Next Article in Journal
Assessing the Uncertainties of Four Precipitation Products for Swat Modeling in Mekong River Basin
Previous Article in Journal
Integrating Temporal Evolution with Cellular Automata for Simulating Land Cover Change
Previous Article in Special Issue
Algorithms for Doppler Spectral Density Data Quality Control and Merging for the Ka-Band Solid-State Transmitter Cloud Radar
Article Menu
Issue 3 (February-1) cover image

Export Article

Open AccessArticle
Remote Sens. 2019, 11(3), 302; https://doi.org/10.3390/rs11030302

Optical and Geometrical Properties of Cirrus Clouds over the Tibetan Plateau Measured by LiDAR and Radiosonde Sounding during the Summertime in 2014

1
Ocean Remote Sensing Institute, Ocean University of China, Qingdao 266100, China
2
Laboratory for Regional Oceanography and Numerical Modeling, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China
3
Laboratory of Severe Weather, Chinese Academy of Meteorological Science, Beijing 100081, China
*
Authors to whom correspondence should be addressed.
Received: 27 December 2018 / Revised: 31 January 2019 / Accepted: 31 January 2019 / Published: 2 February 2019
(This article belongs to the Special Issue Remote Sensing of Clouds)
Full-Text   |   PDF [3970 KB, uploaded 2 February 2019]   |  
  |   Review Reports

Abstract

Optical and geometrical characteristics of the cirrus clouds over Naqu (4508 m a.s.l., 31.48° N, 92.06° E), in the Tibetan Plateau were determined from LiDAR and radiosonde measurements performed during the third TIbetan Plateau EXperiment of atmospheric sciences (TIPEX III) campaign from July to August 2014. For the analysis of the temperature dependence, the simultaneous observations with LiDAR and radiosonde were conducted. Cirrus clouds were generally observed ranging from 5.2 km to 12 km above ground level (AGL) (i.e., 9.7 km to 16.5 km a.s.l.), with the midcloud temperatures ranging from −79.7 to −26.0 °C. The cloud thickness generally differed from 0.12 to 2.55 km with a mean thickness of 1.22 ± 0.70 km, and 85.7% of the measurement cases had thickness smaller than 1.5 km. The retrievals of linear particle depolarization ratio, extinction coefficient, and optical depth of cirrus clouds were provided. Moreover, the multiple scattering effect inside of cirrus clouds was corrected. The linear particle depolarization ratio of the cirrus clouds varied from 0.36 to 0.52, with a mean value of 0.44 ± 0.04. The optical depth of the cirrus clouds was between 0.01 and 3 following the scheme of Fernald-Klett method. Sub-visual, thin, and opaque cirrus clouds were observed at 4.76%, 61.90% and 33.34% of the measured cases, respectively. The temperature and thickness dependencies of the optical properties were studied in detail. A maximum cirrus thickness of around 2 km was found at temperatures between −60 and −50 °C. This study shows that the mean extinction coefficient of the cirrus clouds increases with the increase of temperature. Conversely, the measurements indicate that the linear particle depolarization ratio decreases with the increasing temperature. The relationships between the existence of cirrus clouds and the temperature anomaly (temperature difference from the mean value of the temperature during July and August 2014 over Naqu) and deep convective activity are also discussed. The formation of cirrus clouds is investigated and also its apparent relationship with the South Asia High Pressure, the dynamic processes of Rossby wave, and deep convective activity over the Tibetan Plateau. The outgoing longwave radiation of cirrus clouds is calculated with the Fu-Liou model and is shown to increases monotonously with the increase of optical depth. View Full-Text
Keywords: LiDAR; cirrus cloud; optical properties; the Tibetan Plateau LiDAR; cirrus cloud; optical properties; the Tibetan Plateau
Figures

Graphical abstract

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).
SciFeed

Share & Cite This Article

MDPI and ACS Style

Dai, G.; Wu, S.; Song, X.; Liu, L. Optical and Geometrical Properties of Cirrus Clouds over the Tibetan Plateau Measured by LiDAR and Radiosonde Sounding during the Summertime in 2014. Remote Sens. 2019, 11, 302.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Remote Sens. EISSN 2072-4292 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top