Petermann Glacier

The Petermann Glacier grinds and slides toward the sea along the northwestern coast of Greenland, terminating in a giant floating ice tongue. Like other glaciers that end in the ocean, Petermann periodically calves icebergs. A massive iceberg, or ice island, broke off of the Petermann Glacier in 2010. Now, nearly two years later, another chunk of ice has broken free.

The Moderate Resolution Imaging Spectroradiometer, or MODIS, on NASA’s Aqua satellite observed the new iceberg calving and drifting downstream on July 16–17, 2012. Because Aqua is a polar-orbiting satellite, it makes multiple passes over the polar regions each day.

Image Credit: NASA

NASA Eyeing Southern Gulf of Mexico Low for Tropical Trouble

NASA satellites are providing data on a broad area of low pressure in the south-central Gulf of Mexico that has a medium chance for development into a tropical depression.

Infrared data from the Atmospheric Infrared Sounder (AIRS) instrument that flies onboard NASA's Aqua satellite is helping forecasters at the National Hurricane Center understand what's happening with the low pressure area. In an image captured on June 21 at 0729 (3:29 a.m. EDT), the center of the low pressure area appears to be near the western tip of Cuba near 22 North and 85 West. The strongest thunderstorms and convection (rising air that forms the thunderstorms) have high, cold cloud tops (of -63F/-52C) that indicate strong uplift, southwest and southeast of the center.

The National Hurricane Center noted that the large area of clouds, showers and thunderstorms extend from the northwestern Caribbean Sea north into the southeastern Gulf of Mexico and over Florida.

There are currently strong upper level winds that have been inhibiting development, but those winds are expected to weaken, giving the low more of a chance to get organized. The low continues to move north into the Gulf of Mexico bringning heavy rainfall and possible flooding over Mexico's Yucatan Peninsula, western Cuba and southern Florida over the next couple of days.

Text Credit: Rob Gutro

NASA Goddard Space Flight Center, Greenbelt, Md.

Hurricane Season 2012: System 96W (Western North Pacific Ocean)

NASA Satellite Sees Thunderstorms Banding Around Developing System 96W

A low pressure system that has been lingering in the western North Pacific Ocean for several days appears to be coming together today in infrared imagery from NASA's Aqua satellite.

NASA's Aqua satellite passed over the low pressure area called "System 96W" on March 27 at 0547 UTC (1:47 a.m. EDT) and the Atmospheric Infrared Sounder (AIRS) instrument captured an infrared and visible look at the storm.

On March 27, 2012 at 0600 UTC (2 a.m. EDT), System 96W was located in the western North Pacific Ocean about 205 miles north-northwest of Bandar Seri Begawan, Brunei, near 7.9 North and 113.4 East. Brunei is located north of the island of Borneo in southeastern Asia. It has a shoreline on the South China Sea, and surrounded by the state of Sarawak, Malaysia.

System 96W's maximum sustained winds are currently estimated as high as only 15 knots (17.2 mph/27.7 kph) with stronger gusts in the northwestern quadrant.

The NASA AIRS infrared imagery showed that the center of circulation is consolidating, and there are bands of thunderstorms wrapping along the eastern and western halves of the storm. The AIRS infrared data shows two large areas of convection (rising air that forms thunderstorms that make up the tropical cyclone) east and west of the center. Some of those storms have cloud top temperatures colder than 230 degrees Kelvin (-45.6 F/-43.1C), indicating they're high in the troposphere and strong storms. Storms with cloud heights that cold usually have heavy rainfall.

Forecasters at the Joint Typhoon Warning Center have upped the chance to "medium" for System 96W to strengthen into a tropical depression, based on wind shear remaining week, warm sea surface temperatures.

Text Credit: Rob Gutro

NASA's Goddard Space Flight Center, Greenbelt, Md.

NASA Satellites See Tropical Cyclone Irina Headed for Mozambique

Visible and Infrared satellite imagery together provide a clearer picture of what a tropical cyclone is doing. NASA's Aqua satellite passed over newly strengthened Cyclone Irene and captured both types of images, which showed the extent and power of the storm.

The low pressure area called System 92S that tracked across northern Madagascar this week and brought flooding rains has moved into the Mozambique Channel, strengthen and has been renamed Irina. NASA satellites captured a visible image of Irina as it filled up the northern half of the Mozambique Channel.

System 92S strengthened into Cyclone Irina off Cape St Andre, Madagascar after moving across the northern half of the country as a soaking low pressure area. Now in the warm waters of the Mozambique Channel (the body of water between the island nation of Madagascar and Mozambique on the African mainland), it is strengthening and moving to the west.

NASA's Aqua satellite's MODIS instrument captured a visible image of Tropical Cyclone Irina over the Mozambique Channel on February 29, 2012 at 1100 UTC (6 a.m. EST). It showed the center of Irina in the northern Mozambique Channel and its clouds extended from Mozambique in the west across the channel to Madagascar.

The Atmospheric Infrared Sounder (AIRS) instrument showed another view of the storm: one in infrared light. Infrared light helps determine temperatures of cloud tops and sea surface temperatures, two factors important in tropical cyclones. Warm sea surface temperatures in excess of 26.6 Celsius (80 Fahrenheit) help maintain a cyclone. The warmer the sea surface, the more energy gets fed (evaporation and moisture) into a tropical cyclone, helping it grow stronger. Sea surface temperatures in the Mozambique Channel are near 29 Celsius (84F), which is helping Cyclone Irina develop and strengthen.

The cloud-top temperatures need to be the opposite of sea surface temperatures to indicate strengthening. The colder the cloud top temperatures, the higher and stronger the thunderstorms are that make up the tropical cyclone (a cyclone/hurricane is made up of hundreds of thunderstorms).

Infrared satellite imagery allows forecasters to see where some of the most powerful thunderstorms are in a tropical cyclone. AIRS infrared data has observed that Irina's cloud top temperatures have grown colder since yesterday, February 28, indicating more strength in the storm. North of Irina's center, cloud top temperatures are now colder than -63 Fahrenheit (-52.7C), a threshold in AIRS data that indicates some of the strongest thunderstorms in a tropical cyclone.

Forecasters at the Joint Typhoon Warning Center (JTWC) using infrared satellite data noted that "Deep convection remains confined along the northern half (of the storm)." Vertical wind shear has been weakening slowly, but is still between 10 and 15 knots (11.5 and 17.2 mph /18.5 and 27.8 kph).

On February 29, 2012 at 1500 UTC (10 a.m. EST), Irina was a tropical storm with maximum sustained winds near 35 knots (~40 mph/~65 kph). It is centered in the Mozambique Channel, about 305 nautical miles northwest of Antananarivo, Madagascar, near 16.2 South and 42.6 East.

JTWC forecasters said today, February 29, that they expect the storm to be strongest between March 2 and March 3 as it moves through the center of the Mozambique Channel. Landfall is expected after 72 hours from 1500 UTC on Feb. 29, which would put it around 1500 UTC (10 a.m. EST) on March 3, 2012 when Irina is forecast to make landfall north of Maputo, Mozambique.

Text Credit: Rob Gutro

NASA Goddard Space Flight Center, Greenbelt, Md

Hurricane Season 2011: Tropical Storm 5A (Northern Indian Ocean)

Tropical Storm 5A More 'Well-Rounded' on NASA Infrared Imagery, for Now

Over the past several days Tropical Storm 05A has become better organized on infrared satellite imagery from NASA. Imagery from NASA's Aqua satellite over two days has shown that the cold cloud tops in the cyclone have become more rounded as the storm consolidates and strengthens.

NASA's Aqua satellite made two passes over Tropical Storm 05A (5A) and noticed the changes. The first pass happened on Nov. 26 at 08:23 UTC (3:23 a.m. EST and the infrared image from the Atmospheric Infrared Sounder (AIRS) instrument on Aqua revealed that 5A's clouds were not circular in nature, indicating a struggle within the storm to get organized. At that time, 5A was located near 9.3 North and 73.6 East, about 160 miles (257 km) west-southwest of Cochin, India.

By Nov. 27 at 21:23 UTC (4:23 p.m. EST) 5A had become circular in shape indicating that the storm did get better organized. At that time, maximum sustained winds were near 40 mph (35 knots/65 kmh) and it was 360 miles (579 km) south-southwest of Mumbai, India. That organization may be short-lived however, as wind shear increases and batters the circulation of the storm.

AIRS infrared imagery measures cloud top and sea surface temperatures, two factors that help determine the behavior of tropical cyclones. The colder the cloud tops are the higher the clouds and the stronger the thunderstorm (and heavier rain). The warmer the sea surface temperatures are, the higher the thunderstorm cloud tops are likely to rise and the stronger they are likely to become. Sea surface temperatures of at least 80F (26.6C) are needed to maintain a tropical cyclone, and they are currently near 84.2F (29C) in the Bay of Bengal where 5A lingers.

On Nov. 28 at 1500 UTC (10 a.m. EST), Tropical Storm 05A had maximum sustained winds still holding near 40 mph (35 knots/65 kmh). It was located 590 miles south of Karachi, Pakistan near 15.2 North and 67.8 East. 5A was moving to the northwest at 8 knots (9 mph/14 kmh) and generating seas of 17 feet (5.1 meters) high. Infrared imagery today shows that the banding of thunderstorms in the southeastern quadrant of the storm have thinned, a sign of weakening.

Forecasters say that it will track northwest across the Arabian Sea toward Somalia and strengthen a little more before running into wind shear that is expected to weaken the storm.

Text credit: Rob Gutro, NASA's Goddard Space Flight Center, Greenbelt, Md.

Arctic Sea Ice Continues Decline, Hits Second-Lowest Level

Steve Cole

Headquarters, Washington

Patrick Lynch

Goddard Space Flight Center

WASHINGTON -- Last month the extent of sea ice covering the Arctic Ocean declined to the second-lowest extent on record. Satellite data from NASA and the NASA-supported National Snow and Ice Data Center (NSIDC) at the University of Colorado in Boulder showed that the summertime sea ice cover narrowly avoided a new record low.

The Arctic ice cap grows each winter as the sun sets for several months and shrinks each summer as the sun rises higher in the northern sky. Each year the Arctic sea ice reaches its annual minimum extent in September. It hit a record low in 2007.

The near-record ice-melt followed higher-than-average summer temperatures, but without the unusual weather conditions that contributed to the extreme melt of 2007. "Atmospheric and oceanic conditions were not as conducive to ice loss this year, but the melt still neared 2007 levels," said NSIDC scientist Walt Meier. "This probably reflects loss of multiyear ice in the Beaufort and Chukchi seas as well as other factors that are making the ice more vulnerable."

Joey Comiso, senior scientist at NASA's Goddard Space Flight Center in Greenbelt, Md., said the continued low minimum sea ice levels fits into the large-scale decline pattern that scientists have watched unfold over the past three decades.

"The sea ice is not only declining, the pace of the decline is becoming more drastic," Comiso said. "The older, thicker ice is declining faster than the rest, making for a more vulnerable perennial ice cover."

While the sea ice extent did not dip below the 2007 record, the sea ice area as measured by the microwave radiometer on NASA's Aqua satellite did drop slightly lower than 2007 levels for about 10 days in early September, Comiso said. Sea ice "area" differs from extent in that it equals the actual surface area covered by ice, while extent includes any area where ice covers at least 15 percent of the ocean.

Arctic sea ice extent on Sept. 9, the lowest point this year, was 4.33 million square kilometers (1.67 million square miles). Averaged over the month of September, ice extent was 4.61 million square kilometers (1.78 million square miles). This places 2011 as the second lowest ice extent both for the daily minimum extent and the monthly average. Ice extent was 2.43 million square kilometers (938,000 square miles) below the 1979 to 2000 average.

This summer's low ice extent continued the downward trend seen over the last 30 years, which scientists attribute largely to warming temperatures caused by climate change. Data show that Arctic sea ice has been declining both in extent and thickness. Since 1979, September Arctic sea ice extent has declined by 12 percent per decade.

"The oldest and thickest ice in the Arctic continues to decline, especially in the Beaufort Sea and the Canada Basin," NSIDC scientist Julienne Stroeve said. "This appears to be an important driver for the low sea ice conditions over the past few summers."

Climate models have suggested that the Arctic could lose almost all of its summer ice cover by 2100, but in recent years, ice extent has declined faster than the models predicted.

NASA monitors and studies changing sea ice conditions in both the Arctic and Antarctic with a variety of spaceborne and airborne research capabilities. This month NASA resumes Operation IceBridge, a multi-year series of flights over sea ice and ice sheets at both poles. This fall's campaign will be based out of Punta Arenas, Chile, and make flights over Antarctica . NASA also continues work toward launching ICESat-2 in 2016, which will continue its predecessor's crucial laser altimetry observations of ice cover from space.

To see a NASA data visualization of the 2011 Arctic sea ice minimum as measured by the Advanced Microwave Scanning Radiometer - Earth Observing System (AMSR-E) on Aqua, visit http://www.nasa.gov/topics/earth/features/2011-ice-min.html.

For more information about NASA and agency programs, visit http://www.nasa.gov.

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Hurricane Season 2011: Tropical Depression Noru (Western North Pacific Ocean)

NASA sees Tropical Depression Noru Transitioning, Heading North

Infrared satellite imagery from NASA's Aqua satellite late yesterday revealed that Tropical Depression Noru is losing strength while transitioning into an extra-tropical storm in the western North Pacific Ocean. High pressure is pushing Noru northward into the Sea of Okhotsk.

The Sea of Okhotsk covers 611,000 square miles, and borders eastern Russia. It is northwest of the Sea of Japan, where Tropical Depression Noru is currently tracking through, and will likely be Noru's final resting place.

When Aqua passed over Tropical Storm Noru the Atmospheric Infrared Sounder (AIRS) instrument noticed warmer cloud top temperatures that the day before, indicating that the strength of the rapidly rising air that forms the thunderstorms within, was waning. On Sept. 5 at 10:53 p.m. EDT, the strongest thunderstorms in Noru were southeast of its center.

By Sept. 6 at 8 a.m. EDT, Noru's maximum sustained winds were near 30 knots (35 mph). It was located 425 nautical miles east of Misawa Air Base, Japan near 41.3N and 150.6E. It is moving to the north at 19 knots.

As Noru continues north, the sea surface temperatures are not warm enough to support a tropical cyclone, which is a "warm core system," so the inner core cools and becomes a cold core system which makes it extra-tropical. Over the next couple of days, Noru will continue its journey into the Sea of Okhotsk off the coast of Russia.

Text credit: Rob Gutro, NASA's Goddard Space Flight Center, Greenbelt, Md.

NASA Satellite Sees Quick Birth of Tropical Storm Talas

Iwo To and Chichi Jima are in the projected path of the newest tropical storm that formed in the western North Pacific Ocean, and infrared NASA satellite data revealed some strong, high thunderstorms around the center of Tropical Storm Talas.

NASA's Aqua satellite passed over Talas early today, August 25, 2011. The Atmospheric Infrared Sounder (AIRS) instrument captured an image at 4:00 UTC (12:00 a.m. EDT). The image showed a very large area of strong thunderstorms south of the center of circulation that marked its intensification into a tropical storm. The Joint Typhoon Warning Center noted that the expansive thunderstorm banding from the east to the south side of circulation are characteristic of a monsoon depression.

Tropical Storm Talas strengthened quickly this morning and is currently located about 280 nautical miles south of Iwo Jima near 20.2 North and 140.6 East. It had maximum sustained winds near 40 knots (46 mph). It was moving to the north at 10 knots.

The strong thunderstorms and convection (rapidly rising air that forms the thunderstorms that make up the tropical storm) are indications that Talas is steadily intensifying. Although Talas may interact somewhat with nearby Tropical Storm Nanmadol (which is located east near Luzon, Philippines), it is still expected to continue north.

Text Credit: Rob Gutro, NASA's Goddard Space Flight Center, Greenbelt, Md.

Hurricane Season 2011: Tropical Depression 10W (Atlantic Ocean)

Tropical Depression 10W Bringing Rain to the Philippines

The tenth tropical depression formed in the western North Pacific Ocean this past weekend, and brought rains to the central Philippines as seen on infrared imagery from a NASA satellite.

When NASA's Aqua satellite passed over Tropical Depression 10W on July 25 at 0441 UTC (12:41 a.m. EDT), the infrared image captured by the Atmospheric Infrared Sounder (AIRS) instrument revealed a large area of very cold cloud top temperatures (-63F/-52C) from strong thunderstorms over the central Philippines. A second area of strong thunderstorms on the eastern side of circulation was over the Philippine Sea.

On July 25 at 0600 UTC (2 a.m. EDT) Tropical Depression 10W's maximum sustained winds were near 30 knots (34 mph/55 kmh). It was about 335 nautical miles (385 miles/ 620 km) east of Manila, Philippines near 13.8 North and 126.4 East. Tropical Depression 10W (TD10W) is moving to the northwest at 9 knots (10 mph/17 kmh).

Satellite imagery has shown that the bands of thunderstorms feeding into the center of TD10W's circulation. TD10W continues to become more organized. The system is in an area of low to moderate wind shear which is enabling it to become better organized.

At 11 a.m. EDT on July 25, a weather station in Daet, Philippines was reporting thunderstorms and rain, with winds from the west at 11 mph. Daet is the capital municipality in the Camarines Norte province. The local forecast calls for TD10W to affect the city through the day on July 26.

The Joint Typhoon Warning Center forecasters expect TD10W to slowly intensify over the next two days and make landfall northeast of Hong Kong later this week.

Hurricane Season 2011: Tropical Storm Arlene (Atlantic Ocean/Caribbean Sea)

NASA Satellites See Strong Thunderstorms, Heavy Rain as Arlene Nears Landfall

Two different NASA satellites provided valuable information about the hundreds of thunderstorms that make up Tropical Storm Arlene as it nears landfall in northeastern Mexico. NASA's Aqua satellite measured cloud top temperatures giving clues about the strength of storms, while the TRMM satellite measured rainfall rates and cloud heights. All of this data is useful to forecasters in predicting Arlene's next moves.

The Tropical Rainfall Measuring Mission (TRMM) satellite had a good look at Arlene when it passed above on June 29, 2011 at 0502 UTC (0:02 AM CDT). At that time Arlene's winds were estimated to be about 34 knots (~39 mph) indicating that it was barely a tropical storm.

TRMM's Microwave Imager (TMI) and Precipitation Radar (PR) data showed that Arlene was getting better organized and contained scattered heavy thunderstorms dropping rain at a rate of over 50 mm/hr (~2 inches). Some of the heaviest rainfall was not near the center of Arlene's circulation but was in feeder bands over land along the southwestern Gulf of Mexico. A 3-D analysis of Arlene's vertical structure using TRMM PR revealed that very powerful thunderstorms in a feeder band over the southeastern Yucatan Peninsula reached to heights of 17 km (~10.6 miles).

NASA's Aqua satellite passed over Tropical Storm Arlene on June 29, 2011 at 08:05 UTC (4:05 a.m. EDT). At that time, the Atmospheric Infrared Sounder (AIRS) instrument showed that most of Arlene's heaviest thunderstorms and coldest cloud top temperatures (-63F/-52C) were over the waters of the Gulf of Mexico. That data matched with the TRMM data that showed the heaviest rainfall was over open water.

At 1 p.m. EDT on June 29, Arlene's maximum sustained winds had increased to 50 mph (85 kmh). It was located just 95 miles (155 km) east of Tuxpan, Mexico and 150 miles east-southeast of Tampico. That put Arlene's center near 21.1 North and 95.9 West. It was moving west near 8 mph (13 kmh) and had a minimum central pressure of 1000 millibars. A hurricane watch is in effect for the coast of eastern Mexico from Barra De Nautla Northward to La Cruz and a tropical storm watch extends farther along the coast. For updates, visit: www.nhc.noaa.gov.

Residents in the area of the watches should prepare for gusty winds, heavy rainfall and rough surf.

Text credit: Rob Gutro, NASA's Goddard Space Flight Center, Greenbelt, Md.

Hurricane Season 2011: Tropical Storm Aere (Western North Pacific Ocean)

NASA Satellite Sees Tropical Storm Aere Leave Deadly Path in Philippines

NASA's Aqua satellite flew over what has grown into Tropical Storm Aere every day this past weekend, as it dropped heavy rainfall, created mudslides and took lives in the eastern Philippines. Infrared satellite imagery from Aqua revealed the strong thunderstorms responsible for the heavy rainfall.

In a time series of imagery from NASA's Aqua satellite, the Atmospheric Infrared Sounder (AIRS) instrument showed Tropical Storm Aere's progress over the weekend on May 6 at 16:59 UTC, May 7 at 05:29 UTC, and Monday, May 9 at 05:17 UTC. Infrared data basically takes the temperature of a tropical cyclone's clouds and the coldest areas indicate the strongest thunderstorms and areas of heaviest rainfall. Those coldest cloud temperatures (highest, strongest thunderstorms) and are as cold as or colder than -63F/-52C.

On May 6, when Aere was a tropical depression (03W) it appeared to be more concentrated with the heaviest rainfall and strongest thunderstorms over open ocean. By Saturday, May 7, those heavy rains overspread land areas. On Monday, May 9, the circulation seemed to become weaker and convection (rapidly rising air that forms the thunderstorms) seemed to appear more scattered and has decreased in AIRS imagery.

Warnings are still in effect in the Philippines as Aere continues to move north. Public storm warning signal #1 is in effect in the following provinces: Luzon: Quirino, Ifugao, Mt. Province, Kalinga, Apayao and Batanes. Public storm warning signal #2 is in effect for: Luzon: Cagayan, Babuya and Calayan.

The four fatalities caused by Tropical Storm Aere occurred in Balatan, Camarines Sur where a landslide took three lives, and another person drowned in floodwaters in Leyte. Radio reports also noted that nine people at the Manila airport were injured when lightning struck a plane on the tarmac on May 7.

On May 9 at 1500 UTC (11:00 a.m. EDT), Tropical Storm Aere, formerly known as Tropical Depression 03W continued to bring rainfall to the Philippines. Its center was about 215 miles (346 km) north-northeast of Manila near 18.0 North and 122.3 East. It was moving north near 9 knots and had maximum sustained winds near 40 knots (46 mph/74 kmh). Aere, known locally in the Philippines as "Bebing," was creating rough waves on eastern-facing shores, as wave heights were reaching up to 13 feet (4 meters).

Aere is now moving along the east coast of Luzon Island and the Joint Typhoon Warning Center forecasts the tropical storm to soon move into the open waters south of Taiwan and then move northeast through the Northwestern Pacific Ocean. Aere is expected to become extratropical south of Japan.

Text Credit: Rob Gutro, NASA's Goddard Space Flight Center, Greenbelt, MD