Airborne validation of cirrus cloud properties derived from CALIPSO lidar measurements: Optical properties

2012 ◽  
Vol 117 (D9) ◽  
pp. n/a-n/a ◽  
Author(s):  
Dennis L. Hlavka ◽  
John E. Yorks ◽  
Stuart A. Young ◽  
Mark A. Vaughan ◽  
Ralph E. Kuehn ◽  
...  
Keyword(s):  
Optical Properties ◽  
Cirrus Cloud ◽  
Cloud Properties ◽  
Lidar Measurements

Investigation of tropical cirrus cloud properties using ground based lidar measurements

2016 ◽  
Author(s):  
Reji K. Dhaman ◽  
Malladi Satyanarayana ◽  
V. Krishnakumar ◽  
V. P. Mahadevan Pillai ◽  
G. S. Jayeshlal ◽  
...  
Keyword(s):  
Cirrus Cloud ◽  
Cloud Properties ◽  
Lidar Measurements ◽  
Ground Based Lidar

scholarly journals Variability in cirrus cloud properties using a Polly<sup>XT</sup> Raman lidar over high and tropical latitudes

2020 ◽  
Vol 20 (7) ◽  
pp. 4427-4444 ◽  
Author(s):  
Kalliopi Artemis Voudouri ◽  
Elina Giannakaki ◽  
Mika Komppula ◽  
Dimitris Balis
Keyword(s):  
Optical Properties ◽  
Cirrus Clouds ◽  
Cirrus Cloud ◽  
Raman Lidar ◽  
Mean Values ◽  
Cloud Optical Depth ◽  
Geometrical Properties ◽  
Depolarisation Ratio ◽  
Cloud Properties ◽  
Lidar Ratio

Abstract. Measurements of geometrical and optical properties of cirrus clouds, performed with a multi-wavelength PollyXT Raman lidar during the period 2008 to 2016, are analysed. The measurements were performed with the same instrument, during sequential periods, in three places at different latitudes, Gwal Pahari (28.43∘ N, 77.15∘ E; 243 m a.s.l.) in India, Elandsfontein (26.25∘ S, 29.43∘ E; 1745 m a.s.l.) in South Africa and Kuopio (62.74∘ N, 27.54∘ E; 190 m a.s.l.) in Finland. The lidar dataset was processed by an automatic cirrus cloud masking algorithm, developed in the frame of this work. In the following, we present a statistical analysis of the lidar-retrieved geometrical characteristics (cloud boundaries, geometrical thickness) and optical properties of cirrus clouds (cloud optical depth, lidar ratio, ice crystal depolarisation ratio) measured over the three areas that correspond to subtropical and subarctic regions as well as their seasonal variability. The effect of multiple scattering from ice particles to the derived optical products is also considered and corrected in this study. Our results show that cirrus layers, which have a noticeable monthly variability, were observed between 6.5 and 13 km, with temperatures ranging from −72 to −27 ∘C. The observed differences on cirrus clouds' geometrical and optical properties over the three regions are discussed in terms of latitudinal and temperature dependence. The latitudinal dependence of the geometrical properties is consistent with satellite observations, following the pattern observed with CloudSat, with decreasing values towards the poles. The geometrical boundaries have their highest values in the subtropical regions, and overall, our results seem to demonstrate that subarctic cirrus clouds are colder, lower and optically thinner than subtropical cirrus clouds. The dependence of cirrus cloud geometrical thickness and optical properties on mid-cirrus temperatures shows a quite similar tendency for the three sites but less variability for the subarctic dataset. Cirrus clouds are geometrically and optically thicker at temperatures between −45 and −35 ∘C, and a second peak is observed at lower temperatures ∼-70 ∘C for the subarctic site. Lidar ratio values also exhibit a pattern, showing higher values moving toward the poles, with higher mean values observed over the subarctic site. The dependency of the mid-cirrus temperatures on the lidar ratio values and the particle depolarisation values is further examined. Our study shows that the highest values of the cirrus lidar ratio correspond to higher values of cirrus depolarisation and warmer cirrus. The kind of information presented here can be rather useful in the cirrus parameterisations required as input to radiative transfer models and can be a complementary tool for satellite products that cannot provide cloud vertical structure. In addition, ground-based statistics of the cirrus properties could be useful in the validation and improvement of the corresponding derived products from satellite retrievals.

scholarly journals Multichannel Polarization Lidar Measurements of Aerosols and Cirrus Clouds

2020 ◽  
Vol 237 ◽  
pp. 07020
Author(s):  
Jan Bai Nee
Keyword(s):  
Optical Properties ◽  
Circular Polarization ◽  
Mueller Matrix ◽  
Cirrus Cloud ◽  
Scattering Media ◽  
Lidar System ◽  
Mueller Matrices ◽  
Lidar Measurements ◽  
Stokes Vectors ◽  
Channel Polarization

In this paper we report using a 6-channel polarization detector to measure optical properties of aerosols and clouds. The polarization lidar system is designed to measure Stokes vectors and Mueller matrices from back-scatterings of air, aerosols and clouds by using several polarizers of setting at different angles, and a retarder to measure circular polarization. The 4 components Stokes vectors of the scattering media are constructed and a case of tropopause cirrus cloud and stratospheric aerosols are measured with the Mueller matrix derived.

scholarly journals Changes of cirrus cloud properties and occurrence over Europe during the COVID-19 caused air traffic reduction

2021 ◽  
Author(s):  
Qiang Li ◽  
Silke Groß
Keyword(s):  
Air Traffic ◽  
Cirrus Clouds ◽  
Cirrus Cloud ◽  
Mean Values ◽  
Significance Level ◽  
Ice Cloud ◽  
Cloud Properties ◽  
Lidar Measurements ◽  
Traffic Reduction ◽  
Linear Depolarization Ratio

Abstract. By inducing linear contrails and contrail cirrus, air traffic has a main impact on the ice cloud coverage and occurrence. During the COVID-19 pandemic the civil air traffic over Europe was significantly reduced: in March and April 2020 to about 80 % compared to the year before. This unique situation allows to study the effect of air traffic on cirrus clouds. This work investigates based on satellite lidar measurements if and how cirrus cloud properties and occurrence changed over Europe in the course of COVID-19. Cirrus cloud properties are analyzed for different years, which showed similar meteorological conditions for March and April as they were found for 2020. Comparing these years shows that the cirrus cloud occurrence was reduced by about 30 % with smaller cloud thicknesses found in April 2020. The average thickness of cirrus clouds was reduced to 1.18 km in April 2020 compared to a value of 1.40 km under normal conditions. In addition, the cirrus clouds measured in April 2020 possess smaller mean values of the particle linear depolarization ratio (PLDR) than the previous years at high significance level, especially at colder temperatures (T 

scholarly journals Airborne validation of cirrus cloud properties derived from CALIPSO lidar measurements: Spatial properties

2011 ◽  
Vol 116 (D19) ◽  
Author(s):  
John E. Yorks ◽  
Dennis L. Hlavka ◽  
Mark A. Vaughan ◽  
Matthew J. McGill ◽  
William D. Hart ◽  
...  
Keyword(s):  
Cirrus Cloud ◽  
Spatial Properties ◽  
Cloud Properties ◽  
Lidar Measurements

scholarly journals Comparison of ISS–CATS and CALIPSO–CALIOP Characterization of High Clouds in the Tropics

2020 ◽  
Vol 12 (23) ◽  
pp. 3946
Author(s):  
Pasquale Sellitto ◽  
Silvia Bucci ◽  
Bernard Legras
Keyword(s):  
Optical Properties ◽  
Space Station ◽  
Satellite Observation ◽  
Observation Data ◽  
Upper Troposphere ◽  
Cloud Properties ◽  
Synchronous Orbit ◽  
The Tropics ◽  
High Clouds

Clouds in the tropics have an important role in the energy budget, atmospheric circulation, humidity, and composition of the tropical-to-global upper-troposphere–lower-stratosphere. Due to its non-sun-synchronous orbit, the Cloud–Aerosol Transport System (CATS) onboard the International Space Station (ISS) provided novel information on clouds from space in terms of overpass time in the period of 2015–2017. In this paper, we provide a seasonally resolved comparison of CATS characterization of high clouds (between 13 and 18 km altitude) in the tropics with well-established CALIPSO (Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observation) data, both in terms of clouds’ occurrence and cloud optical properties (optical depth). Despite the fact that cloud statistics for CATS and CALIOP are generated using intrinsically different local overpass times, the characterization of high clouds occurrence and optical properties in the tropics with the two instruments is very similar. Observations from CATS underestimate clouds occurrence (up to 80%, at 18 km) and overestimate the occurrence of very thick clouds (up to 100% for optically very thick clouds, at 18 km) at higher altitudes. Thus, the description of stratospheric overshoots with CATS and CALIOP might be different. While this study hints at the consistency of CATS and CALIOP clouds characterizaton, the small differences highlighted in this work should be taken into account when using CATS for estimating cloud properties and their variability in the tropics.

scholarly journals Balloon-borne and Raman lidar observations of Asian dust and cirrus cloud properties over Tsukuba, Japan

2014 ◽  
Vol 119 (6) ◽  
pp. 3295-3308 ◽  
Author(s):  
Tetsu Sakai ◽  
Narihiro Orikasa ◽  
Tomohiro Nagai ◽  
Masataka Murakami ◽  
Takuya Tajiri ◽  
...  
Keyword(s):  
Asian Dust ◽  
Cirrus Cloud ◽  
Raman Lidar ◽  
Cloud Properties ◽  
Lidar Observations

scholarly journals Remote sensing of aerosol optical properties and solar heating rate by the combination of sky radiometer and lidar measurements

2017 ◽  
Author(s):  
Rei Kudo ◽  
Tomoaki Nishizawa ◽  
Toshinori Aoyagi ◽  
Yasushi Fujiyoshi ◽  
Yuji Higuchi ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Optical Properties ◽  
Heating Rate ◽  
Solar Heating ◽  
Aerosol Optical Properties ◽  
Lidar Measurements
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