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Titel |
Pan-Arctic linkages between snow accumulation and growing-season air temperature, soil moisture and vegetation |
VerfasserIn |
K. A. Luus, Y. Gel, J. C. Lin, R. E. J. Kelly, C. R. Duguay |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1726-4170
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Digitales Dokument |
URL |
Erschienen |
In: Biogeosciences ; 10, no. 11 ; Nr. 10, no. 11 (2013-11-22), S.7575-7597 |
Datensatznummer |
250085435
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Publikation (Nr.) |
copernicus.org/bg-10-7575-2013.pdf |
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Zusammenfassung |
Arctic field studies have indicated that the air temperature, soil
moisture and vegetation at a site influence the quantity of snow
accumulated, and that snow accumulation can alter growing-season soil
moisture and vegetation. Climate change is predicted to bring about
warmer air temperatures, greater snow accumulation and northward
movements of the shrub and tree lines. Understanding the responses of
northern environments to changes in snow and growing-season land
surface characteristics requires: (1) insights into the present-day
linkages between snow and growing-season land surface characteristics;
and (2) the ability to continue to monitor these associations over
time across the vast pan-Arctic. The objective of this study was
therefore to examine the pan-Arctic (north of 60° N)
linkages between two temporally distinct data products created from
AMSR-E satellite passive microwave observations: GlobSnow snow water
equivalent (SWE), and NTSG growing-season AMSR-E Land Parameters (air
temperature, soil moisture and
vegetation transmissivity). Due to the complex and interconnected
nature of processes determining snow and growing-season land surface
characteristics, these associations were analyzed using the modern
nonparametric technique of alternating conditional expectations
(ACE), as this approach does not impose a predefined analytic
form. Findings indicate that regions with lower vegetation
transmissivity (more biomass) at the start and end of the growing
season tend to accumulate less snow at the start and end of the snow
season, possibly due to interception and sublimation. Warmer air
temperatures at the start and end of the growing season were
associated with diminished snow accumulation at the start and end of
the snow season. High latitude sites with warmer mean annual growing-season temperatures tended to accumulate more snow, probably due to
the greater availability of water vapor for snow season precipitation
at warmer locations. Regions with drier soils preceding snow onset
tended to accumulate greater quantities of snow, likely because drier
soils freeze faster and more thoroughly than wetter
soils. Understanding and continuing to monitor these linkages at the
regional scale using the ACE approach can allow insights to be gained
into the complex response of Arctic ecosystems to climate-driven
shifts in air temperature, vegetation, soil moisture and snow
accumulation. |
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