DOI: 10.1175/JCLI-D-15-0590.1
Scopus记录号: 2-s2.0-85008191299
论文题名: Why do different drought indices show distinct future drought risk outcomes in the U.S. Great Plains?
作者: Feng S. ; Trnka M. ; Hayes M. ; Zhang Y.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2017
卷: 30, 期: 1 起始页码: 265
结束页码: 278
语种: 英语
Scopus关键词: Climate models
; Drying
; Evapotranspiration
; Moisture
; Soil moisture
; Soils
; Climate variability
; Community climate system model
; Evaporative demands
; North America
; Palmer drought severity indices
; Penman-Monteith method
; Potential evapotranspiration
; Surface soil moisture
; Drought
英文摘要: Vigorous discussions and disagreements about the future changes in drought intensity in the U.S. Great Plains have been taking place recently within the literature. These discussions have involved widely varying estimates based on drought indices and model-based projections of the future. To investigate and understand the causes for such a disparity between these previous estimates, the authors analyzed the soil moisture at the near-surface soil layer and the entire soil column, as well as the Palmer drought severity index, the Palmer Z index, and the standardized precipitation and evaporation index using the output from the Community Climate System Model, version 4 (CCSM4), and 25 state-of-the-art climate models. These drought indices were computed using potential evapotranspiration estimated by the physically based Penman-Monteith method (PE_pm) and the empirically based Thornthwaite method (PE_th). The results showed that the short-term drought indices are similar to modeled surface soil moisture and show a small but consistent drying trend in the future. The long-term drought indices and the total column soil moisture, however, are consistent in projecting more intense future drought. When normalized, the drought indices with PE_th all show unprecedented future drying, while the drought indices with PE_pm show comparable dryness with the modeled soil moisture. Additionally, the drought indices with PE_pm are closely related to soil moisture during both the twentieth and twenty-first centuries. Overall, the drought indices with PE_pm, as well as the modeled total column soil moisture, suggest a widespread and very significant drying in the Great Plains toward the end of the century. The results suggest that the sharp contrasts about future drought risk in the Great Plains discussed in previous studies are caused by 1) comparing the projected changes in short-term droughts with that of the long-term droughts and/or 2) computing the atmospheric evaporative demand using an empirically based method (e.g., PE_th). The analysis here may be applied for drought projections in other regions across the globe. © 2017 American Meteorological Society. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/49797
Appears in Collections: 气候变化事实与影响
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作者单位: Department of Geosciences, University of Arkansas, Fayetteville, AR, United States; Global Change Research Institute AS CR v.v.i, Institute of Agriculture Systems and Bioclimatology, Mendel University in Brno, Brno, Czech Republic; National Drought Mitigation Center, School of Natural Resources, University of Nebraska-Lincoln, Lincoln, NE, United States
Recommended Citation:
Feng S.,Trnka M.,Hayes M.,et al. Why do different drought indices show distinct future drought risk outcomes in the U.S. Great Plains?[J]. Journal of Climate,2017-01-01,30(1)