NASA MODIS: The Shrinking of the Aral Sea 2001 - 2014

The Aral Sea in 2001

Although irrigation made the desert bloom, it devastated the Aral Sea.

This series of images from the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite documents the changes.

At the start of the series in 2000, the lake was already a fraction of its 1960 extent (black line).

The Northern Aral Sea (sometimes called the Small Aral Sea) had separated from the Southern (Large) Aral Sea.

The Southern Aral Sea had split into eastern and western lobes that remained tenuously connected at both ends.

The Aral Sea in 2014

Read the full story and view the full series of images taken by MODIS from 2001 to 2014, here.

NASA Terra MODIS Image captures Great Lakes in the Fall

A few days after autumn showed up on the calendar in the Northern Hemisphere, it showed up on the landscape of North America. 

Image Credit: Jeff Schmaltz at NASA GSFC. Caption by Mike Carlowicz

The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured this view of fall colors around the Great Lakes on Sept. 26, 2014.

The changing of leaf colour in temperate forests involves several causes and reactions, but the dominant factors are sunlight and heat.

Since temperatures tend to drop sooner and sunlight fades faster at higher latitudes, the progression of fall colour changes tends to move from north to south across North America from mid-September through mid-November.

In late summer and autumn, tree and plant leaves produce less chlorophyll, the green pigment that harvests sunlight for plants to convert water and carbon dioxide into sugars.

The subsidence of chlorophyll allows other chemical compounds in the leaves, particularly carotenoids and flavonoids, to emerge from the green shadow of summer.

These compounds do not decay as fast as chlorophyll, so they shine through in yellows, oranges, and reds as the green fades.

Another set of chemicals, anthocyanins, are associated with the storage of sugars and give the leaves of some species deep purple and red hues.

NASA OCO-2 data to lead scientists forward into the past

Scientists will use measurements from the Orbiting Carbon Observatory-2 to track atmospheric carbon dioxide to sources such as these wildfires in Siberia, whose smoke plumes quickly carry the greenhouse gas worldwide. 

The fires were imaged on May 18 by NASA's Moderate Resolution Imaging Spectrometer instrument on the Terra satellite.

Credit: NASA/LANCE/EOSDIS Rapid Response

NASA's Orbiting Carbon Observatory-2, which launched on July 2, will soon be providing about 100,000 high-quality measurements each day of carbon dioxide concentrations from around the globe.

Atmospheric scientists are excited about that but to understand the processes that control the amount of the greenhouse gas in the atmosphere, they need to know more than just where carbon dioxide is now.

They need to know where it has been. It takes more than great data to figure that out.

"In a sense, you're trying to go backward in time and space," said David Baker, a scientist at Colorado State University in Fort Collins.

"You're reversing the flow of the winds to determine when and where the input of carbon at the Earth's surface had to be to give you the measurements you see now."

Harry Potter used a magical time turner to travel to the past. Atmospheric scientists use a type of computer model called a chemical transport model.

It combines the atmospheric processes found in a climate model with additional information on important chemical compounds, including their reactions, their sources on Earth's surface and the processes that remove them from the air, known as sinks.

Baker used the example of a forest fire to explain how a chemical transport model works. "Where the fire is, at that point in time, you get a pulse of carbon dioxide in the atmosphere from the burning carbon in wood.

The model's winds blow it along, and mixing processes dilute it through the atmosphere. It gradually gets mixed into a wider and wider plume that eventually gets blown around the world."

Some models can be run backward in time, from a point in the plume back to the fire, in other words, to search for the sources of airborne carbon dioxide.

The reactions and processes that must be modeled are so complex that researchers often cycle their chemical transport models backward and forward through the same time period dozens of times, adjusting the model as each set of results reveals new clues.

"You basically start crawling toward a solution," Baker said. "You may not be crawling straight toward the best answer, but you course-correct along the way."

Read the full article here

NASA's Terra satellite image: Tropical Cyclone Kofi in the Southwestern Pacific Ocean

This infrared image of Tropical Cyclone Kofi was captured by NASA's Terra satellite on March 3 at 09:55 UTC/4:55 a.m. EST. 

Credit: NRL/NASA.

NASA's Terra satellite passed over Tropical Cyclone Kofi in the Southwestern Pacific Ocean and captured an infrared image of the storm revealing powerful thunderstorms around center of circulation.

The Moderate Resolution Imaging Spectroradiometer (MODIS) instrument that flies aboard NASA's Terra satellite captured an infrared image on March 3 at 09:55 UTC/4:55 a.m. EST.

Cloud top temperatures were near -80C/-112F indicating very strong thunderstorms around the center.

At 0900 UTC/4 a.m. EST Tropical Storm Kofi had maximum sustained winds near 45 knots51.7 mph/83.3 kph.

It was centered over open water near 27.6 south and 169.1 west, about 803 nautical miles/924 mph/1,487 km south of Pago Pago, American Samoa.

Kofi was moving to the east-southeast at 20 knots/23 mph/37 kph.

The Joint Typhoon Warning Center (JTWC) expects Kofi to continue moving southeast and is no threat to land.

Kofi is already undergoing extra-tropical transitioning, a process that should be complete by March 4.

NASA ASTER Image: Infrared Light Reveals Tornado's Path

On May 20, 2013, central Oklahoma was devastated by a EF-5 tornado, the most severe on the enhanced Fujita scale. 

The Newcastle-Moore tornado killed at least 24 people, injured 377, and affected nearly 33,000 in some way. 

Early estimates suggest that more then $2 billion in damage was done to public and private property; at least 13,000 structures were destroyed or damaged. 

It was the deadliest tornado in the United States since an EF-5 event killed 158 people in Joplin, Missouri, in 2011.

On June 2, 2013, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA’s Terra satellite observed the scar of that tornado on the Oklahoma landscape. 

In this false-colour image, infrared, red, and green wavelengths of light have been combined to better distinguish between water, vegetation, bare ground, and human developments. 

Water is blue. Buildings and paved surfaces are blue-gray. Vegetation is red. The tornado track appears as a beige stripe running west to east across this image; the colour reveals the lack of vegetation in the wake of the storm.

According to the National Weather Service, the tornado was on the ground for 39 minutes, ripping across 17 miles (27 kilometers) from 4.4 miles west of Newcastle to 4.8 miles east of Moore, Oklahoma. 

At its peak, the funnel cloud was 1.3 miles (2.1 kilometers) wide and wind speeds reached 210 miles (340 km) per hour.

Image Credit: NASA Earth Observatory

NASA Terra Mission Image: MODIS Earth Observation - Climate Change

NASA launched the Earth Observing System's flagship satellite "Terra," named for Earth, on December 18, 1999. 

Terra has been collecting data about Earth's changing climate.

On February 24, 2000, sensors on NASA's Terra satellite began opening their shutters and making their first observations. 

The mission ushered in a decade of observations from NASA's Earth Observing System, a coordinated series of satellites that monitor how Earth is changing.

This image is based largely on observations from the Moderate Resolution Imaging Spectroradiometer (MODIS) - a sensor aboard the Terra Satellite - on July 11, 2005. 

Small gaps in MODIS’ coverage between overpasses, as well as Antarctica (which is in polar darkness in July), have been filled in using GOES weather satellites and the latest version of the NASA Blue Marble.

Image Credit: NASA

NASA Terra Satellite- Cloud Streets Off of the Aleutian Islands

Image Credit: NASA/GSFC/Jeff Schmaltz/MODIS Land Rapid Response Team

Strong winds polished the snow of southwestern Alaska and stretched marine stratocumulus clouds into long, parallel streets in early January, 2012.

After crossing Bristol Bay, the winds scraped the clouds across the tall volcanic peaks of the Aleutian Islands.

As the wind impacted the immobile mountains, the airflow became turbulent, swirling in symmetric eddies and carving intricate patterns into the clouds on the leeward side of the islands.

At the top of this image, the bright white color indicates a thick layer of snow overlying the land of southwestern Alaska.

The pristine white is broken by the rugged Ahklun Mountain Range in the east, which is partially covered by a bank of clouds.

Off the coast of Alaska, sea ice floats in Bristol Bay, cracked and chipped by the flow of the waters which lie underneath. A few cloud streets – parallel lines of clouds – can be seen in the far northwest over land.

The clouds increase over the sea ice and become thick over open water, where row upon row of clouds lie close in perfectly parallel formation.

The Aleutian Islands stretch from northeast to southwest across the image. Sea ice, which is bright white here, lies on the windward side of the islands. A few of the tallest volcanic peaks can be seen rising from the icy islands.

The character of the cloud streets change as they impact the Aleutians, especially near the center of the image, where two rows of beautifully symmetric swirls of eddies in the clouds stretch across the sky.

These swirling formations are known as von Karman vortex streets. This true-color image was captured by the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA’s Terra satellite on January 11, 2012.

NASA Terra Satellite Image: Capturing the Fading Colours of the US Fall

NASA Terra Satellite Image; 21 November 2012. There is still a lot of Autumn Fall colours showing over southern Virginia.

NASA Aqua /Terra Satellite Image: Sicily and Mount Etna volcanic eruption

Credit: NASA

Italy's Mount Etna, one of the most active volcanoes on Earth, is spewing out plumes of bluish volcanic gas, as revealed in a recent satellite image.

The restive peak, located on the island of Sicily, has been erupting in spectacular fashion on and off since it ramped up activity in January 2011.

The mountain last spewed out fountains of glowing lava on April 24, and has been relatively quiet ever since.

NASA's Terra satellite image of springtime in Patagonia

Credit: Jeff Schmaltz, MODIS Rapid Response Team, NASA/GSFC.

NASA's Terra satellite captured this striking image of springtime in Patagonia, the mountainous region at the tip of South America.

Patagonia comprises parts of Chile and Argentina.

Although there are no borders overlaid on the image, Chile lies roughly to the west of the Andes Mountains, which run from north to south and are snow-capped in this image.

NASA Modis Image: Wildfire Blaze on Greek Island of Chios

In this image captured by a Nasa Earth Observation satellite, a thick plume of smoke from an intense wildfire on the Greek island of Chios can be seen drifting southward over the island of Crete

Picture: NASA

A major forest blaze broke out shortly after 2 am on Saturday morning, August 18, 2012, on the Greek eastern Aegean Sea island of Chios.

Hundreds of firefighters, soldiers and volunteers were struggling for a third day Monday (August 20) to tame a fire that burnt some 17,000 acres of forest, cultivated land and groves of the island's famed mastic trees.

Chios is famous for the production of mastic, a gum-like resin with a distinctive flavor produced only by trees on certain parts of the island.

It is used widely in confectionery, cooking and cosmetics and a major source of income.

Local authorities said many of the trees had been burned, while the island's beekeepers had also lost 60 percent of their hives.

Smoke from the blaze, which was swept on by gale-force winds, was carried as far as the southern island of Crete, more than 230 miles away.

Those gale-force winds are hampering efforts by about 360 firefighters, soldiers and volunteers, as well as firefighting planes, helicopters and 50 vehicles.

Residents of nine villages and hamlets evacuated their homes over the weekend as a precaution. This natural-color image was taken by the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument on NASA's Aqua satellites on August 18, 2012.

NASA image courtesy Jeff Schmaltz, LANCE MODIS Rapid Response Team at NASA GSFC.

2012 Greenland Ice Melt Strongest On Record, More to Come

New data shows that melting of the vast ice sheet that covers more than three-quarters of Greenland is the strongest ever seen -- and there are still four weeks to go in the melting season.

Marco Tedesco, a researcher at the City College of New York, says the melting that scientists have observed in 2012 has already outstripped the melt in 2010. The melting season typically lasts from June to early September.

"With more yet to come in August, this year's overall melting will fall way above the old records," Tedesco said in a statement Monday.

"That's a goliath year, the greatest melt since satellite recording began in 1979."

This latest observation has not yet been published in a peer-reviewed journal, but Tedesco and his colleagues have a forthcoming paper looking at models projecting gains and losses to the ice sheet throughout the rest of this century.

NASA announced in July that its Earth Observation satellites (Modis, Aqua, Terra) had found that about 97 percent of the ice sheet's 660,000 square-mile surface had undergone melting.

This latest data from Tedesco and his colleagues jives with that finding. They used data from microwave satellite sensors in order to calculate the cumulative melting index, which gauges the "strength" of the melting season.

The index is generated by multiplying the number of days the ice sheet has melted by the total area of the ice sheet that has melted.

Rutgers University in Greenland

Åsa Rennermalm, a Rutgers University Hydrologist and researcher unaffiliated with the current project, studies the streams and rivers both on the ice sheet and those that are fed by meltwater.

She says the residents of Kangerlussauq, a town near her research site, confirm that this season's melt is the biggest they remember.

Kangerlussauq, which contains Greenland's major airport, was directly impacted by the higher melt on July 11, when a major bridge was destroyed by rising river, fed by melt-water.

"It was pretty dramatic," Rennermalm said.

Byrd Polar Research centre

Tedesco's colleague Jason Box, a researcher at Ohio State University's Byrd Polar Research Center, says there's a positive feedback mechanism at play in the ice sheet's melting; as the surface melts, it gets darker, which absorbs more heat from the sun.

In a downward spiraling action, the melted surfaces absorb more heat and this encourages further melting.

NASA Terra Satellite Image: Arctic Ice Melt in Northwest Passage

This image, taken on Aug. 3, 2012, shows that most of the ice in the Parry Channel, part of the Northwest Passage, has melted away.

CREDIT: NASA Earth Observatory

Sea ice has melted and part of the Arctic's Northwest Passage has opened, images captured by NASA's Terra satellite show.

An image taken on July 17 shows ice filled Parry Channel, part of the Passage, at that point. The second photo, taken two weeks later on Aug. 3, shows that most of the ice has melted away.

The Canadian Ice Service reported that ice cover in Parry Channel began to fall below the 30-year median level in mid-July, and the melting sped up in the following two weeks. At the end of July, there was only an ice cover of 30 percent, compared to a median of 79 percent.

While the Parry Channel appears almost entirely free of ice, it's not necessarily open for ships to pass through, according to a NASA release. Sea ice can be thin enough to avoid detection by satellite sensors yet still thick enough to impede ships.

Whether or not ships can easily pass, recent studies have suggested that certain organisms have begun to take advantage of the open water. When the Northwest Passage opened in 2007, a study found that a type of plankton usually found in the Pacific had turned up in the North Atlantic.

Another study found that Pacific and Atlantic populations of Bowhead whale began to overlap in the Northwest Passage in 2010, according to the release.

The search for a shortcut between Europe and Asia though the Arctic dates back to Columbus's journey to the Americas. For centuries, attempts failed due to unfamiliar geography and unforgiving ice.

The passage was first successfully navigated by Norwegian explorer Roald Amundsen in 1906. He used the southern route through the Northwest Passage; Parry Channel is part of the northern, shorter route.