Extreme temperatures linked to the atmospheric blocking events in Turkey between 1977 and 2016


Efe B., Lupo A. R., Deniz A.

NATURAL HAZARDS, vol.104, no.2, pp.1879-1898, 2020 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 104 Issue: 2
  • Publication Date: 2020
  • Doi Number: 10.1007/s11069-020-04252-w
  • Journal Name: NATURAL HAZARDS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, IBZ Online, PASCAL, Aerospace Database, Agricultural & Environmental Science Database, Aquatic Science & Fisheries Abstracts (ASFA), CAB Abstracts, Communication Abstracts, Environment Index, Geobase, INSPEC, Metadex, PAIS International, Pollution Abstracts, Sociological abstracts, Veterinary Science Database, DIALNET, Civil Engineering Abstracts
  • Page Numbers: pp.1879-1898
  • Istanbul Technical University Affiliated: Yes

Abstract

Extreme maximum (Tx) and extreme minimum temperature (Tn) frequency distributions during summer and winter for blocked conditions were analyzed within Turkey during the period from 1977 to 2016 by using observational data. The Tx (0.5-0.8%) and Tn (0.4-2.0%) frequencies vary between these values for the entire period during summer. However, Tx varies between 0.0 and 1.0, while Tn varies between 0.8 and 2.4 during winter. It is quite clear that atmospheric blocking has a greater cooling effect during winter. The maximum values for Tx and Tn are observed when the block center located within the easternmost sector impacting Turkey for summer. The maximum Tx frequency is observed in association with blocking in the westernmost sector, and the maximum Tn frequency is observed with blocking in the easternmost sector impacting Turkey during the winter season. Block intensity has almost no impact on Tx frequency although it has enhancing effect on Tn frequency during the summer. For winter, block intensity has a decreasing effect on both the maximum Tn and maximum Tx. The maximum Tx and Tn values increase with the block size for the summer. During the winter, the maximum Tx frequency decreases with the increase in the size of a blocking event; however, the greatest Tn frequency is observed within the 0 degrees-30 degrees E sector and lowest within the 30 degrees E-60 degrees E sector. The block duration has an enhancing influence on the maximum Tx value, while maximum Tn is observed during short-duration events and a minimum is observed during moderate-duration events during the summer season. For the winter season, the block duration has a decreasing effect for Tx frequencies and increasing effect for Tn.