Project proposal and aims:
Great public attention has been paid to precipitation deficit to have occurred in recent couple of years in central Europe, mainly during the vegetation period. The precipitation deficit, that is, meteorological drought, combined with high temperatures, resulting in enhanced evapotranspiration, transformed into the lack of surface and underground water (hydrological drought), as well as low soil moisture (agricultural drought), with considerable societal and economic ramifications. 
As drought of any kind is among the most severe natural hazards, it is important to understand processes causing it. The scientific objective of the stay is thus setting the recent precipitation deficit in central Europe into a longer-term context and analysis of two most relevant potential causes of it: anthropogenic climate change and natural climate variability, which is materialized in the variability of atmospheric circulation. 

The proposed project will consist of four major tasks: 
1. Identification and spatio-temporal localization of the precipitation deficit; that is, finding the area, period (years), and part of year where and when the deficit occurred. 
2. Framing the precipitation deficit in a wider context. Impacts of the precipitation deficit on hydrosphere and biosphere, that is, induced hazards in terms of hydrological and agricultural drought will be described and quantified. 
3. Analysis of suitable characteristics of atmospheric circulation and of their potential contribution to the precipitation deficit in observed data. The characteristics include (i) modes of low-frequency variability (teleconnections; all modes affecting central Europe will be considered, that is, the analysis will not be limited to the North Atlantic Oscillation as the most widely studied one); (ii) blocking events (assuming blocking anticyclones are conducive to dry weather conditions); (iii) classifications of circulation patterns (several classifications based on different methods will be used in order to avoid method-specific biases to be mistaken for real signal). This step will allow the quantification of influence of atmospheric circulation on the precipitation deficit, that is, to evaluate to what degree atmospheric circulation is responsible for the deficit. 
4. Context with anthropogenic climate change. Climate change projections by regional climate models (RCMs) will be scrutinized with the objective to quantify the likelihood of the observed precipitation deficit under changed (potential future) climate conditions and the likelihood of the circulation anomalies related to the observed precipitation deficit. This will make it possible to determine the effect of anthropogenic climate change on the occurrence of precipitation deficit, as well as to quantify whether, and to what extent, the circulation variability causing the observed precipitation deficit may itself be a manifestation of anthropogenic climate change. 

In summary, the project will tell us (i) when and where the precipitation deficit occurred, (ii) what are its consequences in hydrosphere and biosphere, (iii) whether the deficit is a manifestation of anthropogenic climate change or climate variability (variability of atmospheric circulation) or both, and (iv) whether the atmospheric circulation anomalies conducive to precipitation deficit are themselves rooted in anthropogenic climate change. 
Data from open sources will be used, including databases of station data (ECA&D) and gridded datasets (E-OBS, CRU TS) for precipitation, atmospheric reanalyses for data on atmospheric circulation (sea level pressure and 500 hPa heights), and outputs from RCM simulations within EURO-CORDEX (Coordinated Downscaling Experiment) initiative for future climate conditions. 
We expect publication of results in leading climatic and/or environmental journals, such as Environmental Research Letters and Journal of Climate. 

I declare that:
● co-founding 1000 EUR/month is ensured
● project is approved by head of corresponding department

Co-founding resources: Department of Physical Geography and Geoecology budget

Contact details: 
Prof. RNDr. Radan Huth, DrSc. 
department: Department of Physical Geography and Geolecology
email: radan.huth@natur.cuni.cz
telephone number: 2 2195 1363