Effect of the North Atlantic Thermohaline Circulation on Changes in Climatic Conditions and River Flow in Poland

• Published in: Water
• Main Authors: Dariusz Wrzesiński, Andrzej A. Marsz, Anna Styszyńska, Leszek Sobkowiak
• Format: Article in Journal/Newspaper
• Language: English
• Published: MDPI AG 2019
• Subjects: river flow; thermohaline circulation; North Atlantic; Poland; Hydraulic engineering; TC1-978; Water supply for domestic and industrial purposes; TD201-500; Arctic; North atlantic Thermohaline circulation
• Online Access: https://doi.org/10.3390/w11081622; https://doaj.org/article/074add6ae3744e2b8d51307411880da5

The purpose of this study is to find connections between the North Atlantic Thermohaline Circulation (NA THC), climate elements, such as cloud cover, precipitation, air temperature, sunshine duration, and relative humidity, and flow of rivers in Poland. The intensity of NA THC was characterized by the DG 3L index, which was established to assess changes in the amount of heat transported by NA THC along with the transport of water to the Arctic. The paper explains and discusses the mechanism of impact of the NA THC changeability on the elements of the catchment water balance variability. The positive and negative phases of the DG 3L index are strongly correlated with the heat anomalies in the upper layer of the North Atlantic waters. The obtained results show that changes of NA THC have significant impact on weather conditions and selected climate elements in Poland. Statistically significant positive correlations were found between the DG 3L index and average annual air temperatures, particularly in April, July, and August, while negative between the DG 3L index and the total cloud cover. Consequently, in the years with the positive values of the DG 3L index, there are favorable conditions for the strong increase in evaporation and evapotranspiration from the ground surface. This has impact on flow of rivers in Poland, which shows considerable regional differences.