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| Titel |
Derivation of a new continuous adjustment function for correcting wind-induced loss of solid precipitation: results of a Norwegian field study |
| VerfasserIn |
M. A. Wolff, K. Isaksen, A. Petersen-Øverleir, K. Ødemark, T. Reitan, R. Brækkan |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1027-5606
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| Digitales Dokument |
URL |
| Erschienen |
In: Hydrology and Earth System Sciences ; 19, no. 2 ; Nr. 19, no. 2 (2015-02-20), S.951-967 |
| Datensatznummer |
250120632
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| Publikation (Nr.) |
 copernicus.org/hess-19-951-2015.pdf |
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| Zusammenfassung |
Precipitation measurements exhibit large cold-season biases due to
under-catch in windy conditions. These uncertainties affect water balance
calculations, snowpack monitoring and calibration of remote sensing
algorithms and land surface models. More accurate data would improve the
ability to predict future changes in water resources and mountain hazards in
snow-dominated regions.
In 2010, a comprehensive test site for precipitation measurements was
established on a mountain plateau in southern Norway. Automatic
precipitation gauge data are compared with data from a precipitation gauge
in a Double Fence Intercomparison Reference (DFIR) wind shield construction
which serves as the reference. A large number of other sensors are provided
supporting data for relevant meteorological parameters.
In this paper, data from three winters are used to study and determine the
wind-induced under-catch of solid precipitation. Qualitative analyses and
Bayesian statistics are used to evaluate and objectively choose the model
that best describes the data. A continuous adjustment function and its
uncertainty are derived for measurements of all types of winter
precipitation (from rain to dry snow). A regression analysis does not reveal
any significant misspecifications for the adjustment function, but shows
that the chosen model does not describe the regression noise optimally. The
adjustment function is operationally usable because it is based only on data
available at standard automatic weather stations.
The results show a non-linear relationship between under-catch and wind
speed during winter precipitation events and there is a clear temperature
dependency, mainly reflecting the precipitation type. The results allow, for
the first time, derivation of an adjustment function based on measurements
above 7 m s−1. This extended validity of the adjustment function shows a
stabilization of the wind-induced precipitation loss for higher wind speeds. |
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