Tamas Varnai

Tamas Varnai

  • RES. ASSOC. PROFESSOR
  • 301.614.6408 | 301.614.6307
  • NASA/GSFC
  • Mail Code: 613
  • Greenbelt , MD 20771
  • Employer: UNIVERSITY OF MARYLAND BALTIMORE COUNTY
  • Positions/Employment

    2008 - Present

    Research Associate Professor

    University of Maryland Baltimore County: Joint Center for Earth Systems Technology and the Department of Physics , Baltimore, MD  
    2001 - 2008

    Research Assistant Professor

    University of Maryland Baltimore County: Joint Center for Earth Systems Technology and the Department of Physics, Baltimore, MD  
    1999 - 2001

    Assistant Research Scientist

    University of Maryland Baltimore County: Joint Center for Earth Systems Technology, Baltimore, MD  
    1997 - 1999

    Postdoctoral Research Associate

    University of Arizona, Tucson, AZ  
    1996 - 1997

    Postdoctoral Research Associate

    McGill University, Montreal, Canada  
    1989 - 1991

    Research Meteorologist

    Hungarian Meteorological Service, Budapest, Hungary  

    Education

    1996 - Ph.D. in Atmospheric and Oceanic Sciences, McGill University, Montreal, Canada, Dissertation: "Reflection of solar radiation by inhomogeneous clouds"
    1989 - M.Sc. equivalent degree in Meteorology, Eotvos Lorand University, Budapest, Hungary, Thesis: "The adaptation of a spectral global circulation model"

    Publications

    Refereed

    Marshak, A., T. Várnai, and A. Kostinski. 2017. "Terrestrial glint seen from deep space: Oriented ice crystals detected from the Lagrangian point." Geophysical Research Letters, Online: [10.1002/2017gl073248]

    Fauchez, T., S. Platnick, K. Meyer, et al. C. Cornet, F. Szczap, and T. Várnai. 2017. "Scale dependence of cirrus horizontal heterogeneity effects on TOA measurements – Part I: MODIS brightness temperatures in the thermal infrared." Atmospheric Chemistry and Physics, 17 (13): 8489-8508 [10.5194/acp-17-8489-2017]

    Várnai, T., A. Marshak, and T. F. Eck. 2017. "Observation-Based Study on Aerosol Optical Depth and Particle Size in Partly Cloudy Regions." Journal of Geophysical Research: Atmospheres, 122 (18): 10,013-10,024 [10.1002/2017jd027028]

    Gautam, R., C. K. Gatebe, M. K. Singh, T. Várnai, and R. Poudyal. 2016. "Radiative characteristics of Clouds Embedded in Smoke derived from airborne multi-angular measurements." J. Geophys. Res. Atmos., 121 (15): 9140–9152 [10.1002/2016jd025309]

    Wen, G., A. Marshak, T. Varnai, and R. C. Levy. 2016. "Testing the Two-Layer Model for Correcting Near Cloud Reflectance Enhancement Using LES/SHDOM Simulated Radiances ." J. Geophys. Res., Atmos., (121): 9661–9674 [10.1002/2016JD025021]

    Varnai, T., and A. Marshak. 2015. "Effect of cloud fraction on near-cloud aerosol behavior in the MODIS atmospheric correction ocean color product." Rem. Sens, 7: 5283-5299 [10.3390/rs70505283]

    Varnai, T., and A. Marshak. 2014. "Near-cloud aerosol properties from the 1 km resolution MODIS ocean product." J. Geophys. Res. Atmos., 119 (3): 1546-1554 [10.1002/2013JD020633]

    Marshak, A., K. F. Evans, T. Varnai, and G. Wen. 2014. "Extending 3D near-cloud corrections from shorter to longer wavelengths." Journal of Quantitative Spectroscopy and Radiative Transfer, 147: 79-85 [10.1016/j.jqsrt.2014.05.022]

    Yang, W., A. Marshak, T. Varnai, and R. Wood. 2014. "CALIPSO observations of near-cloud aerosol properties as a function of cloud fraction." Geophys. Res. Lett, 41: 9150-9157 [10.1002/2014GL061896]

    Yang, Y., A. Marshak, A. B. Kostinski, and T. Varnai. 2013. "Shape-induced gravitational sorting of Saharan dust during transatlantic voyage: Evidence from CALIOP lidar depolarization measurements." Geophys. Res. Lett, 40 (12): 3281-3286 [10.1002/grl.50603]

    Wen, G., A. Marshak, R. C. Levy, et al. L. A. Remer, N. Loeb, T. Varnai, and R. F. Cahalan. 2013. "Improvement of MODIS aerosol retrievals near clouds." J. Geophys. Res. Atmos., 118 (16): 9168-9181 [10.1002/jgrd.50617]

    Varnai, T., A. Marshak, and W. Yang. 2013. "Multi-satellite aerosol observations in the vicinity of clouds." Atmos. Chem. Phys., 13 (8): 3899-3908 [10.5194/acp-13-3899-2013]

    Yang, W., A. Marshak, T. Varnai, O. V. Kalashnikova, and A. B. Kostinski. 2012. "CALIPSO observations of transatlantic dust: vertical stratification and effect of clouds." Atmos. Chem. Phys., 12 (23): 11339-11354 [Full Text (Link)] [10.5194/acp-12-11339-2012]

    Yang, W., A. Marshak, T. Varnai, and Z. Liu. 2012. "Effect of CALIPSO cloud–aerosol discrimination (CAD) confidence levels on observations of aerosol properties near clouds." Atmospheric Research, 116: 134-141 [10.1016/j.atmosres.2012.03.013]

    Gatebe, C. K., T. Varnai, R. Poudyal, C. M. Ichoku, and M. D. King. 2012. "Taking the pulse of pyrocumulus clouds." Atmospheric Environment, 52: 121-130 [10.1016/j.atmosenv.2012.01.045]

    Chiu, J., A. Marshak, C. Huang, et al. T. Varnai, R. Hogan, D. Giles, B. Holben, E. OConnor, Y. Knyazikhin, and W. Wiscombe. 2012. "Cloud droplet size and liquid water path retrievals from zenith radiance measurements: examples from the Atmospheric Radiation Measurement Program and the Aerosol Robotic Network." Atmos. Chem. Phys., 12 (21): 10313-10329 [10.5194/acp-12-10313-2012]

    Varnai, T., and A. Marshak. 2012. "Analysis of co-located MODIS and CALIPSO observations near clouds." Atmos Meas Tech, 5 (2): 389-396 [10.5194/amt-5-389-2012]

    Pounder, N., R. Hogan, T. Varnai, A. Battaglia, and R. F. Cahalan. 2012. "A Variational Method to Retrieve the Extinction Profile in Liquid Clouds Using Multiple-Field-of-View Lidar." J Appl Meteor Climatol, 51 (2): 350-365 [10.1175/JAMC-D-10-05007.1]

    Yang, Y., A. Marshak, S. P. Palm, T. Varnai, and W. J. Wiscombe. 2011. "Cloud Impact on Surface Altimetry From a Spaceborne 532-nm Micropulse Photon-Counting Lidar: System Modeling for Cloudy and Clear Atmospheres." IEEE Trans. Geosci. Remote Sensing, 49 (12): 4910-4919 [Full Text (Link)] [10.1109/TGRS.2011.2153860]

    Oreopoulos, L., M. Wilson, and T. Varnai. 2011. "Implementation on Landsat Data of a Simple Cloud-Mask Algorithm Developed for MODIS Land Bands." IEEE Geosci. Remote Sensing Lett., 8 (4): 597-601 [10.1109/LGRS.2010.2095409]

    Varnai, T., and A. Marshak. 2011. "Global CALIPSO Observations of Aerosol Changes Near Clouds." IEEE Geosci. Remote Sensing Lett., 8 (1): 19-23 [10.1109/LGRS.2010.2049982]

    Varnai, T. 2010. "Multiyear Statistics of 2D Shortwave Radiative Effects at Three ARM Sites." J Atmos Sci, 67 (11): 3757-3762 [10.1175/2010JAS3506.1]

    Yang, Y., A. Marshak, T. Varnai, W. J. Wiscombe, and P. Yang. 2010. "Uncertainties in Ice-Sheet Altimetry From a Spaceborne 1064-nm Single-Channel Lidar Due to Undetected Thin Clouds." IEEE Trans. Geosci. Remote Sensing, 48 (1): 250-259 [10.1109/TGRS.2009.2028335]

    Varnai, T., and A. Marshak. 2009. "MODIS observations of enhanced clear sky reflectance near clouds." Geophys. Res. Lett., 36 (6): L06807 [10.1029/2008GL037089]

    Evans, K., A. Marshak, and T. Varnai. 2008. "The Potential for Improved Boundary Layer Cloud Optical Depth Retrievals from the Multiple Directions of MISR." Journal of the Atmospheric Sciences, 65 (10): 3179-3196 [10.1175/2008JAS2627.1]

    Varnai, T., and A. Marshak. 2007. "View angle dependence of cloud optical thicknesses retrieved by Moderate Resolution Imaging Spectroradiometer (MODIS)." J. Geophys. Res., 112 (D6): D06203 [10.1029/2005JD006912]

    Varnai, T., and R. F. Cahalan. 2007. "Potential for airborne offbeam lidar measurements of snow and sea ice thickness." J. Geophys. Res., 112 (C12): C12S90 [10.1029/2007JC004091]

    Oreopoulos, L., A. Marshak, R. F. Cahalan, et al. T. Varnai, A. B. Davis, and A. Macke. 2006. "New directions in the radiative transfer of cloudy atmospheres." Eos Trans. AGU, 87 (5): 52 [10.1029/2006EO050006]

    Marshak, A., S. E. Platnick, T. Varnai, G. Wen, and R. F. Cahalan. 2006. "Impact of three-dimensional radiative effects on satellite retrievals of cloud droplet sizes." J. Geophys. Res., 111 (D9): D09207 [10.1029/2005JD006686]

    Cahalan, R., L. Oreopoulos, A. Marshak, et al. K. Evans, A. Davis, R. Pincus, K. Yetzer, B. Mayer, R. Davies, T. Ackerman, H. Barker, E. Clothiaux, R. Ellingson, M. Garay, E. Kassianov, S. Kinne, O. Macke, O. Macke, O. Macke, P. Partain, S. Prigarin, A. Rublev, G. Stephens, F. Szczap, E. Takara, T. Varnai, G. Wen, and T. Zhuravleva. 2005. "The International Intercomparison of 3D Radiation Codes (I3RC): Bringing together the most advanced radiative transfer tools for cloudy atmospheres." Bull Amer Meteor Soc, 86 (9): 1275-1293 [10.1175/BAMS-86-9-1275]

    Cahalan, R. F., M. J. Mcgill, J. Kolasinski, T. Varnai, and K. Yetzer. 2005. "THOR—Cloud Thickness from Offbeam Lidar Returns." Journal of Atmospheric and Oceanic Technology, 22 (6): 605-627 [10.1175/JTECH1740.1]

    Varnai, T. 2003. "A method for analyzing how various parts of clouds influence each other's brightness." J. Geophys. Res., 108 (D22): 4706 [10.1029/2003JD003561]

    Varnai, T., and A. Marshak. 2002. "Observations of three-dimensional radiative effects that influence satellite retrievals of cloud properties." Quart Jour of Hungarian Meteor Service (Idojaras), 106: 265-278.

    Varnai, T., and A. Marshak. 2002. "Observations of three-dimensional radiative effects that influence MODIS cloud optical thickness retrievals." J Atmos Sci, 59: 1607-1618.

    Varnai, T., and A. Marshak. 2001. "Statistical analysis of the uncertainties in cloud optical depth retrievals caused by three-dimensional radiative effects." J Atmos Sci, 58: 1540-1548.

    Publications

    Refereed

    Marshak, A., T. Várnai, and A. Kostinski. 2017. "Terrestrial glint seen from deep space: Oriented ice crystals detected from the Lagrangian point." Geophysical Research Letters Online [10.1002/2017gl073248]

    Fauchez, T., S. Platnick, K. Meyer, et al. C. Cornet, F. Szczap, and T. Várnai. 2017. "Scale dependence of cirrus horizontal heterogeneity effects on TOA measurements – Part I: MODIS brightness temperatures in the thermal infrared." Atmospheric Chemistry and Physics 17 (13): 8489-8508 [10.5194/acp-17-8489-2017]

    Várnai, T., A. Marshak, and T. F. Eck. 2017. "Observation-Based Study on Aerosol Optical Depth and Particle Size in Partly Cloudy Regions." Journal of Geophysical Research: Atmospheres 122 (18): 10,013-10,024 [10.1002/2017jd027028]

    Gautam, R., C. K. Gatebe, M. K. Singh, T. Várnai, and R. Poudyal. 2016. "Radiative characteristics of Clouds Embedded in Smoke derived from airborne multi-angular measurements." J. Geophys. Res. Atmos. 121 (15): 9140–9152 [10.1002/2016jd025309]

    Wen, G., A. Marshak, T. Varnai, and R. C. Levy. 2016. "Testing the Two-Layer Model for Correcting Near Cloud Reflectance Enhancement Using LES/SHDOM Simulated Radiances ." J. Geophys. Res., Atmos. 9661–9674 [10.1002/2016JD025021]

    Varnai, T., and A. Marshak. 2015. "Effect of cloud fraction on near-cloud aerosol behavior in the MODIS atmospheric correction ocean color product." Rem. Sens 7 5283-5299 [10.3390/rs70505283]

    Varnai, T., and A. Marshak. 2014. "Near-cloud aerosol properties from the 1 km resolution MODIS ocean product." J. Geophys. Res. Atmos. 119 (3): 1546-1554 [10.1002/2013JD020633]

    Marshak, A., K. F. Evans, T. Varnai, and G. Wen. 2014. "Extending 3D near-cloud corrections from shorter to longer wavelengths." Journal of Quantitative Spectroscopy and Radiative Transfer 147 79-85 [10.1016/j.jqsrt.2014.05.022]

    Yang, W., A. Marshak, T. Varnai, and R. Wood. 2014. "CALIPSO observations of near-cloud aerosol properties as a function of cloud fraction." Geophys. Res. Lett 41 9150-9157 [10.1002/2014GL061896]

    Yang, Y., A. Marshak, A. B. Kostinski, and T. Varnai. 2013. "Shape-induced gravitational sorting of Saharan dust during transatlantic voyage: Evidence from CALIOP lidar depolarization measurements." Geophys. Res. Lett 40 (12): 3281-3286 [10.1002/grl.50603]

    Wen, G., A. Marshak, R. C. Levy, et al. L. A. Remer, N. Loeb, T. Varnai, and R. F. Cahalan. 2013. "Improvement of MODIS aerosol retrievals near clouds." J. Geophys. Res. Atmos. 118 (16): 9168-9181 [10.1002/jgrd.50617]

    Varnai, T., A. Marshak, and W. Yang. 2013. "Multi-satellite aerosol observations in the vicinity of clouds." Atmos. Chem. Phys. 13 (8): 3899-3908 [10.5194/acp-13-3899-2013]

    Yang, W., A. Marshak, T. Varnai, O. V. Kalashnikova, and A. B. Kostinski. 2012. "CALIPSO observations of transatlantic dust: vertical stratification and effect of clouds." Atmos. Chem. Phys. 12 (23): 11339-11354 [Full Text (Link)] [10.5194/acp-12-11339-2012]

    Yang, W., A. Marshak, T. Varnai, and Z. Liu. 2012. "Effect of CALIPSO cloud–aerosol discrimination (CAD) confidence levels on observations of aerosol properties near clouds." Atmospheric Research 116 134-141 [10.1016/j.atmosres.2012.03.013]

    Gatebe, C. K., T. Varnai, R. Poudyal, C. M. Ichoku, and M. D. King. 2012. "Taking the pulse of pyrocumulus clouds." Atmospheric Environment 52 121-130 [10.1016/j.atmosenv.2012.01.045]

    Chiu, J., A. Marshak, C. Huang, et al. T. Varnai, R. Hogan, D. Giles, B. Holben, E. OConnor, Y. Knyazikhin, and W. Wiscombe. 2012. "Cloud droplet size and liquid water path retrievals from zenith radiance measurements: examples from the Atmospheric Radiation Measurement Program and the Aerosol Robotic Network." Atmos. Chem. Phys. 12 (21): 10313-10329 [10.5194/acp-12-10313-2012]

    Varnai, T., and A. Marshak. 2012. "Analysis of co-located MODIS and CALIPSO observations near clouds." Atmos Meas Tech 5 (2): 389-396 [10.5194/amt-5-389-2012]

    Pounder, N., R. Hogan, T. Varnai, A. Battaglia, and R. F. Cahalan. 2012. "A Variational Method to Retrieve the Extinction Profile in Liquid Clouds Using Multiple-Field-of-View Lidar." J Appl Meteor Climatol 51 (2): 350-365 [10.1175/JAMC-D-10-05007.1]

    Yang, Y., A. Marshak, S. P. Palm, T. Varnai, and W. J. Wiscombe. 2011. "Cloud Impact on Surface Altimetry From a Spaceborne 532-nm Micropulse Photon-Counting Lidar: System Modeling for Cloudy and Clear Atmospheres." IEEE Trans. Geosci. Remote Sensing 49 (12): 4910-4919 [Full Text (Link)] [10.1109/TGRS.2011.2153860]

    Oreopoulos, L., M. Wilson, and T. Varnai. 2011. "Implementation on Landsat Data of a Simple Cloud-Mask Algorithm Developed for MODIS Land Bands." IEEE Geosci. Remote Sensing Lett. 8 (4): 597-601 [10.1109/LGRS.2010.2095409]

    Varnai, T., and A. Marshak. 2011. "Global CALIPSO Observations of Aerosol Changes Near Clouds." IEEE Geosci. Remote Sensing Lett. 8 (1): 19-23 [10.1109/LGRS.2010.2049982]

    Varnai, T. 2010. "Multiyear Statistics of 2D Shortwave Radiative Effects at Three ARM Sites." J Atmos Sci 67 (11): 3757-3762 [10.1175/2010JAS3506.1]

    Yang, Y., A. Marshak, T. Varnai, W. J. Wiscombe, and P. Yang. 2010. "Uncertainties in Ice-Sheet Altimetry From a Spaceborne 1064-nm Single-Channel Lidar Due to Undetected Thin Clouds." IEEE Trans. Geosci. Remote Sensing 48 (1): 250-259 [10.1109/TGRS.2009.2028335]

    Varnai, T., and A. Marshak. 2009. "MODIS observations of enhanced clear sky reflectance near clouds." Geophys. Res. Lett. 36 (6): L06807 [10.1029/2008GL037089]

    Evans, K., A. Marshak, and T. Varnai. 2008. "The Potential for Improved Boundary Layer Cloud Optical Depth Retrievals from the Multiple Directions of MISR." Journal of the Atmospheric Sciences 65 (10): 3179-3196 [10.1175/2008JAS2627.1]

    Varnai, T., and A. Marshak. 2007. "View angle dependence of cloud optical thicknesses retrieved by Moderate Resolution Imaging Spectroradiometer (MODIS)." J. Geophys. Res. 112 (D6): D06203 [10.1029/2005JD006912]

    Varnai, T., and R. F. Cahalan. 2007. "Potential for airborne offbeam lidar measurements of snow and sea ice thickness." J. Geophys. Res. 112 (C12): C12S90 [10.1029/2007JC004091]

    Oreopoulos, L., A. Marshak, R. F. Cahalan, et al. T. Varnai, A. B. Davis, and A. Macke. 2006. "New directions in the radiative transfer of cloudy atmospheres." Eos Trans. AGU 87 (5): 52 [10.1029/2006EO050006]

    Marshak, A., S. E. Platnick, T. Varnai, G. Wen, and R. F. Cahalan. 2006. "Impact of three-dimensional radiative effects on satellite retrievals of cloud droplet sizes." J. Geophys. Res. 111 (D9): D09207 [10.1029/2005JD006686]

    Cahalan, R., L. Oreopoulos, A. Marshak, et al. K. Evans, A. Davis, R. Pincus, K. Yetzer, B. Mayer, R. Davies, T. Ackerman, H. Barker, E. Clothiaux, R. Ellingson, M. Garay, E. Kassianov, S. Kinne, O. Macke, O. Macke, O. Macke, P. Partain, S. Prigarin, A. Rublev, G. Stephens, F. Szczap, E. Takara, T. Varnai, G. Wen, and T. Zhuravleva. 2005. "The International Intercomparison of 3D Radiation Codes (I3RC): Bringing together the most advanced radiative transfer tools for cloudy atmospheres." Bull Amer Meteor Soc 86 (9): 1275-1293 [10.1175/BAMS-86-9-1275]

    Cahalan, R. F., M. J. Mcgill, J. Kolasinski, T. Varnai, and K. Yetzer. 2005. "THOR—Cloud Thickness from Offbeam Lidar Returns." Journal of Atmospheric and Oceanic Technology 22 (6): 605-627 [10.1175/JTECH1740.1]

    Varnai, T. 2003. "A method for analyzing how various parts of clouds influence each other's brightness." J. Geophys. Res. 108 (D22): 4706 [10.1029/2003JD003561]

    Varnai, T., and A. Marshak. 2002. "Observations of three-dimensional radiative effects that influence satellite retrievals of cloud properties." Quart Jour of Hungarian Meteor Service (Idojaras) 106 265-278

    Varnai, T., and A. Marshak. 2002. "Observations of three-dimensional radiative effects that influence MODIS cloud optical thickness retrievals." J Atmos Sci 59 1607-1618

    Varnai, T., and A. Marshak. 2001. "Statistical analysis of the uncertainties in cloud optical depth retrievals caused by three-dimensional radiative effects." J Atmos Sci 58 1540-1548

                                                                                                                                                                                            
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