Mid-winter (DJF) temperature reconstruction in Jerusalem since 1750 with some regional implications

Abstract. This work presents a statistical reconstruction of average mid-winter (DJF) temperature in Jerusalem since 1750. It is a first comprehensive attempt to reconstruct the temperature in Jerusalem, as a good representation of the Eastern Mediterranean (EM) climate. This representativeness is verified here. The data has been reconstructed by using a statistical model based on Principal Component Regression (PCR), using both instrumental data and high temporal resolution records of proxy data, including tree ring chronologies from Jordan, and records of DJF precipitation and Sea Level Pressure from central and Western Europe. A split validation procedure has resulted in a 0.73 correlation between observed and reconstructed temperature. The warming trend of last decades is well noted in the reconstruction and is in line with other studies. Winters which were cold/warm were historically documented as wet/dry, respectively, consistent with earlier studies pointing a strong relationship between Jerusalem temperatures and precipitation. It is shown here for the first time that the 'First Aliyah' (immigration) to Israel during 1882-1904 initiated during favouring climate conditions (cool and wet) to establish an agricultural community in the region. These conditions were found to be exceptional compared to other periods since 1750.