Summary |
The seasonal cycle of the Intra-Americas Sea Mid Summer Dry Spell (MSD) is characterized by a bimodal rainfall season with peaks occurring in the late spring and late summer. While the MSD is a permanent feature, it undergoes interannual variability. Jamaican farmers have verified that the perceived MSD variability represents a significant obstacle to their cropping strategies, especially in July. The El Nįo Southern Oscillation (ENSO), the North Atlantic Oscillation (NAO), and springtime North American surface heating influence rainfall over Jamaica during July. During warm year (+0) ENSO events rainfall is reduced while the warm year (+1) ENSO events promote wetter than normal conditions during the Jamaican MSD. Positive early Spring NAO values correspond negatively to the upcoming Jamaican MSD rainfall. Surface heating patterns contribute to a thermodynamic effect leading to increased subsidence within the Caribbean that supports NAO influenced Caribbean Low Level Jet flow into region. The impact of the MSD is discerned via a lagged vegetation response observed through a similar summertime bimodal pattern of the normalized difference vegetation index (NDVI) in Jamaica. MSD prediction through a multi-variate regression model (R-square = 0.59) is created to better prepare farmers for MSD rainfall. |
General note | Presented to the faculty of the Department of Geography. |
General note | Advisor: Scott Curtis |
Dissertation note | M.A. East Carolina University 2009 |
Bibliography note | Includes bibliographical references (leaves 79-86). |
Genre/form | Academic theses. |
Genre/form | Academic theses. |
Genre/form | Thèses et écrits académiques. |