Factors Controlling Low-Cloud Evolution over the Eastern Subtropical Oceans: A Lagrangian Perspective Using the A-Train Satellites

Ryan Eastman Department of Atmospheric Sciences, University of Washington, Seattle, Washington

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Robert Wood Department of Atmospheric Sciences, University of Washington, Seattle, Washington

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Abstract

A Lagrangian technique is developed to sample satellite data to quantify and understand factors controlling temporal changes in low-cloud properties (cloud cover, areal-mean liquid water path, and droplet concentration). Over 62 000 low-cloud scenes over the eastern subtropical/tropical oceans are sampled using the A-Train satellites. Horizontal wind fields at 925 hPa from the ERA-Interim are used to compute 24-h, two-dimensional, forward, boundary layer trajectories with trajectory locations starting on the CloudSat/CALIPSO track. Cloud properties from MODIS and AMSR-E are sampled at the trajectory start and end points, allowing for direct measurement of the temporal cloud evolution. The importance of various controls (here, boundary layer depth, lower-tropospheric stability, and precipitation) on cloud evolution is evaluated by comparing cloud evolution for different initial values of these controls. Viewing angle biases are removed and cloud anomalies (diurnal and seasonal cycles removed) are used throughout to quantify cloud evolution relative to the climatological-mean evolution. Cloud property anomalies show temporal changes similar to those expected for a stochastic red noise process, with linear relationships between initial anomalies and their mean 24-h changes. This creates a potential bias when comparing the evolutions of sets of trajectories with different initial anomalies; three methods are introduced and evaluated to account for this. Results provide statistically robust observational support for theoretical/modeling studies by showing that low clouds in deep boundary layers and under weak inversions are prone to break up. Precipitation shows a more complex and less statistically significant relationship with cloud breakup. Cloud cover in shallow precipitating boundary layers is more persistent than in deep precipitating boundary layers. Liquid water path and cloud droplet concentration decrease more rapidly for precipitating clouds and in deep boundary layers.

Corresponding author address: Ryan Eastman, Department of Atmospheric Sciences, University of Washington, Box 351640, Seattle, WA 98195. E-mail: rmeast@atmos.washington.edu

Abstract

A Lagrangian technique is developed to sample satellite data to quantify and understand factors controlling temporal changes in low-cloud properties (cloud cover, areal-mean liquid water path, and droplet concentration). Over 62 000 low-cloud scenes over the eastern subtropical/tropical oceans are sampled using the A-Train satellites. Horizontal wind fields at 925 hPa from the ERA-Interim are used to compute 24-h, two-dimensional, forward, boundary layer trajectories with trajectory locations starting on the CloudSat/CALIPSO track. Cloud properties from MODIS and AMSR-E are sampled at the trajectory start and end points, allowing for direct measurement of the temporal cloud evolution. The importance of various controls (here, boundary layer depth, lower-tropospheric stability, and precipitation) on cloud evolution is evaluated by comparing cloud evolution for different initial values of these controls. Viewing angle biases are removed and cloud anomalies (diurnal and seasonal cycles removed) are used throughout to quantify cloud evolution relative to the climatological-mean evolution. Cloud property anomalies show temporal changes similar to those expected for a stochastic red noise process, with linear relationships between initial anomalies and their mean 24-h changes. This creates a potential bias when comparing the evolutions of sets of trajectories with different initial anomalies; three methods are introduced and evaluated to account for this. Results provide statistically robust observational support for theoretical/modeling studies by showing that low clouds in deep boundary layers and under weak inversions are prone to break up. Precipitation shows a more complex and less statistically significant relationship with cloud breakup. Cloud cover in shallow precipitating boundary layers is more persistent than in deep precipitating boundary layers. Liquid water path and cloud droplet concentration decrease more rapidly for precipitating clouds and in deep boundary layers.

Corresponding author address: Ryan Eastman, Department of Atmospheric Sciences, University of Washington, Box 351640, Seattle, WA 98195. E-mail: rmeast@atmos.washington.edu
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  • Albrecht, B., 1989: Aerosols, cloud microphysics, and fractional cloudiness. Science, 245, 1227–1230, doi:10.1126/science.245.4923.1227.

    • Search Google Scholar
    • Export Citation
  • Bennartz, R., 2007: Global assessment of marine boundary layer cloud droplet number concentration from satellites. J. Geophys. Res., 112, D02201, doi:10.1029/2006JD007547.

    • Search Google Scholar
    • Export Citation
  • Boers, R., J. A. Acarreta, and J. L. Gras, 2006: Satellite monitoring of the first indirect aerosol effect: Retrieval of the droplet concentration of water clouds. J. Geophys. Res., 111, D22208, doi:10.1029/2005JD006838.

    • Search Google Scholar
    • Export Citation
  • Bretherton, C. S., and M. Wyant, 1997: Moisture transport, lower-tropospheric stability, and decoupling of cloud-topped boundary layers. J. Atmos. Sci., 54, 148–167, doi:10.1175/1520-0469(1997)054<0148:MTLTSA>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Bretherton, C. S., and Coauthors, 2004: The EPIC 2001 stratocumulus study. Bull. Amer. Meteor. Soc., 85, 967–977, doi:10.1175/BAMS-85-7-967.

    • Search Google Scholar
    • Export Citation
  • Bretherton, C. S., R. Wood, R. C. George, D. Leon, G. Allen, and X. Zheng, 2010: Southeast Pacific stratocumulus clouds, precipitation and boundary layer structure sampled along 20° S during VOCALS-Rex. Atmos. Chem. Phys., 10, 10 639–10 654, doi:10.5194/acp-10-10639-2010.

    • Search Google Scholar
    • Export Citation
  • Burleyson, C. D., and S. E. Yuter, 2015: Subdiurnal stratocumulus cloud fraction variability and sensitivity to precipitation. J. Climate, 28, 2968–2985, doi:10.1175/JCLI-D-14-00648.1.

  • Comstock, K. K., R. Wood, S. E. Yuter, and C. S. Bretherton, 2004: Reflectivity and rain rate in and below drizzling stratocumulus. Quart. J. Roy. Meteor. Soc., 130, 2891–2918, doi:10.1256/qj.03.187.

    • Search Google Scholar
    • Export Citation
  • Comstock, K. K., C. S. Bretherton, and S. E. Yuter, 2005: Mesoscale variability and drizzle in southeast Pacific stratocumulus. J. Atmos. Sci., 62, 3792–3807, doi:10.1175/JAS3567.1.

    • Search Google Scholar
    • Export Citation
  • Dee, D. P., and Coauthors, 2011: The ERA-Interim reanalysis: Configuration and performance of the data assimilation system. Quart. J. Roy. Meteor. Soc., 137, 553–597, doi:10.1002/qj.828.

    • Search Google Scholar
    • Export Citation
  • Eastman, R., and S. G. Warren, 2014: Diurnal cycles of cumulus, cumulonimbus, stratus, stratocumulus, and fog from surface observations over land and ocean. J. Climate, 27, 2386–2404, doi:10.1175/JCLI-D-13-00352.1.

    • Search Google Scholar
    • Export Citation
  • Gryspeerdt, E., P. Stier, and D. G. Partridge, 2014: Satellite observations of cloud regime development: The role of aerosol processes. Atmos. Chem. Phys., 14, 1141–1158, doi:10.5194/acp-14-1141-2014.

    • Search Google Scholar
    • Export Citation
  • Hahn, C. J., and S. G. Warren, 2007: A gridded climatology of clouds over land (1971-96) and ocean (1954-97) from surface observations worldwide. Department of Energy CDIAC Numeric Data Package NDP-026E, accessed 6 November 2015, doi:10.3334/CDIAC/cli.ndp026e.

  • Hartmann, D. L., and D. A. Short, 1980: On the use of earth radiation budget statistics for studies of clouds and climate. J. Atmos. Sci., 37, 1233–1250, doi:10.1175/1520-0469(1980)037<1233:OTUOER>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Hubanks, P. A., M. D. King, S. Platnick, and R. Pincus, 2008: MODIS atmosphere L3 gridded product. NASA Algorithm Theoretical Basis Doc. ATBD-MOD-30, 90 pp.

  • King, M. D., and Coauthors, 2003: Cloud and aerosol properties, precipitable water, and profiles of temperature and humidity. IEEE Trans. Geosci. Remote Sens., 41, 442–458, doi:10.1109/TGRS.2002.808226.

    • Search Google Scholar
    • Export Citation
  • Klein, S. A., and D. L. Hartmann, 1993: The seasonal cycle of low stratiform clouds. J. Climate, 6, 1587–1606, doi:10.1175/1520-0442(1993)006<1587:TSCOLS>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Klein, S. A., D. L. Hartmann, and J. R. Norris, 1995: On the relationship among low-cloud structure, sea surface temperature and atmospheric circulation in the summertime northeast Pacific. J. Climate, 8, 1140–1155, doi:10.1175/1520-0442(1995)008<1140:OTRALC>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Krueger, S. K., G. T. McLean, and Q. Fu, 1995: Numerical simulation of the stratus-to-cumulus transition in the subtropical marine boundary layer. Part I: Boundary layer structure. J. Atmos. Sci., 52, 2839–2850, doi:10.1175/1520-0469(1995)052<2839:NSOTST>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Lebsock, M. D., and T. S. L’Ecuyer, 2011: The retrieval of warm rain from CloudSat. J. Geophys. Res., 116, D20209, doi:10.1029/2011JD016076.

    • Search Google Scholar
    • Export Citation
  • Lilly, D. K., 1968: Models of cloud-topped mixed layers under a strong inversion. Quart. J. Roy. Meteor. Soc., 94, 292–309, doi:10.1002/qj.49709440106.

    • Search Google Scholar
    • Export Citation
  • Maddux, B. C., S. A. Ackerman, and S. Platnick, 2010: Viewing geometry dependencies in MODIS cloud products. J. Atmos. Oceanic Technol., 27, 1519–1528, doi:10.1175/2010JTECHA1432.1.

    • Search Google Scholar
    • Export Citation
  • Martin, G. M., D. W. Johnson, and A. Spice, 1994: The measurement and parameterization of effective radius of droplets in warm stratocumulus clouds. J. Atmos. Sci., 51, 1823–1842, doi:10.1175/1520-0469(1994)051<1823:TMAPOE>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Mauger, G. S., and J. R. Norris, 2010: Assessing the impact of meteorological history on subtropical cloud fraction. J. Climate, 23, 2926–2940, doi:10.1175/2010JCLI3272.1.

    • Search Google Scholar
    • Export Citation
  • Mechem, D. B., and Y. L. Kogan, 2003: Simulating the transition from drizzling marine stratocumulus to boundary layer cumulus with a mesoscale model. Mon. Wea. Rev., 131, 2342–2360, doi:10.1175/1520-0493(2003)131<2342:STTFDM>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Mitrescu, C., T. L’Ecuyer, J. Haynes, S. Miller, and J. Turk, 2010: CloudSat precipitation profiling algorithm: Model description. J. Appl. Meteor. Climatol., 49, 991–1003, doi:10.1175/2009JAMC2181.1.

    • Search Google Scholar
    • Export Citation
  • Myers, T. A., and J. R. Norris, 2013: Observational evidence that enhanced subsidence reduces subtropical marine boundary layer cloudiness. J. Climate, 26, 7507–7524, doi:10.1175/JCLI-D-12-00736.1.

    • Search Google Scholar
    • Export Citation
  • Nicholls, S., 1984: The dynamics of stratocumulus: Aircraft observations and comparisons with a mixed layer model. Quart. J. Roy. Meteor. Soc., 110, 783–820, doi:10.1002/qj.49711046603.

    • Search Google Scholar
    • Export Citation
  • Nicholls, S., 1989: The structure of radiatively driven convection in stratocumulus. Quart. J. Roy. Meteor. Soc., 115, 487–511, doi:10.1002/qj.49711548704.

    • Search Google Scholar
    • Export Citation
  • Oreopoulos, L., 2005: The impact of subsampling on MODIS level-3 statistics of cloud optical thickness and effective radius. IEEE Trans. Geosci. Remote Sens., 43, 366–373, doi:10.1109/TGRS.2004.841247.

    • Search Google Scholar
    • Export Citation
  • Pincus, R., M. B. Baker, and C. S. Bretherton, 1997: What controls stratocumulus radiative properties? Lagrangian observations of cloud evolution. J. Atmos. Sci., 54, 2215–2236, doi:10.1175/1520-0469(1997)054<2215:WCSRPL>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Randall, D. A., 1984: Stratocumulus cloud deepening through entrainment. Tellus, 36A, 446–457, doi:10.1111/j.1600-0870.1984.tb00261.x.

    • Search Google Scholar
    • Export Citation
  • Rogers, D. P., and D. Koracin, 1992: Radiative transfer and turbulence in the cloud-topped marine atmospheric boundary layer. J. Atmos. Sci., 49, 1473–1486, doi:10.1175/1520-0469(1992)049<1473:RTATIT>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Sandu, I., and B. Stevens, 2011: On the factors modulating the stratocumulus to cumulus transitions. J. Atmos. Sci., 68, 1865–1881, doi:10.1175/2011JAS3614.1.

    • Search Google Scholar
    • Export Citation
  • Sandu, I., B. Stevens, and R. Pincus, 2010: On the transitions in marine boundary layer cloudiness. Atmos. Chem. Phys., 10, 2377–2391, doi:10.5194/acp-10-2377-2010.

    • Search Google Scholar
    • Export Citation
  • Stevens, B., W. R. Cotton, G. Feingold, and C.-H. Moeng, 1998: Large-eddy simulations of strongly precipitating, shallow, stratocumulus-topped boundary layers. J. Atmos. Sci., 55, 3616–3638, doi:10.1175/1520-0469(1998)055<3616:LESOSP>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Stevens, B., G. Vali, K. Comstock, R. Wood, M. VanZanten, P. H. Austin, C. S. Bretherton, and D. H. Lenschow, 2005: Pockets of open cells (POCs) and drizzle in marine stratocumulus. Bull. Amer. Meteor. Soc., 86, 51–57, doi:10.1175/BAMS-86-1-51.

    • Search Google Scholar
    • Export Citation
  • Terai, C. R., C. S. Bretherton, R. Wood, and G. Painter, 2014: Aircraft observations of aerosol, cloud, precipitation, and boundary layer properties in pockets of open cells over the southeast Pacific. Atmos. Chem. Phys., 14, 8071–8088, doi:10.5194/acp-14-8071-2014.

    • Search Google Scholar
    • Export Citation
  • Turton, J. D., and S. Nicholls, 1987: A study of the diurnal variation of stratocumulus using a multiple mixed layer model. Quart. J. Roy. Meteor. Soc., 113, 969–1009, doi:10.1002/qj.49711347712.

    • Search Google Scholar
    • Export Citation
  • Vaughan, M., S. Young, D. Winker, K. Powell, A. Omar, Z. Liu, Y. Hu, and C. Hostetler, 2004: Fully automated analysis of space-based lidar data: An overview of the CALIPSO retrieval algorithms and data products. Laser Radar Techniques for Atmospheric Sensing, U. N. Singh, Ed., International Society for Optical Engineering (SPIE Proceedings, Vol. 5575), 16–30.

  • Wang, H., and G. Feingold, 2009: Modeling mesoscale cellular structures and drizzle in marine stratocumulus. Part I: Impact of drizzle on the formation and evolution of open cells. J. Atmos. Sci., 66, 3237–3256, doi:10.1175/2009JAS3022.1.

    • Search Google Scholar
    • Export Citation
  • Wang, S., and B. A. Albrecht, 1986: A stratocumulus model with an internal circulation. J. Atmos. Sci., 43, 2374–2391, doi:10.1175/1520-0469(1986)043<2374:ASMWAI>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Wentz, F. J., and T. Meissner, 2004: AMSR-E/Aqua L2B global swath ocean products derived from Wentz algorithm, version 2. [L3 LWP]. National Snow and Ice Data Center, Boulder, CO, digital media. [Available online at http://nsidc.org/api/metadata?id=ae_ocean.]

  • Wood, R., 2000: Parametrization of the effect of drizzle upon the droplet effective radius in stratocumulus clouds. Quart. J. Roy. Meteor. Soc., 126, 3309–3324, doi:10.1002/qj.49712657015.

    • Search Google Scholar
    • Export Citation
  • Wood, R., 2012: Stratocumulus clouds. Mon. Wea. Rev., 140, 2373–2423, doi:10.1175/MWR-D-11-00121.1.

  • Wood, R., and C. S. Bretherton, 2004: Boundary layer depth, entrainment, and decoupling in the cloud-capped subtropical and tropical marine boundary layer. J. Climate, 17, 3576–3588, doi:10.1175/1520-0442(2004)017<3576:BLDEAD>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Wood, R., and D. L. Hartmann, 2006: Spatial variability of liquid water path in marine low cloud: The importance of mesoscale cellular convection. J. Climate, 19, 1748–1764, doi:10.1175/JCLI3702.1.

    • Search Google Scholar
    • Export Citation
  • Wood, R., D. Leon, M. Lebsock, J. Snider, and A. D. Clarke, 2012: Precipitation driving droplet concentration variability in low clouds. J. Geophys. Res., 117, D19210, doi:10.1029/2012JD018305.

    • Search Google Scholar
    • Export Citation
  • Wyant, M. C., C. S. Bretherton, H. A. Rand, and D. E. Stevens, 1997: Numerical simulations and a conceptual model of the stratocumulus to trade cumulus transition. J. Atmos. Sci., 54, 168–192, doi:10.1175/1520-0469(1997)054<0168:NSAACM>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Xiao, H., C. M. Wu, and C. R. Mechoso, 2011: Buoyancy reversal, decoupling, and the transition from stratocumulus to shallow cumulus topped marine boundary layers. Climate Dyn., 37, 971–984, doi:10.1007/s00382-010-0882-3.

    • Search Google Scholar
    • Export Citation
  • Zhou, X., P. Kollias, and E. Lewis, 2015: Clouds, precipitation and marine boundary layer structure during the MAGIC field campaign. J. Climate, 28, 2420–2442, doi:10.1175/JCLI-D-14-00320.1.

    • Search Google Scholar
    • Export Citation
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