Interannual Variability of the Mid‐Atlantic Bight Cold Pool

Abstract

The Mid‐Atlantic Bight (MAB) Cold Pool is a bottom‐trapped, cold (temperature below 10°C) and fresh (practical salinity below 34) water mass that is isolated from the surface by the seasonal thermocline and is located over the midshelf and outer shelf of the MAB. The interannual variability of the Cold Pool with regard to its persistence time, volume, temperature, and seasonal along‐shelf propagation is investigated based on a long‐term (1958–2007) high‐resolution regional model of the northwest Atlantic Ocean. A Cold Pool Index is defined and computed in order to quantify the strength of the Cold Pool on the interannual timescale. Anomalous strong, weak, and normal years are categorized and compared based on the Cold Pool Index. A detailed quantitative study of the volume‐averaged heat budget of the Cold Pool region (CPR) has been examined on the interannual timescale. Results suggest that the initial temperature and abnormal warming/cooling due to advection are the primary drivers in the interannual variability of the near‐bottom CPR temperature anomaly during stratified seasons. The long persistence of temperature anomalies from winter to summer in the CPR also suggests a potential for seasonal predictability.

Historical biogeographic range shifts and the influence of climate change on ocean quahogs (Arctica islandica) on the Mid-Atlantic Bight

“…Sea bottom temperatures (SBTs) in the MAB directly affect the distribution of A. islandica (Dahlgren et al, 2000), as seen in the connection between the 16℃ isotherm and the inshore range of these boreal clams (Harding et al, 2008; Mann, 1982). Although A. islandica grow shell at temperatures as low as 0℃–1℃ ( Schöne et al, 2004; Wanamaker et al, 2008, 2011; Witbaard et al, 1998), in the MAB region, the minimum bottom temperature in the Cold Pool ranges between 4℃ and 5℃ (Chen and Curchitser, 2020) and the presence of clear growth increments confirms limited growth at these winter temperatures in MAB populations. Therefore, inferring a practical thermal range for adult ocean quahogs in the MAB to be between 4℃ and 16℃ (Harding et al, 2008), the presence of these shells suggests that bottom temperatures during their lifetimes were within the same thermal range (Powell et al, 2020).…”

Seasonal Prediction of Bottom Temperature on the Northeast U.S. Continental Shelf

“…Variability in bottom temperature on the NES is strongly influenced by local oceanic processes, for example, bottom circulation along the shelf and intrusions of warm and saline slope waters onto the shelf. In the Mid‐Atlantic Bight (MAB), a distinctive seasonal bottom‐trapped cold water mass—the Cold Pool, is maintained by the southwestward advection of winter remnant water formed in the vicinity of Nantucket Shoals and upstream Georges Bank (GB) and GoM water (e.g., Chen & Curchitser, 2020; Chen et al., 2018; Houghton et al., 1982; Lentz, 2017). In the GoM, temperature variations at depth are influenced by two different processes: (a) advective inflow of relatively fresh water from the Scotian Shelf (SS) and its modification through winter convective mixing (Mountain & Manning, 1994) and (b) inflow of warmer and saltier slope waters through the Northeast Channel (NEC), consisting of varying proportions of Labrador slope water and Atlantic temperate slope water, each with their own seasonal property variations (Greene et al., 2013; Ramp et al., 1985; Smith et al., 2001).…”

Seasonal Prediction of Bottom Temperature on the Northeast U.S. Continental Shelf

“…Variability in bottom temperature on the NES is strongly influenced by local oceanic processes, for example, bottom circulation along the shelf and intrusions of warm and saline slope waters onto the shelf. In the Mid-Atlantic Bight (MAB), a distinctive seasonal bottom-trapped cold water mass-the Cold Pool, is maintained by the southwestward advection of winter remnant water formed in the vicinity of Nantucket Shoals and upstream Georges Bank (GB) and GoM water (e.g., Chen & Curchitser, 2020;Houghton et al, 1982;Lentz, 2017). In the GoM, temperature variations at depth are influenced by two different processes: (a) advective inflow of relatively fresh water from the Scotian Shelf (SS) and its modification through winter convective mixing (Mountain & Manning, 1994) and ( and the cyan dots represent the locations of temperature observations along the 15°C isotherm used to generate the 200-m temperature-based Gulf Stream Index .…”