Interannual to decadal variability of Rhine river streamflow and their relationship with large-scale climate anomaly patterns for spring (MAM) and autumn (SON) are investigated through statistical analysis of observed streamflow data and global climate anomaly fields. A wavelet analysis reveals that spring streamflow variability is non-stationary with enhanced variability in the 8–16 years band from 1860 to 1900 and in the 2–8 years and 16–30 years after 1960. A composite analysis reveals that streamflow anomalies during spring are related with a sea surface temperature (SST) pattern which resembles the corresponding El Nino-Southern Oscillation (ENSO) SST pattern. The corresponding atmospheric circulation pattern favors enhanced moisture advection over Rhine catchment area during positive streamflow anomalies. During autumn the streamflow variability follows a distribution similar to spring streamflow but with a strong peak in the 30–60 year band. Autumn streamflow anomalies are significantly related only with the North Atlantic SST anomalies. The atmospheric circulation pattern associated to high streamflow during autumn, which is more regional than the corresponding spring pattern, shows a deep low-pressure system over the British Isles and the north-western part of Europe and a shift southward of the Atlantic jet axis. The orientation of the axis of the Atlantic and African Jet, as well as the advection of the moist air from the ocean, plays a crucial role in the variability of Rhine streamflow both in spring and autumn.
Helmholtz Research Programs > PACES I (2009-2013) > TOPIC 4: Synthesis: The Earth System from a Polar Perspective > WP 4.2: The Earth System on Long Time Scales