DOI: 10.1175/JCLI-D-11-00186.1
Scopus记录号: 2-s2.0-84859343362
论文题名: On the relationship between thermodynamic structure and cloud top, and its climate significance in the Arctic
作者: Sedlar J. ; Shupe M.D. ; Tjernström M.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2012
卷: 25, 期: 7 起始页码: 2374
结束页码: 2393
语种: 英语
Scopus关键词: Arctic
; Cloud droplets
; Cloud forcing
; Long-wave radiation
; Radiative forcings
; Stratiform clouds
; Atmospheric radiation
; Atmospheric temperature
; Climatology
; Clouds
; Convergence of numerical methods
; Drops
; Radiation effects
; Sea ice
; Thermodynamics
; Water supply systems
; Water vapor
; Liquids
; advection
; arctic environment
; climate modeling
; cloud cover
; cloud radiative forcing
; droplet
; longwave radiation
; sea ice
; stratiform cloud
; thermodynamics
; water vapor
; Alaska
; Arctic Ocean
; Barrow
; United States
英文摘要: Cloud and thermodynamic characteristics from three Arctic observation sites are investigated to understand the collocation between low-level clouds and temperature inversions.Aregime where cloud topwas 100-200 mabove the inversion base [cloud inside inversion (CII)] was frequently observed at central Arctic Ocean sites, while observations from Barrow, Alaska, indicate that cloud tops were more frequently constrained to inversion base height [cloud capped by inversion (CCI)]. Cloud base and top heights were lower, and temperature inversions were also stronger and deeper, during CII cases.Both cloud regimeswere often decoupled from the surface except for CCI over Barrow. In-cloud lapse rates differ and suggest increased cloud-mixing potential for CII cases. Specific humidity inversions were collocated with temperature inversions for more than 60% of the CCI and more than 85% of the CII regimes. Horizontal advection of heat and moisture is hypothesized as an important process controlling thermodynamic structure and efficiency of cloud-generated motions. The portion of CII clouds above the inversion contains cloud radar signatures consistent with cloud droplets. The authors test the longwave radiative impact of cloud liquid above the inversion through hypothetical liquid water distributions. Optically thin CII clouds alter the effective cloud emission temperature and can lead to an increase in surface flux on the order of 1.5 W m -2 relative to the same cloud but whose top does not extend above the inversion base. The top of atmosphere impact is even larger, increasing outgoing longwave radiation up to 10 W m -2. These results suggest a potentially significant longwave radiative forcing via simple liquid redistributions for a distinctly dominant cloud regime over sea ice. © 2012 American Meteorological Society. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/52474
Appears in Collections: 气候变化事实与影响
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作者单位: Remote Sensing Division, Research Department, Swedish Meteorological and Hydrological Institute, Norrköping, Sweden; Cooperative Institute for Research in Environmental Sciences, University of Colorado, NOAA/ESRL/PSD, Boulder, CO, United States; Department of Meteorology, Stockholm University, Bert Bolin Centre for Climate Research, Stockholm, Sweden
Recommended Citation:
Sedlar J.,Shupe M.D.,Tjernström M.. On the relationship between thermodynamic structure and cloud top, and its climate significance in the Arctic[J]. Journal of Climate,2012-01-01,25(7)