Decadal variability of the Elbe River streamflow

摘要

The decadal variability (>7 years) of annual Elbe River flow in connection with large-scale atmospheric circulation is analysed for the period 1902-2002. The relationship with temperature over land (TT) and global sea surface temperature (SST) and atmospheric circulation over the Northern Hemisphere is investigated.High anomalies of the river flow are associated with a tripole-like pattern in the North Atlantic and with negative SST anomalies in the central North Pacific and positive anomalies in the eastern and central tropical Pacific. The pattern identified in the sea level pressure (SLP) resembles the negative phase of the Arctic Oscillation pattern.Two distinct decadal time components of approximately 12-13 years and 20 years in the time series were identified by using the Singular Spectral Analysis. To isolate the main frequencies identified by the Singular Spectrum Analysis (SSA) and to analyse the connection between the decadal components and Elbe River streamflow, we have applied a band pass filter to the SST field, to be able to suppress all the variance outside the prescribed windows.