The Effect of Teleconnections on North Atlantic Tropical Cyclone Precipitation

• Main Author: Wang, Yue
• Other Authors: Quiring , Steven M., Frauenfeld , Oliver W., Korty, Robert
• Format: Thesis
• Language: English
• Published: 2015
• Subjects: Tropical cyclone precipitation; Teleconnection; North Atlantic; North Atlantic oscillation
• Online Access: https://hdl.handle.net/1969.1/155063

This study identified how tropical cyclone precipitation (TCP) in the North Atlantic (NAT) varies in space and time. It also determined how climatic oscillations influence TCP in the NAT using 14 years of satellite-derived (TRMM) precipitation data. The analysis focused on the entire NAT as well as the Gulf of Mexico (GMX), Caribbean (CAR), and East Coast (ECO) sub-basins. Tropical cyclones (TC) contributed a mean of 76 mm of precipitation per year in the NAT. TCP is generally higher in the western and central NAT and little TCP occurs in the eastern NAT and south of 15°N latitude. The highest mean annual TCP occurs in the Gulf of Honduras (333 mm). Although there is substantial interannual variability in TCP, no statistically significant trends was detected in TCP volume, total rainfall, and TCP fraction in the NAT between 1998 and 2011. TCP is strongly correlated with TC frequency and intensity. Seasons with more frequent and intense TCs also receive more TCP. The relationship between TCP and four climate oscillations (El Niño/Southern Oscillation (ENSO), North Atlantic Oscillation (NAO), Quasi-Biennial Oscillation (QBO) and Atlantic Meridional Mode (AMM)) was evaluated. AMM has the strongest influence on TCP, especially in the CAR region. The positive phase of AMM is related to increased TCP. NAO also has an influence on TCP, but the sign of the relationship varies by sub-basin because NAO influences the movement of TCs. TCP tends to increase (decrease) in the CAR (ECO) when NAO is positive. Although ENSO has an influence on TCP in NAT, it is not as strong as AMM or NAO. TCP is enhanced during La Niña phase and suppressed during El Niño phase. There is no obvious correlation between TCP and QBO.