Impacts of the North Atlantic Oscillation and the El Ni\~no-Southern Oscillation on Danube river streamflow variability

Rimbu, N., Dima, M., Lohmann, G., and Stefan, S., 2004:

The impact of the North Atlantic Oscillation (NAO) and El Ni\~no-Southern Oscillation (ENSO) on the Danube river streamflow variability is investigated for the period 1840 to 1998. A composite analysis reveals that positive streamflow anomalies are related to a large scale atmospheric circulation pattern that contains elements of the positive phase of the Pacific North American (PNA) pattern and negative phase of the NAO. The corresponding sea surface temperature (SST) pattern shows positive anomalies over most of the tropical region. Opposite atmospheric circulation and SST patterns are associated to negative streamflow anomalies. Significant decadal variations of the NAO and ENSO impact on the Danube streamflow are detected for the observational period. A lag-correlation analysis reveals that winter SST from tropical Pacific and some regions from the North Atlantic are significantly correlated with the streamflow variations from spring and summer suggesting a possible predictive skill of the Danube streamflow anomalies in these seasons using winter SST as a predictor.