• Ackerman, A. S., , M. P. Kirkpatrick, , D. E. Stevens, , and O. B. Toon, 2004: The impact of humidity above stratiform clouds on indirect aerosol climate forcing. Nature, 432 , 10141017.

    • Search Google Scholar
    • Export Citation
  • Adams, J. C., , and P. Swarztruabuer, 1997: SPHEREPACK 2.0: A model development facility. Tech. Note NCAR/TN-436-STR, National Center for Atmospheric Research, Boulder, CO, 58 pp.

  • Betts, A. K., , P. Minnis, , W. Ridgeway, , and D. F. Young, 1992: Integration of satellite and surface data using a radiative convective oceanic boundary layer model. J. Appl. Meteor., 31 , 340350.

    • Search Google Scholar
    • Export Citation
  • Bony, S., , J-L. Dufresne, , H. le Treut, , J-J. Morcrette, , and C. Senior, 2004: On dynamic and thermodynamic components of cloud changes. Climate Dyn., 22 , 7186.

    • Search Google Scholar
    • Export Citation
  • Boville, B., , P. J. Rasch, , J. J. Hack, , and J. R. McCaa, 2006: Representation of clouds and precipitation processes in the Community Atmosphere Model version 3 (CAM3). J. Climate, 19 , 21842198.

    • Search Google Scholar
    • Export Citation
  • Bretherton, C. S., , and R. Pincus, 1995: Cloudiness and marine boundary layer dynamics in the ASTEX Lagrangian experiments. Part I: Synoptic setting and vertical structure. J. Atmos. Sci., 52 , 27072723.

    • Search Google Scholar
    • Export Citation
  • Bretherton, C. S., , J. R. McCaa, , and H. Grenier, 2004a: A new parameterization for shallow cumulus convection and its application to marine subtropical cloud-topped boundary layers. Part I: Description and 1D results. Mon. Wea. Rev., 132 , 864882.

    • Search Google Scholar
    • Export Citation
  • Bretherton, C. S., and Coauthors, 2004b: The EPIC 2001 stratocumulus study. Bull. Amer. Meteor. Soc., 85 , 967977.

  • Caldwell, P., , C. S. Bretherton, , and R. Wood, 2005: Mixed-layer budget analysis of the diurnal cycle of entrainment in southeast Pacific stratocumulus. J. Atmos. Sci., 62 , 37753791.

    • Search Google Scholar
    • Export Citation
  • Campbell, G. G., 2004: View angle dependence of cloudiness and the trend in ISCCP cloudiness. Preprints, 13th Conf. on Satellite Meteorology and Oceanography, Norfolk, VA, Amer. Meteor. Soc., CD-ROM, P6.7.

  • Duynkerke, P. G., , and J. Teixeira, 2001: Comparison of the ECMWF reanalysis with FIRE I observations: Diurnal variation of marine stratocumulus. J. Climate, 14 , 14661478.

    • Search Google Scholar
    • Export Citation
  • Fiorino, M., 2004: A multi-decadal daily sea surface temperature and sea-ice concentration data set for the ERA-40 reanalysis. ERA-40 Project Rep. Series 12, ECMWF, 22 pp.

  • Garreaud, R. D., , and R. C. Muñoz, 2005: The low-level jet off the west coast of subtropical South America: Structure and variability. Mon. Wea. Rev., 133 , 22462261.

    • Search Google Scholar
    • Export Citation
  • Gentemann, C. L., , F. J. Wentz, , C. A. Mears, , and D. K. Smith, 2004: In situ validation of Tropical Rainfall Measuring Mission microwave sea surface temperatures. J. Geophys. Res., 109 .C04201, doi:10.1029/2003JC002092.

    • Search Google Scholar
    • Export Citation
  • Gibson, J. K., , P. Kållberg, , S. Uppala, , A. Nomura, , A. Hernadez, , and E. Serrano, 1997: ERA description. ERA-15 Project Rep. Series 1, ECMWF, 71 pp.

  • Goldberg, M. D., 1999: Generation of retrieval products from AMSU-A: Methodology and validation. Tech. Proc. 10th Int. TOVS Study Conf., Boulder, CO, Bureau of Meteorological Research Center, 215–219.

  • Grody, N., , J. Zhao, , R. Ferraro, , F. Weng, , and R. Boers, 2001: Determination of precipitable water and cloud liquid water over oceans from the NOAA-15 Advanced Microwave Sounding Unit. J. Geophys. Res., 106 , 29432953.

    • Search Google Scholar
    • Export Citation
  • Guan, L., , and H. Kawamura, 2003: SST availabilities of satellite infrared and microwave measurements. J. Oceanogr., 59 , 201209.

  • Kalnay, E., and Coauthors, 1996: The NCEP/NCAR 40-Year Reanalysis Project. Bull. Amer. Meteor. Soc., 77 , 437471.

  • Kilpatrick, K. A., , G. P. Podestá, , and R. Evans, 2001: Overview of the NOAA/NASA Advanced Very High Resolution Radiometer pathfinder algorithm for sea surface temperature and associated match-up database. J. Geophys. Res., 106 , 91799197.

    • Search Google Scholar
    • Export Citation
  • Klein, S. A., 1997: Synoptic variability of low-cloud properties and meteorological parameters in the subtropical trade wind boundary layer. J. Climate, 10 , 20182039.

    • Search Google Scholar
    • Export Citation
  • Klein, S. A., , and D. L. Hartmann, 1993: The seasonal cycle of low stratiform clouds. J. Climate, 6 , 15871606.

  • Lenschow, D. H., , P. B. Krummel, , and S. T. Siems, 1999: Measuring entrainment, divergence, and vorticity on the mesoscale from aircraft. J. Atmos. Oceanic Technol., 16 , 13841400.

    • Search Google Scholar
    • Export Citation
  • Lock, A., 2004: The sensitivity of a GCM’s marine stratocumulus to cloud-top entrainment. Quart. J. Roy. Meteor. Soc., 130 , 33233338.

    • Search Google Scholar
    • Export Citation
  • Lothon, M., , D. H. Lenschow, , D. Leon, , and G. Vali, 2005: Turbulence measurements in marine stratocumulus with airborne Doppler radar. Quart. J. Roy. Meteor. Soc., 131 , 20632080.

    • Search Google Scholar
    • Export Citation
  • McNoldy, B. D., , P. E. Ciesielski, , W. H. Schubert, , and R. H. Johnson, 2004: Surface winds, divergence, and vorticity in stratocumulus regions using QuikSCAT and ranalysis winds. Geophys. Res. Lett., 31 .L08105, doi:10.1029/2004GL019768.

    • Search Google Scholar
    • Export Citation
  • Miller, R. L., 1997: Tropical thermostats and low cloud cover. J. Climate, 10 , 409440.

  • Minnis, P., , D. Young, , C. Fairall, , and J. Snider, 1992: Stratocumulus cloud properties from simultaneous satellite and island-based instrumentation during FIRE. J. Appl. Meteor., 31 , 317339.

    • Search Google Scholar
    • Export Citation
  • Norris, J. R., 1998: Low cloud type over the ocean from surface observations. Part I: Relationship to surface meteorology and the vertical distribution of temperature and moisture. J. Climate, 11 , 369382.

    • Search Google Scholar
    • Export Citation
  • Norris, J. R., 1999: On trends and possible artifacts in global ocean cloud cover between 1952 and 1995. J. Climate, 12 , 18641870.

  • Norris, J. R., , and S. A. Klein, 2000: Low cloud type over the ocean from surface observations. Part III: Relationship to vertical motion and the regional surface synoptic environment. J. Climate, 13 , 245256.

    • Search Google Scholar
    • Export Citation
  • Reynolds, R. W., , N. A. Rayner, , T. M. Smith, , D. C. Stokes, , and W. Wang, 2002: An improved in situ and satellite SST analysis for climate. J. Climate, 15 , 16091625.

    • Search Google Scholar
    • Export Citation
  • Rossow, W., , and R. A. Schiffer, 1999: Advances in understanding clouds from ISCCP. Bull. Amer. Meteor. Soc., 80 , 22612287.

  • Rozendall, M. A., , and W. B. Rossow, 2003: Characterizing some of the influences of the general circulation on subtropical marine boundary layer clouds. J. Atmos. Sci., 60 , 711728.

    • Search Google Scholar
    • Export Citation
  • Savic-Jovcic, V., , B. Stevens, , and D. H. Lenschow, 2002: Estimating divergence and vorticity from aircraft data in the stratocumulus topped boundary layer. Preprints, 15th Symp. on Boundary Layers and Turbulence, Wageningen, Netherlands, Amer. Meteor. Soc., 112–113.

  • Schlax, M. G., , D. B. Chelton, , and M. H. Freilich, 2001: Sampling errors in wind fields constructed from single and tandem scatterometer datasets. J. Atmos. Oceanic Technol., 18 , 10141036.

    • Search Google Scholar
    • Export Citation
  • Slingo, J., 1980: Cloud parameterization scheme derived from GATE data for use with a numerical model. Quart. J. Roy. Meteor. Soc., 106 , 747770.

    • Search Google Scholar
    • Export Citation
  • Stephens, G. L., 1978: Radiation profiles in extended water clouds. Part II: Parameterization schemes. J. Atmos. Sci., 35 , 21232132.

  • Stephens, G. L., and Coauthors, 2002: The CloudSat mission and the A-Train: A new dimension of space-based observations of clouds and precipitation. Bull. Amer. Meteor. Soc., 83 , 17711790.

    • Search Google Scholar
    • Export Citation
  • Stevens, B., and Coauthors, 2003a: On entrainment in nocturnal marine stratocumulus. Quart. J. Roy. Meteor. Soc., 129 , 34693492.

  • Stevens, B., and Coauthors, 2003b: Dynamics and Chemistry of Marine Stratocumulus—DYCOMS-II. Bull. Amer. Meteor. Soc., 84 , 579593.

  • Stevens, B., and Coauthors, 2005a: Evaluation of large-eddy simulations via observations of nocturnal marine stratocumulus. Mon. Wea. Rev., 133 , 14431462.

    • Search Google Scholar
    • Export Citation
  • Stevens, B., , G. Vali, , K. Comstock, , R. Wood, , M. C. van Zanten, , P. H. Austin, , C. S. Bretherton, , and D. H. Lenschow, 2005b: Pockets of open cells and drizzle in marine stratocumulus. Bull. Amer. Meteor. Soc., 86 , 5157.

    • Search Google Scholar
    • Export Citation
  • Taylor, K. E., 2001: Summarizing multiple aspects of model performance in a single diagram. J. Geophys. Res., 106 , 71837192.

  • Troen, I. B., , and L. Mahrt, 1986: A simple model of the atmospheric boundary layer: Sensitivity to surface evaporation. Bound.-Layer Meteor., 36 , 129148.

    • Search Google Scholar
    • Export Citation
  • Uppala, S. M., and Coauthors, 2005: The ERA-40 re-analysis. Quart. J. Roy. Meteor. Soc., 131 , 29613012.

  • vanZanten, M. C., , and B. Stevens, 2005: Observations of the structure of heavily precipitating marine stratocumulus. J. Atmos. Sci., 62 , 43274342.

    • Search Google Scholar
    • Export Citation
  • vanZanten, M. C., , B. Stevens, , G. Vali, , and D. H. Lenschow, 2005: Observations of drizzle in nocturnal marine stratocumulus. J. Atmos. Sci., 62 , 88106.

    • Search Google Scholar
    • Export Citation
  • Wang, J., 2005: Evaluation of the dropsonde humidity sensor using data from DYCOMS-II and IHOP 2002. J. Atmos. Oceanic Technol., 22 , 247257.

    • Search Google Scholar
    • Export Citation
  • Wang, J., , W. B. Rossow, , T. Uttal, , and M. Rozendaal, 1999: Variability of cloud vertical structure during ASTEX observed from a combination of rawinsonde, radar, celiometer, and satellite. Mon. Wea. Rev., 127 , 24842502.

    • Search Google Scholar
    • Export Citation
  • Wood, R., , and C. S. Bretheron, 2004: Boundary layer depth, entrainment, and decoupling in the cloud-capped subtropical and tropical marine boundary layer. J. Climate, 17 , 35763588.

    • Search Google Scholar
    • Export Citation
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On the Structure of the Lower Troposphere in the Summertime Stratocumulus Regime of the Northeast Pacific

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  • * Department of Atmospheric and Oceanic Sciences, University of California, Los Angeles, Los Angeles, California
  • | + European Centre for Medium-Range Weather Forecasts, Reading, United Kingdom
  • | # Department of Meteorology, University of Utah, Salt Lake City, Utah
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Abstract

Data collected in situ as part of the second field study of the Dynamics and Chemistry of Marine Stratocumulus field program are used to evaluate the state of the atmosphere in the region of field operations near 30°N, 120°W during July 2001, as well as its representation by a variety of routinely available data. The routine data include both the 40-yr European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis (ERA-40) and NCEP–NCAR reanalyses, forecasts from their respective forecast systems (the Integrated and Global Forecast Systems), the 30-km archive from the International Satellite Cloud Climatology Project (ISCCP), the Quick Scatterometer surface winds, and remotely sensed fields derived from radiances measured by the Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI), the Advanced Microwave Sounding Unit, and the Advanced Very High Resolution Radiometer. The analysis shows that outside of the boundary layer the state of the lower troposphere is reasonably represented by the reanalysis and forecast products, with the caveat of a slight warm bias at 850 hPa in the NCEP–NCAR products. Within the planetary boundary layer (PBL) the agreement is not as good: both the boundary layer depth and cloud amount are underpredicted, and the boundary layer temperature correlates poorly with the available data, which may be related to a poor representation of SSTs in this region of persistent cloud cover. ERA-40 also suffers from persistently weak zonal winds within the PBL. Among the satellite records the ISCCP data are found to be especially valuable, evincing skill in both predicting boundary layer depth (from cloud-top temperatures and TMI surface temperatures) and cloud liquid water paths (from cloud optical depths). An analysis of interannual variability (among Julys) based on ERA-40 and the 1983–2001 ISCCP record suggests that thermodynamic quantities show similar interannual and synoptic variability, principally concentrated just above the PBL, while dynamic quantities vary much more on synoptic time scales. Furthermore, the analysis suggests that the correlation between stratocumulus cloud amount and lower-tropospheric stability exhibits considerable spatial structure and is less pronounced than previously thought.

Corresponding author address: Bjorn Stevens, Department of Atmospheric and Oceanic Sciences, University of California, Los Angeles, 405 Hilgard Ave., Box 951565, Los Angeles, CA 90095-1565. Email: bstevens@atmos.ucla.edu

Abstract

Data collected in situ as part of the second field study of the Dynamics and Chemistry of Marine Stratocumulus field program are used to evaluate the state of the atmosphere in the region of field operations near 30°N, 120°W during July 2001, as well as its representation by a variety of routinely available data. The routine data include both the 40-yr European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis (ERA-40) and NCEP–NCAR reanalyses, forecasts from their respective forecast systems (the Integrated and Global Forecast Systems), the 30-km archive from the International Satellite Cloud Climatology Project (ISCCP), the Quick Scatterometer surface winds, and remotely sensed fields derived from radiances measured by the Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI), the Advanced Microwave Sounding Unit, and the Advanced Very High Resolution Radiometer. The analysis shows that outside of the boundary layer the state of the lower troposphere is reasonably represented by the reanalysis and forecast products, with the caveat of a slight warm bias at 850 hPa in the NCEP–NCAR products. Within the planetary boundary layer (PBL) the agreement is not as good: both the boundary layer depth and cloud amount are underpredicted, and the boundary layer temperature correlates poorly with the available data, which may be related to a poor representation of SSTs in this region of persistent cloud cover. ERA-40 also suffers from persistently weak zonal winds within the PBL. Among the satellite records the ISCCP data are found to be especially valuable, evincing skill in both predicting boundary layer depth (from cloud-top temperatures and TMI surface temperatures) and cloud liquid water paths (from cloud optical depths). An analysis of interannual variability (among Julys) based on ERA-40 and the 1983–2001 ISCCP record suggests that thermodynamic quantities show similar interannual and synoptic variability, principally concentrated just above the PBL, while dynamic quantities vary much more on synoptic time scales. Furthermore, the analysis suggests that the correlation between stratocumulus cloud amount and lower-tropospheric stability exhibits considerable spatial structure and is less pronounced than previously thought.

Corresponding author address: Bjorn Stevens, Department of Atmospheric and Oceanic Sciences, University of California, Los Angeles, 405 Hilgard Ave., Box 951565, Los Angeles, CA 90095-1565. Email: bstevens@atmos.ucla.edu

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