Sea ice is a fundamental part of the Arctic Ocean. During winter months, sea ice covers the Arctic Ocean almost entirely. During summer months, some ice melts because of warmer air temperatures and longer days of sunlight. Sea ice is usually at its minimum thickness and extent during mid-September, and at its maximum in during winter with about twice the thickness and extent.
The presence of Arctic sea ice is a significant indicator of changes in global climate because warmer air and water temperatures are reducing the amount of sea ice covering large areas of water. Because sea ice has a higher albedo, it reflects more sunlight back to space than seawater. By doing this, sea ice plays an important role in regulating arctic temperatures and the planet’s overall energy balance. With decreasing amounts of sea ice and more open water throughout the year, a positive feedback loop is occurring. When more low-albedo open water is present more heating of water occurring and in turn, more melting of sea ice.
While sea ice being depleted does indeed have negative ecological impacts, however some commercial opportunities arise. Shipping lanes through the Arctic open up and for better or worse natural resource opportunities arise as well.
Data began to be collected through routine monitoring by satellites from 1979 to 2016. By definition, sea ice extent is “the area of ocean where at least 15 percent of the surface is frozen”. Data is collected year round, however the graph below highlights the months
of September and March, the months of minimum and maximum sea ice extent. Data was gathered by the National Snow and Ice Data Center using satellite imaging technology and data processing methods developed by National Aeronautics and Space Administration.
The graph below shows a close up on May through September NSIDC data. It also highlights outliers, recent years, and the current 2019 data.
