Satellite images

Moving across to the Mid Atlantic area, Rutgers University has set up "The Cool Room", where real-time data-sets are available from satellite images and temperatures are available off the coast of New Jersey from their marine remote sensing lab. They map out ocean currents, coastal wave measurements, weather, and have LEO-Node Data of undersea temperatures and wave heights from their offshore Node 14m under the ocean surface. Researchers will be interested in their archives, which go back several years.

Eyes in the sky
Gravity maps of continents and oceans: oceanographers catch first wave of gravity mission's success. The joint NASA-German Aerospace Center Gravity Recovery and Climate Experiment (Grace) mission has released its first science product, the most accurate maps of Earth's gravity field. Grace is the newest tool for scientists working to unlock secrets of ocean circulation and its effects on climate. Using just a few months of globally uniform quality data, Grace has improved the accuracy of Earth's gravity model by a factor between 10 and nearly 100. Grace measures minute variations in gravitational pull by using two identical spacecraft following the same orbit approximately 220 kilometers apart. It is in the fine detail that Grace excels, particularly with the constantly shifting masses of the oceans. The ocean surface, while appearing flat, is actually covered with hills and valleys caused by currents, winds and tides, and also by variations in the Earth gravity field. Portrait of a drying sea: earth's youngest desert used to be the fourth largest lake in the world. Over the past 40 years the Aral Sea, in central Asia, has evaporated back to half its original surface area and a quarter of its initial volume. It has left a 40,000 square kilometer zone of dry white colored salt terrain now called the Aralkum Desert shown in pictures taken by a MERIS Satellite in July. The water level has dropped 13 meters since the 1960s and is expected to dry out completely by 2020. The Aral Sea shows what happens when the concept of sustainable development is disregarded. For local people the results have been disastrous. Wildlife habitats have been destroyed, and communities find themselves without clean water supplies. The retreat of the waters has also altered the regional microclimate. Winters are colder and the summers hotter.

Celebrating ten years of ocean observation: Topex/Poseidon is a little satellite that could! Launched on August 10, 1992, the joint U.S.- French spacecraft was designed to fly for three to five years-but is still going strong. It will have made 46,763 trips around the Earth measuring the height of the oceans to within 4 centimeters. Since its launch, it will have faithfully provided more than 98 percent of the science data it was designed to collect despite technical and mechanical challenges, and its advancing years. The aging spacecraft has recently been positioned in a parallel orbit with Jason I, which was launched last year and will double the amount of data being collected. Jason-1 is the first follow-on to the highly successful Topex/Poseidon mission that measured ocean surface topography that has enabled scientists to forecast the 1997-98 El Nino and improved understanding of ocean circulation and its effects on global climate. Like its predecessor Jason-1does include both U.S. and French instruments. Its mission is to monitor global climate interactions between the sea and atmosphere and provide a 5-year view of global ocean surface topography. Altimeter data will be a part of a suite of data provided by other managed ocean missions-the Grace mission will use two satellites to accurately measure Earth's mass distribution, and QuikSCAT scatterometer mission will measure ocean-surface winds.

Ocean Satellites: a page of the PostGraduate Naval School in Monterey, providing access to numerous ocean satellite home pages (TOPEX, ERS, MOS, RADARSAT, SeaWiFS, etc.).

Extreme Sea Level Changes: rather striking images of our planet, created from the ETOPO5 data set, showing the effects (a) of a 65-m sea level rise and (b) of a 140-m decrease.

The Natural Hazards site, set up by NASA, tracks global disasters by satellite in near real time and covers: wildfires, severe storms, floods, volcanic eruptions and major air pollution events, such as dust storms, smog and smoke.