HR: 10:56h
AN: A32B-03    [Abstracts]
TI: The Long-Term (1965-2003) Relationship Between Dust Concentrations in the Trade Winds at Barbados and Tropical Cyclone and Hurricane Activity in the Atlantic and Caribbean
AU: * Prospero, J M
EM: jprospero@rsmas.miami.edu
AF: University of Miami RSMAS Cooperative Inst. Marine and Atmospheric Studies, 4600 Rickenbacker Causeway, Miami, FL 33149 United States
AU: Dunion, J P
EM: Jason.Dunion@noaa.gov
AF: University of Miami RSMAS Cooperative Inst. Marine and Atmospheric Studies, 4600 Rickenbacker Causeway, Miami, FL 33149 United States
AU: Landsea, C W
EM: Chris.Landsea@noaa.gov
AF: NOAA AOML/Hurricane Research Division, 4301 Rickenbacker Causeway, Miami, FL 33149 United States
AB: Recent studies show that the development of tropical cyclones (TCs) can be strongly impacted by interactions with the Saharan Air Layer (SAL) [Dunion, J.P., and C.S. Velden, The Impact of the Saharan Air Layer on Atlantic Tropical Cyclone Activity. Bull. Amer. Meteor. Soc., 85 353-365 (2004)]. The SAL is a layer of hot, dry, dust-laden air that is often present over large areas of the tropical and sub-tropical North Atlantic and Caribbean Sea during the summer and fall. In the presence of the SAL tropical waves and disturbances often do not strengthen as predicted by models and TCs tend to weaken. A number of mechanisms have been proposed to explain these effects, some of them involving dust-related processes. If dust does indeed play a role in modulating TC intensity, then changes in climate that affect dust generation and transport over the Atlantic could have an impact on the occurrence and properties of TCs. Large changes in dust transport have indeed occurred over this region as shown by aerosol measurements made on Barbados in the West Indies since 1965. [Prospero, J. M., Lamb, P. J., African Droughts and Dust Transport to the Caribbean: Climate Change Implications. Science 302: 1024 1027, 2003]. Large interannual-decadal changes in dust concentrations in the trade winds are highly anti-correlated with rainfall in the Sahel-Soudano region of North Africa, a region that includes many major dust sources. If African dust carried in the SAL is playing a role in modulating TC activity, then we might expect to see a relationship between dust transport and various measures of TC activity. In this presentation we report on the relationships between Barbados dust concentrations and a number of measures of TC activity including the number of named storms, the number of hurricanes, the number of major hurricanes and the Accumulated Cyclone Energy (ACE) index, which accounts for the collective intensity and duration of Atlantic tropical storms and hurricanes during a given hurricane season. Preliminary results suggest that TC activity was indeed lower during years when dust concentrations were high but the relationship is not a clear one.
DE: 3374 Tropical meteorology
DE: 1620 Climate dynamics (3309)
DE: 0305 Aerosols and particles (0345, 4801)
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting