Giant winds

MARY Margaret’s most apposite article published in Nov 10 thesundaypost was purely coincidental following the Super Typhoon Haiyan, which two days before swept over the Philippines. Her article drew our attention to the greater frequency of such gigantic storms in the last three decades. Devastation, destruction and death from such violent atmospheric turbulence have been regularly reported in the world’s press with graphic and heart-jerking reportage.

There is certainly much debate amongst the world’s leading meteorologists over the impact of human-generated influences on the causes of climatic change. This is simply because our knowledge base, through in-depth collection of meteorological data and modern technology, has radically improved in less than half a century.

Three weeks before Super Typhoon Haiyan hit the Philippines, I experienced, where I live in the South West of England, the sting in the tail of a Mid-Atlantic Ocean hurricane. Wind speeds reached up to 225km per hour. The aged Victorian tiles on my roof rattled but did not take off in the same way as a third of my roof disappeared in a more violent storm in October 1987. Yet, some beautiful trees were uprooted in the surrounding fields and power and telephone lines blocked roads.

The sting in this deep centred area of low pressure spun its course as air was injected downwards from the overhead jet stream in the upper atmosphere many kilometres, in its route, above ground level. The sheer power of Typhoon Haiyan, at wind speeds of 320 to 380km per hour at the exceedingly low pressure of 858 to 884 millibars, rapidly sucked in air from slightly higher pressure areas beyond this vortex. Winds blow from high to low pressure areas, replacing air that rises in areas of low pressure. Essentially, the Philippines are a multitude of islands. As the typhoon passed over land frictional drag caused much devastation and as the typhoon continued over open water with a reduction of friction wind speeds again increased with little energy loss.

As there is a sting in a scorpion’s tail, so there was a sting in the tail of Typhoon Haiyan. This came in the form of a storm surge in seawaters which rose to a height of six metres. As the typhoon hit the city of Tacloban, its sudden low pressure pushed waters up into the funnel shaped bay, thus concentrating its impact.

This was equivalent to tsunami destruction as most houses were just a few metres higher than normal high tide level. To date, from United Nations sources, 13 million people in the Philippines have been affected with three million displaced persons, some 500,000 homeless without food, drinking water, sanitation and the smell of death of unburied bodies. Tacloban, once a city of 218,000 people, has lost at least 10,000 of its original population.

Is a typhoon different from a hurricane or a cyclone? Not really, for it depends upon which area in the world we live. The word cyclone is derived from the Greek word ‘kyklon’ meaning air moving in circular coils like those of a snake. The Nasa shots from outer space confirm this anticlockwise circulation of air in the northern hemisphere.

Captain Henry Piddington, whilst stationed in Kolkata in 1789, first coined the word. Typhoon could have originated from the ancient Arabic ‘tafon’ or more likely from the Chinese ‘tai fung’ meaning, in each language, a big wind. Whatever terminology is used, all have one thing in common – deep low pressure areas with winds sucked in from neighbouring high pressure areas to replace the rising air in the low pressure system.

The steeper the pressure gradient between low and high pressure areas, the faster the winds. Just as closer contour lines on a topographic map indicate a steepening of gradient and greater energy for humans to expend in climbing a steep hill, so on a meteorological chart the closer the isobar lines the steeper the pressure gradient and the faster the wind speeds.

A one-time naval captain later buccaneer, William Dampier, who was born in the village of East Coker, Somerset, in the United Kingdom, only 60km from my hamlet, circumnavigated the world and in doing so recorded wind speeds and the direction of ocean currents wherever he was. He observed, in particular, seasonal changes in the Trade Wind patterns whilst on visits to the Malay Archipelago, witnessing a severe storm near Banda Aceh (Sumatra) in 1698.

His book ‘A Discourse of Winds’ was published in London in 1705. This publication influenced Captain James Cook and later Admiral Horatio Nelson in their voyages. Dampier’s first mate, William Funnell, is referred to by Alfred Russell Wallace in his book ‘The Malay Archipelago’ (1869), recalling Funnell’s experiences of earthquakes at Amboyna (now Ambon in the Banda Sea).

It is likely that the early 18th century records by Dampier of winds and ocean currents influenced Charles Darwin, Alfred Wallace and a famous German meteorologist, Alexander von Humboldt a century and more later. Dampier Strait (Selat Dampier) between Irian Jaya and Utara still retains his name. He is also accredited with introducing such exotic words as avocado, barbecue, breadfruit, chopsticks and sub-species to the English language. A true recorder of currents, tides and atmospheric events, he died in relative poverty in 1715, at the age of 63.

Just imagine, based on the evidence of climatic change and global warming, if the winds above Sabah, Brunei, Sarawak and Kalimantan dropped lower by a few degrees of latitude. How would we cope with roofs ripped off and inevitable power cuts as electricity poles and trees collapsed on roads and buildings, disrupting all means of communication?

Where would we go for shelter, even with national meteorological warnings, to avoid storm surges which could affect all settlements below 10 metres above normal high tide mark? The plight of our near neighbours, the Philippines, brings home to the entire world, the fragility of our planet in all forms of life. In the Banda Aceh tsunami in the Indian Ocean earthquake, it has taken almost a decade for the people there to rebuild their lives.

Wherever we are in the world, we need to heed the warnings of our local meteorological services of impending severe storms and batten down our hatches and explore possible means of escape. The devastation in the Philippines has awoken the world to mankind’s plight when the forces of nature exceed 21st century living.

For more read ‘Ready for changing temperatures?’ by Mary Margaret in the Nov 10, 2013 thesundaypost and ‘The sting in the tail of a tropical cyclone’ by Alan Rogers in the Sept 25, 2011 thesundaypost.

The Malaysian Nature Society
Established in the 1940, the Malaysian Nature Society is the oldest scientific and non-governmental organisation in Malaysia. Our mission is ‘to promote the study, appreciation, conservation and protection of Malaysia’s nature heritage’. Our 5,000-strong membership, spread across 12 branches nationwide, come from all walks of life, bound by a common interest in nature. For further information on membership or our activities in Kuching, call Kwan on 019-8349499. For information on our activities in Miri, call Nazeri Abghani on 085-453185. You can also visit www.mns.org.my or http://[email protected].