Climate Variability and Change—Hydrological Impacts (Proceedings of the Fifth FRIEND World
Conference held at Havana, Cuba, November 2006), IAHS Publ. 308, 2006, 526–532.
Influence of the North Atlantic Oscillation on spatial
and temporal patterns in Eurasian river flows
RAIMUND RÖDEL
Department of Geography and Geology, University of Greifswald, Jahnstraße 16, D-17489 Greifswald, Germany
roedel@uni-greifswald.de
Abstract Atmospheric circulation
indices can be used to explain the variability of runoff at a continental
scale. In Eurasia, besides well-known zonal anomalies of runoff that correlate
with phases of the North Atlantic Oscillation (NAO), drifting fields of annual
discharge anomalies exist. With the trend of the NAO these fields drift along a
longitudinal direction from Western Russia to the Lena River basin in Siberia
and back again. Similar observations can also be applied to changing river flow
regimes. Drifting fields can be identified by a cluster approach. The centroids
of the clusters can be linked to the driving processes of the NAO. Thus, the
spatial drifting can be understood as an autoregressive process where the
NAO-index determines the drifting direction. This paper describes the origin
and causes of these fields which can explain important processes of climate
variability in the Northern hemisphere.
Key words Eurasia; North
Atlantic Oscillation; discharge anomalies; flow regimes; drifting fields;
autoregressive process