Frequently Asked Questions
- How does the U.S. National Ice Center (NIC) determine how much ice is in the polar regions?
- The remoteness of the Polar Regions limits the amount of direct observation of sea ice. Hence, more than 95% of the data used in sea ice analyses are derived from the remote sensors on polar-orbiting satellites. Sea ice analyses and forecasts are primarily prepared using satellite imagery and ice reconnaissance.
- What areas does NIC cover?
- NIC provides worldwide operational sea ice analyses and forecasts. NIC produces these analyses and forecasts of Arctic, Antarctic, Great Lakes, and Chesapeake Bay ice conditions to support customers with global, regional, and tactical scale interests.
- How small can an iceberg be?
- To be classified as an iceberg, the ice must originate from glaciers or shelf ice. The height must be greater than 5 meters above sea-level, the thickness must be 30-50 meters, and the area must cover at least 500 square meters. There are smaller pieces of ice known as bergy bits and growlers. Bergy bits and growlers can originate from glaciers or shelf ice, and may also be the result of a large iceberg that has broken up. A bergy bit is classified as a medium to large fragment of ice. Its height is generally greater than 1 meter but less than 5 meters above sea-level and its area is normally about 100-300 square meters. Growlers are smaller fragments of ice and are roughly the size of a truck or grand piano. They are often transparent but can appear green or black in color. They extend less than 1 meter above the sea surface and occupy an area of about 20 square meters.
- When was U.S. National Ice Center established?
- The National Ice Center was established in 1995, when the U.S. Coast Guard joined the Navy/National Oceanic and Atmospheric Administration (NOAA) Joint Ice Center.
- Why are you called the U.S. National Ice Center?
- The U.S. National Ice Center was established as an interagency comprised of three components: the Naval Ice Center, NOAA, and the U.S. Coast Guard.
- What is the egg code?
- The World Meteorology Organization (WMO) system for sea ice symbology is frequently referred to as the "Egg Code" due to the oval shape of the symbol.
- How do you interpret the egg code on the charts?
- The egg code on the ice charts defines the concentration, stage of development, and forms of ice. Refer to the following links for more information: Egg Code and SIGRID.
- How often is the iceberg database updated?
- The iceberg database, which includes icebergs only in the southern hemisphere, is updated weekly. The NIC is the only organization that names and tracks all Antarctic Icebergs.
- Does the U.S. National Ice Center do any research on Global Warming?
- No. The primary mission of the NIC is to provide strategic, tactical, and operational ice products and services to meet requirements of U.S. national interests and U. S. government agencies. Our products, available on the World Wide Web, are used by outside organizations to derive or interpret information of scientific value.
- What is the International Ice Patrol and why was it formed?
The mission of the International Ice Patrol is to monitor iceberg dangers near the Grand Banks of Newfoundland and provide the limits of all known ice to the maritime community. While icebergs are a constant navigational hazard in the Arctic, the cold Labrador Current carries some of them south to the vicinity of the Grand Banks and into the great circle shipping lanes between Europe and the major ports of the United States and Canada. Vessels transiting this area try to make their voyage as short and as economical as possible. Therefore, ships in the vicinity of the "limits of all known ice" normally will pass just to the south of this boundary. Vessels passing through the Ice Patrolís published ice limit run the risk of a collision with an iceberg. In this area, the Labrador Current meets the warm Gulf Stream and the temperature differences between the two water masses can reach up to 20 degrees Celsius, which may result in dense fog. The combination of icebergs, fog, severe storms, fishing vessels, and busy Trans-Atlantic shipping lanes makes this area one of the most dangerous to navigate through. This fact was grimly brought to light with the sinking of the R.M.S. TITANIC in 1912, after it struck an iceberg and approximately 1,517 passengers and crew perished.
Source: The International Ice Patrol - http://www.navcen.uscg.gov/?pageName=IIPHome