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Pawan Bhartia

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Papers by Pawan Bhartia

Research paper thumbnail of Space-Based Measurement of Chemical Tracers (gaseous) and Aerosol Pollutants: Past, Present, and Future Needs (Core Science Keynote)

Research paper thumbnail of Space-based Measurement of Gaseous and Aerosol Pollutants (Invited Presentation)

Research paper thumbnail of An assessment of the long-term drift in TOMS total ozone data, based on comparison with the Dobson Network

Geophysical Research Letters, 1988

Using techniques very similar to those used in comparing SBUV total ozone with Dobson [Fleig et a... more Using techniques very similar to those used in comparing SBUV total ozone with Dobson [Fleig et al. 1986A], seven years of total ozone data derived from the TOMS instrument on Nimbus‐7 are compared with results from 41 Dobson stations. In this study however, a ...

Research paper thumbnail of Nimbus 7 solar backscatter ultraviolet (SBUV) ozone products user's guide

Three ozone tape products from the Solar Backscatter Ultraviolet (SBUV) experiment aboard Nimbus ... more Three ozone tape products from the Solar Backscatter Ultraviolet (SBUV) experiment aboard Nimbus 7 were archived at the National Space Science Data Center. The experiment measures the fraction of incoming radiation backscattered by the Earth's atmosphere at 12 wavelengths. In-flight measurements were used to monitor changes in the instrument sensitivity. Total column ozone is derived by comparing the measurements with calculations of what would be measured for different total ozone amounts. The altitude distribution is retrieved using an optimum statistical technique for the inversion. The estimated initial error in the absolute scale for total ozone is 2 percent, with a 3 percent drift over 8 years. The profile error depends on latitude and height, smallest at 3 to 10 mbar; the drift increases with increasing altitude. Three tape products are described. The High Density SBUV (HDSBUV) tape contains the final derived products - the total ozone and the vertical ozone profile - as ...

Research paper thumbnail of Ozone profile retrieval from Global Ozone Monitoring Experiment (GOME) data using a neural network approach (Neural Network Ozone Retrieval System (NNORSY))

Journal of Geophysical Research, 2003

Research paper thumbnail of A Color Ratio Method for Simultaneous Retrieval of Aerosol and Cloud Optical Thickness of Above-Cloud Absorbing Aerosols From Passive Sensors: Application to MODIS Measurements

IEEE Transactions on Geoscience and Remote Sensing, 2013

Research paper thumbnail of Ozone profile retrieval from Global Ozone Monitoring Experiment (GOME) data using a neural network approach (Neural Network Ozone Retrieval System (NNORSY))

Journal of Geophysical Research, 2003

Research paper thumbnail of Band residual difference algorithm for retrieval of SO/sub 2/ from the aura ozone monitoring instrument (OMI)

IEEE Transactions on Geoscience and Remote Sensing, 2006

Research paper thumbnail of Band residual difference algorithm for retrieval of SO/sub 2/ from the aura ozone monitoring instrument (OMI)

IEEE Transactions on Geoscience and Remote Sensing, 2006

Research paper thumbnail of Overview of the EOS aura mission

IEEE Transactions on Geoscience and Remote Sensing, 2006

Research paper thumbnail of Global pictures of the ozone field, from high altitudes, from DE-I

Advances in Space Research, 1982

... REFERENCES 1. GHB Dobson and DN Harrison, Proc. Roy. Soc., Ser. A 110, 660 (1926) 2. FE Fowle... more ... REFERENCES 1. GHB Dobson and DN Harrison, Proc. Roy. Soc., Ser. A 110, 660 (1926) 2. FE Fowle, Smithsonian Miscellaneous Collections 81, 1 (1929) 3. GM Keating, L. Frank, JD Craven, D. Young, J. Nicholson, P. Bhartia, D. Gordon, EOS, Trans. ...

Research paper thumbnail of Science objectives of the ozone monitoring instrument

IEEE Transactions on Geoscience and Remote Sensing, 2006

Research paper thumbnail of Evaluation of tropospheric ozone residual measurements derived from TOMS-V9 and hyper-spectral total ozone algorithms

<p>The NASA TOMS V9 (TOMS-V9) total ozone retrieval algorithm is tested<br>for sensit... more <p>The NASA TOMS V9 (TOMS-V9) total ozone retrieval algorithm is tested<br>for sensitvity to boundary-layer ozone and suitability to make daily<br>maps of tropospheric ozone residual (TOR). &#160;Daily maps of TOR are<br>derived by differencing co-located MERRA-2 assimilated MLS<br>stratospheric column ozone (SCO) from total column ozone from the Aura<br>Ozone Monitoring Instrument (OMI). &#160;The TOMS-V9 algorithm uses a few<br>discrete channels with an order of magnitude range in ozone<br>senstivity. We compare the TOR results from TOMS-V9 with results from<br>several hyper-spectral total ozone retrievals: GODFIT v4 (BIRA-IASB),<br>OMI-DOAS (KNMI), and total ozone from the SAO PROFOZ algorithm. We<br>compare all satellite-retrieved TOR with TOR derived from ozonesondes,<br>lidar, and the Goddard Modeling Initiative (GMI) model simulation.</p><p>&#160;</p><p>&#160;</p>

Research paper thumbnail of OMPS Limb Profiler Daily Ozone Level 2 Data Product

Research paper thumbnail of OMPS Limb Profiler Daily Aerosol Level 2 Product

Research paper thumbnail of OMPS Limb Profiler Gridded Level 1 Ancillary Product

Research paper thumbnail of Measuring Aerosol Absorption from Omi Near Uv Observations

An assessment of OMI retrievals of aerosol properties is presented. We compare OMI retrieved valu... more An assessment of OMI retrievals of aerosol properties is presented. We compare OMI retrieved values of extinction and absorption optical depth, and aerosol single scattering albedo to AERONET ground-based measurements. An evaluation of the accuracy of the retrievals for a limited number of observations under cloud-free conditions shows a positive offset of about 0.03 in retrieved optical depth. This small offset is an indication of accurate sensor calibration to the 1% level. The retrieved SSA values agree well with RMS differences of 0.02-0.03 compared with the AERONET observations. This result shows that the UV technique is a very valuable tool for measuring aerosol absorption from space.

Research paper thumbnail of Scientific Results from the OMPS Limb Profiler Sensor on Suomi NPP satellite

Research paper thumbnail of Community input to the NRC Decadal Survey from the NCAR Workshop on Air Quality Remote Sensing From Space: Defining an optimum observing strategy

Research paper thumbnail of SO2 data from the ozone monitoring instrument

We discuss collection 2 SO2 data from the Dutch-Finnish Ozone Monitoring Instrument (OMI) on boar... more We discuss collection 2 SO2 data from the Dutch-Finnish Ozone Monitoring Instrument (OMI) on board NASA EOS/Aura spacecraft and show examples of detected volcanic and anthropogenic SO2 emissions. Quantification of anthropogenic SO2 emissions requires collection 3 reprocessing available in the fall 2007.

Research paper thumbnail of Space-Based Measurement of Chemical Tracers (gaseous) and Aerosol Pollutants: Past, Present, and Future Needs (Core Science Keynote)

Research paper thumbnail of Space-based Measurement of Gaseous and Aerosol Pollutants (Invited Presentation)

Research paper thumbnail of An assessment of the long-term drift in TOMS total ozone data, based on comparison with the Dobson Network

Geophysical Research Letters, 1988

Using techniques very similar to those used in comparing SBUV total ozone with Dobson [Fleig et a... more Using techniques very similar to those used in comparing SBUV total ozone with Dobson [Fleig et al. 1986A], seven years of total ozone data derived from the TOMS instrument on Nimbus‐7 are compared with results from 41 Dobson stations. In this study however, a ...

Research paper thumbnail of Nimbus 7 solar backscatter ultraviolet (SBUV) ozone products user's guide

Three ozone tape products from the Solar Backscatter Ultraviolet (SBUV) experiment aboard Nimbus ... more Three ozone tape products from the Solar Backscatter Ultraviolet (SBUV) experiment aboard Nimbus 7 were archived at the National Space Science Data Center. The experiment measures the fraction of incoming radiation backscattered by the Earth's atmosphere at 12 wavelengths. In-flight measurements were used to monitor changes in the instrument sensitivity. Total column ozone is derived by comparing the measurements with calculations of what would be measured for different total ozone amounts. The altitude distribution is retrieved using an optimum statistical technique for the inversion. The estimated initial error in the absolute scale for total ozone is 2 percent, with a 3 percent drift over 8 years. The profile error depends on latitude and height, smallest at 3 to 10 mbar; the drift increases with increasing altitude. Three tape products are described. The High Density SBUV (HDSBUV) tape contains the final derived products - the total ozone and the vertical ozone profile - as ...

Research paper thumbnail of Ozone profile retrieval from Global Ozone Monitoring Experiment (GOME) data using a neural network approach (Neural Network Ozone Retrieval System (NNORSY))

Journal of Geophysical Research, 2003

Research paper thumbnail of A Color Ratio Method for Simultaneous Retrieval of Aerosol and Cloud Optical Thickness of Above-Cloud Absorbing Aerosols From Passive Sensors: Application to MODIS Measurements

IEEE Transactions on Geoscience and Remote Sensing, 2013

Research paper thumbnail of Ozone profile retrieval from Global Ozone Monitoring Experiment (GOME) data using a neural network approach (Neural Network Ozone Retrieval System (NNORSY))

Journal of Geophysical Research, 2003

Research paper thumbnail of Band residual difference algorithm for retrieval of SO/sub 2/ from the aura ozone monitoring instrument (OMI)

IEEE Transactions on Geoscience and Remote Sensing, 2006

Research paper thumbnail of Band residual difference algorithm for retrieval of SO/sub 2/ from the aura ozone monitoring instrument (OMI)

IEEE Transactions on Geoscience and Remote Sensing, 2006

Research paper thumbnail of Overview of the EOS aura mission

IEEE Transactions on Geoscience and Remote Sensing, 2006

Research paper thumbnail of Global pictures of the ozone field, from high altitudes, from DE-I

Advances in Space Research, 1982

... REFERENCES 1. GHB Dobson and DN Harrison, Proc. Roy. Soc., Ser. A 110, 660 (1926) 2. FE Fowle... more ... REFERENCES 1. GHB Dobson and DN Harrison, Proc. Roy. Soc., Ser. A 110, 660 (1926) 2. FE Fowle, Smithsonian Miscellaneous Collections 81, 1 (1929) 3. GM Keating, L. Frank, JD Craven, D. Young, J. Nicholson, P. Bhartia, D. Gordon, EOS, Trans. ...

Research paper thumbnail of Science objectives of the ozone monitoring instrument

IEEE Transactions on Geoscience and Remote Sensing, 2006

Research paper thumbnail of Evaluation of tropospheric ozone residual measurements derived from TOMS-V9 and hyper-spectral total ozone algorithms

<p>The NASA TOMS V9 (TOMS-V9) total ozone retrieval algorithm is tested<br>for sensit... more <p>The NASA TOMS V9 (TOMS-V9) total ozone retrieval algorithm is tested<br>for sensitvity to boundary-layer ozone and suitability to make daily<br>maps of tropospheric ozone residual (TOR). &#160;Daily maps of TOR are<br>derived by differencing co-located MERRA-2 assimilated MLS<br>stratospheric column ozone (SCO) from total column ozone from the Aura<br>Ozone Monitoring Instrument (OMI). &#160;The TOMS-V9 algorithm uses a few<br>discrete channels with an order of magnitude range in ozone<br>senstivity. We compare the TOR results from TOMS-V9 with results from<br>several hyper-spectral total ozone retrievals: GODFIT v4 (BIRA-IASB),<br>OMI-DOAS (KNMI), and total ozone from the SAO PROFOZ algorithm. We<br>compare all satellite-retrieved TOR with TOR derived from ozonesondes,<br>lidar, and the Goddard Modeling Initiative (GMI) model simulation.</p><p>&#160;</p><p>&#160;</p>

Research paper thumbnail of OMPS Limb Profiler Daily Ozone Level 2 Data Product

Research paper thumbnail of OMPS Limb Profiler Daily Aerosol Level 2 Product

Research paper thumbnail of OMPS Limb Profiler Gridded Level 1 Ancillary Product

Research paper thumbnail of Measuring Aerosol Absorption from Omi Near Uv Observations

An assessment of OMI retrievals of aerosol properties is presented. We compare OMI retrieved valu... more An assessment of OMI retrievals of aerosol properties is presented. We compare OMI retrieved values of extinction and absorption optical depth, and aerosol single scattering albedo to AERONET ground-based measurements. An evaluation of the accuracy of the retrievals for a limited number of observations under cloud-free conditions shows a positive offset of about 0.03 in retrieved optical depth. This small offset is an indication of accurate sensor calibration to the 1% level. The retrieved SSA values agree well with RMS differences of 0.02-0.03 compared with the AERONET observations. This result shows that the UV technique is a very valuable tool for measuring aerosol absorption from space.

Research paper thumbnail of Scientific Results from the OMPS Limb Profiler Sensor on Suomi NPP satellite

Research paper thumbnail of Community input to the NRC Decadal Survey from the NCAR Workshop on Air Quality Remote Sensing From Space: Defining an optimum observing strategy

Research paper thumbnail of SO2 data from the ozone monitoring instrument

We discuss collection 2 SO2 data from the Dutch-Finnish Ozone Monitoring Instrument (OMI) on boar... more We discuss collection 2 SO2 data from the Dutch-Finnish Ozone Monitoring Instrument (OMI) on board NASA EOS/Aura spacecraft and show examples of detected volcanic and anthropogenic SO2 emissions. Quantification of anthropogenic SO2 emissions requires collection 3 reprocessing available in the fall 2007.

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