Effects of the Saharan Air Layer on the 2006 Atlantic Hurricane Season, using level 2.0 AERONET AOT/AOD datasets

After the 2005 very strong hurricane season, CSU and NOAA predicted an above average season for 2006. However, 2006 resulted in a weak season; producing a deviation of 61.54% from the original forecast. Three factors were associated with the decrease in cyclonic activity: the appearance of a moderate El Niņo Event, the steady presence of a secondary high pressure system on the Azores and strong outbreaks of Saharan Air Dust. Several studies in the last years have linked SAL with tampering with tropical storm cyclogenesis by limiting downdrafts, humidity and increasing vertical windshear due to its aerosol properties.  This study evaluates the effects of the Saharan Air Dust in the 2006 Atlantic Hurricane Season by determining how much SAL was released into the Atlantic in comparison with previous (2005) and successive (2007) years. Level 2.0 Aerosol Robotic Network (AERONET) 1020, 870 and 675 nm bands AOD/AOT datasets along with precipitable water information from Cape Verde AERONET station were used to determine the percentage difference for the periods of study. Based on the collected data from AERONET Cape Verde Station and the conducted analyses, there was an increase of 14.71%1020 nm AOD/AOT, a 17.66% increase detected by the 870 band and 17.31% increase in 675 nm AOD/AOT values between the years 2005 and 2006. On the other hand, there was a decrease between 2006 and 2007 SAL AOD/AOT values for all bands: 10.68% for the 1020 nm band, a 9.30% for the 870 nm and a 9.35% reduction for the 675 band. PW was reduced by 12.79% between the 2005 and 2006 periods of study. An increase of 4.51% in PW values took place between 2006 and 2007 selected datasets. The study was also conducted using Santa Cruz, Tenerife AERONET datasets for June-September 2005 and 2006.