ADVICE (Annual to Decadal Variability in Climate in Europe)
(Started spring 1996)
The page is still under construction!
Proposal
General Summary
Global warming has occurred over the last 100 years or so, almost certainly as result of increased atmospheric concentrations of greenhouse gases due to anthropogenic activity. A key uncertainty in the detection, and quantification, of any climate response is the charaterisation of the background variability; that is, the noise against which the anthropogenic signal must be detected. The overall objective of ADVICE is to fully characterise the climate variability of "greater" Europe (extending to Iceland, "European" Russia, the Near East and North Africa) before any significant anthropogenic effect, and then make comparisons with the modern period. ADVICE will also model some of the linkages between the North Atlantic and the European climate in order to examine the role of this aspect of "internal variability" in the observed (reconstructed) background climatic variability.
Existing European datasets are adequate for the full characterisation of surface climate variability from 1860 to the present-day (the Modern Instrumental Period; MIP). Advice will reconstruct European climate during the Early Instrumental Period (EIP; 1780-1860); and during an earlier period of recognised interest, because of its apparent marked variability, the Late Maunder Minimum (LMM; 1675-1715).
The starting point for the climate reconstructions in the EIP will be an extended and enhanced gridded monthly mean sea-level pressure dataset. Previously-unused instrumental data (pressure, temperature, precipitation, wind) will be utilised. This will allow an objective assessment of variability over the full 215 years of the EIP and the MIP combined, and an indication of whether or not circulation modes were different before, and during, the period of anthropogenic influence. "Anomalous" periods in the EIP will be chosen for closer examination, including the reconstruction of daily synoptic charts, in order to compare synoptic development and sequences in the EIP and the MIP.
In the early decades of the EIP, documentary data will be used to reconstruct monthly climatic patterns and, for the first time, objective assessments will be conducted through comparison with the instrumental data based reconstructions, and appropriate tree-ring data. This will allow validation of selective reconstruction methodologies to be applied with documentary data for the LMM. Extreme circulation modes will be identified from the monthly LMM charts, compared with the EIP and MIP, and also subjected to the reconstruction of quasi-daily (depending on availability of information) synopic charts.
European climate is linked to surface conditions in the North Atlantic Ocean. An atmospheric general circulation model (GCM) will be forced with lower boundary conditions consistent with sea-surface temperature (SST) and sea-ice cover associated with heavy Icelandic sea-ice conditions. SST and sea-ice reconstructions off Iceland are part of ADVICE. The resulting European climate patterns from the GCM will be compared with the anomalous patterns reconstructed for the EIP and LMM.
Contact: juerg Luterbacher.
For further information about ADVICE contact: Institute of History,
University of Berne
15.09.1996 Jürg Luterbacher (juerg@giub.unibe.ch)