Multidecadal Changes in the Relationship of Storm Frequency over Euro-Mediterranean Region and ENSO During Boreal Winter

Abstract

Background The El Niño-Southern Oscillation (ENSO) influence over Euro-Mediterranean boreal winter season (December to February) precipitation anomalies has changed along the twentieth century. Purpose The precipitation anomalies are closely associated with storm track frequency. The changing relationship between the interannual variability of storm track frequency and ENSO is investigated at interannual and multidecadal timescales. Methods The Melbourne University cyclone tracking scheme (MS) is applied to reanalyse 200-hPa geopotential height (Z200) datasets to track the winter storms over the Euro-Mediterranean region for the period 1950-2016. Results The maximum of climatological storm track frequency is found to prevail in the study domain with large interannual variability. The multidecadal changes show a phase shift in the relationship between storm track frequency and ENSO from the 1950s to the recent decades. The storm track frequency is negatively correlated (-0.24) to ENSO for the early period , whereas it is positively correlated with a maximum correlation value of 0.44 for the recent period . The correlation departure (0.68) between the two periods shows a significant change in the multidecadal relationship between storm track frequency and ENSO. Conclusion The ENSO-associated significant changes are noted in the upper and lower tropospheric height anomalies over the North Atlantic and Euro-Mediterranean sector in the recent period with respect to the earlier period, which may largely influencing the storm activity (Frequency/Intensity) and precipitation anomalies over the Euro-Mediterranean region. The findings of this study can have important implications in Euro-Mediterranean seasonal predictability.

Rainfall Trends and Extremes in Saudi Arabia in Recent Decades

“…Similar trend behavior was observed for the wet season rainfall data ( Figure 3b). The wet season- The wet season rainfall spatial distribution patterns are influenced through the Mediterranean and central Asian troughs [49,50]. Wet season rainfall distributions show maxima in the central parts of Saudi Arabia, with values of more than 150 mm (Figure 2c,d).…”

Temperature Changes over the CORDEX-MENA Domain in the 21st Century Using CMIP5 Data Downscaled with RegCM4: A Focus on the Arabian Peninsula

“…erefore, the uncertainty at each location must be considered for climate change impact studies using model data. Further study may require using data from the newly developed Saudi-KAU Global Climate Model and focusing on the simulation of climate over the Arabian Peninsula [52][53][54].…”

La Niña's Diminishing Fingerprint on the Central Indian Summer Monsoon

“…Our results indicate further drying of the middle‐east region during post‐1980 La Niñas (Figure c). It may be related to changes in post‐1980 IO SST and winter storm activity (Kamil et al, ). Consistent with CRU observations, IMD observational data set also documents similar changes (Figures d–f) in rainfall patterns during post‐1980 La Niña (up to 6% reduction in ISM rainfall), thereby confirming that the results are not just artifacts of data processing.…”