Massive accumulations of heat pulled from the top layers of tropical ocean water and set spinning due to planetary rotation form a hurricane's spiraling vortex. But powering the inside of these storms we find one of nature's most astounding natural engines: hot towers. Scientists discovered hot towers in recent years by observing storms from space and creating advanced supercomputer models to decipher how a hurricane sustains its winding movement. The models show that when air spirals inward toward the eye of a hurricane it collides with an unstable region of air at the eyewall, where the strongest winds are found, and suddenly deflects upwards. This rush of warm, moist air is accelerated by surrounding patches of convective clouds, called hot towers, which strengthen and propel the hurricane by keeping the vertical ring of clouds in motion. Watch the first video below as NASA researchers look under the hood of these cloud super-engines to reveal exciting findings about a hurricane's internal motor. ||

A gold standard for supercomputer models that simulate Earth is the ability to recreate real events—snowstorms, tropical cyclones, long-term climate trends. By that benchmark, this 20-day run of one of the highest-resolution climate models in the world glitters. Called GEOS-5, the model was given data leading up to Feb. 2, 2010 and then predicted the atmosphere's response until Feb. 22, 2010 without any further input. The model simulated real weather events that took place during this period—two major snowstorms that struck the East Coast and a Pacific cyclone that formed out of intense convection in the tropics. A closer look at the simulation below reveals its complexity: 3-D cloud layers, the day-night cycle of humidity appearing and disappearing over the Amazon and streaky "cloud streets" that trail across the Atlantic from the U.S. coastline. ||

We've grown used to seeing landscapes from above. The terrain that early explorers once took years to cross we now conquer during a routine business flight on a weekday morning. Yet there remain places too remote and too rugged for most to reach. This is Antarctica, where ice sheets stretch across the eastern part of the continent like a frozen Great Plains, and mountains that would be at home in the Rockies crop up in nearly snow-free, dry regions. Otherwise experienced by only a small group of scientists and polar travelers, NASA, in partnership with the National Science Foundation, the U.S. Geological Survey, and the British Antarctic Survey, has made Antarctica accessible to all by piecing together Landsat 7 satellite images to create a mosaic that represents the first true-color, high-resolution map of the continent. Even without crampons and an ice ax, you can now explore one of the world's most brutal environments in this flyover view of Antarctica. ||

NASA gave the command last week to power on its newest Earth-observing satellite, Aquarius. It may seem a somewhat peculiar measurement to make, but Aquarius, which launched in June 2011, will measure salinity across all the oceans every week. The data will undoubtedly help answer some of our most pressing questions about climate change. Why measure ocean salinity? The density of ocean water is determined by salinity and water temperature. Density drives the pattern of deep ocean currents, and ocean currents drive global climate. In recent decades, scientists have seen ocean salinity shift in ways that only climate change seems able to explain. Until now, salinity data came from slow-moving ships and a network of floating sensors that could only provide a limited global picture. Satellite technology changes that: From 400 miles (644 km) above Earth Aquarius' hypersensitive microwave radiometer can detect differences in ocean salinity to within a pinch of salt in a gallon of water. Let the science begin. ||

By the numbers the 2005 Atlantic tropical storm season was unlike any other: A total 27 tropical storms, including 15 hurricanes, made it a record-breaking year. The season also gave rise to Katrina, one of the most intense and costliest hurricanes that resulted in 1,200 deaths and more than $100 billion in damages. The unusually high frequency and strength of these tropical storms were linked to favorable development conditions observed in the ocean and atmosphere between the Caribbean Sea and west coast of Africa where they form. Easterly winds blowing off the African continent seeded the Atlantic with a large number of proto-hurricanes—swirling air masses that grow over tropical waters. Ideal open ocean wind patterns on the surface and high above permitted storm clouds to easily mature into vigorous convective cells—the building blocks of hurricanes. Warmer ocean surface waters slightly above their 80 degrees Fahrenheit average further strengthened the storms and sent the spinning hurricanes into overdrive. The visualization below tracks the paths of all 27 tropical storms that made up this historical year. ||

What do nearly ten years of satellite fire observations look like? Instruments on two NASA Earth-observing satellites have answered that question by scanning the surface for signs of fire four times a day since 2002. The instruments have generated an ever-growing string of data that researchers have used to map the distribution of the world's fires in unprecedented detail. The visualization below provides a global tour of these observations using red to indicate actively burning fires, green to show vegetation and white to show snow. It begins with heavy grassland fires that speckle the dry interior of Australia in 2002. The view then pans to Asia and fire-prone Africa where waves of agricultural and management fires sweep across large portions of these continents in sync with seasonal surges of vegetation and retreating snow. A glimpse of a mild South American fire season in 2009 follows, along with intermittent flashes from wildfires that ravaged areas of Texas in the spring of 2011. Such data has more than aesthetic value: scientists use it to track fire trends over time and to refine calculations that show how greenhouse gases and particles emitted by fires in different regions contribute to climate change. ||

Since 1965 scientists have observed unusual cloud lines that crisscross over the ocean in certain satellite images. Researchers initially speculated that aircraft, missiles, or even natural patterns of air circulation might have caused the oddly shaped clouds to form. But ultimately seafaring ships proved to be the culprits; specifically tiny particles found in the exhaust that billows from their smokestacks. The streaky clouds, called ship tracks, are found throughout the world's oceans. They form in the same manner as marine clouds, which are made of individual cloud droplets created when water condenses around sea salt and other airborne particles known as aerosols. Ship fumes, however, inject extra particles into the air that boost the overall number of particles and cause an abundance of small, more reflective cloud droplets to form. The result: lines of unusually bright and narrow clouds such as those seen in the video below. ||

While previous studies have focused on Antarctica's and Greenland's massive ice sheets, this year scientists offered the first detailed estimate of how much all the world's ice deposits are melting and contributing to sea level rise. Using data from NASA's twin GRACE satellites, researchers concluded that Earth has lost a total of 4.3 trillion tons of ice between 2003 and 2010. Greenland and Antarctica lost the bulk of the ice, but nearly a quarter of the losses came from glaciers in Alaska, Canada and Patagonia. The total melting during this period added about half an inch to global sea levels—enough to cover the United States with a layer of water one-and-a-half feet thick. GRACE's inventory of North and South America is shown on a rotating globe in the visualization below, where yellow dots mark the location of individual glaciers and areas with greatest ice loss are shaded purple and blue. ||

Satellites provide dramatic views of clouds, but in order to understand the processes that underlie how clouds form and evolve, scientists turn to complex computer models that simulate Earth's atmosphere. By feeding a range of ground, aircraft and satellite data into Goddard's Earth Observing System Model (GEOS-5), research meteorologists can see how closely the mathematical equations used to simulate atmospheric dynamics match reality. Such models are by no means perfect, but they have improved tremendously in recent years. The visualizations below, based on GEOS-5 model runs from February 2010, show how well the model reproduced the massive blizzard known as "Snowmageddon." In the visualization, watch Snowmageddon's sprawling, comma-shaped cloud system—complete with a tail that reaches all the way to the Caribbean—as it churns up the Eastern Seaboard dumping three feet of snow in some areas. ||

Thunderstorms produce more than just lightning. As these powerful storms roll over Earth, their electric fields can eject a burst of gamma rays known as a terrestrial gamma-ray flash. And now scientists have discovered that these flashes also create the asymmetrical opposite of matter—antimatter. NASA's Fermi Gamma-ray Space Telescope was designed to monitor gamma rays, the highest-energy form of light, in outer space. But it also observes these flashes from thunderstorms. In 2009, Fermi detected gamma rays from a thunderstorm that was located well beyond the horizon from where it could directly observe the storm. So where did the rays come from? When antimatter collides with matter, the particles annihilate and emit gamma rays. This means the gamma rays detected by Fermi could only have come from an antimatter collision with the spacecraft itself, providing the first-ever clue that these Earth-bound storms can send antimatter into space. In the videos below, see a map of terrestrial gamma-ray flashes detected by Fermi and a breakdown of how this explosive, mysterious process unfolds. ||