Publication Abstracts

Wang and Rossow 1995

Wang, J., and W.B. Rossow, 1995: Determination of cloud vertical structure from upper-air observations. J. Appl. Meteorol., 34, 2243-2258, doi:10.1175/1520-0450(1995)034<2243:DOCVSF>2.0.CO;2.

A method is described to use rawinsonde data to estimate cloud vertical structure, including cloud-top and cloud-base heights, cloud-layer thickness, and the characteristics of multilayerd clouds. Cloud-layer base and top locations are identified based on three criteria: maximum relative humidity in a cloud at least 87%, minimum relative humidity of at least 84%, and relative humidity jumps exceeding 3% at cloud-layer top and base, where relative humidity is with respect to liquid water at temperatures greater than or equal to 0°C and with respect to ice temperatures less than 0°C. The analysis method is tested at 30 ocean sites by comparing with cloud properties derived from other independent data sources. Comparison of layer-cloud frequencies of occurrence with surface observations shows that rawinsonde observations (RAOBS) usually detect the same number of cloud layers for low and middle clouds as the surface observers, but disagree for high-level clouds. There is good agreement between the seasonal variations of RAOBS-determined top pressure of the highest cloud and that from the International Satellite Cloud Climatology Project (ISCCP), but RAOBS often fail to detect very high and thin clouds. The frequency of multilayered clouds is qualitatively consistent with that estimated from surface observations. In cloudy soundings at these ocean sites, multilayered clouds occur 56% of the time and are predominately two layered. Multilayered clouds are most frequent (∼ ∼70%) in the Tropics (10°S-10°N) and least frequent at subtropical eastern Pacific stations. The frequency of multilayerd clouds is higher in summer than in winter at low-latitude stations (30°S-30°N), but the opposite variation appears at the two subtropical stations. The frequency distributions of cloud top, cloud base, and cloud-layer thickness and cloud occurrence as a function of height are also presented. The lowest layer of multilayered cloud systems is usually located in the atmospheric boundary layer.

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BibTeX Citation

  author={Wang, J. and Rossow, W. B.},
  title={Determination of cloud vertical structure from upper-air observations},
  journal={J. Appl. Meteorol.},

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RIS Citation

ID  - wa01000b
AU  - Wang, J.
AU  - Rossow, W. B.
PY  - 1995
TI  - Determination of cloud vertical structure from upper-air observations
JA  - J. Appl. Meteorol.
VL  - 34
SP  - 2243
EP  - 2258
DO  - 10.1175/1520-0450(1995)034%3C2243%3ADOCVSF%3E2.0.CO;2
ER  -

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