P1.41
Nile Delta Storm :Tropical Cyclone Occurence Recurving Transition
Therese Schneck, Consulting Engineer, Puteaux La Defense, Paris, France
The storm system which tracked across the eastern Mediterranean region on december 2002 brought strong winds and heavy rainfall.Flooding was reported , winds gusted to 60 mph and waves 4 meters height (limited sea room in the Mediterranean Basin) after the transition.The maximum waves,generated with a predominant direction similar to that of wind, were estimated since 1921 as high as 2.5 meters (a maximum wind speed of 40 mph) in the Nile delta Region.
The Nile Delta extratropical cyclone was a recurving tropical cyclone transition to a fast moving storm.The intensity or wind speed in m/s at the time of extratropical transition could have reached 14 to 26 m/s ( 1990-1997).The wind profile at different stages beyond a cyclone center shows the increase in wind speed more than twice the initial value.The North Indian Basin has a double peak of activity,the severe cyclonic storms(33m/s[76mph]occur almost exclusively from April to June and late September to early december.
The occurrence of Tropical Cyclone can be related to the phases of the sunspot cycle.The storms greatest number seem to occur in Phase 7 of the index.The Hurricane Andrew was in phase 6 in 1992.
Daily concentration of Be7 in air has been observed in Japan at the ground level during the year 2000 maximum solar activity.The mass 7 specific reaction take place in the helium zone where the neutrino flux is lower than in the carbon and oxygen zone,but the temperature is higher than in the Hydrogen zone so that any mass-7 produced is more easily destroyed. Furthermore neutrino spallation in the helium zone can yield He3 and H3 which can react He4 to build mass 7. Boeegaard and al have found that Beryllium increases with Iron,and that Beryllium increase 8 times faster than Oxygen, a rate consistent with cosmic ray creation.There is an evidence for an intrinsic spread in Be at a given [Fe/H] or [O/H].There is currently no evidence of a primordial plateau level of Be down to log N(Be/H)=-13.5 The concentration of helium ions in the upper atmosphere varies with the changes in solar radiation.
Changes in the frequency of tropical cyclones developing over the north indian ocean have also been studied utilizing 122 years (1877-1998) data , the tropical cyclone frequency declined during the months of most severe cyclone formation-November and May-when ENSO is in a warm phase. They can pose a serious threat to coastal and offshore activities.
Poster Session 1, Posters
Wednesday, 5 May 2004, 1:30 PM-1:30 PM, Richelieu Room
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