Browsing by Author "Wibig, Joanna"

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    How reliable are selected methods of projections of future thermal conditions? A case from Poland
    (Wydział Nauk Geograficznych i Geologicznych Uniwersytetu im. Adama Mickiewicza, 2015) Wibig, Joanna; Jędruszkiewicz, Joanna
    The aim of the paper was to assess the robustness of four bias correction techniques: simple bias correction, distribution based bias correction, delta change and distribution based delta change. Data from nine RCM simulations of CORDEX project and 41 Polish weather stations were used. The methods were calibrated in the period 1971–1985 and evaluated in 1991–2005. The improvement in mean, 10th and 90th percentiles was shown, without significant differences among methods. For 1st and 99th percentiles the improvement was generally weaker and simple methods seem to be more robust than the distribution based ones. Strong differences between individual models were found, so the use of model ensemble is recommended.
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    Spatial distribution and synoptic conditions of snow accumulation and snow ablation in the West Siberian Plain
    (Wydział Nauk Geograficznych i Geologicznych Uniwersytetu im. Adama Mickiewicza, 2015) Bednorz, Ewa; Wibig, Joanna
    The mean duration of snow coverage in the West Siberian Plain is approximately eight months in the north to about five months in the south. While the period of intense snow melting is short (one or two months between March and May), snow accumulation persists for most of the cold season. Snow accumulation is associated with negative anomalies of sea level pressure, which means increased cyclonal activity and weaker than normal Siberian High. Much lower anomalies of sea level pressure occur during snow ablation. This suggests smaller influence of air circulation on snow cover reduction in spring.