Skip Navigation
Search for People:
Search for Projects:

Vijay Natraj

Photo of Vijay Natraj

Address:

4800 Oak Grove Drive
M/S 233-201

Pasadena, CA 91109

Phone:

818.354.9229

Fax:

818.354.5148

Curriculum Vitae:

Click here

Member of:

Aerosols And Clouds

Biography

Vijay Natraj is a Research Scientist in the Aerosols and Clouds group at JPL. He has 18 years of experience in radiative transfer modeling with application to remote sensing of Earth and (exo)planetary atmospheres. He leads several projects on using innovative radiative transfer techniques to retrieve atmospheric reactive and greenhouse gases and surface reflectance, understand aerosol vertical distribution, profile temperature and water vapor in the planetary boundary layer and improve diagnosis of clouds in climate models. These efforts are directly related to important missions recommended by the 2017 Earth Science Decadal Survey. In addition, he leads a project to utilize measurements of Earth's sunlit disk from Lagrangian orbit to model the Earth as a proxy exoplanet.

Professional Experience

  • Jet Propulsion Laboratory, California Institute of Technology, Pasadena, USA (2010-Present)
    • Research Scientist (2018-present)
    • Scientist (2010-2017)
    • NASA ESUSPI: Principal Investigator (2017-Present)
    • NASA IDS: Institutional PI (2020-Present)
    • NASA ACCDAM: Co-Investigator (2021-Present)
    • NASA XRP: Collaborator (2020-Present)
    • NASA MEaSUREs: Co-Investigator (2018-Present)
    • JPL R&TD: Principal Investigator (2017-Present)
    • OCO/OCO-2 (2003-Present)
    • AIRS (2016-Present)
    • TROPESS (2019-Present)
  • California Institute of Technology, Pasadena, USA (2001-Present)
    • Visiting Associate in Planetary Science (2020-Present)
    • Visitor in Planetary Science (2010-2020)
    • Researcher (2007-2010)
    • Research Assistant (2001-2007)
  • Joint Institute for Regional Earth System Science and Engineering, University of California at Los Angeles, Westwood, USA (2012-Present)
    • Associate Project Scientist III (2018-Present)
    • Associate Project Scientist II (2016-2018)
    • Associate Project Scientist I (2014-2016)
    • Visiting Assistant Researcher (2012-2014)
  • Co-mentor, Summer Undergraduate Research Fellowship (SURF) Program (2006-Present)

Research Interests

  • Trace gas retrievals for air quality and climate applications
  • Aerosol composition and vertical profiling
  • Radiative transfer in cloudy atmospheres
  • Coupled surface-atmosphere retrievals for imaging spectroscopy
  • Fast radiative transfer techniques for retrievals, OSSEs and climate models
  • Information theoretical analyses for instrument design
  • Earth and (exo)planetary atmospheric characterization using scattering, emission and polarimetry

Selected Awards

  • JPL Voyager award for pioneering a radiative transfer technique for imaging spectroscopy (2019)
  • NASA Early Career Achievement Medal for developing fast and accurate RT models needed for current and future atmospheric composition remote sensing missions (2016)
  • NASA group achievement award (2016)
  • JPL Voyager award for contributions to the field of Atmospheric Radiation and Remote Sensing (2015)
  • Richard M. Goody award for Atmospheric Radiation and Remote Sensing  (2014)
  • JPL/NASA team bonus awards (2010, 2012, 2014, 2015, 2016)
  • JQSRT best reviewer (2009)
  • "Turning Coal into Diamonds" award for OCO retrieval algorithm development (2003)
  • Caltech departmental fellowship (2001)

Selected Publications

Including Invited Book Chapters; Asterisks Indicate Students/Postdocs Supervised; H-Index: 21.

  1. *Gu, L., S. Fan, J.-Z. Li, S. J. Bartlett, V. Natraj, et al. (2021), Earth as a Proxy Exoplanet: Deconstructing and Reconstructing Spectrophotometric Light Curves, Astrophys. J., 161(3), 122, doi:10.3847/1538-3881/abd54a.
  2. Huang, Y., V. Natraj, Z.-C. Zeng, P. Kopparla, and Y. L. Yung (2020), Quantifying the Impact of Aerosol Scattering on the Retrieval of Methane from Airborne Remote Sensing Measurements, Atmos. Meas. Tech., 13(12), 6755–6769, doi:10.5194/amt-13-6755-2020. Corresponding author.
  3. *Sasi, S., V. Natraj, V. M. Garcia, D. S. Efremenko, D. Loyola, and A. Doicu (2020), Model Selection in Atmospheric Remote Sensing with Application to Aerosol Retrieval from DSCOVR/ EPIC. Part 1: Theory, Remote Sens., 12(22), 3724, doi:10.3390/rs12223724. Corresponding author.
  4. *Sasi, S., V. Natraj, V. M. Garcia, D. S. Efremenko, D. Loyola, and A. Doicu (2020), Model Selection in Atmospheric Remote Sensing with Application to Aerosol Retrieval from DSCOVR/ EPIC. Part 2: Numerical Analysis, Remote Sens., 12(21), 3656, doi:10.3390/rs12213656. Corresponding author.
  5. Kuang, S., B. Wang, M. J. Newchurch, P. Tucker, E. W. Eloranta, V. Natraj, et al. (2020), Evaluation of UV Aerosol Retrievals from an Ozone Lidar, Atmos. Meas. Tech., 13(10), 5277–5292, doi:10.5194/amt-13-5277-2020.
  6. Zeng, Z.-C., Y. Wang, T. J. Pongetti, S. Newman, Y. Li, V. Natraj, et al. (2020), Tracking the Atmospheric Pulse of a North American Megacity from a Mountain-top Remote Sensing Observatory, Remote Sens. Environ., 248, 112000, doi:10.1016/j.rse.2020.112000.
  7. Liu, C., B. Yao, V. Natraj, et al. (2020), A Spectral Data Compression (SDCOMP) Radiative Transfer Model for High Spectral Resolution Radiation Simulations, J. Atmos. Sci., 77(6), 2055–2066, doi:10.1175/JAS-D-19-0238.1. Corresponding author.
  8. *Le, T., C. Liu, B. Yao, V. Natraj, and Y. L. Yung (2020), Application of Machine Learning Technique to Hyperspectral Radiative Transfer Simulations, J. Quant. Spectrosc. Radiat. Transfer, 246, 106928, doi:10.1016/j.jqsrt.2020.106928.
  9. Zeng, Z.-C., F. Xu, V. Natraj, T. J. Pongetti, R.-L. Shia, Q. Zhang, et al. (2020), Remote Sensing of Angular Scattering Effect of Aerosols in a North American Megacity, Remote Sens. Environ., 242, 111760, doi:10.1016/j.rse.2020.111760.
  10. Zeng, Z.-C., S. Chen, V. Natraj, T. Le, F. Xu, A. Merrelli, et al. (2020), Constraining Coastal Aerosol Vertical Distribution Using OCO-2 O2 A-band Measurements, Remote Sens. Environ., 236, 111494, doi:10.1016/j.rse.2019.111494.
  11. *Fan, S., C. Li, J.-Z. Li, S. J. Bartlett, J. H. Jiang, V. Natraj, et al. (2019), Earth as an Exoplanet: A Two-Dimensional Alien Map, Astrophys. J. Lett., 882(1), L1, doi:10.3847/2041-8213/ab3a49. Highlighted in Science. https://www.sciencemag.org/news/2019/08/here-s-what-earth-might-look-aliens
  12. Thompson, D. R., V. Natraj, et al. (2019), Optimal Estimation of Spectral Surface Reflectance in Challenging Atmospheres, Remote Sens. Environ., 232, 111258, doi:10.1016/j.rse.2019.111258.
  13. Thompson, D. R., V. Natraj, et al. (2019), A Unified Approach to Estimate Land and Water Reflectances with Uncertainties for Coastal Ocean Imaging Spectroscopy, Remote Sens. Environ., 231, 111198, doi:10.1016/j.rse.2019.05.017.
  14. Bue, B. D., D. R. Thompson, V. Natraj, et al. (2019), Neural Network Radiative Transfer for Imaging Spectroscopy, Atmos. Meas. Tech., 12(4), 2567–2578, doi:10.5194/amt-12-2567-2019.
  15. *Li, J., S. Fan, P. Kopparla. C. Liu, J. H. Jiang, V. Natraj, et al. (2019), Study of Terrestrial Glints Based on DSCOVR Observations, Earth Space Sci., 6(1), 166–173, doi:10.1029/2018EA000509.
  16. O’Dell, C. W., A. Eldering, P. O. Wennberg, V. Natraj, et al. (2018), Improved Retrievals of Carbon Dioxide from the Orbiting Carbon Observatory-2 with the Version 8 ACOS Algorithm, Atmos. Meas. Tech., 11(12), 6539–6576, doi:10.5194/amt-11-6539-2018.
  17. *Zeng, Z.-C., V. Natraj, et al. (2018), Constraining Aerosol Vertical Profile in the Boundary Layer Using Hyperspectral Measurements of Oxygen Absorption, Geophys. Res. Lett., 45, doi: 10.1029/2018GL079286. Editor's Highlight.
  18. *Kopparla, P., V. Natraj, D. Crisp, K. Bott, M. R. Swain and Y. L. Yung (2018), Observing Oceans in Tightly Packed Planetary Systems: Perspectives from Polarization Modeling of the TRAPPIST-1 System, Astron. J., 156(4), 143, doi:10.3847/1538-3881/aad9a1.
  19. Thompson, D. R., V. Natraj, R. O. Green, M. C. Helmlinger, B.-C. Gao, and M. L. Eastwood (2018), Optimal Estimation for Imaging Spectrometer Atmospheric Correction, Remote Sens. Environ., 216, 355-373, doi:10.1016/j.rse.2018.07.003.
  20. Jiang, J. H., A. J. Zhai, J. Herman, C. Zhai, R. Hu, V. Natraj, et al. (2018), Using Deep Space Climate Observatory Measurements to Study the Earth as An Exoplanet, Astron. J., 156(1), 26, doi:10.3847/1538-3881/aac6e2.
  21. Kim, S.-W., V. Natraj, et al. (2018), Impact of High-Resolution A Priori Profiles on Satellite-Based Formaldehyde Retrievals, Atmos. Chem. Phys., 18(10), 7639-7655, doi:10.5194/acp-18-7639-2018.
  22. Aumann, H. H., V. Natraj, et al. (2018), Evaluation of Radiative Transfer Models with Clouds, J. Geophys. Res., 123(11), 6142-6157, doi:10.1029/2017JD028063.
  23. *Somkuti, P., H. Bösch, V. Natraj, and P. Kopparla (2017), Application of a PCA-based Fast Radiative Transfer Model to XCO2 Retrievals in the Shortwave Infrared, J. Geophys. Res., 122(19), 10268-10287, doi:10.1002/2017JD027013.
  24. *Kopparla, P., V. Natraj, et al. (2017), PCA-Based Radiative Transfer: Improvements to Aerosol Scheme, Vertical Layering and Spectral Binning, J. Quant. Spectrosc. Radiat. Transfer, 198, 104-111, doi:10.1016/j.jqsrt.2017.05.005.
  25. *Chang, K.-W., T. S. L'Ecuyer, B. H. Kahn, and V. Natraj (2017), Information Content of Visible and Midinfrared Radiances for Retrieving Tropical Ice Cloud Properties, J. Geophys. Res., 122, doi:10.1002/2016JD026357.
  26. *Zeng, Z.-C., Q. Zhang, V. Natraj, et al. (2017), Aerosol Scattering Effects on Water Vapor Retrievals over the Los Angeles Basin, Atmos. Chem. Phys., 17(4), 2495-2508, doi:10.5194/acp-17-2495-2017.
  27. Eldering, A., V. Natraj, et al. (2017), The Orbiting Carbon Observatory-2: First 18 Months of Science Data Products, Atmos. Meas. Tech., 10(2), 549-563, doi:10.5194/amt-10-549-2017.
  28. Zoogman, P., V. Natraj, et al. (2017), Tropospheric Emissions: Monitoring of Pollution (TEMPO), J. Quant. Spectrosc. Radiat. Transfer, 186, 17-39, doi:10.1016/j.jqsrt.2016.05.008.
  29. (invited book chapter) Spurr, R. J. D., V. Natraj, P. Kopparla, and M. Christi (2017), Application of Principal Component Analysis to Performance Enhancement of Hyperspectral Radiative Transfer Computations, in: Principal Component Analysis: Methods, Applications and Technology (ed. V. Gray), Nova Science Publishers: New York, ISBN:978-1-53610-911-5.
  30. *Kopparla, P., V. Natraj, R. J. D. Spurr, R.-L. Shia, Y. L. Yung, and D. Crisp (2016), A Fast and Accurate PCA Based Radiative Transfer Model: Extension to the Broadband Shortwave Region, J. Quant. Spectrosc. Radiat. Transfer, 173, 65-71, doi:10.1016/j.jqsrt.2016.01.014.
  31. *Kopparla, P., V. Natraj, X. Zhang, M R. Swain, S. J. Wiktorowicz, and Y. L. Yung (2016), A Multiple Scattering Polarized Radiative Transfer Model: Application to HD189733b, Astrophys. J., 817(1), doi:10.3847/0004-637X/817/1/32.
  32. Fu, D., K. W. Bowman, H. M. Worden, V. Natraj, et al. (2016), High-Resolution Tropospheric Carbon Monoxide Profiles Retrieved from CrIS and TROPOMI, Atmos. Meas. Tech., 9(6), 2567-2579, doi:10.5194/amt-9-2567-2016.
  33. Bousserez, N., V. Natraj, et al. (2016), Constraints on Methane Emissions in North America from Future Geostationary Remote Sensing Measurements, Atmos. Chem. Phys., 16(10), 6175-6190, doi:10.5194/acp-16-6175-2016.
  34. *Colosimo, S. F., V. Natraj, S. P. Sander, and J. Stutz (2016), A Sensitivity Study on the Retrieval of Aerosol Vertical Profiles Using the Oxygen A-band, Atmos. Meas. Tech., 9(4), 1889-1905, doi:10.5194/amt-9-1889-2016.
  35. *Su, Z., X. Xi., V. Natraj, K.-F. Li, R.-L. Shia, C. E Miller, and Y. L. Yung (2016), Information-Rich Spectral Channels for Simulated Retrievals of Partial Column-Averaged Methane, Earth Space Sci., 3, doi:10.1002/2015EA000120.
  36. *Zhang, Q., V. Natraj, et al. (2015), Accounting for Aerosol Scattering in the CLARS Retrieval of Column Averaged CO2 Mixing Ratios, J. Geophys. Res., 120(14), 7205-7218, doi:10.1002/2015JD023499.
  37. Kokhanovsky, A. A., A. B. Davis, V. Natraj, et al. (2015), Space-Based Remote Sensing of Atmospheric Aerosols: The Multi-Angle Spectro-Polarimetric Frontier, Earth Sci. Rev., doi:10.1016/j.earscirev.2015.01.012.
  38. *Xi, X., V. Natraj, et al. (2015), Simulated Retrievals for the Remote Sensing of CO2, CH4, CO and H2O from Geostationary Orbit, Atmos. Meas. Tech., 8(11), 4817-4830, doi:10.5194/amt-8-4817-2015.
  39. Hache, E., J.-L. Attié, V. Natraj, et al. (2014), The Added Value of a Visible Channel to a Geostationary Thermal Infrared Instrument to Monitor Ozone for Air Quality, Atmos. Meas. Tech., 7(7), 2185-2201, doi:10.5194/amt-7-2185-2014.
  40. O'Brien, D. M., I. Polonsky, V. Natraj, et al. (2013), Testing the Polarization Model for TANSO-FTS on GOSAT against Clear-sky Observations of Sun-glint over the Ocean, IEEE Trans. Geosci. Remote Sens., 51(12), 5199-5209, doi:10.1109/TGRS.2012.2232673.
  41. (invited book chapter) Natraj, V. (2013), A Review of Fast Radiative Transfer Techniques, in: Light Scattering Reviews Vol. 8 (ed: A A. Kokhanovsky), 475-504, Springer: Berlin, doi:10.1007/978-3-642-32106-1_10.
  42. Spurr, R. J. D., V. Natraj, C. Lerot, M. Van Roozendael, and D. Loyola (2013), Linearization of the Principal Component Analysis Method for Radiative Transfer Acceleration: Application to Retrieval Algorithms and Sensitivity Studies, J. Quant. Spectrosc. Radiat. Transfer, 125, 1-17, doi:10.1016/j.jqsrt.2013.04.002.
  43. Sanghavi, S., and V. Natraj (2013), Using Analytical Derivatives to Assess the Impact of Phase Function Fourier Decomposition Technique on the Accuracy of a Radiative Transfer Model, J. Quant. Spectrosc. Radiat. Transfer, 119, 137-149, doi:10.1016/j.jqsrt.2012.12.028.
  44. Fu, D., J. R. Worden, X. Liu, S. S. Kulawik, K. W. Bowman, and V. Natraj (2013), Characterization of Ozone Profiles Derived from Aura TES and OMI Radiances, Atmos. Chem. Phys., 13(6), 3445-3462, doi:10.5194/acp-13-3445-2013.
  45. *Kuai, L., J. Worden, V. Natraj, et al. (2013), Profiling Tropospheric CO2 using the Aura TES and TCCON instruments, Atmos. Meas. Tech., 6(1), 63-79, doi:10.5194/amt-6-63-2013.
  46. Thompson, D. R., V. Natraj, et al. (2012), C. E. Miller, Atmospheric Validation of High Accuracy CO2 Absorption Coefficients for the OCO-2 Mission, J. Quant. Spectrosc. Radiat. Transfer, 113(17), 2265-2276, doi:10.1016/j.jqsrt.2012.05.021.
  47. Crisp, D., B. M. Fisher, C. O'Dell, C. Frankenberg, V. Natraj, et al. (2012), The ACOS CO2 Retrieval Algorithm - Part II: Global XCO2 Data Characterization, Atmos. Meas. Tech., 5(4), 687-707, doi:10.5194/amt-5-687-2012.
  48. O'Dell, C. W., B. Connor, H. Bösch, D. O'Brien, C. Frankenberg, V. Natraj, et al. (2012), The ACOS CO2 Retrieval Algorithm - Part 1: Description and Validation against Synthetic Observations, Atmos. Meas. Tech., 5(1), 99-121, doi:10.5194/amt-5-99-2012.
  49. Fishman, J., L. T. Iraci, V. Natraj, et al. (2012), The United States' Next Generation of Atmospheric Composition and Coastal Ecosystem Measurements: NASA's Geostationary Coastal and Air Pollution Events (GEO-CAPE) Mission, Bull. Am. Meteorol. Soc., doi:10.1175/BAMS-D-11-00201.1.
  50. Line, M. R., X. Zhang, G. Vasisht, V. Natraj, P. Chen, and Y. L. Yung (2012), Information Content of Exoplanetary Transit Spectra: An Initial Look, Astrophys. J., 749(1), 93, doi:10.1088/0004-637X/749/1/93.
  51. Natraj, V., and J. W. Hovenier (2012), Polarized Light Reflected and Transmitted by Thick Rayleigh Scattering Atmospheres, Astrophys. J., 748(1), 28, doi:10.1088/0004-637X/748/1/28.
  52. Natraj, V., X. Liu, et al. (2011), Multi-spectral Sensitivity Studies for the Retrieval of Tropospheric and Lowermost Tropospheric Ozone from Simulated Clear-sky GEO-CAPE Measurements, Atmos. Environ., 45(39), 7151-7165, doi:10.1016/j.atmosenv.2011.09.014.
  53. Zoogman, P., D. J. Jacob, K. Chance, L. Zhang, P. Le Sager, V. Natraj, et al. (2011), Ozone Air Quality Measurement Requirements for a Geostationary Satellite Mission, Atmos. Environ., 45(39), 7143-7150, doi:10.1016/j.atmosenv.2011.05.058.
  54. Spurr, R. J. D., and V. Natraj, (2011), A Linearized 2-Stream Radiative Transfer Code for Fast Approximation of Multiple-Scatter Fields, J. Quant. Spectrosc. Radiat. Transfer, 112(16), 2630-2637, doi:10.1016/j.jqsrt.2011.06.014.
  55. *Kuai, L., V. Natraj, R.-L. Shia, C. E. Miller, and Y. L. Yung (2010), Channel Selection using Information Content Analysis: A Case Study of CO2 Retrieval from Near Infrared Measurements, J. Quant. Spectrosc. Radiat. Transfer, 111(9), 1296-1304, doi:10.1016/j.jqsrt.2010.02.011.
  56. Natraj, V., R.-L. Shia, and Y. L. Yung (2010), On the use of Principal Component Analysis to Speed up Radiative Transfer Calculations, J. Quant. Spectrosc. Radiat. Transfer, 111(5), 810-816, doi:10.1016/j.jqsrt.2009.11.004.
  57. Natraj, V., K.-F. Li, and Y. L. Yung (2009), Rayleigh Scattering in Planetary Atmospheres: Corrected Tables Through Accurate Computation of X and Y Functions, Astrophys. J., 691(2), 1909-1920, doi:10.1088/0004-637X/691/2/1909.
  58. Natraj, V., H. Bösch, R. J. D. Spurr, and Y. L. Yung (2008), Retrieval of XCO2 from Simulated Orbiting Carbon Observatory Measurements using the Fast Linearized R-2OS Radiative Transfer Model, J. Geophys. Res., 113, D11212, doi:10.1029/2007JD009017.
  59. Natraj, V., and R. J. D. Spurr (2007), A Fast Linearized Pseudo-Spherical Two Orders of Scattering Model to Account for Polarization in Vertically Inhomogeneous Scattering-Absorbing Media, J. Quant. Spectrosc. Radiat. Transfer, 107(2), 263-293, doi:10.1016/j.jqsrt.2007.02.011.
  60. Natraj, V., R. J. D. Spurr, H. Bösch, Y. Jiang, and Y. L. Yung (2007), Evaluation of Errors from Neglecting Polarization in the Forward Modeling of O2 A-Band Measurements from Space, with Relevance to CO2 Column Retrieval from Polarization-Sensitive Instruments, J. Quant. Spectrosc. Radiat. Transfer, 103(2), 245-259, doi:10.1016/j.jqsrt.2006.02.073.
  61. Guo, X., V. Natraj, et al. (2007), Retrieval of Ozone Profile from Ground-Based Measurements with Polarization: A Synthetic Study, J. Quant. Spectrosc. Radiat. Transfer, 103(1), 175-192, doi:10.1016/j.jqsrt.2006.05.008.
  62. Bösch, H., G. C. Toon, B. Sen, R. A. Washenfelder, V. Natraj, et al. (2006), Space-based Near-infrared CO2 Measurements: Testing the Orbiting Carbon Observatory Retrieval Algorithm and Validation Concept using SCIAMACHY Observations over Park Falls, Wisconsin, J. Geophys. Res., 111, D23302, doi:10.1029/2006JD007080.
  63. Natraj, V., X. Jiang, R.-L. Shia, X. Huang, J. S. Margolis, and Y. L. Yung (2005), Application of Principal Component Analysis to High Spectral Resolution Radiative Transfer: A Case Study of the O2 A-Band, J. Quant. Spectrosc. Radiat. Transfer, 95(4), 539-556, doi:10.1016/j.jqsrt.2004.12.024.
  64. Natraj, V., and S. B. Chen (2003), Diffusion Coefficient of a Charged Porous Sphere, Chem. Eng. Sci., 58(16), 3621-3628, doi:10.1016/S0009-2509(03)00252-5.
  65. Natraj, V., and S. B. Chen (2002), Primary Electroviscous Effect in a Suspension of Charged Porous Spheres, J. Coll. Interface Sci., 251(1), 200-207, doi:10.1006/jcis.2002.8434.

Projects

OCO-2 - Orbiting Carbon Observatory
AIRS
AVIRIS
Geo-Cape
JIFRESSE