scholarly journals Characteristics of tropical thin cirrus clouds deduced from joint CloudSat and CALIPSO observations

2009 ◽  
Vol 114 ◽  
Author(s):  
Taryn Haladay ◽  
Graeme Stephens
Keyword(s):  
Cirrus Clouds

Cirrus Clouds and the Climate

1971 ◽  
Vol 28 (8) ◽  
pp. 1513-1515 ◽  
Author(s):  
Stephen K. Cox
Keyword(s):  
Cirrus Clouds

Specular scattering in cirrus clouds

1995 ◽  
Author(s):  
Joseph G. Shanks ◽  
David K. Lynch
Keyword(s):  
Cirrus Clouds ◽  
Specular Scattering

scholarly journals Correction Method for RS80-A Humicap Humidity Profiles and Their Validation by Lidar Backscattering Profiles in Tropical Cirrus Clouds

2005 ◽  
Vol 22 (1) ◽  
pp. 18-29 ◽  
Author(s):  
Ulrich Leiterer ◽  
Horst Dier ◽  
Dagmar Nagel ◽  
Tatjana Naebert ◽  
Dietrich Althausen ◽  
...  
Keyword(s):  
Evaluation Method ◽  
Time Lag ◽  
Correction Method ◽  
Cirrus Clouds ◽  
Temperature Dependent ◽  
Upper Troposphere ◽  
Statistical Comparison ◽  
Daily Show ◽  
Tropical Tropopause ◽  
Humidity Profiles

Abstract Routine radiosonde relative humidity (RH) measurements are not reliable as they are presently used in the global upper-air network. The new Lindenberg measuring and evaluation method, which provides RH profile measurements with an accuracy of ±1% RΗ in the temperature range from 35° to −70°C near the tropical tropopause is described. This Standardized Frequencies (FN) method uses a thin-film capacitive polymer sensor of a modified RS90-H Humicap radiosonde. These research humidity reference radiosondes (FN sondes) are used to develop a correction method for operational RS80-A Humicap humidity profiles. All steps of correction and quality control for RS80-A radiosondes are shown: ground-check correction, time-lag and temperature-dependent correction, and the recognition of icing during the ascent. The results of a statistical comparison between FN sondes and RS80-A sondes are presented. Corrected humidity data of operational RS80-A sondes used in Lindenberg (4 times daily) show no bias when compared to FN radiosondes and have an uncertainty of about ±3% RH at the 1 σ or 68% confidence level from 1000 to about 150 hPa. Only a small dry bias of at most −2% RH remains in the lowest part of the boundary layer (up to 500-m height). Finally, some examples of corrected RS80-A RH profiles in cirrus clouds validated by lidar backscattering profiles in a region of the intertropical convergence (Maldive Islands) are demonstrated. The soundings indicate that ice-saturated and ice-supersaturated air above 10-km height were connected with cirrus clouds in all 47 investigated cases, and, second, that the corrected RS80-A RH profiles also provide good quality information on water vapor in the upper troposphere.

Limitations of AERONET SDA product in presence of cirrus clouds

2018 ◽  
Vol 206 ◽  
pp. 338-341 ◽  
Author(s):  
A. Smirnov ◽  
T.B. Zhuravleva ◽  
M. Segal-Rosenheimer ◽  
B.N. Holben
Keyword(s):  
Cirrus Clouds

Operational cloud motion winds from meteosat and the use of cirrus clouds as tracers

1992 ◽  
Vol 12 (7) ◽  
pp. 95-104 ◽  
Author(s):  
Johannes Schmetz ◽  
Kenneth Holmlund
Keyword(s):  
Cirrus Clouds ◽  
Cloud Motion

scholarly journals Cirrus clouds in a global climate model with a statistical cirrus cloud scheme

2010 ◽  
Vol 10 (12) ◽  
pp. 5449-5474 ◽  
Author(s):  
M. Wang ◽  
J. E. Penner
Keyword(s):  
Climate Model ◽  
Global Climate ◽  
Global Climate Model ◽  
Lower Troposphere ◽  
Circulation Model ◽  
Cirrus Clouds ◽  
Cloud Formation ◽  
Cirrus Cloud ◽  
Ice Crystal ◽  
Homogeneous Freezing

Abstract. A statistical cirrus cloud scheme that accounts for mesoscale temperature perturbations is implemented in a coupled aerosol and atmospheric circulation model to better represent both subgrid-scale supersaturation and cloud formation. This new scheme treats the effects of aerosol on cloud formation and ice freezing in an improved manner, and both homogeneous freezing and heterogeneous freezing are included. The scheme is able to better simulate the observed probability distribution of relative humidity compared to the scheme that was implemented in an older version of the model. Heterogeneous ice nuclei (IN) are shown to decrease the frequency of occurrence of supersaturation, and improve the comparison with observations at 192 hPa. Homogeneous freezing alone can not reproduce observed ice crystal number concentrations at low temperatures (<205 K), but the addition of heterogeneous IN improves the comparison somewhat. Increases in heterogeneous IN affect both high level cirrus clouds and low level liquid clouds. Increases in cirrus clouds lead to a more cloudy and moist lower troposphere with less precipitation, effects which we associate with the decreased convective activity. The change in the net cloud forcing is not very sensitive to the change in ice crystal concentrations, but the change in the net radiative flux at the top of the atmosphere is still large because of changes in water vapor. Changes in the magnitude of the assumed mesoscale temperature perturbations by 25% alter the ice crystal number concentrations and the net radiative fluxes by an amount that is comparable to that from a factor of 10 change in the heterogeneous IN number concentrations. Further improvements on the representation of mesoscale temperature perturbations, heterogeneous IN and the competition between homogeneous freezing and heterogeneous freezing are needed.

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