The influence of Atlantic tropical cyclones (TCs) on drought over the eastern US (1980-2007)
Speaker: Jonghun Kam, Graduate Student
Series: EEWR Brown Bag Seminars
Location: Engineering Quad E225
Date/Time: Friday, April 6, 2012, 12:00 p.m. - 1:00 p.m.
In the past, the role of tropical cyclone in drought mechanism has been poorly understood due to their different temporal and spatial scales. Here, the Variable Infiltration Capacity (VIC) land surface hydrologic model is simulated separately forced by NLDAS-2 rainfall and non- TC related rainfall to assess the influence of Atlantic TCs on the eastern US drought regime. Here, the impacts of Hurricane Katrina and Atlantic TCs in 28 years on the eastern US drought are examined at local and regional scales, respectively. Overall, the hidden benefits from Atlantic TCs include shorter drought duration and mitigated drought coverage. Hurricane Katrina in 2005 plays a different role in local drought: 1) late drought initiation, 2) weak drought persistence, and 3) early drought recovery. Our results indicates that Atlantic TCs in 28 years decrease total duration of moderate severe and short-term (long-term) drought by more than 150 days (100 days) and destroy at least two short-term and one long- term drought events over more than 50% of the study regions. Also, our results show that Atlantic TCs impede drought initiation mainly along the coastline of the Gulf of Mexico and the Atlantic Ocean and advance drought recovery especially in South and Northeastern regions. This study succeeds to appreciate the role of TCs in drought mechanism and also underscores linkage between TCs and drought. Finally, it speculates that Atlantic TCs are more crucial water resources for drought relief over the eastern US under the future climate change.