Scientists decipher the hydroclimatic conditions of Europe over the last 1000 years
These findings can help scientists to further investigate the physical mechanisms that cause hydroclimatic changes and understand which are the processes that are related to them. Most importantly, societies can benefit from them by developing long-term policies for the sustainable management of our water resources. The article can be found here.
Y. Markonis, M. Hanel, P. Máca and J. Kyselý have worked closely with Prof. E. R. Cook from Lamont-Doherty Earth Observatory of Columbia University, a world-known expert on the field of tree-ring palaeoclimatology. Using the Old World Drought Atlas, a reconstruction of European hydroclimate of the last millennium, they investigated the multi-decadal propagation of dry and wet periods of the past and compared them with the current hydroclimatic regime. Links with temperature and atmospheric/oceanic circulation patterns, were also examined, highlighting their complex influence to the observed shifts. In central Europe, changes were found to be more localized and over Czech lands the prevailing increase of wet conditions has been disrupted in the 1980s, followed by an abrupt shift towards dry conditions since then.
Hydroclimate involves the interplay between water, in its various forms, and the atmosphere. As it fluctuates across different time scales, from months to decades or even centuries, its study still remains challenging because most of the observations are not long enough to make any confident statement about its evolution. Thus, it is yet unclear which is the current state and dynamics of hydroclimatic conditions over Europe compared to its long-term characteristics. Now, researchers from the Faculty of Environmental Sciences have shown that during the last hundred years there has been a persistent change in European hydroclimate which has driven it to its millennial limits. The change is twofold; the northern regions reached their wettest maxima, while in the south there is evidence of unprecedented dryness.
Long-term hydroclimatic change over Europe:
Mean of the non-exceedance probability of the self-calibrated Palmer Drought Severity Index (scPDSI) for Europe at 30-year scale (black circled line) and percentage of area under dry (orange) and wet (blue) conditions.
Empirical probability densities of 30-year scPDSI values over Europe – 1 means drought, 0 corresponds to pluvial (grey lines: different 30-year intervals for the 992-1922 period, green line: 1923-1952 interval, light blue line: 1953-1982 interval, dark blue line: 1983-2012 interval).