| DOI: | 10.1002/grl.50642
|
| 论文题名: | Are atmospheric surface layer flows ergodic? |
| 作者: | Higgins C.W.; Katul G.G.; Froidevaux M.; Simeonov V.; Parlange M.B.
|
| 刊名: | Geophysical Research Letters
|
| ISSN: | 0094-8902
|
| EISSN: | 1944-8633
|
| 出版年: | 2013
|
| 卷: | 40, 期:12 | | 起始页码: | 3342
|
| 结束页码: | 3346
|
| 语种: | 英语
|
| 英文关键词: | Atmospheric surface layer
; Ergodic Hypothesis
; Lidar
; water vapor concentration
|
| Scopus关键词: | Atmospheric surface layers
; Concentration statistics
; Ergodic hypothesis
; In-laboratory experiments
; Non-ideal conditions
; Scalar concentration
; Surface transitions
; Water vapor concentration
; Acoustic field measurement
; Atmospheric turbulence
; Lakes
; Optical radar
; Surface measurement
; Water vapor
; Atmospheric thermodynamics
; atmospheric motion
; flow modeling
; hypothesis testing
; lidar
; micrometeorology
; numerical model
; surface layer
; turbulence
; water vapor
|
| 英文摘要: | The transposition of atmospheric turbulence statistics from the time domain, as conventionally sampled in field experiments, is explained by the so-called ergodic hypothesis. In micrometeorology, this hypothesis assumes that the time average of a measured flow variable represents an ensemble of independent realizations from similar meteorological states and boundary conditions. That is, the averaging duration must be sufficiently long to include a large number of independent realizations of the sampled flow variable so as to represent the ensemble. While the validity of the ergodic hypothesis for turbulence has been confirmed in laboratory experiments, and numerical simulations for idealized conditions, evidence for its validity in the atmospheric surface layer (ASL), especially for nonideal conditions, continues to defy experimental efforts. There is some urgency to make progress on this problem given the proliferation of tall tower scalar concentration networks aimed at constraining climate models yet are impacted by nonideal conditions at the land surface. Recent advancements in water vapor concentration lidar measurements that simultaneously sample spatial and temporal series in the ASL are used to investigate the validity of the ergodic hypothesis for the first time. It is shown that ergodicity is valid in a strict sense above uniform surfaces away from abrupt surface transitions. Surprisingly, ergodicity may be used to infer the ensemble concentration statistics of a composite grass-lake system using only water vapor concentration measurements collected above the sharp transition delineating the lake from the grass surface. Key Points Ergodicity is valid over uniform surfaces Ergodicity is only valid near land surface transitions over variable surfaces Land surface transitions encode information about the ensemble system ©2013. American Geophysical Union. All Rights Reserved. |
| URL: | https://www.scopus.com/inward/record.uri?eid=2-s2.0-84880559573&doi=10.1002%2fgrl.50642&partnerID=40&md5=8068b183975247288918865e123e9488
|
| Citation statistics: |
|
| 资源类型: | 期刊论文
|
| 标识符: | http://119.78.100.158/handle/2HF3EXSE/6166
|
| Appears in Collections: | 气候减缓与适应
|
|
There are no files associated with this item.
|
|
作者单位: | School of Architecture Civil and Environmental Engineering, Ecole Polytechnique Federal de Lausanne, CH-1015 Lausanne, Switzerland
|
| Recommended Citation: | |
Higgins C.W.,Katul G.G.,Froidevaux M.,et al. Are atmospheric surface layer flows ergodic?[J]. Geophysical Research Letters,2013-01-01,40(12).
|
|
|