Oman is a country with a history of various cyclonic and storm events that have resulted in the loss of human lives, huge infrastructural damage and destruction of crops and animals.
On October 3, a powerful cyclone Shaheen made landfall in Oman, near Muscat, after barrelling up the Arabian Sea in the Indian Ocean and travelling through the Sea of Oman.
Shaheen brought on heavy rainfall, and excessive flooding in the wadis and the cyclone’s high winds generated massive storm surges along the coast.
While it wreaked havoc in many parts of the Sultanate, surrounding countries have also felt the effects in the form of enhanced rainfall and winds in the United Arab Emirates and Iran, with the latter suffering structural damages, injuries and fatalities.
It is not uncommon for tropical cyclones to form in the north Indian Ocean on the southeastern Arabian Sea. In the last over two decades, cyclones have become so frequent in the Arabian Sea that they are a looming threat to a vast population in the coastal areas.
Not just the frequency, the intensity and duration of the cyclones over the Arabian Sea too are changing, according to a paper published recently in Springer’s Climate Dynamics journal.
Studies have found that the combination of warm sea surface temperatures in proximity to the equator, where the earth absorbs most solar radiation and atmospheric moisture (high relative humidity), creates suitable conditions necessary to generate tropical cyclones.
But what are tropical cyclones? They are low-pressure systems that form over warm tropical waters, with gale-force winds near the centre. The winds can extend hundreds of kilometres from the eye of the storm.
Sucking up vast quantities of water, they often produce torrential rains and flooding resulting in major loss of life and property damage.
They are also known as hurricanes or typhoons, depending on where they originate in the world, when they reach sustained winds of at least 119 kilometres per hour.
According to Nasa observations, oceans soak up more than 90 per cent of the heat generated by greenhouse gases, leading to rising water temperatures.
Rising sea levels could also boost storm surges from cyclones, making them even more deadly and destructive. As cyclones draw their energy from warm waters, the rising temperatures are causing intense storms to become more common.
Almost half of the tropical cyclones that are generated in the Arabian Sea do not make landfall, and most that do in the Arabian Peninsula become severely weakened essentially downgraded in intensity to a depression.
According to Mohammed Mahmoud, Director of Climate and Water Programme and a senior fellow at the Middle East Institute, some cyclones travel further west towards the Horn of Africa but tend to also lose intensity in that trajectory due to the relatively cooler waters of the western Arabian Sea.
Oman and Yemen have historically been the most impacted countries in the peninsula from cyclone activity due to the length of their combined coastline on the Arabian Sea.
While very few cyclonic storms make landfall in these two countries at the higher level of cyclone intensity they may have possessed when formed in the Arabian Sea, these storms still bring with them the triumvirate of corresponding calamities: flooding, death and destruction.
“Compared to significant tropical cyclones of the past that originate in the North Indian Ocean, the behaviour of cyclone Shaheen is somewhat unprecedented in the modern era and could represent a potential shift in how climate change is influencing the formation of extreme weather events that can afflict the Middle East”, he points out in a report.
Traditionally, tropical cyclones forming in the Arabian Sea do not travel beyond the Sea of Oman or deep inland across the Arabian Peninsula. The dry air and reduced moisture over the Arabian Peninsula in comparison to the Indian Ocean is an impediment to that type of cyclone trajectory, robbing a potentially severe cyclone of its intensity and accelerating its eventual dissipation.
But the increased warming of the oceans and seas near the equator as evidenced by rising sea surface temperatures, coupled with climate projections of increased global warming in the future, signals the potential of more frequent and intense cyclones landing well into the Arabian Peninsula and surrounding regions.
“This makes Shaheen both a reminder of the peninsula’s vulnerability to extreme weather events and an early indicator of how climate change is exacerbating that vulnerability”, he points out in the report.
According to a research paper by Amna bint Mohammed al Ruhaili, the vulnerability of the Omani coastal zone, for instance, is also related to the area’s socio-economic significance.
Sixty-seven per cent of the Omani population resides along the coast; population growth, infrastructure development, and economic activity, for example the fisheries and tourism industries, are also clustered in the coastal area.
“Frequent exposure to flash flooding of wadis as a result of the cyclones or short-term extreme weather events, serves to illustrate Oman’s inability to mitigate such events”, the research report points out.
Measuring exposure due to projected future sea level rise resulting from climate change, reveals vulnerabilities of Oman’s population, cities, and infrastructure. “These flood events also demonstrate the urgency of the need for Oman to adapt to the consequences of climate change”, it suggests.