Using Windshear and SSTs

Many general circulation climate models predict an increase of the vertical wind-shear in the Main Development Region in the future due to anthropogenic forcing (Vecchi and Soden, 2007). As the windshear has an important effect on hurricane formation, this could affect future hurricane rates. In the last few decades, we have seen that the windshear in the Atlantic MDR region is quite strongly correlated with the MDR SSTs, so that as the SSTs increase, the windshear decreases (see Fig. 6). However, some climate model integrations imply that this relationship may decouple in the future meaning that it will be difficult to predict future changes just from past data. To take this into consideration we include this final model which estimates future changes in windshear and SST from the IPCC ensemble means while the current state is estimated from the historical record. The windshear estimates are based on the climate predictions of Vecchi and Soden [2007] and the SST estimates are based on the predictions from Laepple et al. [2007]. The framework of the Poisson Generalized Linear Model provides a combined relationship with basin hurricane numbers so that the predictions of windshear and SST can

Time (years)

Fig. 6 Historically, there has been a strong correlation between Windshear and SSTs in the MDR region. The solid line shows the normalized 2D windshear between 800 and 250hPa, averaged from July to September and from 15-70W and 10-20N is shown. The dashed line shows the inverse of the normalized HadlSSTs averaged over the same time and area from 1948-2006

Time (years)

Fig. 6 Historically, there has been a strong correlation between Windshear and SSTs in the MDR region. The solid line shows the normalized 2D windshear between 800 and 250hPa, averaged from July to September and from 15-70W and 10-20N is shown. The dashed line shows the inverse of the normalized HadlSSTs averaged over the same time and area from 1948-2006

be converted to basin numbers which are in turn converted to a prediction of landfalling numbers. The results are shown in row 18 of summary Table 4.

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This is a collection of 3 guides all about survival. Within this collection you find the following titles: Outdoor Survival Skills, Survival Basics and The Wilderness Survival Guide.

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