The Impact of the Dust-Shortwave Radiation Effect on Atlantic Hurricane Activity in 2007

• Main Author: Isik, Ayse Gokcen
• Format: Dissertation
• Language: English
• Published: ProQuest Dissertations & Theses 01-01-2015
• Subjects: Atmospheric sciences; Meteorology
• ISBN: 9781339544090; 1339544091

Mineral dust particles play a vital role in climate and the Earth's energy budget and can have impact on weather as well. This research is to investigate the dust-radiation effect on Atlantic tropical cyclone (TC) activities. The first objective of the research is to follow the development of knowledge about the Saharan air layer (SAL). To investigate how the SAL and Saharan dust affect Atlantic tropical activities, tropical cyclone activities in 2005 and 2007 were studied and connected to environmental conditions, such as sea surface temperature (SST) anomaly, vertical wind shear, and aerosol optical depth (AOD). The 2005 hurricane season was very active, while the 2007 was a normal year. Compared to the normal year 2007, the 2005 hurricane season had a lower dust load, weaker deep shear and warm SST anomaly. The second objective of the research is to study the dust-radiation interaction on Atlantic seasonal TC activity in 2007 using a dust numerical model. Two numerical experiments were conducted. The dust short-wave radiation interaction was activated in one simulation (ON) and deactivated in the other one (OFF). An automatic program was developed to track simulated TCs. Nine TCs formed in the ON experiment, while only two TCs formed in the OFF experiment through July to September. The results show that for a normal year the dust-radiation interaction reduces vertical wind shear over West Atlantic and thus increases the TC development over region, which is more comparable to observations. It is unfortunate that the model did not produce any TC over the main developing region in both experiments, while five TCs formed in reality.