Activity at Kizimen Volcano

Earth Image of the day

Kizimen Volcano on Russia’s Kamchatka Peninsula remained active in March 2013. The Advanced Land Imager (ALI) on NASA’s Earth Observing-1 (EO-1) satellite captured this natural-color image on March 12. A plume rose from the summit, while snow covered a lava flow on the volcano’s eastern flank. That lava was actively advancing in February 2012, and still growing a year later.

Kizimen is a steep-sloped stratovolcano composed of alternating layers of volcanic ash, lava, and debris. According to the Global Volcanism Program at the Smithsonian Institution, Kizimen has a shape similar to Mount St. Helens prior to its 1980 eruption. Kizimen experienced a bout of eruptive activity in the late 1920s, then remained quiet for the rest of the 20th century. The volcano began showing signs of unrest in July 2009, with a swarm of seismic activity—up to 120 earthquakes a day. In November 2010, the volcano had a strong fissure eruption, and pyroclastic flows—avalanches of rocks and hot gases—began in February 2011.

Reports from the Kamchatka Volcanic Eruption Response Team noted that Kizimen experienced moderate seismic activity, incandescent lava extrusions, hot avalanches on the eastern and western flanks, and gas and steam eruptions in early March 2013………Read More.

Living in Kulusuk, Greenland

Image of the Day

Living in Kulusuk, Greenland, requires having a high tolerance for overcast skies. They are clear less than 10 percent of the year, and there is more than a forty percent chance that precipitation will fall on any given day. Winters last from November to April and tend to be cloudy, windy, and cold (average low of -7°C or 19°F). The shortest day of the year (December 21) provides just three hours of sunlight.

The long days of summer do offer some respite. On the longest day of the year (June 20), the town basks in more than 23 hours of sunlight. Daily summer highs average about 8°C (47°F).

The sharp contrast in weather makes for dramatic seasonal changes on the landscape. During winter, the waters around Kulusuk are choked with pack ice. That ice thins during the warmer months, opening the settlement up to boat traffic. However, it’s the airport a few kilometers east of town that provides the most critical link to the world. The airport’s gravel runway is visible in the satellite view shown above from the Advanced Land Imager (ALI) on NASA’s Earth Observing-1 (EO-1) satellite.

Planes and helicopters bring critical supplies to Kulusuk, but increasingly they also bring tourists eager for a glimpse of Greenland’s scenery. The raw beauty of Kulusuk was captured in the second image by Andrew Bossi, one of the winners of a photography contest sponsored by the Global Precipitation Mission. An engineer and avid traveler, Bossi arrived in Kulusuk near the peak of summer, when only a thin layer of ice covered the waters of the harbor. He took this photo on June 9, 2011, about 5 years after the satellite shot. Bossi was facing north when he took a photograph of this house along the shore.

The GPM satellite is scheduled to launch in 2014 and will make global observations of rain and snow. This is the mission’s second photography contest; the first focused on extreme weather. The mission is also running an anime contest focused on precipitation that is currently accepting submissions………Read More.

Atmospheric eddy off the Coast of Southern California

eddy off Catalina

On February 17, 2013, the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite captured this natural-color image of an atmospheric eddy off the coast of Southern California. The swirling, circular pattern in the clouds was due west of San Diego when Terra flew over around local noon.

The pattern is known to meteorologists as a Catalina eddy, or coastal eddy, and it forms as upper-level flows interact with the rugged coastline and islands off of Southern California. The interaction of high-pressure—bringing offshore winds blowing out of the north—and low-pressure—driving coastal winds blowing out of the south—combine with the topography to give the marine stratus clouds a cyclonic, counter-clockwise spin. The eddy is named for Santa Catalina Island, one of the Channel Islands offshore between Los Angeles and San Diego.

Catalina eddies can bring cooler weather, fog, and better air quality into Southern California as they push the marine boundary layer further inland. These mesoscale eddy patterns can stretch across 100 to 200 kilometers (60 to 120 miles) and can last from a few hours to a few days. They most often form between April and October, peaking in June.

A downloadable time-lapse video from the GOES-West weather satellite is linked below the image and shows the evolution of the eddy over roughly eight to ten hours. Images of the pattern in other wavelengths are available on the CIMSS Satellite Blog. And you can watch a short video here describing how the eddy develops…….Read More.

Storms get all sorts of names

indianocean_met_201301290800

Storms get all sorts of names. Weather forecasters use terms like snowstorms, hailstorms, blizzards, low-pressure systems, hurricanes, derechos, and twisters. Individual tropical storms have long been named by the U.S. National Hurricane Center and the World Meteorological Organization; more recently, media outlets have started naming winter storms.

Research meteorologists and climatologists have a simpler way of classifying storms: thunderstorms, tropical cyclones, and extra-tropical cyclones. All are atmospheric disturbances that redistribute heat and produce some combination of clouds, precipitation, and wind.

A EUMETSAT weather satellite acquired this image on January 29, 2013. It shows examples of all three types of storm. Thunderstorms are the smallest, tropical cyclones are significantly larger, and extra-tropical cyclones are the largest. In satellite imagery, the clouds of a mature extra-tropical cyclone are sprawling and comma-shaped, whereas mature tropical cyclones are spiral-shaped and often have a distinct eye at their center. Thunderstorm clouds are irregularly shaped and have towering cumulus clouds that billow upward, creating a textured appearance on the tops of clouds layers.

All three require moisture, energy, and certain wind conditions to develop, but the combination of ingredients varies depending on the type of storm and the local meteorological conditions. For example, thunderstorms form when a trigger—a cold front, converging near-surface winds, or rugged topography—destabilizes a mass of warm, humid air and causes it to rise. The air expands and cools as it ascends, increasing the humidity until the water vapor condenses into liquid droplets or ice crystals in precipitation-making clouds.

Tropical cyclones—more commonly known as hurricanes and typhoons—occur when many thunderstorms organize into a larger system and begin flowing in a circular pattern around a low-pressure center. These storms thrive on warm ocean temperatures for energy; sea surface temperatures need to be above 80°F (26.5°C) for a tropical cyclone to form. However, they cannot thrive when wind shear is strong. Wind shear occurs when surface-level and higher-level winds are blowing at different speeds or in different directions.