Hurricane Sandy storm surges observed by HY-2A satellite altimetry and tide gauges

摘要

Hurricane Sandy made landfall to the northeast of Atlantic City, New Jersey at 23:30 UTC on 29 October 2012 and caused large storm surges and devastating flooding along the New Jersey and New York coasts. Here we combine sea surface height measurements from the HaiYang-2A (HY-2A) satellite altimeter with coastal tide-gauge data to study the features of the Hurricane Sandy storm surges. The HY-2A altimeter captured the cross-shelf profile of surge at the time of Sandy’s peak surge, with a surge magnitude of about 1.83 m at the coast and a cross-shelf decaying scale of 68 km. The altimetric surge magnitude agrees approximately with tide-gauge estimate of 1.73 m at nearby Montauk. Further analysis suggests that continental shelf waves were generated during the passage of Sandy. The continental shelf wave observed by altimetry has a propagating speed of 6.5 m/s. The post landfall free shelf wave at Atlantic City observed by tide gauges has a propagating phase speed of 6.8 m/s and cross-shelf e-folding scale of 75 km. In contrast, the post landfall sea level oscillation at Montauk is not associated with a continental shelf wave. The study indicates that satellite altimetry is capable of observing and useful for understanding features of storm surges, complementing existing coastal tide gauges.