This study provides the first countrywide assessment of Syria’s climate variability for 1980–2024 using high-resolution ERA5-Land reanalysis, benchmarked over overlapping years against 21 in-situ rain stations, most of which cover 1992–2010, while three have longer overlapping records (Damascus, 1986–2020; AlQamishli, 1993–2024; Raas Alin, 1993–2024), with additional extended records at Tal Hadya for temperature (1980–2007) and at Homs for precipitation (1986–2015). These stations provide a climate-stratified performance benchmark across Syria’s main climate zones and elevation gradients, rather than a complete national observing network. Agreement with observations is strong: air temperature (r = 0.99) and precipitation (typically r = 0.80–0.94, R2 = 0.64–0.88), supporting the use of ERA5-Land for monthly/seasonal climatology and trend analysis in data-scarce settings (with greater uncertainty expected for local extremes, especially in complex terrain). Trends from the modified Mann–Kendall test with Sen’s slope show a clear warming, with annual temperature increases up to 0.07 °C year−1, the strongest warming occurring in the north and northeast. Precipitation exhibits significant declines in annual totals, with Sen’s slope locally reaching − 2.77 mm year−1, most pronounced in the arid eastern and southern regions. Seasonally, decreases are largest during winter (DJF) and during spring (MAM) over the eastern (BSh, BWh) and central (BSk, BWk) regions (reaching approximately − 1.13 mm season−1 year−1 in DJF and − 1.17 mm season−1 year−1 in MAM). In comparison, autumn (SON) drying is concentrated in the Mediterranean (Csa) zone (down to about − 1.50 mm season−1 year−1). Interannual variability (CV) is lowest in the west (~ 19–25%) and increases inland (~ 30–38.5%). The Zone-mean precipitation concentration (PCI) clusters around 13.4–13.8% (moderate seasonality), with the lowest values (< 13%) along the coast and higher values (≥ 15%) in the far southwest and parts of the eastern and northeastern deserts. Drought diagnostics using the SPEI-3, -6, and -12 indicate that short wet spells rarely offset multi-season deficits; across zones, MMK–Sen trends of − 0.003 to − 0.0035 SPEI/month indicate increasing aridification in Syria. Overall, Syria is becoming warmer and drier, with increasing persistence of droughts and shifts in seasonality. The validated ERA5-Land data enable climate monitoring and risk assessment over Syria and are transferable to other data-scarce regions. Future work should link these signals to sectoral indicators and integrate downscaled projections to assess evolving extremes at regional scales for future periods.

Spatiotemporal Analysis of Temperature and Precipitation in Syria

期刊论文
发表日期：

2026年3月18日

查看全文

Omar Alsenjar,
Hakan Aksu

摘要

This study provides the first countrywide assessment of Syria’s climate variability for 1980–2024 using high-resolution ERA5-Land reanalysis, benchmarked over overlapping years against 21 in-situ rain stations, most of which cover 1992–2010, while three have longer overlapping records (Damascus, 1986–2020; AlQamishli, 1993–2024; Raas Alin, 1993–2024), with additional extended records at Tal Hadya for temperature (1980–2007) and at Homs for precipitation (1986–2015). These stations provide a climate-stratified performance benchmark across Syria’s main climate zones and elevation gradients, rather than a complete national observing network. Agreement with observations is strong: air temperature (r = 0.99) and precipitation (typically r = 0.80–0.94, R² = 0.64–0.88), supporting the use of ERA5-Land for monthly/seasonal climatology and trend analysis in data-scarce settings (with greater uncertainty expected for local extremes, especially in complex terrain). Trends from the modified Mann–Kendall test with Sen’s slope show a clear warming, with annual temperature increases up to 0.07 °C year⁻¹, the strongest warming occurring in the north and northeast. Precipitation exhibits significant declines in annual totals, with Sen’s slope locally reaching − 2.77 mm year⁻¹, most pronounced in the arid eastern and southern regions. Seasonally, decreases are largest during winter (DJF) and during spring (MAM) over the eastern (BSh, BWh) and central (BSk, BWk) regions (reaching approximately − 1.13 mm season⁻¹ year⁻¹ in DJF and − 1.17 mm season⁻¹ year⁻¹ in MAM). In comparison, autumn (SON) drying is concentrated in the Mediterranean (Csa) zone (down to about − 1.50 mm season⁻¹ year⁻¹). Interannual variability (CV) is lowest in the west (~ 19–25%) and increases inland (~ 30–38.5%). The Zone-mean precipitation concentration (PCI) clusters around 13.4–13.8% (moderate seasonality), with the lowest values (< 13%) along the coast and higher values (≥ 15%) in the far southwest and parts of the eastern and northeastern deserts. Drought diagnostics using the SPEI-3, -6, and -12 indicate that short wet spells rarely offset multi-season deficits; across zones, MMK–Sen trends of − 0.003 to − 0.0035 SPEI/month indicate increasing aridification in Syria. Overall, Syria is becoming warmer and drier, with increasing persistence of droughts and shifts in seasonality. The validated ERA5-Land data enable climate monitoring and risk assessment over Syria and are transferable to other data-scarce regions. Future work should link these signals to sectoral indicators and integrate downscaled projections to assess evolving extremes at regional scales for future periods.