Changes in extreme temperature and precipitation indices: Using an innovative daily homogenized database in Israel. (15th May 2019)

• Record Type: Journal Article
• Authors: Yosef, Yizhak; Aguilar, Enric; Alpert, Pinhas
• Is Part Of: International journal of climatology. Volume 39:Number 13(2019)
• Page Start: 5022
• Page End: 5045
• Publication Date: 2019-05-15
• Subjects: climate change -- East Mediterranean -- extreme indices -- homogenization -- Israel -- precipitation -- temperature -- trend analysis; Climatology -- Periodicals; Climat -- Périodiques; Climatologie -- Périodiques; 551.605
• DOI: 10.1002/joc.6125
• Languages: English
• ISSNs: 0899-8418

Abstract

Abstract: This study examines the 1950–2017 temporal changes in climate extremes in Israel, which is located in the East Mediterranean (EM), a region which suffers from a scarcity of long and reliable datasets. It is well known that most long‐term records are affected by artificial shifts most commonly caused by station relocation, instrumental modification and local environmental changes. Therefore, for the first time, a thorough homogenization (detection and correction) routine was developed and implemented in the long‐term records. Consequently, a new daily adjusted dataset has been generated, including 34 temperature stations and 60 precipitation stations. Based on this comprehensive dataset, 38 extreme indices recommended by the Expert Team on Climate Change Detection and the Expert Team on Sector‐specific Climate Indices have been calculated. These indices will help various sectors to plan properly mitigation actions and adaptation for climate change, in addition to facilitating future studies for the EM. The results showed highly significant changes in temperature extremes associated with warming, especially for those indices derived from the daily minimum temperature (TN, 1950–2017), whereas the maximum temperature (TX) exhibited a similar increasing magnitude of the TN (~0.55°C/decade) in the last 30 years. The warming trends, which are non‐monotonic, seem to have been particularly strong since the early 1990s. The coastal area is characterized by higher heat stress during the nighttime, while mountains exhibit a strong tendency towards increasing temperatures during the noon hours. A reduction in the total precipitation amount and in the number of wet days with a tendency towards more intense wet days was found. Although all the regional trends of the precipitation indices were not statistically significant ( p ≤ .05), they showed a fine spatial coherence. Abstract : This study examines the 1950–2017 temporal changes in climate extremes in Israel. A thorough homogenization (detection and correction) routine was developed and implemented on long‐term daily records. Based on this new daily homogenized dataset, 38 extreme indices were calculated. For example, the trends of the warm spell duration index (WSDI) showed slight increases in some stations during the period 1950–2017, while for the last 30 years trends have been much stronger throughout the entire country. Trends in the WSDI during 1950–2017 (left panel) and 1988–2017 (right panel). Upward red triangles represent increasing trends. Significant changes ( p ≤ .05) are indicated by filled triangles (unit: days/decade).