Publication Date:
2021-07-19
Description:
Our study analyses satellite and land-based
observations of the Yakutsk region centred at the Lena watershed,
an area characterised mainly by continuous permafrost.
Using monthly solutions of the Gravity Recovery And Climate
Experiment satellite mission, we detect amass increase
over central Siberia from 2002 to 2007 which reverses into a
mass decrease between 2007 and 2011. No significant mass
trend is visible for the whole observation period. To further
quantify this behaviour, different mass signal components
are studied in detail: (1) inter-annual variation in the
atmospheric mass, (2) a possible effect of glacial isostatic
adjustment (GIA), and (3) hydrological mass variations. In
standard processing the atmospheric mass signal is reduced
based on the data from numerical weather prediction models.
We use surface pressure observations in order to validate
this atmospheric reduction. On inter-annual time scale the
difference between the atmospheric mass signal from model
prediction and from surface pressure observation is 〈4mm
in equivalentwater height. The effect of GIA on the mass signal
over Siberia is calculated using a global ice model and a
spherically symmetric, compressible, Maxwell-viscoelastic
earth model. The calculation shows that for the investigated
area any effect of GIA can be ruled out. Hence, the main part
of the signal can be attributed to hydrological mass varia-tions. We briefly discuss potential hydrological effects such as changes in precipitation, river discharge, surface and subsurface
water storage.
Repository Name:
EPIC Alfred Wegener Institut
Type:
Article
,
isiRev
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