AUSTIN (KXAN) — By comparing estimated global temperatures and carbon dioxide levels that are expected by the end of this century with climate data estimated in the Neogene time period (13-17 million years ago), we can get a better idea of what will happen with our projected sea ice in the Antarctic.
The latest research from new climate modeling is now showing a more dire rapid retreat and loss of sea ice.
Sea ice in the Antarctic is melting from global warming. As the ice sheet melts and exposes the rocky ground below it, it is changing the albedo. The albedo is a measure of reflectivity. Snow and ice have a higher albedo because they can reflect sunlight and further cool a surface.
But a dark surface, including rocky ground, will absorb more heat. Therefore, lowering the albedo and causing more warming and therefore more melting of the ice. This is called positive feedback, where one action further enhances the reaction.
This has major impacts on the surface influence with the atmosphere and the overall global weather pattern. As the globe continues to warm, and sea ice continues to melt, the poles are warming at a significantly faster rate than areas closer to the equator. This tends to produce more chaotic weather patterns and typically dislodges cold air from the poles toward the equator.
We have been seeing this more frequently in North America with the weakening of the polar vortex. The polar vortex feeds off the temperature contrast between the poles and areas southward. But as sea ice melts and warming increases twice as fast, there is now a lesser temperature gradient.
This dislodges the cold air southward and brings deeper jet streams and often more frequent snowstorms or cold spells to areas that typically don’t experience them often.
The wind pattern over the continent of Antarctica is typically outward, from land out to sea wind. This is caused by the difference in air temperature over the cold ice sheet to warmer sea surface temperatures.
This prevailing wind is actually called a monsoon. In this specific case, it results in a dry weather pattern. However, if sea ice continues to melt and the continent continues to warm, it’ll eventually be warmer than the surrounding ocean water. This would in return change the direction of the prevailing wind from offshore to onshore. This would result in a rainy weather pattern.
The rain would cause further melting of ice and more freshwater runoff into the sea. Because this newly added freshwater is less dense than saltwater, it accumulates to the top and doesn’t mix well. This cuts off any circulation from deep underneath the ocean surface, causing the water at the top to continue to warm even further, which enhances the warming of the ice shelf from down below.