Intensification of the East Australian Current After ∼1400 CE

Abstract

The South Pacific poleward-flowing western boundary current (WBC)-the East Australian Current (EAC)flows along the east coast of Australia and redistributes heat and moisture between the tropics and the mid-latitudes, and thus plays an important role in climate changes in the southwest Pacific. For example, the timing and intensity of EAC changes have been shown to influence both regional climates (e.g., Sprintall et al., 1995) and East Coast lows (severe weather events) along the east Australian coast (Hopkins & Holland, 1997). Specifically, a weaker EAC transport is linked to anomalous cool conditions in New Zealand (Sprintall et al., 1995), whereas a stronger EAC is shown to increase rainfall along the eastern Australian coast (Shi et al., 2008). Furthermore, the EAC also exerts a strong influence on the marine productivity offshore eastern Australia through formation of eddies and coastal upwelling (Roughan & Middleton, 2004;Schaeffer et al., 2014;Suthers et al., 2011). The EAC is the result of the bifurcation of the South Equatorial Current (SEC) between 13° and 25°S (Hu et al., 2015), when it collides with the Queensland Plateau (Ridgway & Dunn, 2003) (Figure S1 in Supporting Information S1). After its formation, the EAC follows the coastline until ∼30°S, where the outflow of the EAC current separates and flows east across the Tasman Sea forming the Tasman Front (TF) (Andrews et al., 1980). A minor portion of the EAC continue to flow south along the Australian coast as EAC extension (Ridgway & Godfrey, 1994;Wyrtki, 1962). The EAC is strongest during austral summer and weakens during the austral winter (Godfrey

Sea Surface Temperatures Across the Coral Sea Over the Last Glacial‐Interglacial Cycle

“…Meridional SST gradients calculated between sites located along the northeastern Australian coast were used as an indicator for changes in the EAC strength and related changes in the regional ocean circulation and climate (e.g., Anderson et al., 1989; Barrows et al., 2000; Felis et al., 2014; Zhai et al., 2022). For instance, a study on fossil corals from the GBR suggests a steeper‐than‐today meridional SST gradient in the Coral Sea during the Last Glacial Maximum (LGM) and the last deglaciation (Felis et al., 2014).…”