The modulation of the seasonal cross‐shelf sea level variation by the cold pool in the Middle Atlantic Bight

Abstract

AbstractThis study explores the influence of the cold pool in the Middle Atlantic Bight (MAB) to cross‐shelf sea surface slope by fitting an annual harmonic to temperature and salinity profiles from 1993 to 2012 and compares to the 20 year averaged altimetry sea level anomaly (SLA). The consistency within the bottom temperature, thermal steric height, total steric height, and altimetry observation validates that the cold pool induces a depressed sea level in the middle shelf overlapping with the dominant surface seasonal cycles. Temporally, the cold pool pattern is most apparent in July and August as a result of magnitude competition between the thermal and haline steric height. In addition, Ensemble Empirical Mode Decomposition (EEMD) is employed to reconstruct the altimetry SLA and reveals the middle‐shelf depression pattern from single year's SLA data. The locations of the SLA depression from 1993 to 2012 agree with the cold pool locations identified from in situ measurements, suggesting a promising application of altimetry SLA in the cold pool study. Conclusively, this study reveals the modulation of the cross‐shelf sea level variation by the cold pool, and contributes to the understanding of the sea level response to water masses on the continental shelf.