoluha, G.E., B.J. Connor, T. Mooney, J.W. Barrett, A. Parrish, R.M. Gomez, I. Boyd, D.R. Allen, M. Kotkamp, S. Kremser, T. Deshler, P. Newman, and M.L. Santee, 20 years of ClO measurements in the Antarctic lower stratosphere, Atmos. Chem. Phys., 16, 10,725-10,734, doi:10.5194/acp-16-10725-2016, 2016.
  31. Damiani, A., B. Funke, M. Lopez Puertas, M.L. Santee, R.R. Cordero, and S. Watanabe, Energetic particle precipitation: A major driver of the ozone budget in the Antarctic upper stratosphere, Geophys. Res. Lett., 43, 3554–3562, doi:10.1002/2016GL068279, 2016.
  32. Dhomse, S.S., M.P. Chipperfield, W. Feng, R. Hossaini, G.W. Mann, and M.L. Santee, Revisiting the hemispheric asymmetry in mid-latitude ozone changes following the Mount Pinatubo eruption: A 3-D model study, Geophys. Res. Lett., 42, doi:10.1002/2015GL063052, 2015.
  33. Lawrence, Z.D., G.L. Manney, K. Minschwaner, M.L. Santee, and A. Lambert, Comparisons of polar processing diagnostics from 34 years of the ERA-Interim and MERRA reanalyses, Atmos. Chem. Phys., 15, 3873–3892, 2015.
  34. Livesey, N.J., M.L. Santee, and G.L. Manney, A Match-based approach to the estimation of polar stratospheric ozone loss using Aura Microwave Limb Sounder observations, Atmos. Chem. Phys., 15, 9945–9963, 2015.
  35. Manney, G.L., Z.D. Lawrence, M.L. Santee, N.J. Livesey, A. Lambert, and M.C. Pitts, Polar processing in a split vortex: Arctic ozone loss in early winter 2012/2013, Atmos. Chem. Phys., 15, 5381–5403, 2015.
  36. Manney, G.L., Z.D. Lawrence, M.L. Santee, W.G. Read, N.J. Livesey, A. Lambert, L. Froidevaux, H.C. Pumphrey, and M.J. Schwartz, A minor sudden stratospheric warming with a major impact: Transport and polar processing in the 2014/2015 Arctic winter, Geophys. Res. Lett., 42, doi:10.1002/2015GL065864, 2015.
  37. Neu, J., T. Flury, G.L. Manney, M.L. Santee, N.J. Livesey, J. Worden, Tropospheric ozone variations governed by changes in the stratospheric circulation, Nature Geosci., 7, 340–344, 2014.
  38. Manney, G.L., M.I. Hegglin, W.H. Daffer, M.J. Schwartz, M.L. Santee, and S. Pawson, Climatology of Upper Tropospheric/Lower Stratospheric (UTLS) Jets and Tropopauses in MERRA, J. Clim., 27, 3248–3271, doi:10.1175/JCLI-D-13-00243.1, 2014.
  39. Santee, M.L., N.J. Livesey, G.L. Manney, A. Lambert, and W.G. Read, Methyl chloride from the Aura Microwave Limb Sounder: First global climatology and assessment of variability in the upper troposphere and stratosphere, J. Geophys. Res. Atmos., 118, doi:10.1002/2013JD020235, 2013.
  40. Schwartz, M.J., W.G. Read, M.L. Santee, N.J. Livesey, L. Froidevaux, A. Lambert, and G.L. Manney, Convectively injected water vapor in the North American summer lowermost stratosphere, Geophys. Res. Lett., 40, 2316-2321, doi:10.1002/grl.50421, 2013.
  41. Wohltmann, I., T. Wegner, R. Mu¨ller, R. Lehmann, M. Rex, G.L. Manney, M.L. Santee, P. Bernath, O. Suminska-Ebersoldt, F. Stroh, M. von Hobe, C.M. Volk, and E. Hosen, Uncertainties in modeling heterogeneous chemistry and Arctic ozone depletion in the winter 2009/2010, Atmos. Chem. Phys., 13, 3909-3929, 2013.
  42. Brakebusch, M., C.E. Randall, D.E. Kinnison, S. Tilmes, M.L. Santee, and G.L. Manney, Evaluation of Whole Atmosphere Community Climate Model simulations of ozone during Arctic winter 2004-2005, J. Geophys. Res., 118, 2673-2688, doi:10.1002/jgrd.50226, 2013.
  43. Wang, S., K.-F. Li, T.J. Pongetti, S.P. Sander, Y.L. Yung, M.-C. Liang, N.J Livesey, M.L. Santee, J.W. Harder, M. Snow, F.P. Mills, Midlatitude atmospheric OH response to the most recent 11-y solar cycle, PNAS, 110, 2023-2028, 2013.
  44. Livesey, N.J., J.A. Logan, M.L. Santee, J.W. Waters, R.M. Doherty, W.G. Read, L. Froidevaux, and J.H. Jiang, Interrelated variations of O3, CO and deep convection in the tropical/subtropical upper troposphere observed by the Aura Microwave Limb Sounder (MLS) during 2004-2011, Atmos. Chem. Phys., 13, 579- 598, 2013.
  45. Lambert, A., M.L. Santee, D.L. Wu, and J.H. Chae, A-train CALIOP and MLS observations of early winter Antarctic polar stratospheric clouds and nitric acid in 2008, Atmos. Chem. Phys., 12, 2899-2931, 2012.
  46. Manney, G.L., M.L. Santee, M. Rex, N.J. Livesey, M.C. Pitts, P. Veefkind, E.R. Nash, I. Wohltmann, R. Lehmann, L. Froidevaux, L.R. Poole, M.R. Schoeberl, D.P. Haffner, J. Davies, V. Dorokhov, H. Gernandt, B. Johnson, R. Kivi, E. Kyro¨, N. Larsen, P.F. Levelt, A. Makshtas, C.T. McElroy, H. Nakajima, M.C. Parrondo, D.W. Tarasick, P. von der Gathen, K.A. Walker, and N.S. Zinoviev, Unprecedented Arctic ozone loss in 2011, Nature, 478, 469-475, doi:10.1038/nature10556, 2011.
  47. Santee, M.L., G.L. Manney, N.J. Livesey, L. Froidevaux, M.J. Schwartz, and W.G. Read, Trace gas evolution in the lowermost stratosphere from Aura Microwave Limb Sounder measurements, J. Geophys. Res., 116, D18306, doi:10.1029/2011JD015590, 2011.
  48. Manney, G.L., M.I. Hegglin, W.H. Daffer, M.L. Santee, E.A. Ray, S. Pawson, M.J. Schwartz, C.D. Boone, L. Froidevaux, N.J. Livesey, W.G. Read, and K.A. Walker, Jet characterization in the upper troposphere/lower stratosphere (UTLS): Applications to climatology and transport studies, Atmos. Chem. Phys., 11, 6115- 6137, 2011.
  49. Pumphrey, H.C., M.L. Santee, N.J. Livesey, M.J. Schwartz, and W.G. Read, Microwave Limb Sounder observations of biomass-burning products from the Australian bush fires of February 2009, Atmos. Chem. Phys., 11, 6285-6296, 2011.
  50. Santee, M.L., S.P. Sander, N.J. Livesey, and L. Froidevaux, Constraining the chlorine monoxide (ClO)/chlorine peroxide (ClOOCl) equilibrium constant from Aura Microwave Limb Sounder measurements of nighttime ClO, PNAS, 107, 6588-6593, 2010.
  51. 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, and J.W. Waters, A study of stratospheric chlorine partitioning based on new satellite measurements and modeling, J. Geophys. Res., 113, D12307, doi:10.1029/2007JD009057, 2008.
  52. Santee, M.L., et al., Validation of the Aura Microwave Limb Sounder ClO measurements, J. Geophys. Res., 113, D15S22, doi:10.1029/2007JD008762, 2008.
  53. Santee, M.L., et al., Validation of the Aura Microwave Limb Sounder HNO3 measurements, J. Geophys. Res., 112, D24S40, doi:10.1029/2007JD008721, 2007.