Abstract
Freshening and warming of Antarctic Bottom Water (AABW) between the 1980s and 2000s are quantified, assessing the relative contributions of water-mass changes and isotherm heave. The analysis uses highly accurate, full-depth, ship-based, conductivity–temperature–depth measurements taken along repeated oceanographic sections around the Southern Ocean. Fresher varieties of AABW are present within the South Pacific and south Indian Oceans in the 2000s compared to the 1990s, with the strongest freshening in the newest waters adjacent to the Antarctic continental slope and rise indicating a recent shift in the salinity of AABW produced in this region. Bottom waters in the Weddell Sea exhibit significantly less water-mass freshening than those in the other two southern basins. However, a decrease in the volume of the coldest, deepest waters is observed throughout the entire Southern Ocean. This isotherm heave causes a salinification and warming on isobaths from the bottom up to the shallow potential temperature maximum. The water-mass freshening of AABW in the Indian and Pacific Ocean sectors is equivalent to a freshwater flux of 73 ± 26 Gt yr−1, roughly half of the estimated recent mass loss of the West Antarctic Ice Sheet. Isotherm heave integrated below 2000 m and south of 30°S equates to a net heat uptake of 34 ± 14 TW of excess energy entering the deep ocean from deep volume loss of AABW and 0.37 ± 0.15 mm yr−1 of sea level rise from associated thermal expansion.
When I tell people that ocean water is warming from the bottom up a common response that I get is:
“Do you mean that the hottest waters are at the bottom?”
This is a great illustration of the intellectual bankruptcy of atheism. Atheists can’t comprehend simple logic, and one of the ways that they cope with it is to instinctively warp whatever you said into something that they can understand. Since atheists automatically assume that everyone who disagrees with them is idiotic, they intentionally misinterpret whatever you said into something idiotic.
My response is simple enough:
Water warms at the bottom, as this happens the water is displaced upward by colder water.
The article appears to confirm this. Bottom water is freshening because of an influx of water from melting polar ice. This is also driving ocean circulation.
Matty (Headwind) 