MLS Research

Air Pollution in the Upper Troposphere

Contact Nathaniel Livesey

MLS observations of ozone (O3) and carbon monoxide (CO) provide important information on the chemical and transport processes affecting air pollution in the upper troposphere (~10-15km altitude).

CO is a byproduct of combustion associated with both vehicles and industry and with forest fires and domestic fires using for cooking and heating. CO is also produced when other organic molecules in the atmoshpere break down. CO has a lifetime of about a month in the upper troposphere, making it a good marker of recently polluted air.

O3 forms down wind of pollution sources, and is the result of the reaction of 'NOx' species (typically emitted from industry and cars, or formed in lightning flashes) with breakdown products from organic species (emitted from industrial and natural sources).

Ozone is an important contributor to poor air quality and has a strong daily cycle in the lowest ~2km of the atmosphere. However, its chemical lifetime can be over a month once it is transported to higher altitudes. Descent of ozone-rich air from the stratosphere can increase tropospheric ozone. MLS also measures nitric acid (HNO3) in the upper troposphere, giving information on 'NOx' pollution for which it is an end product.

Improvements of weather forecast and climate change predictions require extensive evaluation of model simulations by comparison with global satellite observations. The Aura MLS measurements of water vapor, clouds and other tracer gases provide a unique opportunity to evaluate model performance in the upper troposphere (~8-15km altitude) and to improve model parameterizations of key processes such as convection.

MLS-related publications concerning air pollution in the upper troposphere

  1. Rawat, P., M. Naja, E. Fishbein, P. Thapliyal, R. Kumar, P. Bhardwaj, A. Jaiswal, S. Tiwari, S. Venkataramani and S. Lal
    Performance of AIRS ozone retrieval over the central Himalayas: Case studies of biomass burning, downward ozone transport and radiative forcing using long-term observations
    Atmospheric Measurement Techniques Discussions doi:10.5194/amt-2022-187, in review
  2. Vogel, A., J. Ungermann and H. Elbern
    Analyzing trace gas filaments in the Ex-UTLS by 4D-variationalassimilation of airborne tomographic retrievals
    Atmos. Chem. Phys. Discuss. doi:10.5194/acp-2017-308, in review
  3. Liang, Z., F. Zhu, T. Liang, F. Luo and J. Luo
    Spatiotemporal Distribution of CO in the UTLS Region in the Asian Summer Monsoon Season: Analysis of MLS Observations and CMIP6 Simulations
    Remote Sens. doi:10.3390/rs15020367, 2023
  4. Roy, C., A.R. Ravishankara, P. Newman, L. David, S. Fadnavis, S. Rathod, L. Lait, R. Krishnan, H. Clark and B. Sauvage
    Estimation of Stratospheric Intrusions During Indian Cyclones
    Journal of Geophysical Research: Atmospheres doi:10.1029/2022jd037519, 2023
  5. Solomon, S., K. Stone, P. Yu, D.M. Murphy, D. Kinnison, A.R. Ravishankara and P. Wang
    Chlorine activation and enhanced ozone depletion induced by wildfire aerosol
  6. Wang, P., S. Solomon and K. Stone
    Stratospheric chlorine processing after the 2020 Australian wildfires derived from satellite data
    Proc. Nat. Acad. Sci. doi:10.1073/pnas.2213910120, 2023
  7. Blunden, J. and T. Boyer
    State of the Climate in 2021
    Bull. Am. Meteorol. Soc. doi:10.1175/2022bamsstateoftheclimate.1, 2022
  8. Daskalakis, N., L. Gallardo, M. Kanakidou, J. Nüß, C. Menares, R. Rondanelli, A. Thompson and M. Vrekoussis
    Impact of biomass burning and stratospheric intrusions in the remote South Pacific Ocean troposphere
    Atmos. Chem. Phys. 10.5194/acp-22-4075-2022, 2022
  9. Fazel-Rastgar, F. and V. Sivakumar
    A severe weather system accompanied by a stratospheric intrusion during unusual warm winter in 2015 over the South Africa: An initial synoptic analysis
    Remote Sensing Applications: Society and Environment doi:10.1016/j.rsase.2022.100833, 2022
  10. Fujiwara, M., G.L. Manney, L.J. Gray and J.S. Wright
    SPARC Reanalysis Intercomparison Project S-RIP Final Report
    n/a 2022
  11. Kumar, A.H., M.V. Ratnam and C. Jain
    Influence of background dynamics on the vertical distribution of trace gases CO/WV/O3 in the UTLS region during COVID-19 lockdown over India
  12. Li, D., J. Bian, X. Zhang, B. Vogel, R. Müller and G. Günther
    Impact of typhoon Soudelor on ozone and water vapor in the Asian monsoon anticyclone western Pacific mode
    Atmospheric Science Letters doi:10.1002/asl.1147, 2022
  13. Martinsson, B., J. Friberg, O. Sandvik and M. Sporre
    Five-satellite-sensor study of the rapid decline of wildfire smoke in the stratosphere
    Atmos. Chem. Phys. 10.5194/acp-22-3967-2022, 2022
  14. Pan, L., D. Kinnison, Q. Liang, M. Chin, M. Santee, J. Flemming, W. Smith, S. Honomichl, J. Bresch, L. Lait, Y. Zhu, S. Tilmes, P. Colarco, J. Warner, A. Vuvan, C. Clerbaux, E. Atlas, P. Newman, T. Thornberry, W. Randel and O. Toon
    A Multimodel Investigation of Asian Summer Monsoon UTLS Transport Over the Western Pacific
    Journal of Geophysical Research: Atmospheres doi:10.1029/2022jd037511, 2022
  15. Peng, K., J. Luo, J. Mu, X. Cao, H. Tian, L. Shang and Y. Guo
    Impact of intensity variability of the Asian summer monsoon anticyclone on the chemical distribution in the upper troposphere and lower stratosphere
    Atmospheric and Oceanic Science Letters 10.1016/j.aosl.2021.100144, 2022
  16. Qie, K., W. Wang, W. Tian, R. Huang, M. Xu, T. Wang and Y. Peng
    Enhanced upward motion through the troposphere over the tropical western Pacific and its implications for the transport of trace gases from the troposphere to the stratosphere
    Atmos. Chem. Phys. doi:10.5194/acp-22-4393-2022, 2022
  17. Salawitch, R. and L. McBride
    Australian wildfires depleted the ozone layer
  18. 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. doi:10.1029/2021gl096270, 2022
  19. Xiong, X., X. Liu, W. Wu, K.E. Knowland, Q. Yang, J. Welsh and D. Zhou
    Satellite observation of stratospheric intrusions and ozone transport using CrIS on SNPP
    Atmospheric Environment doi:10.1016/j.atmosenv.2022.118956, 2022
  20. Babu, S.R., M.V. Ratnam, G. Basha, S. Pani and N. Lin
    Structure, dynamics, and trace gas variability within the Asian summer monsoon anticyclone in the extreme El Niño of 2015–2016
    Atmos. Chem. Phys. doi:10.5194/acp-21-5533-2021, 2021
  21. Blunden, J. and T. Boyer
    State of the Climate in 2020
    Bull. Am. Meteorol. Soc. doi:10.1175/2021bamsstateoftheclimate.1, 2021
  22. Bossolasco, A., F. Jegou, P. Sellitto, G. Berthet, C. Kloss and B. Legras
    Global modeling studies of composition and decadal trends of the Asian Tropopause Aerosol Layer
    Atmos. Chem. Phys. doi:10.5194/acp-21-2745-2021, 2021
  23. Emmanuel, M., S.V. Sunilkumar, M. Muhsin, P.R.S. Chandran, K. Parameswaran, B.S. Kumar, A. Maitra, A.N.V. Satyanarayana and N. Nagendra
    Effect of monsoon dynamics and deep convection on the upper troposphere lower stratosphere water vapour over Indian monsoon region
  24. Fujiwara, M., T. Sakai, T. Nagai, K. Shiraishi, Y. Inai, S. Khaykin, H. Xi, T. Shibata, M. Shiotani and L. Pan
    Lower-stratospheric aerosol measurements in eastward-shedding vortices over Japan from the Asian summer monsoon anticyclone during the summer of 2018
    Atmos. Chem. Phys. doi:10.5194/acp-21-3073-2021, 2021
  25. Gharibzadeh, M., A. Bidokhti and K. Alam
    The interaction of ozone and aerosol in a semi-arid region in the Middle East: Ozone formation and radiative forcing implications
    Atmospheric Environment doi:10.1016/j.atmosenv.2020.118015, 2021
  26. He, X., J. Luo, X. Xu, L. Ren, H. Tian, L. Shang and P. Xu
    The QBO Modulation on CO Distribution in the UTLS Over the Asian Monsoon Region During Boreal Summer
    Front. Earth Sci. doi:10.3389/feart.2021.625990, 2021
  27. Jenkins, G., V.D. Castro, B. Cunha, I. Fontanez and R. Holzworth
    The Evolution of the Wave‐One Ozone Maximum During the 2017 LASIC Field Campaign at Ascension Island
    Journal of Geophysical Research: Atmospheres doi:10.1029/2020jd033972, 2021
  28. Karpowicz, B., W. McCarty and K. Wargan
    Investigating the utility of hyperspectral sounders in the 9.6 μm band to improve ozone analyses
    Q. J. Roy. Meteorol. Soc. doi:10.1002/qj.4198, 2021
  29. Kloss, C., P. Sellitto, M. von Hobe, G. Berthet, D. Smale, G. Krysztofiak, C. Xue, C. Qiu, F. Jégou, I. Ouerghemmi and B. Legras
    Australian Fires 2019–2020: Tropospheric and Stratospheric Pollution Throughout the Whole Fire Season
    Front. Environ. Sci doi:10.3389/fenvs.2021.652024, 2021
  30. Kumar, K., B. Singh and Kumar, K.
    Intriguing aspects of Asian Summer Monsoon Anticyclone Ozone variability from Microwave Limb Sounder measurements
    Atmos. Res. 10.1016/j.atmosres.2021.105479, 2021
  31. Park, M., H. Worden, D. Kinnison, B. Gaubert, S. Tilmes, L. Emmons, M. Santee, L. Froidevaux and C. Boone
    Fate of pollution emitted during the 2015 Indonesian Fire Season
    Journal of Geophysical Research: Atmospheres doi:10.1029/2020jd033474, 2021
  32. Plaza, N., A. Podglajen, C. Peña-Ortiz and F. Ploeger
    Processes influencing lower stratospheric water vapour in monsoon anticyclones: insights from Lagrangian modelling
    Atmos. Chem. Phys. doi:10.5194/acp-21-9585-2021, 2021
  33. Pumphrey, H., M. Schwartz, M. Santee, G. Kablick III, M. Fromm and N. Livesey
    Microwave Limb Sounder MLS observations of biomass burning products in the stratosphere from Canadian forest fires in August 2017
    Atmos. Chem. Phys. doi:10.5194/acp-21-16645-2021, 2021
  34. Rieger, L.A., W.J. Randel, A.E. Bourassa and S. Solomon
    Stratospheric Temperature and Ozone Anomalies Associated With the 2020 Australian New Year Fires
    Geophys. Res. Lett. doi:10.1029/2021gl095898, 2021
  35. Tang, Q., M. Prather, J. Hsu, D. Ruiz, P. Cameron-Smith, S. Xie and J. Golaz
    Evaluation of the interactive stratospheric ozone O3v2 module in the E3SM version 1 Earth system model
    Geoscientific Model Development doi:10.5194/gmd-14-1219-2021, 2021
  36. Barret, B., E. Emili and E.L. Flochmoen
    A tropopause-related climatological a priori profile for IASI-SOFRID ozone retrievals: improvements and validation
    Atmospheric Measurement Techniques doi:10.5194/amt-13-5237-2020, 2020
  37. Blunden, J. and D.S. Arndt
    State of the Climate in 2019
    Bull. Am. Meteorol. Soc. doi:10.1175/2020bamsstateoftheclimate.1, 2020
  38. Fadnavis, S., C. Sioris, N. Wagh, R. Chattopadhyay, M. Tao, P. Chavan and T. Chakroborty
    A rising trend of double tropopauses over South Asia in a warming environment: Implications for moistening of the lower stratosphere
    International Journal of Climatology doi:10.1002/joc.6677, 2020
  39. Girach, I., P. Nair, N. Ojha and L. Sahu
    Tropospheric carbon monoxide over the northern Indian Ocean during winter: influence of inter-continental transport
    Climate Dynamics doi:10.1007/s00382-020-05269-4, 2020
  40. Honomichl, S. and L. Pan
    Transport From the Asian Summer Monsoon Anticyclone Over the Western Pacific
    Journal of Geophysical Research: Atmospheres doi:10.1029/2019jd032094, 2020
  41. Itahashi, S., R. Mathur, C. Hogrefe and Y. Zhang
    Modeling stratospheric intrusion and trans-Pacific transport on tropospheric ozone using hemispheric CMAQ during April 2010 -- Part 1: Model evaluation and air mass characterization for stratosphere-troposphere transport
    Atmos. Chem. Phys. doi:10.5194/acp-20-3373-2020, 2020
  42. Miyazaki, K., K. Bowman, K. Yumimoto, T. Walker and K. Sudo
    Evaluation of a multi-model, multi-constituent assimilation framework for tropospheric chemical reanalysis
    Atmos. Chem. Phys. doi:10.5194/acp-20-931-2020, 2020
  43. Qu, Z., Y. Huang, P. Vaillancourt, J. Cole, J. Milbrandt, M. Yau, K. Walker and J.D. Grandpré
    Simulation of convective moistening of the extratropical lower stratosphere using a numerical weather prediction model
    Atmos. Chem. Phys. doi:10.5194/acp-20-2143-2020, 2020
  44. Robinson, J., A. Kotsakis, F. Santos, R. Swap, K.E. Knowland, G. Labow, V. Connors, M. Tzortziou, N. Abuhassan, M. Tiefengraber and A. Cede
    Using networked Pandora observations to capture spatiotemporal changes in total column ozone associated with stratosphere-to-troposphere transport
  45. Schoeberl, M.R., L. Pfister, T. Wang, J. Kummer, A.E. Dessler and W. Yu
    Erythemal Radiation, Column Ozone, and the North American Monsoon
    Journal of Geophysical Research: Atmospheres doi:10.1029/2019jd032283, 2020
  46. Schwartz, M., M. Santee, H. Pumphrey, G. Manney, A. Lambert, N. Livesey, L. Millán, J. Neu, W. Read and F. Werner
    Australian New Year's PyroCb Impact on Stratospheric Composition
    Geophys. Res. Lett. doi:10.1029/2020gl090831, 2020
  47. Uma, K.N., T.S. Mohan and S. Das
    Role of Intra-Seasonal Variability in the Indian Summer Monsoon on the Hydration and Dehydration of the Upper Troposphere
    Theoretical and Applied Climatology doi:10.1007/s00704-020-03243-y, 2020
  48. Werner, F., M.J. Schwartz, N.J. Livesey, W.G. 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. doi:10.1029/2020gl090131, 2020
  49. Xu, X., H. Tian, K. Qie, X. He, R. Zhang and H. Tu
    A Study on the Trend of the Upper Tropospheric Water Vapor over the Tibetan Plateau in Summer
    Asia-Pacific Journal of Atmospheric Sciences doi:10.1007/s13143-020-00191-5, 2020
  50. Yu, W., A. Dessler, M. Park and E. Jensen
    Influence of convection on stratospheric water vapor in the North American monsoon region
    Atmos. Chem. Phys. doi:10.5194/acp-20-12153-2020, 2020