Outlines the evolution of satellite-borne remote sensing of polar regions, evaluates satellites currently in operation, and considers future developments.

The United States has enduring national and strategic interests in the polar regions, including citizens living above the Arctic circle and three year-round scientific stations in the Antarctic. Polar icebreaking ships are needed to access both regions. Over the past several decades, the U.S. government has supported a fleet of four icebreakersâ€"three multi-mission U.S. Coast Guard ships (the POLAR SEA, POLAR STAR, and HEALY) and the National Science Foundation's PALMER, which is dedicated solely to scientific research. Today, the POLAR STAR and the POLAR SEA are at the end of their service lives, and a lack of funds and no plans for an extension of the program has put U.S. icebreaking capability at risk. This report concludes that the United States should continue to support its interests in the Arctic and Antarctic for multiple missions, including maintaining leadership in polar science. The report recommends that the United States immediately program, budget, design, and construct two new polar icebreakers to be operated by the U.S. Coast Guard. The POLAR SEA should remain mission capable and the POLAR STAR should remain available for reactivation until the new polar icebreakers enter service. The U.S. Coast Guard should be provided sufficient operations and maintenance budget to support an increased, regular, and influential presence in the Arctic, with support from other agencies. The report also calls for a Presidential Decision Directive to clearly align agency responsibilities and budgetary authorities.

Only a few centuries ago, we knew very little about our planet Earth. The Earth was considered flat by many although it was postulated by a few like Aristotle that it is spherical based on observations that included the study of lunar eclipses. Much later, Christopher Columbus successfully sailed to the West to discover the New World and Ferdinand Magellan’s ship circumnavigated the globe to prove once and for all that the Earth is indeed a sphere. Worldwide navigation and explorations that followed made it clear that the Earth is huge and rather impossible to study solely by foot or by water. The advent of air travel made it a lot easier to do exploratory studies and enabled the mapping of the boundaries of continents and the oceans. But aircraft coverage was limited and it was not until the satellite era that full c- erage of the Earth’s surface became available. Many of the early satellites were research satellites and that meant in part the development of engineering measurement systems with no definite applications in mind. The Nimbus-5 Electrically Scanning Microwave Radiometer (ESMR) was a classic case in point. The sensor was built with the idea that it may be useful for meteorological research and especially rainfall studies over the oceans, but success in this area of study was very limited.

The high latitudes of the Arctic and Antarctic, together with some mountainous areas with glaciers and long-lasting snow, are sometimes called the cryosphere-defined as that portion of the planet where water is perennially or seasonally frozen as sea ice, snow cover, permafrost, ice sheets, and glaciers. Variations in the extent and characteristics of surface ice and snow in the high latitudes are of fundamental importance to global climate because of the amount of the sun's radiation that is reflected from these often white surfaces. Thus, the cryosphere is an important frontier for scientists seeking to understand past climate events, current weather, and climate variability. Obtaining the data necessary for such research requires the capability to observe and measure a variety of characteristics and processes exhibited by major ice sheets and large-scale patterns of snow and sea ice extent, and much of these data are gathered using satellites. As part of its efforts to better support the researchers studying the cryosphere and climate, the National Aeronautics and Space Administration (NASA)-using sophisticated satellite technology-measures a range of variables from atmospheric temperature, cloud properties, and aerosol concentration to ice sheet elevation, snow cover on land, and ocean salinity. These raw data are compiled and processed into products, or data sets, useful to scientists. These so-called "polar geophysical data sets" can then be studied and interpreted to answer questions related to atmosphere and climate, ice sheets, terrestrial systems, sea ice, ocean processes, and many other phenomena in the cryosphere. The goal of this report is to provide a brief review of the strategy, scope, and quality of existing polar geophysical data sets and help NASA find ways to make these products and future polar data sets more useful to researchers, especially those working on the global change questions that lie at the heart of NASA's Earth Science Enterprise.

In the 8 years since a contract was awarded, the National Polar-Orbiting Operational Environ. Satellite System (NPOESS) -- a tri-agency program managed by NOAA, DoD, and NASA -- has experienced escalating costs, schedule delays, and ineffective interagency mgmt. The launch date for a demo. satellite has been delayed by 5 years and the cost estimate for the program has more than doubled. In Feb. 2010, NPOESS was disbanded, and, instead, the agencies have undertaken separate acquisitions. This report: (1) assessed efforts to establish separate satellite programs; (2) evaluated the status and risks of the NPOESS components still under development; and (3) evaluated the implications of using the demo. satellite's data operationally. Illus.