Global S&T Development Trend Analysis Platform of Resources and Environment
DOI | 10.1016/j.atmosres.2017.06.010 |
The thin border between cloud and aerosol: Sensitivity of several ground based observation techniques | |
Calbo, Josep1; Long, Charles N.2,3; Gonzalez, Josep-Abel1; Augustine, John3; McComiskey, Allison3 | |
2017-11-01 | |
发表期刊 | ATMOSPHERIC RESEARCH |
ISSN | 0169-8095 |
EISSN | 1873-2895 |
出版年 | 2017 |
卷号 | 196 |
文章类型 | Article |
语种 | 英语 |
国家 | Spain; USA |
英文摘要 | Cloud and aerosol are two manifestations of what it is essentially the same physical phenomenon: a suspension of particles in the air. The differences between the two come from the different composition (e.g., much higher amount of condensed water in particles constituting a cloud) and/or particle size, and also from the different number of such particles (10-10,000 particles per cubic centimeter depending on conditions). However, there exist situations in which the distinction is far from obvious, and even when broken or scattered clouds are present in the sky, the borders between cloud/not cloud are not always well defined, a transition area that has been coined as the "twilight zone". The current paper presents a discussion on the definition of cloud and aerosol, the need for distinguishing or for considering the continuum between the two, and suggests a quantification of the importance and frequency of such ambiguous situations, founded on several ground-based observing techniques. Specifically, sensitivity analyses are applied on sky camera images and broadband and spectral radiometric measurements taken at Girona (Spain) and Boulder (Co, USA). Results indicate that, at these sites, in more than 5% of the daytime hours the sky may be considered cloudless (but containing aerosols) or cloudy (with some kind of optically thin clouds) depending on the observing system and the thresholds applied. Similarly, at least 10% of the time the extension of scattered or broken clouds into clear areas is problematic to establish, and depends on where the limit is put between cloud and aerosol. These findings are relevant to both technical approaches for cloud screening and sky cover categorization algorithms and radiative transfer studies, given the different effect of clouds and aerosols (and the different treatment in models) on the Earth's radiation balance. |
领域 | 地球科学 |
收录类别 | SCI-E |
WOS记录号 | WOS:000409290200021 |
WOS关键词 | RADIATION BUDGET NETWORK ; SOUTHERN GREAT-PLAINS ; OPTICAL DEPTH ; TRANSITION-ZONE ; CLASSIFICATION ; RADIOMETER ; ALGORITHM ; RETRIEVAL ; VICINITY ; SURFRAD |
WOS类目 | Meteorology & Atmospheric Sciences |
WOS研究方向 | Meteorology & Atmospheric Sciences |
引用统计 | |
文献类型 | 期刊论文 |
条目标识符 | http://119.78.100.173/C666/handle/2XK7JSWQ/38398 |
专题 | 地球科学 |
作者单位 | 1.Univ Girona, Dept Fis, Girona, Spain; 2.Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA; 3.NOAA, Earth Syst Res Lab, Global Monitoring Div, Boulder, CO USA |
推荐引用方式 GB/T 7714 | Calbo, Josep,Long, Charles N.,Gonzalez, Josep-Abel,et al. The thin border between cloud and aerosol: Sensitivity of several ground based observation techniques[J]. ATMOSPHERIC RESEARCH,2017,196. |
APA | Calbo, Josep,Long, Charles N.,Gonzalez, Josep-Abel,Augustine, John,&McComiskey, Allison.(2017).The thin border between cloud and aerosol: Sensitivity of several ground based observation techniques.ATMOSPHERIC RESEARCH,196. |
MLA | Calbo, Josep,et al."The thin border between cloud and aerosol: Sensitivity of several ground based observation techniques".ATMOSPHERIC RESEARCH 196(2017). |
条目包含的文件 | 条目无相关文件。 |
除非特别说明,本系统中所有内容都受版权保护,并保留所有权利。
修改评论