DOI: 10.1007/s00382-017-3983-4
Scopus记录号: 2-s2.0-85033461464
论文题名: Seasonal and latitudinal variations of surface fluxes at two Arctic terrestrial sites
作者: Grachev A.A. ; Persson P.O.G. ; Uttal T. ; Akish E.A. ; Cox C.J. ; Morris S.M. ; Fairall C.W. ; Stone R.S. ; Lesins G. ; Makshtas A.P. ; Repina I.A.
刊名: Climate Dynamics
ISSN: 9307575
出版年: 2018
卷: 51, 期: 2018-05-06 起始页码: 1793
结束页码: 1818
语种: 英语
英文关键词: Arctic
; Carbon dioxide
; Latitudinal variations
; Radiative fluxes
; Turbulent fluxes
Scopus关键词: boundary layer
; carbon dioxide
; latitude
; seasonal variation
; solar radiation
; summer
; surface flux
; turbulent flow
; Arctic Ocean
; Canada
; Ellesmere Island
; Eureka
; Nunavut
; Queen Elizabeth Islands
; Russian Federation
; Sakha
; Tiksi
英文摘要: This observational study compares seasonal variations of surface fluxes (turbulent, radiative, and soil heat) and other ancillary atmospheric/surface/permafrost data based on in-situ measurements made at terrestrial research observatories located near the coast of the Arctic Ocean. Hourly-averaged multiyear data sets collected at Eureka (Nunavut, Canada) and Tiksi (East Siberia, Russia) are analyzed in more detail to elucidate similarities and differences in the seasonal cycles at these two Arctic stations, which are situated at significantly different latitudes (80.0°N and 71.6°N, respectively). While significant gross similarities exist in the annual cycles of various meteorological parameters and fluxes, the differences in latitude, local topography, cloud cover, snowfall, and soil characteristics produce noticeable differences in fluxes and in the structures of the atmospheric boundary layer and upper soil temperature profiles. An important factor is that even though higher latitude sites (in this case Eureka) generally receive less annual incoming solar radiation but more total daily incoming solar radiation throughout the summer months than lower latitude sites (in this case Tiksi). This leads to a counter-intuitive state where the average active layer (or thaw line) is deeper and the topsoil temperature in midsummer are higher in Eureka which is located almost 10° north of Tiksi. The study further highlights the differences in the seasonal and latitudinal variations of the incoming shortwave and net radiation as well as the moderating cloudiness effects that lead to temporal and spatial differences in the structure of the atmospheric boundary layer and the uppermost ground layer. Specifically the warm season (Arctic summer) is shorter and mid-summer amplitude of the surface fluxes near solar noon is generally less in Eureka than in Tiksi. During the dark Polar night and cold seasons (Arctic winter) when the ground is covered with snow and air temperatures are sufficiently below freezing, the near-surface environment is generally stably stratified and the hourly averaged turbulent fluxes are quite small and irregular with on average small downward sensible heat fluxes and upward latent heat and carbon dioxide fluxes. The magnitude of the turbulent fluxes increases rapidly when surface snow disappears and the air temperatures rise above freezing during spring melt and eventually reaches a summer maximum. Throughout the summer months strong upward sensible and latent heat fluxes and downward carbon dioxide (uptake by the surface) are typically observed indicating persistent unstable (convective) stratification. Due to the combined effects of day length and solar zenith angle, the convective boundary layer forms in the High Arctic (e.g., in Eureka) and can reach long-lived quasi-stationary states in summer. During late summer and early autumn all turbulent fluxes rapidly decrease in magnitude when the air temperature decreases and falls below freezing. Unlike Eureka, a pronounced zero-curtain effect consisting of a sustained surface temperature hiatus at the freezing point is observed in Tiksi during fall due to wetter and/or water saturated soils. © 2017, Springer-Verlag GmbH Germany. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/109152
Appears in Collections: 影响、适应和脆弱性 气候变化事实与影响
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作者单位: NOAA Earth System Research Laboratory, 325 Broadway, R/PSD3, Boulder, CO 80305-3337, United States; Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO, United States; Science and Technology Corporation, Boulder, CO, United States; Department of Physics and Atmospheric Science, Dalhousie University, Halifax, NS, Canada; Arctic and Antarctic Research Institute, St. Petersburg, Russian Federation; A.M. Obukhov Institute of Atmospheric Physics, Russian Academy Sciences, Moscow, Russian Federation
Recommended Citation:
Grachev A.A.,Persson P.O.G.,Uttal T.,et al. Seasonal and latitudinal variations of surface fluxes at two Arctic terrestrial sites[J]. Climate Dynamics,2018-01-01,51(2018-05-06)