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Dr. Florian Tornow

Photo of FLORIAN TORNOW

Dr. Florian Tornow

  • Post Doc
  • 212.678.5631
  • NASA GISS
  • 2880 Broadway
  • Employer: TRUSTEES OF COLUMBIA UNIVERSITY

    • Research Interests

    Clouds and Satellite-based Estimates of their Albedo

    Clouds reflect large portions of incoming sunlight back to space. To quantify this portion (termed cloud albedo) satellite-borne radiometry of Earth’s atmosphere is essential. Since clouds reflect sunlight unevenly into different space-facing directions and a satellite is only able to capture one of these directions at a time, assumptions are necessary of much reflected radiation went into all unobserved directions. So called angular distribution models rely on past satellite observations to statistically capture reflection patterns for different cloud properties and states of Earth’s surface. In my recent work (Tornow et al., 2020) I developed a novel semi-statistical angular distribution model that incorporates additional cloud microphysical and atmospheric properties and that may improve determining clouds’ albedo from satellite (Tornow et al., 2021a).

    Cloud Microphysical Processes

    The life of clouds is in large parts determined at the smallest scales. In my current work, I’m using large-eddy simulations to investigate how clouds, which form during marine cold air outbreaks, evolve as they interact with aerosols from within the boundary layer as well as the free troposphere that contributes through entrainment. In our latest work, we assess the role of frozen hydrometeors to accelerate the cloud transition from overcast to broken state (Tornow et al., 2021b).

    Current Projects

    ACTIVATE (Aerosol Cloud Meteorology Interactions Over the Western Atlantic Experiment), funded by NASA’s Science Mission Directorate through the Earth Venture Suborbital Program

    We aim to improve our understanding of cloud-aerosol interaction through the use of in-situ and remote sensing data gathered from two aircrafts as well as numeric simulations. In my work, I use large-eddy simulations to study the evolution of clouds in cold air outbreaks and the role of microphysical processes in them.

    Positions/Employment

    12/2019 - Present

    Post-doctoral research scientist

    Columbia University, Columbia University Center for Climate System Research and NASA GISS, New York, NY
    9/2014 - 11/2019

    Research Assistant

    Institute for Space Sciences, Freie Universität Berlin, Berlin, Germany
    5/2014 - 8/2014

    Intern

    Royal Meteorological Institute of Belgium, Brussels, Belgium
    2/2012 - 2/2014

    Student Assistant

    Institute for Space Sciences, Freie Universität Berlin, Berlin, Germany

    Education

    2018    PhD, Freie Universität Berlin, Berlin, Germany, Thesis: “Contributions to Estimating Top-Of-Atmosphere Radiative Fluxes using EarthCARE’s BroadBand Radiometer” (Magna cum laude), Advisor: Prof. Dr. Jürgen Fischer

    2014.   M. Sc., Freie Universität Berlin, Berlin, Germany, Thesis: “Analysis of radiance co-registration methods for the multi-angular BBR in the framework of the EarthCARE mission”, Advisor: Prof. Dr. Jürgen Fischer

     

    Publications

    Refereed

    Painemal, D., S. Chellappan, W. L. Smith, et al. D. Spangenberg, J. M. Park, A. Ackerman, J. Chen, E. Crosbie, R. Ferrare, J. Hair, S. Kirschler, X. Li, A. McComiskey, R. H. Moore, K. Sanchez, A. Sorooshian, F. Tornow, C. Voigt, H. Wang, E. Winstead, X. Zeng, L. Ziemba, and P. Zuidema. 2023. "Wintertime synoptic patterns of midlatitude boundary layer clouds over the western North Atlantic: Climatology and insights from in‐situ ACTIVATE observations." Journal of Geophysical Research: Atmospheres, [10.1029/2022jd037725]

    Li, X.-Y., H. Wang, J. Chen, et al. S. Endo, S. Kirschler, C. Voigt, E. Crosbie, L. D. Ziemba, D. Painemal, B. Cairns, J. W. Hair, A. F. Corral, C. Robinson, H. Dadashazar, A. Sorooshian, G. Chen, R. A. Ferrare, M. M. Kleb, H. Liu, R. Moore, A. J. Scarino, M. A. Shook, T. J. Shingler, K. L. Thornhill, F. Tornow, H. Xiao, and X. Zeng. 2023. "Large-Eddy Simulations of Marine Boundary Layer Clouds Associated with Cold-Air Outbreaks during the ACTIVATE Campaign. Part II: Aerosol–Meteorology–Cloud Interaction." Journal of the Atmospheric Sciences, 80 (4): 1025-1045 [10.1175/jas-d-21-0324.1]

    Tornow, F., A. S. Ackerman, A. M. Fridlind, et al. B. Cairns, E. C. Crosbie, S. Kirschler, R. H. Moore, D. Painemal, C. E. Robinson, C. Seethala, M. A. Shook, C. Voigt, E. L. Winstead, L. D. Ziemba, P. Zuidema, and A. Sorooshian. 2022. "Dilution of Boundary Layer Cloud Condensation Nucleus Concentrations by Free Tropospheric Entrainment During Marine Cold Air Outbreaks." Geophysical Research Letters, 49 (11): [10.1029/2022gl098444]

    Seethala, C., P. Zuidema, J. Edson, et al. M. Brunke, G. Chen, X. Li, D. Painemal, C. Robinson, T. Shingler, M. Shook, A. Sorooshian, L. Thornhill, F. Tornow, H. Wang, X. Zeng, and L. Ziemba. 2021. "On Assessing ERA5 and MERRA2 Representations of Cold‐Air Outbreaks Across the Gulf Stream." Geophysical Research Letters, 48 (19): [10.1029/2021gl094364]

    Tornow, F., A. S. Ackerman, and A. M. Fridlind. 2021. "Preconditioning of overcast-to-broken cloud transitions by riming in marine cold air outbreaks." Atmospheric Chemistry and Physics, 21 (15): 12049-12067 [10.5194/acp-21-12049-2021]

    Gristey, J. J., W. Su, N. G. Loeb, et al. T. H. Vonder Haar, F. Tornow, K. S. Schmidt, M. Z. Hakuba, P. Pilewskie, and J. E. Russell. 2021. "Shortwave Radiance to Irradiance Conversion for Earth Radiation Budget Satellite Observations: A Review." Remote Sensing, 13 (13): 2640 [10.3390/rs13132640]

    Tornow, F., C. Domenech, J. N. Cole, N. Madenach, and J. Fischer. 2021. "Changes in TOA SW Fluxes over Marine Clouds When Estimated via Semi-Physical Angular Distribution Models." Journal of Atmospheric and Oceanic Technology, (Accepted) [10.1175/jtech-d-20-0107.1]

    Tornow, F., C. Domenech, H. W. Barker, R. Preusker, and J. Fischer. 2020. "Using two-stream theory to capture fluctuations of satellite-perceived TOA SW radiances reflected from clouds over ocean." Atmospheric Measurement Techniques, 13 (7): 3909-3922 [10.5194/amt-13-3909-2020]

    Tornow, F., C. Domenech, and J. Fischer. 2019. "On the Use of Geophysical Parameters for the Top-of-Atmosphere Shortwave Clear-Sky Radiance-to-Flux Conversion in EarthCARE." Journal of Atmospheric and Oceanic Technology, 36 (4): 717-732 [10.1175/jtech-d-18-0087.1]

    Tornow, F., H. W. Barker, V. Blázquez, C. Domenech, and J. Fischer. 2018. "EarthCARE’s Broadband Radiometer: Uncertainties Associated with Cloudy Atmospheres." Journal of Atmospheric and Oceanic Technology, 35 (11): 2201-2211 [10.1175/jtech-d-18-0083.1]

    Tornow, F., R. Preusker, C. Domenech, et al. C. Carbajal Henken, S. Testorp, and J. Fischer. 2018. "Top-of-Atmosphere Shortwave Anisotropy over Liquid Clouds: Sensitivity to Clouds’ Microphysical Structure and Cloud-Topped Moisture." Atmosphere, 9 (7): 256 [10.3390/atmos9070256]

    Tornow, F., N. Clerbaux, A. Ipe, and M. Urbain. 2017. "An improved method to estimate reference cloud-free images for the visible band of geostationary satellites." International Journal of Remote Sensing, 38 (23): 7220-7241 [10.1080/01431161.2017.1372859]

    Tornow, F., H. W. Barker, and C. Domenech. 2015. "On the use of simulated photon paths to co‐register top‐of‐atmosphere radiances in EarthCARE radiative closure experiments." Quarterly Journal of the Royal Meteorological Society, 141 (693): 3239-3251 [10.1002/qj.2606]

    Publications

    Refereed

    Painemal, D., S. Chellappan, W. L. Smith, et al. D. Spangenberg, J. M. Park, A. Ackerman, J. Chen, E. Crosbie, R. Ferrare, J. Hair, S. Kirschler, X. Li, A. McComiskey, R. H. Moore, K. Sanchez, A. Sorooshian, F. Tornow, C. Voigt, H. Wang, E. Winstead, X. Zeng, L. Ziemba, and P. Zuidema. 2023. "Wintertime synoptic patterns of midlatitude boundary layer clouds over the western North Atlantic: Climatology and insights from in‐situ ACTIVATE observations." Journal of Geophysical Research: Atmospheres [10.1029/2022jd037725]

    Li, X.-Y., H. Wang, J. Chen, et al. S. Endo, S. Kirschler, C. Voigt, E. Crosbie, L. D. Ziemba, D. Painemal, B. Cairns, J. W. Hair, A. F. Corral, C. Robinson, H. Dadashazar, A. Sorooshian, G. Chen, R. A. Ferrare, M. M. Kleb, H. Liu, R. Moore, A. J. Scarino, M. A. Shook, T. J. Shingler, K. L. Thornhill, F. Tornow, H. Xiao, and X. Zeng. 2023. "Large-Eddy Simulations of Marine Boundary Layer Clouds Associated with Cold-Air Outbreaks during the ACTIVATE Campaign. Part II: Aerosol–Meteorology–Cloud Interaction." Journal of the Atmospheric Sciences 80 (4): 1025-1045 [10.1175/jas-d-21-0324.1]

    Tornow, F., A. S. Ackerman, A. M. Fridlind, et al. B. Cairns, E. C. Crosbie, S. Kirschler, R. H. Moore, D. Painemal, C. E. Robinson, C. Seethala, M. A. Shook, C. Voigt, E. L. Winstead, L. D. Ziemba, P. Zuidema, and A. Sorooshian. 2022. "Dilution of Boundary Layer Cloud Condensation Nucleus Concentrations by Free Tropospheric Entrainment During Marine Cold Air Outbreaks." Geophysical Research Letters 49 (11): [10.1029/2022gl098444]

    Seethala, C., P. Zuidema, J. Edson, et al. M. Brunke, G. Chen, X. Li, D. Painemal, C. Robinson, T. Shingler, M. Shook, A. Sorooshian, L. Thornhill, F. Tornow, H. Wang, X. Zeng, and L. Ziemba. 2021. "On Assessing ERA5 and MERRA2 Representations of Cold‐Air Outbreaks Across the Gulf Stream." Geophysical Research Letters 48 (19): [10.1029/2021gl094364]

    Tornow, F., A. S. Ackerman, and A. M. Fridlind. 2021. "Preconditioning of overcast-to-broken cloud transitions by riming in marine cold air outbreaks." Atmospheric Chemistry and Physics 21 (15): 12049-12067 [10.5194/acp-21-12049-2021]

    Gristey, J. J., W. Su, N. G. Loeb, et al. T. H. Vonder Haar, F. Tornow, K. S. Schmidt, M. Z. Hakuba, P. Pilewskie, and J. E. Russell. 2021. "Shortwave Radiance to Irradiance Conversion for Earth Radiation Budget Satellite Observations: A Review." Remote Sensing 13 (13): 2640 [10.3390/rs13132640]

    Tornow, F., C. Domenech, J. N. Cole, N. Madenach, and J. Fischer. 2021. "Changes in TOA SW Fluxes over Marine Clouds When Estimated via Semi-Physical Angular Distribution Models." Journal of Atmospheric and Oceanic Technology (Accepted) [10.1175/jtech-d-20-0107.1]

    Tornow, F., C. Domenech, H. W. Barker, R. Preusker, and J. Fischer. 2020. "Using two-stream theory to capture fluctuations of satellite-perceived TOA SW radiances reflected from clouds over ocean." Atmospheric Measurement Techniques 13 (7): 3909-3922 [10.5194/amt-13-3909-2020]

    Tornow, F., C. Domenech, and J. Fischer. 2019. "On the Use of Geophysical Parameters for the Top-of-Atmosphere Shortwave Clear-Sky Radiance-to-Flux Conversion in EarthCARE." Journal of Atmospheric and Oceanic Technology 36 (4): 717-732 [10.1175/jtech-d-18-0087.1]

    Tornow, F., H. W. Barker, V. Blázquez, C. Domenech, and J. Fischer. 2018. "EarthCARE’s Broadband Radiometer: Uncertainties Associated with Cloudy Atmospheres." Journal of Atmospheric and Oceanic Technology 35 (11): 2201-2211 [10.1175/jtech-d-18-0083.1]

    Tornow, F., R. Preusker, C. Domenech, et al. C. Carbajal Henken, S. Testorp, and J. Fischer. 2018. "Top-of-Atmosphere Shortwave Anisotropy over Liquid Clouds: Sensitivity to Clouds’ Microphysical Structure and Cloud-Topped Moisture." Atmosphere 9 (7): 256 [10.3390/atmos9070256]

    Tornow, F., N. Clerbaux, A. Ipe, and M. Urbain. 2017. "An improved method to estimate reference cloud-free images for the visible band of geostationary satellites." International Journal of Remote Sensing 38 (23): 7220-7241 [10.1080/01431161.2017.1372859]

    Tornow, F., H. W. Barker, and C. Domenech. 2015. "On the use of simulated photon paths to co‐register top‐of‐atmosphere radiances in EarthCARE radiative closure experiments." Quarterly Journal of the Royal Meteorological Society 141 (693): 3239-3251 [10.1002/qj.2606]

                                                                                                                                                                                            
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    • Last Updated: 06/06/2023