Sciences and Exploration Directorate

Pawan K Bhartia


Pawan K Bhartia's Contact Card & Information.
Phone: 301.614.5731
Org Code: 610
Mail Code 614
Greenbelt, MD 20771
Employer: EMERITUS

Brief Bio

Dr. Bhartia is an internationally known expert on ultraviolet remote sensing of Earth from space. He developed the algorithms that have been used to produce ozone data from SBUV and TOMS series of instruments, and is a co-developer of the TOMS aerosol retrieval algorithm that produces unique daily global maps of smoke and dust, and can directly measure aerosol absorption from space. Algorithms and calibration techniques developed under Dr. Bhartia’s direction have been adapted by groups around the world to process data from advanced hyperspectral instruments on US and European satellites, including the OMI instrument currently flying on the EOS Aura satellite, and the OMPS instrument suite on the Suomi NPP satellite. He is currently serving as the OMPS-LP  Sensor Team Lead.


Senior Research Scientist

NASA - Mail Code 614, Goddard Space Flight Center Greenbelt, Maryland USA 20771

October 1991 - Present


Ph. D, Physics, Purdue University, W. Lafayette, IN (1977)
MS, Computer Science, Purdue University, W. Lafayette, IN (1977)


2016- Robert H. Goddard Award of Merit, NASA GSFC
2014 - Remote Sensing Prize, AMS
2013 - Distinguished Service Medal, NASA
2012- Yoram J. Kaufman Award, AGU, Atm. Sciences Section
2006 - William T. Pecora Team Award, NASA & Dept of Interior
2004 - Outstanding Leadership Medal, NASA
2003 – William Nordberg Medal, NASA GSFC
1997 – Exceptional Scientific Achievement Award, NASA GSFC



2024. "Comparison of proxy-Shortwave Cloud albedo from SBUV observations with CMIP6 models." Journal of Climate [10.1175/jcli-d-23-0170.1] [Journal Article/Letter]

2022. "Estimating Spectral Effects of Absorbing Aerosols on Backscattered UV Radiation." Earth and Space Science 9 (12): [10.1029/2022ea002354] [Journal Article/Letter]

2022. "NASA Satellite Measurements Show Global‐Scale Reductions in Free Tropospheric Ozone in 2020 and Again in 2021 During COVID‐19." Geophysical Research Letters 49 (15): [10.1029/2022gl098712] [Journal Article/Letter]

2021. "A global ozone profile climatology for satellite retrieval algorithms based on Aura MLS measurements and the MERRA-2 GMI simulation." Atmospheric Measurement Techniques 14 (10): 6407-6418 [10.5194/amt-14-6407-2021] [Journal Article/Letter]

2020. "Inter-calibration of nine UV sensing instruments over Antarctica and Greenland since 1980." Atmospheric Measurement Techniques 13 (10): 5715-5723 [10.5194/amt-13-5715-2020] [Journal Article/Letter]

2020. "OMPS LP Observations of PSC Variability During the NH 2019–2020 Season." Geophysical Research Letters 47 (20): [10.1029/2020gl090216] [Journal Article/Letter]

2020. "Evaluation of the OMPS/LP stratospheric aerosol extinction product using SAGE III/ISS observations." Atmospheric Measurement Techniques 13 (6): 3471-3485 [10.5194/amt-13-3471-2020] [Journal Article/Letter]

2020. "A Long-Term Cloud Albedo Data Record Since 1980 from UV Satellite Sensors." Remote Sensing 12 (12): 1982 [10.3390/rs12121982] [Journal Article/Letter]

2020. "Model-based Climatology of Diurnal Variability in Stratospheric Ozone as a Data Analysis Tool." Atmos. Meas. Tech. 13 2733–2749 [10.5194/amt-13-2733-2020] [Journal Article/Letter]

2020. "A comparison of lognormal and gamma size distributions for characterizing the stratospheric aerosol phase function from optical particle counter measurements." Atmospheric Measurement Techniques 13 (3): 1071-1087 [10.5194/amt-13-1071-2020] [Journal Article/Letter]

2019. "New Era of Air Quality Monitoring from Space: Geostationary Environment Monitoring Spectrometer (GEMS)." Bulletin of the American Meteorological Society 101 (1): E1-E22 [10.1175/bams-d-18-0013.1] [Journal Article/Letter]

2019. "Trends in global tropospheric ozone inferred from a composite record of TOMS/OMI/MLS/OMPS satellite measurements and the MERRA-2 GMI simulation." Atmospheric Chemistry and Physics 19 (5): 3257-3269 [10.5194/acp-19-3257-2019] [Journal Article/Letter]

2018. "Improvement of stratospheric aerosol extinction retrieval from OMPS/LP using a new aerosol model." Atmospheric Measurement Techniques 11 (12): 6495-6509 [10.5194/amt-11-6495-2018] [Journal Article/Letter]

2018. "A cloud algorithm based on the O2-O2 477 nm absorption band featuring an advanced spectral fitting method and the use of surface geometry-dependent Lambertian-equivalent reflectivity." Atmospheric Measurement Techniques 11 (7): 4093-4107 [10.5194/amt-11-4093-2018] [Journal Article/Letter]

2018. "Validation of ozone profile retrievals derived from the OMPS LP version 2.5 algorithm against correlative satellite measurements." Atmospheric Measurement Techniques 11 (5): 2837-2861 [10.5194/amt-11-2837-2018] [Journal Article/Letter]

2018. "Impact of the ozone monitoring instrument row anomaly on the long-term record of aerosol products." Atmospheric Measurement Techniques 11 (5): 2701-2715 [10.5194/amt-11-2701-2018] [Journal Article/Letter]

2018. "The Ozone Mapping and Profiler Suite (OMPS) Limb Profiler (LP) Version 1 aerosol extinction retrieval algorithm: theoretical basis." Atmospheric Measurement Techniques 11 (5): 2633-2651 [10.5194/amt-11-2633-2018] [Journal Article/Letter]

2018. "The Ozone Monitoring Instrument: overview of 14 years in space." Atmospheric Chemistry and Physics 18 (8): 5699-5745 [10.5194/acp-18-5699-2018] [Journal Article/Letter]

2018. "Satellites See the World’s Atmosphere." Meteorological Monographs 59 4.1-4.53 [10.1175/amsmonographs-d-18-0009.1] [Journal Article/Letter]

2017. "A cloud-ozone data product from Aura OMI and MLS satellite measurements." Atmospheric Measurement Techniques 10 (11): 4067-4078 [10.5194/amt-10-4067-2017] [Journal Article/Letter]

2017. "Merged SAGE II, Ozone_cci and OMPS ozone profiles dataset and evaluation of ozone trends in the stratosphere." Atmospheric Chemistry and Physics 17 12533-12552 [10.5194/acp-17-12533-2017] [Journal Article/Letter]

2017. "An update on ozone profile trends for the period 2000 to 2016." Atmospheric Chemistry and Physics 1-16 [10.5194/acp-17-10675-2017] [Journal Article/Letter]

2017. "Validation of 10-year SAO OMI Ozone Profile (PROFOZ) product using ozonesonde observations." Atmospheric Measurement Techniques 10 (7): 2455-2475 [10.5194/amt-10-2455-2017] [Journal Article/Letter]

2017. "Altitude registration of limb-scattered radiation." Atmospheric Measurement Techniques 10 (1): 167-178 [10.5194/amt-10-167-2017] [Journal Article/Letter]

2016. "Top-of-the-atmosphere shortwave flux estimation from satellite observations: an empirical neural network approach applied with data from the A-train constellation." Atmospheric Measurement Techniques 9 (7): 2813-2826 [10.5194/amt-9-2813-2016] [Journal Article/Letter]

2016. "An optimal-estimation-based aerosol retrieval algorithm using OMI near-UV observations." Atmospheric Chemistry and Physics 16 (1): 177-193 [10.5194/acp-16-177-2016] [Journal Article/Letter]

2015. "Past changes in the vertical distribution of ozone – Part 3: Analysis and interpretation of trends." Atmos. Chem. Phys. 15 (17): 9965-9982 [10.5194/acp-15-9965-2015] [Journal Article/Letter]

2015. "A total ozone-dependent ozone profile climatology based on ozonesondes and Aura MLS data." J. Geophys. Res. Atmos. 120 (6): 2537-2545 [10.1002/2014jd022634] [Journal Article/Letter]

2015. "Gauss–Seidel limb scattering (GSLS) radiative transfer model development in support of the Ozone Mapping and Profiler Suite (OMPS) limb profiler mission." Atmos. Chem. Phys. 15 (6): 3007-3020 [10.5194/acp-15-3007-2015] [Journal Article/Letter]

2014. "Recent changes in total column ozone based on the SBUV Version 8.6 Merged Ozone Data Set." J. Geophys. Res. Atmos. 119 (16): 9735–9751 [10.1002/2014JD021889] [Journal Article/Letter]

2014. "OMPS Limb Profiler instrument performance assessment." J. Geophys. Res. Atmos. 119 (7): 4399-4412 [10.1002/2013JD020482] [Journal Article/Letter]

2014. "Past changes in the vertical distribution of ozone - Part 1: Measurement techniques, uncertainties and availability." Atmos. Meas. Tech. 7 1395-1427 [10.5194/amt-7-1395-2014] [Journal Article/Letter]

2014. "Diurnal variations of stratospheric ozone measured by ground-based microwave remote sensing at the Mauna Loa NDACC site: measurement validation and GEOSCCM model comparison." Atmos. Chem. Phys. 14 7255-7272 [10.5194/acp-14-7255-2014] [Journal Article/Letter]

2014. "Comparison of profile total ozone from SBUV (v8.6) with GOME-type and ground-based total ozone for a 16-year period (1996 to 2011)." Atmos. Meas. Tech. 7 1681-1692 [10.5194/amt-7-1681-2014] [Journal Article/Letter]

2014. "Measuring the Antarctic ozone hole with the new Ozone Mapping and Profiler Suite (OMPS)." Atmos. Chem. Phys. 14 (5): 2353-2361 [10.5194/acp-14-2353-2014] [Journal Article/Letter]

2014. "Assessment and applications of NASA ozone data products derived from Aura OMI/MLS satellite measurements in context of the GMI chemical transport model." J. Geophys. Res. Atmos. 119 (9): 5671-5699 [10.1002/2013JD020914] [Journal Article/Letter]

2013. "A fast and sensitive new satellite SO2 retrieval algorithm based on principal component analysis: Application to the ozone monitoring instrument." Geophysical Research Letters 40 (23): 6314-6318 [10.1002/2013gl058134] [Journal Article/Letter]

2013. "Validation of ozone monthly zonal mean profiles obtained from the version 8.6 Solar Backscatter Ultraviolet algorithm." Atmos. Chem. Phys. 13 (14): 6887-6905 [10.5194/acp-13-6887-2013] [Journal Article/Letter]

2013. "A new stratospheric and tropospheric NO2 retrieval algorithm for nadir-viewing satellite instruments: applications to OMI." Atmospheric Measurement Techniques 6 (10): 2607-2626 [10.5194/amt-6-2607-2013] [Journal Article/Letter]

2013. "Solar Backscatter UV (SBUV) total ozone and profile algorithm." Atmos. Meas. Tech. 6 (10): 2533-2548 [10.5194/amt-6-2533-2013] [Journal Article/Letter]

2013. "Interpreting SBUV smoothing errors: an example using the quasi-biennial oscillation." Atmos. Meas. Tech. 6 (8): 2089-2099 [10.5194/amt-6-2089-2013] [Journal Article/Letter]

2013. "The version 8.6 SBUV ozone data record: An overview." J. Geophys. Res. Atmos. 118 (14): 8032–8039 [10.1002/jgrd.50597] [Journal Article/Letter]

2013. "A comparison of 40 years of SBUV measurements of column ozone with data from the Dobson/Brewer network." J. Geophys. Res. Atmos. 118 (13): 7370-7378 [10.1002/jgrd.50503] [Journal Article/Letter]

2012. "Fast simulators for satellite cloud optical centroid pressure retrievals; evaluation of OMI cloud retrievals." Atmospheric Measurement Techniques 5 (3): 529-545 [Full Text] [10.5194/amt-5-529-2012] [Journal Article/Letter]

2012. "Retrieval of Aerosol Optical Depth above Clouds from OMI Observations: Sensitivity Analysis and Case Studies." Journal of the Atmospheric Sciences 69 (3): 1037-1053 [10.1175/JAS-D-11-0130.1] [Journal Article/Letter]

2011. "A global climatology of tropospheric and stratospheric ozone derived from Aura OMI and MLS measurements." Atmos. Chem. Phys. 11 (17): 9237-9251 [10.5194/acp-11-9237-2011] [Journal Article/Letter]

2010. "A new interpretation of total column BrO during Arctic spring." Geophysical Research Letters 37 (21): L21805 [10.1029/2010GL043798] [Journal Article/Letter]

2010. "Direct retrieval of sulfur dioxide amount and altitude from spaceborne hyperspectral UV measurements: Theory and application." Journal of Geophysical Research 115 D00L09 [10.1029/2010jd013982] [Journal Article/Letter]

2010. "A study of tropospheric ozone column enhancements over North America using satellite data and a global chemical model." J. Geophys. Res. 115 D08302 [doi: 10.1029/2009JD012616] [Journal Article/Letter]

2010. "Detection of multi-layer and vertically-extended clouds using A-train sensors." Atmos Meas Tech 3 (1): 233-247 [10.5194/amt-3-233-2010] [Journal Article/Letter]

2010. "What do satellite backscatter ultraviolet and visible spectrometers see over snow and ice? A study of clouds and ozone using the A-train." Atmos Meas Tech 3 (3): 619-629 [10.5194/amt-3-619-2010] [Journal Article/Letter]

2010. "OMI and MODIS observations of the anomalous 2008–2009 Southern Hemisphere biomass burning seasons." Atmos. Chem. Phys. 10 (8): 3505-3513 [10.5194/acp-10-3505-2010] [Journal Article/Letter]

2010. "A new ENSO index derived from satellite measurements of column ozone." Atmos Chem Phys 10 3711-3721 [10.5194/acp-10-3711-2010] [Journal Article/Letter]

2010. "Temperature diurnal variations (migrating tides) in the stratosphere and lower mesosphere based on measurements from SABER on TIMED." J Geophys Res 115 (D16): D16121 [10.1029/2009JD013698] [Journal Article/Letter]

2009. "Impacts of Background Ozone Production on Houston and Dallas, TX, Air Quality during the TEXAQS Field Mission." J. Geophys. Res.-Atmos. 114 D00F09 [doi:10.1029/2008JD011337] [Journal Article/Letter]

2009. "Ozone mixing ratios inside tropical deep convective clouds from OMI satellite measurements." Atmos Chem Phys 9 573-583 [Journal Article/Letter]

2009. "Improving retrieval of volcanic sulfur dioxide from backscattered UV satellite observations." Geophysical Research Letters 36 (3): L03102 [10.1029/2008GL036036] [Journal Article/Letter]

2009. "Recent biomass burning in the tropics and related changes in tropospheric ozone." Geophysical Research Letters 36 (15): L15819 [10.1029/2009GL039303] [Journal Article/Letter]

2008. "Comparison of Ozone Monitoring Instrument UV Aerosol Products with Aqua/Moderate Resolution Imaging Spectroradiometer and Multiangle Imaging Spectroradiometer observations in 2006." J Geophy Res 113 (D16S27): [10.1029/2007JD008832] [Journal Article/Letter]

2008. "Validation of SO2 retrievals from the Ozone Monitoring Instrument over NE China." J Geophys Res 113 (D16S40, doi:101029/): [Journal Article/Letter]

2008. "Validation of the Aura Ozone Monitoring Instrument total column ozone product." J Geopohys Res 113 (D15S14, doi:101029/): [Journal Article/Letter]

2008. "Evaluation of the OMI cloud pressures derived from rotational Raman scattering by comparisons with other satellite data and radiative transfer simulations." J. Geophys. Res. 113 (D15): D15S19 [10.1029/2007JD008689] [Journal Article/Letter]

2007. "A trajectory-based estimate of the tropospheric ozone column using the residual method." Journal of Geophysical Research 112 (D24): D24S49 [10.1029/2007jd008773] [Journal Article/Letter]

2007. "Retrieval of large volcanic SO 2 columns from the Aura Ozone Monitoring Instrument: Comparison and limitations." Journal of Geophysical Research 112 (D24): D24S43 [10.1029/2007jd008825] [Journal Article/Letter]

2007. "Effects of the 2004 El Niño on tropospheric ozone and water vapor." Geophy Res Lett 34 (6): L06802 [10.1029/2006GL028779] [Journal Article/Letter]

2007. "Aerosols and Surface UV Products from OMI Observations: An Overview." J. Geophys. Res. 112 (D24): D24S47 [10.1029/2007JD008809] [Journal Article/Letter]

2007. "Intra-seasonal variability in tropospheric ozone and water vapor in the tropics." GeopHy Res Lett 34 (L17804, doi:101029/): [Journal Article/Letter]

2006. "Band Residual Difference Algorithm for Retrieval of SO2 from the Aura Ozone Monitoring Instrument (OMI)." IEEE Transactions on Geoscience and Remote Sensing 44 (5): 1259-1266 [10.1109/TGRS.2005.861932] [Journal Article/Letter]

2006. "Long-term evolution of upper stratospheric ozone at selected stations of the network for the detection of stratospheric change (NDSC)." J Geophys Res 111 D10308 [Journal Article/Letter]

2006. "Overview of the EOS Aura Mission." IEEE Trans on Geosc And Remote Sensing 44 (5): IGRSD2 1066-1074 [Journal Article/Letter]

2006. "Science objectives of the Ozone Monitoring Instrument." IEEE Trans on Geosc And Remote Sensing 44 (5): IGRSD2 1199-1208 [Journal Article/Letter]

2006. "Tropospheric ozone determined from Aura OMI and MLS: Evaluation of measurements and comparison with the Global Modeling Initiative's Chemical Transport Model." J. Geophys. Res. 111 (D19): D19303 [10.1029/2006JD007089] [Journal Article/Letter]

2006. "Observations over hurricanes from the ozone monitoring instrument." Geophysical Research Letters 33 (6): L06807 [10.1029/2005GL025592] [Journal Article/Letter]

2005. "Aerosol ultraviolet absorption experiment (2002 to 2004), part 1: ultraviolet multifilter rotating shadowband radiometer calibration and intercomparison with CIMEL sunphotometers." Opt Eng 44 (4): 041004-1 - 041004-17 [10.1117/1.1886818] [Journal Article/Letter]

2005. "Total Ozone Mapping Spectrometer measurements of aerosol absorption from space: Comparison to SAFARI 2000 ground-based observations." J. Geophys. Res. 110 (D10): D10S18 [10.1029/2004JD004611] [Journal Article/Letter]

2005. "Description and sensitivity analysis of a limb scattering ozone retrieval algorithm." J. Geophys. Res. 110 (D19): D19301 [10.1029/2004JD005429] [Journal Article/Letter]

2005. "Aerosol ultraviolet absorption experiment (2002 to 2004), part 2: absorption optical thickness, refractive index, and single scattering albedo." Opt Eng 44 (4): 041005-1 - 041005-17 [10.1117/1.1886819] [Journal Article/Letter]

2004. "Improving total column ozone retrievals using cloud pressures derived from Raman scattering in the UV." Geophys Res Lett 31 (L20109): [10.1029/2004GL020603] [Journal Article/Letter]

2004. "Spectral properties of backscattered UV radiation in cloudy atmospheres." J. Geophys. Res. 109 (D1): D01201 [10.1029/2003JD003395] [Journal Article/Letter]

2004. "Retrieval of cloud pressure and oceanic chlorophyll content using Raman scattering in GOME ultraviolet spectra." J Geophys Res 109 (D01109): [Journal Article/Letter]

2002. "A long term record of aerosol optical depth from TOMS observations and comparison to AERONET measurements." J. Atm. Sci. 59 (3): 398-413 [10.1175/1520-0469(2002)059<0398:ALTROA>2.0.CO;2] [Journal Article/Letter]

2002. "Version 2 TOMS UV algorithm: problems and enhancements." Opt. Eng. 41 (12): 3028-3039 [doi: 10.1117/1.1519541] [Journal Article/Letter]

2002. "Aerosol properties from EP-TOMS near UV observations." Adv. Space Res. 29 1771-1780. [Journal Article/Letter]

2002. "A cohesive total ozone data set from the SBUV(/2) satellite system." J. Geophys. Res. 107 (D23): 4701 [10.1029/2001JD000853] [Journal Article/Letter]

2002. "Version 2 total ozone mapping spectrometer ultraviolet algorithm: problems and enhancements." Optical Engineering 41 (12): 3028-3039 [10.1117/1.1519541] [Journal Article/Letter]

2002. "Ocean Raman scattering in satellite backscatter ultraviolet measurements." Geophys Res Lett 29 (17): 1837-1840 [10.1029/2002GL014955] [Journal Article/Letter]

1999. "Impact of tropospheric aerosol absorption on ozone retrieval from buv measurements." J.Geophys. Res. 104 21569-21578. [Journal Article/Letter]

1998. "Radiative transfer in the 9.6 μm HIRS ozone channel using collocated SBUV‐determined ozone abundances." Journal of Geophysical Research: Atmospheres 103 (D15): 19213-19229 [10.1029/98jd01382] [Journal Article/Letter]

1998. "Derivation of aerosol properties from satellite measurements of backscattered ultraviolet radiation. Theoretical basis." J Geophys Res 103 (D14): 17099-17110 [10.1029/98JD00900] [Journal Article/Letter]

1998. "Radiative transfer in the 96 micron HIRS ozone channel using collocated SBUV-determined ozone abundances." J Geophys Res 103 19213-19229 [Journal Article/Letter]

1997. "Detection of volcanic ash clouds from Nimbus-7/Total Ozone Mapping Spectrometer." J. Geophys. Res. 102 (D14): 16749-16760 [10.1029/97JD00925] [Journal Article/Letter]

1997. "Global distribution of UV-absorbing aerosols from Nimbus-7/TOMS data." J. Geophys. Res. 102 16911-16921. [Journal Article/Letter]

1997. "Accurate Determination of Total Ozone using SBUV Continuous Spectral Scan Measurements." J Geophys Res 102 (D11): 12,957-12,969 [10.1029/97JD00902] [Journal Article/Letter]

1996. "Detection of biomass burning smoke from TOMS measurements." Geophy. Res. Lett. 23 (7): 745-748 [10.1029/96GL00455] [Journal Article/Letter]

1996. "UV-B increases (1979-1992) from decrease in total ozone." Geophys Res Lett 23 21107-21120 [Journal Article/Letter]

1995. "Effect of stratospheric aerosol on ozone profile from BUV measurements." Geophys. Res. Let. 22 (3): 235-238 [10.1029/94GL02994] [Journal Article/Letter]

1995. "Properties of Mt. Pinatubo Aerosols as derived from Nimbus 7 TOMS measurements." J. Geophys. Res. 100 14043 14055 [Journal Article/Letter]

1995. "Meteor-3 Total Ozone Mapping Spectrometer Observations of the 1993 Ozone Hole." J. Geophys. Res 100 2973-2983 [Journal Article/Letter]

1995. "Effect of molecular anisotropy on backscattered ultraviolet radiance." Applied Optics 34 (36): 8309 [10.1364/AO.34.008309] [Journal Article/Letter]

1995. "Rotational-Raman Scattering (Ring Effect) in Satellite Backscatter Ultraviolet Measurements." Appl Opt 34 4513-4525 [Journal Article/Letter]

1995. "The Determination of Cloud Pressures from Rotational-Raman Scattering in Satellite Backscatter Ultraviolet Measurements." J Geophys Res 100 23019-23026 [10.1029/95JD02675] [Journal Article/Letter]

1994. "Properties of mount Pinatubo aerosols as derived from Nimbus-TOMS measurements." J Geophys Res 100 14043-14055 [Journal Article/Letter]

1993. "Effect of Mt. Pinatubo Aerosols on Total Ozone Measurements from Backscatter Ultraviolet (BUV) Experiments." J. Geophys. Res. 98 (D10): 18547 18554 [10.1029/93JD01739] [Journal Article/Letter]

1993. "Tropical Ozone Loss Following the Eruption of Mt. Pinatubo." Geophys. Res. Let. 20 29 32. [Journal Article/Letter]

1993. "Record Low Global Ozone in 1992." Science 260 523-526 [Journal Article/Letter]


1997. "Detection of global absorbing aerosols using TOMS data." IRS'96: Current problems in atmospheric radiation 1 877-880 [Proceedings]