气候变化领域集成服务门户(CCPortal): Seasonal components of freshwater runoff in Glacier Bay, Alaska: Diverse spatial patterns and temporal change

CCPortal

DOI	10.5194/tc-13-1597-2019
	Seasonal components of freshwater runoff in Glacier Bay, Alaska: Diverse spatial patterns and temporal change
	Crumley R.L.; Hill D.F.; Beamer J.P.; Holzenthal E.R.
发表日期	2019
ISSN	19940416
EISSN	13
起始页码	1597
结束页码	1619
卷号	13 期号:6
英文摘要	A high spatial resolution (250 m), distributed snow evolution and ablation model, SnowModel, is used to estimate current and future scenario freshwater runoff into Glacier Bay, Alaska, a fjord estuary that makes up part of Glacier Bay National Park and Preserve. The watersheds of Glacier Bay contain significant glacier cover (tidewater and land-terminating) and strong spatial gradients in topography, land cover, and precipitation. The physical complexity and variability of the region produce a variety of hydrological regimes, including rainfall-, snowmelt-, and icemelt- dominated responses. The purpose of this study is to characterize the recent historical components of freshwater runoff to Glacier Bay and quantify the potential hydrological changes that accompany the worst-case climate scenario during the final decades of the 21st century. The historical (1979-2015) mean annual runoff into Glacier Bay is found to be 24.5 km3 yr-1, or equivalent to a specific runoff of 3.1myr-1, with a peak in July, due to the overall dominance of snowmelt processes that are largely supplemented by ice melt. Future scenarios (2070-2099) of climate and glacier cover are used to estimate changes in the hydrologic response of Glacier Bay. Under the representative concentration pathway (RCP) 8.5, the mean of five climate models produces a mean annual runoff of 27.5 km3 yr-1, 3.5myr-1, representing a 13% increase from historical conditions. When spatially aggregated over the entire bay region, the projection scenario seasonal hydrograph is flatter, with weaker summer flows and higher winter flows. The peak flows shift to late summer and early fall, and rain runoff becomes the dominant overall process. The timing and magnitudes of modeled historical runoff are supported by a freshwater content analysis from a 24-year oceanographic conductivity- temperature-depth (CTD) dataset from the U.S. National Park Service's Southeast Alaska Inventory and Monitoring Network (SEAN). The hydrographs of individual watersheds display a diversity of changes between the historical period and projection scenario simulations, depending upon total glacier coverage, elevation distribution, landscape characteristics, and seasonal changes to the freezing line altitude. © Author(s) 2019.
学科领域	ablation; fjord; freshwater; glacial hydrology; hydrograph; hydrological change; hydrological modeling; hydrological response; peak flow; runoff; seasonal variation; snowmelt; spatial resolution; watershed; Alaska; Glacier Bay; Glacier Bay National Park; United States
语种	英语
scopus关键词	ablation; fjord; freshwater; glacial hydrology; hydrograph; hydrological change; hydrological modeling; hydrological response; peak flow; runoff; seasonal variation; snowmelt; spatial resolution; watershed; Alaska; Glacier Bay; Glacier Bay National Park; United States
来源期刊	The Cryosphere
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/118876
作者单位	Water Resources Science, Oregon State University, Corvallis, OR 97331, United States; School of Civil and Construction Engineering, Oregon State University, Corvallis, OR 97331, United States; Oregon Water Resources Department, Salem, OR 97301, United States
推荐引用方式 GB/T 7714	Crumley R.L.,Hill D.F.,Beamer J.P.,et al. Seasonal components of freshwater runoff in Glacier Bay, Alaska: Diverse spatial patterns and temporal change[J],2019,13(6).
APA	Crumley R.L.,Hill D.F.,Beamer J.P.,&Holzenthal E.R..(2019).Seasonal components of freshwater runoff in Glacier Bay, Alaska: Diverse spatial patterns and temporal change.The Cryosphere,13(6).
MLA	Crumley R.L.,et al."Seasonal components of freshwater runoff in Glacier Bay, Alaska: Diverse spatial patterns and temporal change".The Cryosphere 13.6(2019).