气候变化领域集成服务门户(CCPortal): Surface energy budget responses to radiative forcing at Summit, Greenland

CCPortal

DOI	10.5194/tc-11-497-2017
	Surface energy budget responses to radiative forcing at Summit, Greenland
	Miller N.B.; Shupe M.D.; Cox C.J.; Noone D.; Persson P.O.G.; Steffen K.
发表日期	2017
ISSN	19940416
卷号	11 期号:1
英文摘要	Greenland Ice Sheet surface temperatures are controlled by an exchange of energy at the surface, which includes radiative, turbulent, and ground heat fluxes. Data collected by multiple projects are leveraged to calculate all surface energy budget (SEB) terms at Summit, Greenland, for the full annual cycle from July 2013 to June 2014 and extend to longer periods for the radiative and turbulent SEB terms. Radiative fluxes are measured directly by a suite of broadband radiometers. Turbulent sensible heat flux is estimated via the bulk aerodynamic and eddy correlation methods, and the turbulent latent heat flux is calculated via a two-level approach using measurements at 10 and 2 m. The subsurface heat flux is calculated using a string of thermistors buried in the snow pack. Extensive quality-control data processing produced a data set in which all terms of the SEB are present 75 % of the full annual cycle, despite the harsh conditions. By including a storage term for a near-surface layer, the SEB is balanced in this data set to within the aggregated uncertainties for the individual terms. November and August case studies illustrate that surface radiative forcing is driven by synoptically forced cloud characteristics, especially by low-level, liquid-bearing clouds. The annual cycle and seasonal diurnal cycles of all SEB components indicate that the non-radiative terms are anticorrelated to changes in the total radiative flux and are hence responding to cloud radiative forcing. Generally, the non-radiative SEB terms and the upwelling longwave radiation component compensate for changes in downwelling radiation, although exact partitioning of energy in the response terms varies with season and near-surface characteristics such as stability and moisture availability. Substantial surface warming from low-level clouds typically leads to a change from a very stable to a weakly stable near-surface regime with no solar radiation or from a weakly stable to neutral/unstable regime with solar radiation. Relationships between forcing terms and responding surface fluxes show that the upwelling longwave radiation produces 65-85 % (50-60 %) of the total response in the winter (summer) and the non-radiative terms compensate for the remaining change in the combined downwelling longwave and net shortwave radiation. Because melt conditions are rarely reached at Summit, these relationships are documented for conditions of surface temperature below 0 °C, with and without solar radiation. This is the first time that forcing and response term relationships have been investigated in detail for the Greenland SEB. These results should both advance understanding of process relationships over the Greenland Ice Sheet and be useful for model validation. © The Author(s) 2017.
学科领域	annual cycle; data processing; data set; diurnal variation; downwelling; energy budget; latent heat flux; longwave radiation; model validation; radiative forcing; sensible heat flux; solar radiation; surface energy; surface temperature; Arctic; Greenland; Greenland Ice Sheet
语种	英语
scopus关键词	annual cycle; data processing; data set; diurnal variation; downwelling; energy budget; latent heat flux; longwave radiation; model validation; radiative forcing; sensible heat flux; solar radiation; surface energy; surface temperature; Arctic; Greenland; Greenland Ice Sheet
来源期刊	Cryosphere
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/119439
作者单位	Cooperative Institute for Research in Environmental Science, University of Colorado, Boulder, CO, United States; NOAA-ESRL, Boulder, CO, United States; College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR, United States; Swiss Federal Research Institute WSL, Birmensdorf, Switzerland
推荐引用方式 GB/T 7714	Miller N.B.,Shupe M.D.,Cox C.J.,et al. Surface energy budget responses to radiative forcing at Summit, Greenland[J],2017,11(1).
APA	Miller N.B.,Shupe M.D.,Cox C.J.,Noone D.,Persson P.O.G.,&Steffen K..(2017).Surface energy budget responses to radiative forcing at Summit, Greenland.Cryosphere,11(1).
MLA	Miller N.B.,et al."Surface energy budget responses to radiative forcing at Summit, Greenland".Cryosphere 11.1(2017).