We’ve been experiencing a lot of severe weather systems this past year. From flash floods, to hurricanes, to wildfires, this year has not been without climate-driven challenges. There is something else that could make the severe weather systems we’ve been experiencing even worse.
Two new studies, published in Nature and the Journal of Climate, looked for evidence in the massive amount of data from buoys, drones, drifters and satellites. Through model simulations, a “characteristic spatial and seasonal sea-surface temperature ‘fingerprint'” was calibrated. Indications were found of changing seawater temperatures suggesting cooling in the subpolar Atlantic Ocean (the Greenland Sea) and warming in the Gulf Stream region.
The Arctic Ocean has melted back from two thirds covered by sea ice to less than one third sea ice. There is twice the amount of open sea when winter arrives in October. Sea ice forms as frozen freshwater. The very salty cold seawater around the new ice is very dense. The sinking action that follows sea ice formation combined with the centrifugal motion from rotation of the Earth drives the thermohaline circulation of the world’s ocean.
Jetting through the Denmark Strait between Iceland and Greenland, cold nutrient-rich Arctic water collides with warm nutrient-poor Atlantic water. Here, Arctic water cataracts down eleven thousand feet to form the Greenland Current. Rushing around Greenland into the Labrador Sea, the dense water body becomes the southbound Labrador Current.
On the surface, the less dense Gulf Stream flows north. It is squeezed through the Florida Straits and must release energy by meandering, much like in a train crash where train cars go every which way. In 2011, the Gulf Stream meandered further up onto the Continental Shelf, closer to Rhode Island, releasing more energy than ever before.
Svalbard, the Norwegian archipelago on the threshold between the Atlantic and Arctic Ocean, used to be the end of the road north for the Gulf Stream. In 2007, the Gulf Stream surfaced in Svalbard to commence the melting of glaciers on the land. More warm water from the Gulf Stream is now entering the Arctic Ocean to circulate counterclockwise as midwater. Heat from below warms the surface waters to further increase the summer melt of sea ice.
We know that climate change is already here and its wreaking havoc on our planet. It’s now up to us to mitigate just how bad the climate crisis will be for future generations. All lawmakers need to wake up to the urgency of acting on climate. There is no time to waste.