DOI: 10.1002/2015JD024320
论文题名: Air parcel trajectory dispersion near the tropical tropopause
作者: Bergman J.W. ; Jensen E.J. ; Pfister L. ; Bui T.V.
刊名: Journal of Geophysical Research: Atmospheres
ISSN: 2169897X
出版年: 2016
卷: 121, 期: 8 起始页码: 3759
结束页码: 3775
语种: 英语
英文关键词: model uncertainty
; trajectory dispersion
; transport
; upper tropical troposphere
Scopus关键词: data set
; dispersion
; latitude
; numerical model
; trajectory
; tropopause
; troposphere
; uncertainty analysis
; wind forcing
英文摘要: Dispersion of backward air parcel trajectories that are initially tightly grouped near the tropical tropopause is examined using three ensemble approaches: "RANWIND," in which different ensemble members use identical resolved wind fluctuations but different realizations of stochastic, multifractal simulations of unresolved winds; "PERTLOC," in which members use identical resolved wind fields but initial locations are perturbed 2° in latitude and longitude; and a multimodel ensemble ("MULTIMODEL") that uses identical initial conditions but different resolved wind fields and/or trajectory formulations. Comparisons among the approaches distinguish, to some degree, physical dispersion from that due to data uncertainty and the impacts of unresolved wind fluctuations from those of resolved variability. Dispersion rates are robust properties of trajectories near the tropical tropopause. Horizontal dispersion rates are typically ~3°/d, which is large enough to spread parcels throughout the tropics within typical tropical tropopause layer transport times (30-60 days) and underscores the importance of averaging large collections of trajectories to obtain reliable parcel source and pathway distributions. Vertical dispersion rates away from convection are ~2-3 hPa/d. Dispersion is primarily carried out by the resolved flow, and the RANWIND approach provides a plausible representation of actual trajectory dispersion rates, while PERTLOC provides a reasonable and inexpensive alternative to RANWIND. In contrast, dispersion from the MULTIMODEL calculations is important because it reflects systematic differences in resolved wind fields from different reanalysis data sets. ©2016. American Geophysical Union. All Rights Reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/62914
Appears in Collections: 影响、适应和脆弱性 气候减缓与适应
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作者单位: Bay Area Environmental Research Institute, Petaluma, CA, United States; Atmospheric Chemistry Observations and Modeling Laboratory, National Center for Atmospheric Research, Boulder, CO, United States; Earth Science Division, NASA Ames Research Center, Moffett Field, CA, United States
Recommended Citation:
Bergman J.W.,Jensen E.J.,Pfister L.,et al. Air parcel trajectory dispersion near the tropical tropopause[J]. Journal of Geophysical Research: Atmospheres,2016-01-01,121(8)