Journal of Ocean University of China

, Volume 9, Issue 4, pp 333–342 | Cite as

Comparison of CloudSat cloud liquid water paths in arctic summer using ground-based microwave radiometer



Arctic clouds strongly influence the regional radiation balance, temperature, melting of sea ice, and freezing of sea water. Despite their importance, there is a lack of systematic and reliable observations of Arctic clouds. The CloudSat satellite launched in 2006 with a 94 GHz Cloud Profiling Radar (CPR) may contribute to close this gap. Here we compare one of the key parameters, the cloud liquid water path (LWP) retrieved from CloudSat observations and from microwave radiometer (MWR) data taken during the ASCOS (Arctic Summer Cloud Ocean Study) cruise of the research vessel Oden from August to September 2008. Over the 45 days of the ASCOS cruise, collocations closer than 3 h and 100 km were found in only 9 d, and collocations closer than 1 h and 30 km in only 2 d. The poor correlations in the scatter plots of the two LWP retrievals can be explained by the patchiness of the cloud cover in these two days (August 5th and September 7th), as confirmed by coincident MODIS (Moderate-resolution Imaging Spectroradiometer) images. The averages of Oden-observed LWP values are systematically higher (40–70 g m−2) than the corresponding CloudSat observations (0–50 g m−2). These are cases of generally low LWP with presumably small droplets, and may be explained by the little sensitivity of the CPR to small droplets or by the surface clutter.

Key words

CloudSat liquid water path Arctic microwave radiometer collocation Oden 


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  1. Austin, R. T., and Stephens, G. L., 2001. Retrieval of stratus cloud microphysical parameters using millimeter-wave radar and visible optical depth in preparation for CloudSat. J. Geophys. Res., 106: 28 233–28 242.CrossRefGoogle Scholar
  2. Brunke, M. A., de Szoeke, S. P., Zuidema, P., and Zeng, X., 2010. A comparison of ship and satellite measurements of cloud properties in the southeast Pacific stratus deck. Atmos. Chem. Phys. Discuss., 10: 3301–3318.CrossRefGoogle Scholar
  3. Curry, J. A., Hobbs, P. V., King, M. D., Randall, D. A., Minnis, P., Isaac, G. A., et al., 2000. FIRE Arctic clouds experiments. Bull. Amer. Meteorol. Soc., 81(1): 29pp.Google Scholar
  4. Curry, J. A., Rossow, W. B., Randall, D., and Schramm, J. L., 1996. Overview of Arctic Cloud and Radiation Characteristics. J. Clim., 9: 1731–1762.CrossRefGoogle Scholar
  5. Greenwald, T. J., L’Ecuyer, T. S., and Christopher, S. A., 2007. Evaluating specific error characteristics of microwave-derived cloud liquid water products. Geophys. Res. Lett., 34, doi: 10.1029/2007GL031180.Google Scholar
  6. Grenier, P., Blanchet, J. P., and Muñoz-Alpizar, R., 2009. Study of polar thin ice clouds and aerosols seen by CloudSat and CALIPSO during midwinter 2007. J. Geophys. Res., 114, doi:10.1029/2008JD010927.Google Scholar
  7. Karstens, U., Simmer, C., and Ruprecht, E., 1994. Remote sensing of cloud liquid water. Meteorol. Atmos. Phys., 54: 157–171.CrossRefGoogle Scholar
  8. Key, J. R., and Intrieri, J. M., 2000. Cloud particle phase determination with the AVHRR. J. Appl. Meteorol., 39: 1797–1804.CrossRefGoogle Scholar
  9. Li, L., Durden, S., and Tanelli, S., 2007. Level 1B CPR Process Description and Interface Control Document. Pasadena, California, version 5.3, 27 June 2007, 24pp.Google Scholar
  10. Liljegren, J. C., Clothiaux, E. E., Mace, G. G., Kato, S., and Dong, X. Q., 2001. A new retrieval for cloud liquid water path using a ground-based microwave radiometer and measurements of cloud temperature. J. Geophys. Res., 106: 14 485–14 500.CrossRefGoogle Scholar
  11. Liu, G., and Curry, J. A., 1993. Determination of characteristic features of cloud liquid water from satellite microwave measurements. J. Geophys. Res., 98: 5069–5092.CrossRefGoogle Scholar
  12. Miller, S. D., and Stephens, G. L., 2001. CloudSat instrument requirements as determined from ECMWF forecasts of global cloudiness, J. Geophys. Res., 106: 17 713–17 733. doi: 10.1029/2000JD900645.Google Scholar
  13. Nagle, F. W., and Holz, R. E., 2008. Computationally efficient methods of collocating satellite, aircraft, and ground observations. J. Atmos. Ocean. Technol., 26: 1585–1595.CrossRefGoogle Scholar
  14. O’Dell, C. W, Wentz, F. J., and Bennartz, R., 2007. Cloud liquid water path from satellite-based passive microwave observation: A new climatology over the global ocean. J. Clim., 21: 1721–1739.CrossRefGoogle Scholar
  15. Probert-Jones, J. R., 1962. The radar equation for meteorology. Quart. J. Royal Meteor. Soc., 88: 485–495.CrossRefGoogle Scholar
  16. Rees, G., 2001. Physical Principles of Remote Sensing. Cambridge University Press, Cambridge, 360pp.Google Scholar
  17. Sassen, K., Mace, G. G., Wang, Z., Poellot, M. R., Sekelsky, S. M., and McIntosh, R. E., 1999. Continental stratus clouds: A case study using coordinated remote sensing and aircraft measurements. J. Atmos. Sci., 56: 2345–2358.CrossRefGoogle Scholar
  18. Shupe, M. D., Uttal, T., and Matrosov, S. Y., 2007. Arctic cloud microphysics retrievals from surface-based remote sensors at SHEBA. J. Appl. Meteorol., 44: 1544–1562.CrossRefGoogle Scholar
  19. Spreen, G., Kaleschke, L., and Heygster, G., 2008. Sea ice remote sensing using AMSR-E 89GHz channels. J. Geophys. Res., 113, doi: 10.1029/2005JC003384.Google Scholar
  20. Stephens, G. L., and Kummerow, C. D., 2006. The remote sensing of clouds and precipitation from space: a review. J. Atmos. Sci., 64: 3742–3765.CrossRefGoogle Scholar
  21. Greenwald, T. J., L’Ecuyer, T. S., and Christopher, S. A., 2007. Evaluating specific error characteristics of microwave-derived cloud liquid water products. Geophys. Res. Lett., 34: L22807, doi:10.1029/2007GL031180.CrossRefGoogle Scholar
  22. Turner, D. D., 2005. Arctic mixed-phase cloud properties from AERI-lidar observations: Algorithm and results from SHEBA. J. Appl. Meteorol., 44: 427–444.CrossRefGoogle Scholar
  23. Turner, D. D., 2007. Improved ground-based liquid water path retrievals using a combined infrared and microwave approach. J. Geophys. Res., 112: D15024, doi:10.1029/2007JD008530.CrossRefGoogle Scholar
  24. Vicente, G. A., Smith, P., Kempler, Tewari, S., K., Kummerer, R., and Leptoukh, G. G., 2006. CloudSat and MODIS data merging: the first step toward the implementation of the NASA A-Train Data Depot. The 14th Conference on Satellite Meteorology and Oceanography at the 86th AMS Annual Meeting, January 28–February 3, Atlanta, GA, USA.Google Scholar
  25. Walsh, J. E., Chapman, W. L., and Portis, D. H., 2008. Arctic Cloud Fraction and Radiative Fluxes in Atmospheric Reanalyses. J. Clim., 22: 2316–2334. doi: 10.1175/2008JCLI-2213.1.CrossRefGoogle Scholar
  26. Westwater, E. R., Han, Y., Shupe, M. D., and Matrosov, S., 2001. Analysis of integrated cloud liquid and precipitable water vapor retrievals from microwave radiometers during the surface heat budget of the Arctic Ocean Project. J. Geophys. Res., 106: 32 019–32 030.CrossRefGoogle Scholar
  27. Wood, N., 2008. Level 2B Radar-Visible Optical Depth Cloud Water Content (2B-CWC-RVOD) Process Description Document. Version: 5.1, 23 October 2008.Google Scholar

Copyright information

© Science Press, Ocean University of China and Springer-Verlag Berlin Heidelberg 2010

Authors and Affiliations

  1. 1.College of Physical and Environmental OceanographyOcean University of ChinaQingdaoP. R. China
  2. 2.Institute of Environmental PhysicsUniversity of BremenBremenGermany

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