Scientific Analysis | Where did the depressions disappear and does this indicate climate change?

Arab Weather - The entire eastern Mediterranean basin is witnessing a complete absence of depressions and winter weather patterns, although we are only a few days away from the onset of winter astronomically. However, the weather is still similar to spring, relatively warm during the daytime hours, without any signs that herald the return of mature or important depressions.

Where have the depressions disappeared from the region and can they return soon?

Meteorologists at the Arab Weather Regional Center said, after conducting a comprehensive follow-up of the weather systems and the distribution of prevailing atmospheric pressures in the northern hemisphere, that it was observed that the prevailing weather systems do not allow the advance of air depressions towards the eastern basin of the Mediterranean Sea. This is due to the weakness and disruption of the polar vortex, which leads to the concentration of cold surges towards the central Mediterranean Sea, and the formation of air depressions that affect southern Europe, specifically the islands of Italy and Greece, and North Africa.

Looking at the general situation, storms are active in the North Atlantic, where they pull cold air masses and gather them in high latitudes. The Siberian high also extends towards Turkey and Iran, acting as a barrier system to the advance of cold air masses that cause depressions when they reach the warmer water surface. Thus, the weather system does not bode well for the return of depressions anytime soon.

Significant weakness in the polar vortex and the formation of high atmospheric pressures

The polar vortex is clearly weakening and destabilizing, with the atmospheric pressure rising, affecting the layers close to the ground. This explains why polar surges are concentrated towards the North Atlantic and the European continent, promoting the formation of strong highs over the eastern Mediterranean and the Arabian Peninsula.

Is the absence of depressions an indicator of climate change?

The atmosphere and oceans follow natural cycles of 5 to 30 years, which lead to specific weather patterns in the northern hemisphere. The Earth is also experiencing global warming, as humans have played a major role in increasing the emission of greenhouse gases since the beginning of the industrial revolution in 1840, which store heat inside and radiate it back to the Earth. This has contributed to an increase in the Earth's temperature of between 1-2 degrees Celsius.

Although global warming has been around for years, the weather phenomena it causes are linked to ocean surface temperatures and the distribution of air masses around the Earth. This has had a clear impact on the weakness of the rainy season in the Arabian Peninsula. Global warming also leads to an increase in extreme weather conditions. But looking at archival data, we find that the absence of depressions is not unprecedented, but has happened in the past, and is likely to happen again in the future more frequently.

And God knows best.