Effects of Hurricane Ike on the Louisiana–Texas coast from satellite and model data

Abstract

The river-influenced Mississippi–Louisiana–Texas (MsLaTex) coast in the northern Gulf of Mexico was in 2008 impacted by Hurricane Ike that made landfall along the Texas coast on 13 September 2008, causing widespread damage due to storm surge and coastal inundation. We examine the effects of the hurricane on the MsLaTex coast using remote sensing, model simulation and field observations. Moderate resolution imaging spectroradiometer sea surface temperature imagery indicated an approximately 2–4°C decrease in temperature to the right of the hurricane track. The high-resolution (∼2 km) three-dimensional Navy Coastal Ocean Model simulation and tide data suggested the generation of a coastally trapped ‘barotropic Kelvin’ wave during the passage of Ike, which may have contributed to an earlier than expected surge in sea level. A distinct elevated band of suspended particulate matter (SPM) concentration extending from Louisiana to Texas (∼90.5–94.5°W) coast was observed offshore in sea-viewing wide field-of-view sensor-derived imagery of 17 and 25 September that appeared to be associated with the coastally trapped Kelvin wave that was enhanced west of the Mississippi Canyon. Two intermittent wind events on 15 and 21 September likely kept the SPM in suspension for an extended period. Subsequently, on 27 and 30 September, SPM decreased along the elevated band and near the landfall site but increased near the bays and passes due to receding flood waters. Off the Atchafalaya and Mississippi deltas a large pulse of river discharge containing elevated SPM levels caused a plume around the two river deltas and its offshore dispersion into the open Gulf of Mexico.