How much ice is in the Arctic?

Arctic sea ice generally reaches its maximum extent each March and its minimum extent each September. This ice has historically ranged from roughly 14-16 million square kilometers (about 5.4-6.2 million square miles) in late winter to roughly 7 million square kilometers (about 2.7 million square miles) each September.

How much ice has melted in the Arctic?

From the thin ice shield covering most of the Arctic Ocean to the mile-thick mantle of the polar ice sheets, ice losses have soared from about 760 billion tons per year in the 1990s to more than 1.2 trillion tons per year in the 2010s, a new study released Monday shows.

How do you measure Arctic ice?

A laser or radar pulse directed downward from a satellite (or aircraft) can measure the distance between the satellite and the Earth’s surface (see Figure 3). Using this method the difference between the ocean surface (in the leads between sea ice floes) and the sea ice surface – i.e., the freeboard – can be measured.

How do you calculate sea ice concentration?

To estimate ice area, scientists calculate the percentage of sea ice in each pixel, multiply by the pixel area, and total the amounts. To estimate ice extent, scientists set a threshold percentage, and count every pixel meeting or exceeding that threshold as “ice-covered.” The common threshold is 15 percent.

What is causing the ice to melt in the Arctic?

Melting ice speeds up climate change. Global warming is causing Arctic ice to melt – ice reflects sunlight, while water absorbs it. When the Arctic ice melts, the oceans around it absorb more sunlight and heat up, making the world warmer as a result.

How fast is ice melting in the Arctic?

Arctic sea ice reaches its minimum each September. September Arctic sea ice is now declining at a rate of 13.1 percent per decade, relative to the 1981 to 2010 average. This graph shows the average monthly Arctic sea ice extent each September since 1979, derived from satellite observations.

How is sea ice monitored?

To monitor Arctic sea ice, NSIDC primarily has used the NASA Advanced Microwave Scanning Radiometer–Earth Observing System (AMSR-E) instrument on the NASA Aqua satellite and the Special Sensor Microwave/Imager (SSM/I) instrument on the Defense Meteorological Satellite Program (DMSP) satellite.

How is ice thickness measured?

At present ice thickness can be reliably determined by drilling a hole and measuring the thickness by some form of hook gage. This procedure requires, however, that individuals venture out on what is possibly “too thin” ice to make the measurement.

How are sea ice levels measured in the Arctic?

Figure 1: Average summer minimum (grey) and winter maximum (white) Arctic sea ice extent derived from satellite sea ice concentration measurements taken over the period 1981-2010. Sea ice concentration may also be provided through ice charts.

Where can I find sea ice concentration maps?

All sea ice concentration data (in .hdf-format) of the University of Bremen (Institute for environmental physics) and high resolution maps of the daily sea ice concentration in the Arctic and Antarctic dating back to 19 June 2002, can be downloaded here from the DataPortal for the Arctic and Antarctic.

What was the Arctic sea ice extent in September 2019?

Arctic sea ice extent for September 2019 was 4.32 million square kilometers (1.67 million square miles). The magenta line shows the 1981 to 2010 average extent for that month. Sea Ice Index data. About the data Credit: National Snow and Ice Data Center High-resolution image Figure 1b.

How is the extent of sea ice changing?

Sea ice extent and concentration in the Arctic and Antarctic are changing daily. Information on these parameters is gained from satellite observations and is presented here as daily maps of sea ice concentrations and time series of sea ice extent and area.