Antarctic sea ice: Antarctic sea ice reached its third-lowest winter peak extent in satellite observations in 2025. The peak extent was estimated at 17.81 million square kilometers (km²), about 900,000 km² below the 1981–2010 average. It was the lowest peak extent in only two years of the 47-year satellite record. Scientists say this indicates a lack of winter ice formation and a weakening of the structure of the ice that has formed. This irregular formation and loss of ice can have real impacts on geographic and climate systems. Today, we will analyze, explain, and discuss in detail the possible causes and effects in the following paragraphs.
Introduction and context
Atlantic sea ice is a factor that maintains the balance of the entire continent’s environment. Around Antarctica, sea water is converted to rain or water at depths of the ocean during the winter and forms ice during the summer. This process creates the largest “winter maximum extent” once a year, which usually occurs in September or October. Although scientists have been observing it with satellites for many years, it is believed that this observation began in 1979. From which we can say that the extent of the ice is increasing significantly every year. Also, the maximum and minimum values of the ice size are being determined. You will be surprised to know that in 2025, the peak value of the Antarctic winter ice extent was 17.81 million square kilometers. This is an amount that is about 900,000 square kilometers less than the average peak value from 1981–2010. This value remains the third lowest peak extent in the 47-year satellite record — that is, only two years have been lower. From here it is clear that the phenomenon is not just a number. From this we understand that climate change is going to be an important signal for the future. In addition, changes in Antarctic sea ice activity and faulty ocean-related processes are bearing a negative forecast for the future.
Why is this peak extent so low?
There are various reasons and processes involved in reducing the peak extent of winter ice. Scientists have come to a conclusion through research on these reasons and processes day after day. Notable among them is that global warming is increasing the temperature in the ocean and the surrounding atmosphere every day. As a result, the amount of ice in both polar regions is decreasing. Therefore, these ice balls are accumulating in the Antarctic sea ice, further weakening the cooling process. And that melted water is not able to completely freeze again in winter. More melting means that the cooling process required for ice formation in winter is weakened. Again, it is believed that the weakness of the ice formation process is another special reason. As a result, the frozen point that is created for new large formations in winter is not reaching its peak. As a result, cold water from the depths is not able to gradually come down and the water in the Antarctic sea is increasing. Since the frozen point is not reaching the appropriate amount of ice formation, ice formation is constantly being hindered.
Again, some scientists think that Antarctic sea ice are not forming due to the wind speed and air-sea interaction. Atmospheric trends such as South Pole winds, storms, high-low pressure patterns, etc. affect the movement of heat and water between ice and seawater. Sometimes strong cyclones or air currents can break the ice or reduce the ice expansion. On the other hand, ocean currents and ocean heat are helping to melt it. As a result, warm water from the Southern Ocean melt is gradually rising upwards. And ice formation is constantly being hindered in winter. If you think that this is the only reason why ice formation is difficult. It is not. Another big reason is that the large expanse of Antarctica shows us a lot of variability every year. But a trend that has increased slightly until 2014 can be observed. It is thought that the response in one year will be quite different from another. But the trend that is currently being seen is gradually decreasing. And the amount of going to this room has been significantly noticeable since 2015. Therefore, it can be thought that it is not possible to understand this diversity and variability in a day. It is not possible to know the specific reasons unless scientists study the factors based on continuous changes.
Impact and importance
The impact and importance of this record of Antarctic sea ice can be analyzed from many perspectives. For example, the whiteness of the ice reflects sunlight. As a result, the open ocean or meltwater above is absorbing sunlight more strongly. The most important phenomenon that is occurring as a result of this is that the thermal conductivity is increasing. This is thought to be a positive feedback. As a result, the pinkish-blue water is absorbing more light from the sun. We can think of this as a decrease in albedo. Another phenomenon is that warm water rises to the surface. As the meltwater rises to the surface, excess heat can reach the upper layers, which prevents ice formation. Again, sea ice is a habitat for various microorganisms, algae, phytoplankton and candle elements. If the ice decreases, this ecosystem can be disrupted and the food chain can be affected.
Conclusion:
In 2025, the Antarctic sea ice can be extent to 17.81 million km². Which is the third lowest in the history of satellite observations. This is about 900,000 km² less than the average. Therefore, we can assume that this change is not just a sign of climate change. It could have a significant impact on the ocean and the environment in the future. With deeper monitoring and improved modeling, we can prepare for this future crisis. The increase in melting in Russia and the loss of biodiversity could have negative impacts on the environment later or even more.