View : 3 Download: 0

Characteristics of cloud occurrence using ceilometer measurements and its relationship to precipitation over Seoul

Title
Characteristics of cloud occurrence using ceilometer measurements and its relationship to precipitation over Seoul
Authors
Lee, SangheeHwang, Seung-OnKim, JhoonAhn, Myoung-Hwan
Ewha Authors
안명환
SCOPUS Author ID
안명환scopus
Issue Date
2018
Journal Title
ATMOSPHERIC RESEARCH
ISSN
0169-8095JCR Link1873-2895JCR Link
Citation
vol. 201, pp. 46 - 57
Keywords
Cloud base heightCloud occurrenceCloud vertical frequencyCeilometerMicrowave radiometer
Publisher
ELSEVIER SCIENCE INC
Indexed
SCOPUS; SCI; SCIE WOS scopus
Abstract
Clouds are an important component of the atmosphere that affects both climate and weather, however, their contributions can be very difficult to determine. Ceilometer measurements can provide high resolution information on atmospheric conditions such as cloud base height (CBH) and vertical frequency of cloud occurrence (CVF). This study presents the first comprehensive analysis of CBH and CVF derived using Vaisala CL51 ceilometers at two urban stations in Seoul, Korea, during a three-year period from January 2014 to December 2016. The average frequency of cloud occurrence detected by the ceilometers is 54.3%. It is found that the CL51 is better able to capture CBH as compared to another ceilometer CL31 at a nearby meteorological station because it could detect high clouds more accurately. Frequency distributions for CBH up to 13,000 m providing detailed vertical features with 500-m interval show 55% of CBHs below 2 km for aggregated CBHs. A bimodal frequency distribution was observed for three-layers CBHs. A monthly variation of CVF reveals that frequency concentration of lower clouds is found in summer and winter, and higher clouds more often detected in spring and autumn. Monthly distribution features of cloud occurrence and precipitation are depending on seasons and it might be easy to define their relationship due to higher degree of variability of precipitation than cloud occurrence. However, a fluctuation of cloud occurrence frequency in summer is similar to precipitation in trend, whereas clouds in winter are relatively frequent but precipitation is not accompanied. In addition, recent decrease of summer precipitation could be mostly explained by a decrease of cloud occurrence. Anomalous precipitation recorded sometimes is considerably related to corresponding cloud occurrence. The diurnal and daily variations of CBH and CVF from ceilometer observations and the analysis of microwave radiometer measurements for two typical cloudiness cases are also reviewed in parallel. This analysis in finer temporal scale exhibits that utilization of ground-based observations together could help to analyze the cloud behaviors.
DOI
10.1016/j.atmosres.2017.10.010
Appears in Collections:
일반대학원 > 대기과학공학과 > Journal papers
Files in This Item:
There are no files associated with this item.


qrcode

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

BROWSE