Publication Abstracts

Naud et al. 2010

Naud, C.M., A. Del Genio, M. Haeffelin, Y. Morille, V. Noel, J.-C. Dupont, D.D. Turner, C. Lo, and J. Comstock, 2010: Thermodynamic phase profiles of optically thin midlatitude clouds and their relation to temperature. J. Geophys. Res., 115, D11202, doi:10.1029/2009JD012889.

The relationship between cloud thermodynamic phase and temperature in some aircraft measurements conducted in midlatitude frontal clouds suggests that significant liquid does not exist at temperatures colder than 258 K. This dataset is often used to verify parameterizations of cloud phase in general circulation models. However, other aircraft campaigns and different instruments suggest a different relationship. Here, we examine the temperature-phase relationship for midlatitude optically thin winter clouds. Cloud phase and temperature profiles derived from five years of ground-based lidar depolarization and radiosonde measurements are analyzed for two midlatitude locations: the United States Atmospheric Radiation Measurement Program Southern Great Plains (SGP) site and the Site Instrumental de Recherche par Télédétection Atmosphérique (SIRTA) in France. Because lidars are attenuated in optically thick clouds, the dataset only includes clouds with optical thickness < 3. Cloud phase is obtained using the classical method based on a depolarization ratio threshold of 11% for differentiating liquid from ice. The frequency of occurrence of clouds either completely liquid or completely glaciated in the temperature range 233-273 K is similar to previous observations in the midlatitudes but somewhat greater than in the Arctic. The relationship between ice phase occurrence and temperature only slightly changes between cloud base and top. At both sites liquid is more prevalent at colder temperatures than has been found previously in some thicker frontal clouds, suggesting different processes for glaciation in non-frontal optically thin clouds.

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BibTeX Citation

  author={Naud, C. M. and Del Genio, A. and Haeffelin, M. and Morille, Y. and Noel, V. and Dupont, J.-C. and Turner, D. D. and Lo, C. and Comstock, J.},
  title={Thermodynamic phase profiles of optically thin midlatitude clouds and their relation to temperature},
  journal={J. Geophys. Res.},

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RIS Citation

ID  - na00200p
AU  - Naud, C. M.
AU  - Del Genio, A.
AU  - Haeffelin, M.
AU  - Morille, Y.
AU  - Noel, V.
AU  - Dupont, J.-C.
AU  - Turner, D. D.
AU  - Lo, C.
AU  - Comstock, J.
PY  - 2010
TI  - Thermodynamic phase profiles of optically thin midlatitude clouds and their relation to temperature
JA  - J. Geophys. Res.
VL  - 115
SP  - D11202
DO  - 10.1029/2009JD012889
ER  -

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