Ocean-Atmosphere Interactions Cause Abrupt Changes in Sea Ice

The southernmost sea in the world to experience seasonal freezing is the Okhotsk Sea, located in the western Pacific Ocean and bordered by Russia and Japan.

Although there is active sea ice creation in this shallow sea's northwest, it is still unclear why the amount of sea ice varies from year to year.

Annual Changes In Sea Ice Linked To Ocean-Atmosphere Interactions

(Photo : MARCO BERTORELLO/AFP via Getty Images)

These interannual changes are linked to ocean-atmosphere dynamics, according to research from the University of Tsukuba that was recently published in the journal Atmosphere-Ocean, as per Phys.org.

Lead author Professor Hiroaki Ueda notes that freezing often begins in late October, peaks in late February or early March, and the ice disappears by June.

However, the amount of sea ice varies significantly between years.

Regional cold air masses and low-pressure systems, as well as large-scale phenomena like the Pacific-North American Pattern linked to the El Nio/Southern Oscillation, all have an impact on sea ice in the Okhotsk Sea (ENSO).

Sea ice has experienced long-term alterations as a result of climate change.

Between 1979 and 2010, there was a 9% loss in sea ice extent per decade, which is the second-highest rate of decline in the northern hemisphere.

The researchers examined variations in the amount of sea ice in connection to meteorological factors such cold air masses, extratropical cyclones, and atmosphere-ocean heat exchange using satellite photos of sea ice from 1971 to 2018

90% of the water was covered by sea ice at its largest size.

Years might generally be divided between heavy and light sea-ice years.

The Aleutian low, a semi-permanent low-pressure system, deepened and cold air accumulated during heavy-ice years.

Southeasterly winds and warm air advection have been linked to an increase in extra-tropical cyclones off the Kamchatka Peninsula in years with little sea ice.

The Aleutian low also began to diminish.

These monthly and yearly variations in sea ice suggested that there might be a positive feedback process between the Aleutian low and the cold air masses connected to sea ice anomalies.

The anticyclonic anomalies that predominate in the Okhotsk Sea during light sea-ice years are intimately linked with the spread of a stationary Rossby wave, demonstrating another distant influence of the tropical ocean.

The South China Sea-area enhanced convection associated with warm sea surface temperature anomalies similar to La Nia serves as the wave's anchor.

While some of the important processes at work in the Okhotsk Sea have been highlighted by the study, additional field research is required to acquire a fuller understanding of how sea ice is likely to alter in connection to shifting ocean-atmosphere dynamics.

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Climate Change Indicators: Oceans

Sea surface temperatures are rising and the sea level is rising as a result of the oceans absorbing more heat as a result of greenhouse gas emissions, as per EPA.

Climate patterns will shift globally as a result of changes in ocean temperatures and currents brought on by climate change.

For instance, warmer waters may encourage the development of storms that are more powerful in the tropics, which can lead to the destruction of property and fatalities.

Coastal areas should pay particular attention to the effects of rising sea levels and more powerful storm surges.

The seas store a lot of carbon dioxide, which helps slow down climate change but rising dissolved carbon levels are altering the chemistry of saltwater and raising its acidity.

Some creatures, including corals and shellfish, find it harder to assemble their skeletons and shells when ocean acidity rises.

The biodiversity and productivity of ocean ecosystems may be significantly changed as a result of these consequences.

While storms can form and fade in the course of a single day in the sky, changes in ocean systems often take place over considerably longer time periods.

Both the movement of water within the seas, including the mixing of deep and shallow waters, and the interactions between the oceans and atmosphere happen gradually over many months to years.

Hence, trends have the potential to last for millennia or more.

It would therefore take many more years-decades to centuries-for the oceans to adapt to the already-occurring changes in the atmosphere and climate, even if greenhouse gas emissions were stabilized tomorrow.

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