کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4463643 1621685 2012 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Rocky Mountain hydroclimate: Holocene variability and the role of insolation, ENSO, and the North American Monsoon
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات فرآیندهای سطح زمین
پیش نمایش صفحه اول مقاله
Rocky Mountain hydroclimate: Holocene variability and the role of insolation, ENSO, and the North American Monsoon
چکیده انگلیسی

Over the period of instrumental records, precipitation maximum in the headwaters of the Colorado Rocky Mountains has been dominated by winter snow, with a substantial degree of interannual variability linked to Pacific ocean–atmosphere dynamics. High-elevation snowpack is an important water storage that is carefully observed in order to meet increasing water demands in the greater semi-arid region. The purpose here is to consider Rocky Mountain water trends during the Holocene when known changes in earth's energy balance were caused by precession-driven insolation variability. Changes in solar insolation are thought to have influenced the variability and intensity of the El Niño Southern Oscillation (ENSO), Pacific Decadal Oscillation (PDO), and North American Monsoon and the seasonal precipitation balance between rain and snow at upper elevations. Holocene records are presented from two high elevation lakes located in northwest Colorado that document decade-to-century scale precipitation seasonality for the past ~ 7000 years. Comparisons with sub-tropical records of ENSO indicate that the snowfall-dominated precipitation maxima developed ~ 3000 and 4000 years ago, coincident with evidence for enhanced ENSO/PDO dynamics. During the early-to-mid Holocene the records suggest a more monsoon affected precipitation regime with reduced snowpack, more rainfall, and net moisture deficits that were more severe than recent droughts. The Holocene perspective of precipitation indicates a far broader range of variability than that of the past century and highlights the non-linear character of hydroclimate in the U.S. west.


► Oxygen isotope records of NW Colorado precipitation seasonality since ~ 7 ka.
► Regime shifts from monsoon affected mid-Holocene to winter-storm dominated late Holocene.
► Snowfall maxima after ~ 3.5 ka and during Little Ice Age.
► Holocene context for recent precipitation trends.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Global and Planetary Change - Volumes 92–93, July 2012, Pages 198–208
نویسندگان
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