Peak water temperatures up to 6 ° C above average on a massive ocean bay east of New Zealand are likely due to an “anti-cyclone” weather system, says a scientist.
The patch, which appears on the heat maps as a dark red spot, occupies at least a million square kilometers in the Pacific Ocean – an area nearly 1.5 times larger than Texas or four times larger than New Zealand.
James Renwick, head of geography, environment and earth sciences at Victoria University in Wellington, said the magnitude of the temperature fluctuation near the sparsely populated archipelago of the Chatham Islands is remarkable and has been building for weeks.
“It is now the biggest flood of above-average warming on the planet. Normally temperatures are around 15 ° C when they are around 20 ° C, “he said.
Renwick said the ball could be associated with increasing greenhouse gas emissions in the atmosphere due to climate change, but he expected it to be largely due to natural variability – a strong high-pressure system and a lack of wind.
“It’s not uncommon to see hot water spots in New Zealand, but this size of four, five, to six degrees is quite unusual,” Renwick said.
“It is probably a very thin layer of ocean that has warmed up and has not been cooled for several weeks.”
Anticyclones are formed when the amount of air cools, constricts and becomes denser, increasing the weight of the atmosphere and the surface air pressure.
Renwick said that increasing sea heat in the short run can be difficult for local marine life if it penetrates far beyond the surface. Ocean temperatures are less susceptible to sharp changes than onshore due to the amount of energy needed to heat the water area.
He said that scientists would study this point in the coming weeks to get a better understanding of its cause and local impact. Two years ago, a wave of sea followed that drove the hottest hottest summer in New Zealand, more than 3C above average, leading to tropical fish from Australia being found along the coast of the country.
The World Meteorological Organization around the world claims that the last decade was almost certainly the hottest record for land and oceans. The seas have also grown more acid because they absorb carbon dioxide from the atmosphere.
Temperatures from 2010 to 2019 were approximately 1.1 ° C above the pre-industrial average. According to preliminary findings of the WMO Annual Report on Global Climate Report published earlier this month, this year is likely to be the warmest second or third since the record began.