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NASA & Hurricane Dorian from Outer Space

Dorian Moves Over Storm-Fueling Waters

Heading into the Labor Day holiday weekend in United States, citizens and government officials braced for a potent hurricane that has been intensifying in the tropical Atlantic Ocean. By the afternoon of August 30, 2019, Hurricane Dorian had reached category 3 intensity and was headed for the northern Bahamas and the east coast of Florida as a major hurricane, the first of the 2019 Atlantic season.

The photograph above was shot by an astronaut on the International Space Station at 11:12 a.m. Atlantic Standard Time (17:12 Universal Time) on August 29, 2019. At that time Dorian had maximum sustained winds of 85 miles (135 kilometers) per hour and a central pressure of 986 millibars, according to the National Hurricane Center. As of 2 p.m. AST (18:00 UT) on August 30, the center of the storm was about 445 miles (715 kilometers) east of the northwestern Bahamas and 625 miles (1005 kilometers) east of West Palm Beach, Florida. Sustained winds were measured at 115 mph (185 kmph) and the minimum central pressure was 970 millibars.

A key factor in the development of a hurricane is the warmth of the ocean surface. Warm water is the fuel that leads a storm to intensify, as heat and moisture move from the ocean to the atmosphere. This map above shows sea surface temperatures (SSTs) in the western Atlantic as of August 28, as well as population density in the U.S. Southeast and several Caribbean islands. Meteorologists generally agree that SSTs should be above 27.8°Celsius (82°Fahrenheit) to sustain and intensify hurricanes (although there are some exceptions).

The data for the map come from the MUR Global Foundation Sea Surface Temperature Analysis, produced at NASA’s Jet Propulsion Laboratory. It is based on observations from several satellite instruments, including the NASA Advanced Microwave Scanning Radiometer-EOS (AMSRE), the Moderate Resolution Imaging Spectroradiometer (MODIS) on the NASA Aqua and Terra platforms, the U.S. Navy microwave WindSat radiometer, the Advanced Very High Resolution Radiometer (AVHRR) on several NOAA satellites, and on in situ SST observations from NOAA. Population data come from the Socioeconomic Data and Applications Center (SEDAC).

NHC Forecasters reported on August 30: “Life-threatening storm surge and devastating hurricane-force winds are likely in portions of the northwestern Bahamas, where a hurricane watch is in effect…A prolonged period of storm surge, high winds and rainfall is likely in portions of Florida into next week, including the possibility of hurricane-force winds over inland portions of the Florida peninsula.”

NASA Earth Observatory images by Joshua Stevens and Lauren Dauphin, using MUR Global Foundation Sea Surface Temperature Analysis data from the Physical Oceanography Distributed Active Archive Center (PODAAC) at NASA/JPL, and population data from the Socioeconomic Data and Applications Center (SEDAC). Astronaut photograph ISS060-E-47508 was acquired on August 29, 2019, with a Nikon D5 digital camera using a 28 millimeter lens and is provided by the ISS Crew Earth Observations Facility and the Earth Science and Remote Sensing Unit, Johnson Space Center. The image was taken by a member of the Expedition 60 crew. The image has been cropped and enhanced to improve contrast, and lens artifacts have been removed. Story by Michael Carlowicz.

Raikoke Volcano on the Kuril Islands rarely erupts. The small, oval-shaped island most recently exploded in 1924 and in 1778. The dormant period ended around 4:00 a.m. local time on June 22, 2019

Raikoke Erupts


Unlike some of its perpetually active neighbors on the Kamchatka Peninsula, Raikoke Volcano on the Kuril Islands rarely erupts. The small, oval-shaped island most recently exploded in 1924 and in 1778.

The dormant period ended around 4:00 a.m. local time on June 22, 2019, when a vast plume of ash and volcanic gases shot up from its 700-meter-wide crater. Several satellites—as well as astronauts on the International Space Station—observed as a thick plume rose and then streamed east as it was pulled into the circulation of a storm in the North Pacific.

On the morning of June 22, astronauts shot a photograph (above) of the volcanic plume rising in a narrow column and then spreading out in a part of the plume known as the umbrella region. That is the area where the density of the plume and the surrounding air equalize and the plume stops rising. The ring of clouds at the base of the column appears to be water vapor.

“What a spectacular image. It reminds me of the classic Sarychev Peak astronaut photograph of an eruption in the Kuriles from about ten years ago,” said Simon Carn, a volcanologist at Michigan Tech. “The ring of white puffy clouds at the base of the column might be a sign of ambient air being drawn into the column and the condensation of water vapor. Or it could be a rising plume from interaction between magma and seawater because Raikoke is a small island and flows likely entered the water.”

The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite acquired the second image on the morning of June 22. At the time, the most concentrated ash was on the western edge of the plume, above Raikoke. The third image, an oblique, composite view based on data from the Visible Infrared Imaging Radiometer Suite (VIIRS) on Suomi NPP, shows the plume a few hours later. After an initial surge of activity that included several distinct explosive pulses, activity subsided and strong winds spread the ash across the Pacific. By the next day, just a faint remnant of the ash remained visible to MODIS.

Since ash contains sharp fragments of rock and volcanic glass, it poses a serious hazard to aircraft. The Tokyo and Anchorage Volcanic Ash Advisory Centers have been tracking the plume closely and have issued several notes to aviators indicating that ash had reached an altitude of 13 kilometers (8 miles). Meanwhile, data from the CALIPSO satellite indicate that parts of the plume may have reached 17 kilometers (10 miles).

In addition to tracking ash, satellite sensors can also track the movements of volcanic gases. In this case, Raikoke produced a concentrated plume of sulfur dioxide (SO2) that separated from the ash and swirled throughout the North Pacific as the plume interacted with the storm.

“Radiosonde data from the region indicate a tropopause altitude of about 11 kilometers, so altitudes of 13 to 17 kilometers suggest that the eruption cloud is mostly in the stratosphere,” said Carn. “The persistence of large SO2 amounts over the last two days also indicates stratospheric injection.”

Volcanologists watch closely for plumes that reach the stratosphere because they tend to stay aloft for longer than those that remain within the troposphere. That is why plumes that reaches the stratosphere typically have the greatest effects on aviation and climate.

NASA Earth Observatory images by Joshua Stevens, using MODIS and VIIRS data from NASA EOSDIS/LANCE and GIBS/Worldview and the Suomi National Polar-orbiting Partnership. Astronaut photograph ISS059-E-119250 was acquired on June 22, 2019, with a Nikon D5 digital camera and is provided by the ISS Crew Earth Observations Facility and the Earth Science and Remote Sensing Unit, Johnson Space Center. The image was taken by a member of the Expedition 59 crew. The image has been cropped and enhanced to improve contrast, and lens artifacts have been removed. Story by Adam Voiland, with information from Erik Klemetti (Denison University), Simon Carn (Michigan Tech), and Andrew Prata (Barcelona Supercomputing Center).

NASA: 2018 was Fourth Warmest Year in Continued Warming Trend


Global map of temperature anomalyOne frame of an animation of the GFWED Fire Index

Global map of surface temperature anomaly for the period 2005-2014

Colorbar showing range of values in global map

According to an ongoing temperature analysis conducted by scientists at NASA’s Goddard Institute for Space Studies, the average global temperature on Earth has increased by about 0.8° Celsius (1.4° Fahrenheit) since 1880. Two-thirds of the warming has occurred since 1975, at a rate of roughly 0.15-0.20°C per decade.


NASA: Camp Fire Photos from Space

Camp Fire Rages in California


On November 8, 2018, the Camp Fire erupted 90 miles (140 kilometers) north of Sacramento, California. As of 10 a.m. Pacific Standard Time on November 9, the fire had consumed 70,000 acres of land and was five percent contained, or surrounded by a barrier.

The Operational Land Imager on Landsat 8 acquired this image on November 8, 2018, around 10:45 a.m. local time (18:45 Universal Time). The image was created using Landsat bands 4-3-2 (visible light), along with shortwave-infrared light to highlight the active fire. The fire started around 6:30 a.m. Pacific Standard Time, and by 8:00 p.m., it had burned 20,000 acres of land.


Strong winds pushed the fire to the south and southwest overnight, tripling its size and spreading smoke over the Sacramento Valley. The Moderate Resolution Imaging Spectrometer (MODIS) on NASA’s Terra satellite captured the natural-color image above on November 9. The High-Resolution Rapid Refresh Smoke model, using data from National Oceanic and Atmospheric Administration (NOAA) and NASA satellites, shows the smoke should continue to spread west. The image also shows two more fires in southern California, the Hill and Woolsey Fires.

More than 2,000 personnel have been sent to fight the Camp Fire, which is predicted to be fully contained by November 30. Firefighters are having difficulty containing it due to strong winds, which fan the flames and carry burning vegetation downwind. The area also has heavy and dry fuel loads, or flammable material.

State and local officials have closed several major highways, including portions of Highway 191. They also ordered evacuations in several towns, including Concow and Paradise, where the fatal fire burned through the town.

NASA Earth Observatory image by Joshua Stevens, using Landsat data from the U.S. Geological Survey, and MODIS data from NASA EOSDIS/LANCE and GIBS/Worldview. Story by Kasha Patel.

NASA: Florida Slammed by Hurricane Michael

Florida Slammed by Hurricane Michael
Florida Slammed by Hurricane Michael

At approximately 1:30 p.m. Eastern Daylight Time (17:30 Universal Time) on October 10, 2018, Hurricane Michael made landfall near Mexico Beach, Florida. Wind speeds were estimated to be 155 miles (250 kilometers) per hour, which would make the category 4 hurricane the strongest on record to hit the Florida Panhandle. The storm has already destroyed homes and knocked out electric power in the area. Forecasters expect Michael to bring heavy winds and rain to the southeastern United States for several days.

The Geostationary Operational Environmental Satellite 16 (GOES-16) acquired data for the composite images above around 1 p.m. Eastern Time on October 10. GOES-16 data (band 2) were overlaid on a MODIS “blue marble.” GOES-16 is operated by the National Oceanic and Atmospheric Administration (NOAA); NASA helps develop and launch the GOES series of satellites.

The National Weather Service office in Tallahassee issued an extreme wind warning as the storm approached. Forecasters were expecting large storm surges—rising seawater that moves inland as it is pushed onshore by hurricane-force winds. The worst surges were expected to inundate areas between Tyndall Air Force Base and Keaton Beach with 9 to 14 feet of water on October 10.

As the storm moves inland, forecasters expect life-threatening winds to also affect parts of Alabama and Georgia. Areas as far as southeastern Virginia could see several inches over the next three days. North Carolina has declared a state of emergency as the storm forecast has it passing over areas that were affected by Hurricane Florence last month.

NASA Earth Observatory images by Joshua Stevens, using data from GOES-16. Story by Kasha Patel.

NASA: New Delhi in 1989 and 2018

The capital of India, New Delhi, has been experiencing one of the fastest urban expansions in the world. Vast areas of croplands and grasslands are being turned into streets, buildings, and parking lots, attracting an unprecedented amount of new residents. By 2050, the United Nations projects India will add 400 million urban dwellers, which would be the largest urban migration in the world for the thirty-two year period.

These images show the growth in the city of New Delhi and its adjacent areas—a territory collectively known as Delhi—from December 5, 1989, (left) to June 5, 2018 (right). These false-color images use a combination of visible and short-wave infrared light to make it easier to distinguish urban areas. The 1989 image was acquired by the Thematic Mapper on Landsat 5 (bands 7,5,3), and the 2018 image was acquired by Operational Land Imager on Landsat 8 (bands 7,6,4).

Most of the expansion in Delhi has occurred on the peripheries of New Delhi, as rural areas have become more urban. The geographic size of Delhi has almost doubled from 1991 to 2011, with the number of urban households doubling while the number of rural houses declined by half. Cities outside of Delhi—Bahadurgarh, Ghaziabad, Noida, Faridabad, and Gurugram—have also experienced urban growth over the past three decades, as shown in these images.

With a flourishing service economy, Delhi is a draw for migrants because it has one of India’s highest per capita incomes. According to the latest census data, most people (and their families) move into the city for work. The Times of India reported that the nation’s capital grew by nearly 1,000 people each day in 2016, of which 300 moved into the city. By 2028, New Delhi is expected to surpass Tokyo as the most populous city in the world.

The increased urbanization has had several consequences. One is that the temperatures of the urban areas are often hotter than surrounding vegetated areas. Manmade structures absorb the heat and then radiate that into the air at night, increasing the local temperature (the urban heat island effect). Research has shown that densely built parts of Delhi can be 7°C (45°F) to 9°C (48°F) warmer in the wintertime than undeveloped regions.

Additionally, sprawling cities can have several environmental consequences, such as increasing traffic congestion, greenhouse gas emissions, and air pollution. From 2005 to 2014, NASA scientists have observed an increase in air pollution in India due to the country’s fast-growing economies and expanding industry.

India is one of many countries with fast-growing cities. By 2050, China is projected to add 250 million people in its urban areas, and Nigeria may add 190 million urban dwellers. In total, India, China and Nigeria are expected to account for 35 percent of the world’s urban population growth between 2018 and 2050.

NASA Earth Observatory images by Lauren Dauphin, using Landsat data from the U.S. Geological Survey. Story by Kasha Patel.

NASA: How temperatures are changing the force of Florence

Florence Crossing Warm Waters on the Way to the Carolinas

As millions of people along the Atlantic Coast of the United States board up windows and evacuate before Hurricane Florence makes landfall, remote sensing researchers and forecasters are monitoring the environmental conditions fueling the powerful storm. They are assembling a suite of satellite images and data products that could aid storm preparedness and recovery efforts by federal and local partners.

As Florence approaches land, two key factors will help govern the severity of the storm: ocean temperatures and wind shear, the difference in wind speeds at upper and lower parts of a storm. Warm ocean water and low wind shear are required to sustain and intensify a hurricane.

The map above shows sea surface temperatures on September 11, 2018. Meteorologists generally agree that sea surface temperatures (SSTs) should be above 27.8°C (82°F) to sustain and intensify hurricanes (although there are some exceptions). In Florence’s case, National Hurricane Center forecasters expect the storm to pass over water with temperatures well above that threshold. The data for the map were compiled by Coral Reef Watch, which blends observations from the Suomi NPP, MTSAT, Meteosat, and GOES satellites and computer models. Information about the storm track and winds come from the National Hurricane Center.

Florence will be traveling over water that is anomalously warm for this time of year, noted Marangelly Fuentes, a NASA atmospheric scientist who has been tracking the storm with models maintained by NASA’s Global Modeling and Assimilation Office (GMAO). As the storm approaches land, sea surface temperatures off of the Carolinas were between 0.5 and 1.5 degrees Celsius warmer than usual.

However, the warm coastal water is not the only reason that the Carolinas may be hit by one of the strongest hurricanes to ever make landfall at such a northerly latitude in this region.“While it is common to see storms this strong or even stronger over the ocean at this latitude,” said Gary Partyka, another atmospheric scientist with GMAO. “What set this situation apart was an unusually strong blocking high north of the storm that directed it towards the United States. Usually with storms at this latitude large-scale circulation patterns drive them to the north and east, well away from the coast.”

Forecasters have warned that life-threatening storm surges, catastrophic flooding, damaging winds, and dangerous rip currents will likely occur along the coastlines of North Carolina, South Carolina, and Virginia when the storm arrives late on September 13. There is growing concern that the presence of another atmospheric blocking ridge in the Mid-Atlantic region may cause the storm to stall and possibly move south and west toward Georgia, potentially extending the amount of time it remains over warm water and increasing the rainfall totals.

With forecasters expecting prodigious amounts of rain, NASA’s Disasters Program has mobilized a team that will use NASA sensors to monitor soil moisture, soil saturation, and rainfall rates. During and after the storm, this team will produce and disseminate information about where satellites observe floods and other effects of the storm. For more awesome, frightening views of Hurricane Florence, see this story.

NASA Earth Observatory image by Joshua Stevens, using sea surface temperature data from Coral Reef Watch and wind probabilities from the National Hurricane Center. Story by Adam Voiland.

Awesome, Frightening Views of Hurricane Florence

NASA: Tropical cyclones and storms in the Atlantic

Trouble Brewing in the Atlantic

The Atlantic basin was relatively quiet for much of August 2018, but September brought a surge in storm activity. On September 9, 2018, Florence, Isaac, and Helene were all churning up the North Atlantic. The trio of storms is visible in this image acquired by the Visible Infrared Imaging Radiometer Suite (VIIRS) on the Suomi NPP satellite.

Category 4 Hurricane Florence was the most ominous for people in the United States. Forecasters at the National Hurricane Center expect the slow-moving storm to reach the coast of the Carolinas on September 12 or 13, bringing a life-threatening storm surge, exceptionally heavy inland rains, and damaging winds. Though weakening, Category 1 Hurricane Isaac is on a path to cross the Lesser Antilles islands and move into the eastern Caribbean Sea on September 13. Category 2 Hurricane Helene was strengthening, but is expected to veer northward into the open ocean.

The bright strips in the image are reflected sunlight, or “glint,” which can show up over ocean areas in the middle of each orbit.

NASA Earth Observatory image by Joshua Stevens, using VIIRS data from the Suomi National Polar-orbiting Partnership. Caption by Adam Voiland.

NASA: Wildfires Blanket Western States With Smoke

Wildfires Blanket Western States With Smoke

The 2018 wildfire season in North America is well under way, with blazes having burned more acres than average through the end of July. Earlier in the summer, satellite images showed smoke and burn scars from fires in western states including California and Colorado. As the calendar turns to August, smoke is now streaming from fires in nearly every western state.

The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra and Aqua satellites acquired these natural-color images on July 28 and 29. The animation shows how winds can make smoke plumes vary daily in direction and distance from their source.

A notable amount of the smoke stems from the Carr Fire, which is burning in Shasta County near Redding, California. The fire ignited on July 23 amid warm, dry conditions. By July 30, it had burned 98,724 acres and was just 20 percent contained, according to Cal Fire. News reports noted that shifting, gusty winds and a lack of rain in the forecast could worsen the situation.

Other states also contributed to the smoke pall over the West. According to the National Interagency Fire Center, 98 large active fires were burning across the United States on July 30, having consumed 1.2 million acres. States with the largest fires counts included Oregon (16), Alaska (15), Arizona (10), Colorado (13), and California (9).

Most areas of burning land are not directly visible in satellite imagery, obscured from view by smoke and clouds. The Perry Fire in Nevada is an exception; check out these Landsat images to see how the fire advanced over the span of a day.

NASA Earth Observatory images by Lauren Dauphin, using MODIS data from LANCE/EOSDIS Rapid Response. Story by Kathryn Hansen.

NASA: Volcán de Fuego

A Deadly Eruption Rocks Guatemala

A Deadly Eruption Rocks Guatemala

Fuego in Guatemala is one of Central America’s most active volcanoes. For years, the towering Volcán de Fuego has puffed continuously, punctuated by occasional episodes of explosive activity, big ash plumes, lava flows, and avalanche-like debris slides known as pyroclastic flows.

Just before noon on June 3, 2018, the volcano produced an explosive eruption that sent ash billowing thousands of meters into the air. A deadly mixture of ash, rock fragments, and hot gases rushed down ravines and stream channels on the sides of the volcano. Since these pyroclastic flows often move at speeds of greater than 80 kilometers (50 miles) per hour, they easily topple trees, homes, or anything else in their path. According to news reports, more than two dozen people were killed. As a precautionary measure, thousands of other people have been evacuated.

The Visible Infrared Imaging Radiometer Suite (VIIRS) on Suomi NPP acquired this image of the ash plume at 1 p.m. local time (19:00 Universal Time) on June 3, 2018, after the ash (brown) had punched through a deck of clouds. A report from the Washington Volcanic Ash Advisory Center estimated the plume’s maximum height at 15 kilometers (9 miles). Imagery from a geostationary satellite showed winds blowing the plume to the east. The eruption deposited ash on several communities surrounding the volcano, including Guatemala City, which is 70 kilometers (40 miles) to the east.

In addition to ash, the plume contains gaseous components invisible to the human eye, including sulfur dioxide (SO2). The gas can affect human health—irritating the nose and throat when breathed in—and reacts with water vapor to produce acid rain. Sulfur dioxide also can react in the atmosphere to form aerosol particles, which can contribute to outbreaks of haze and sometimes cool the climate.

Satellite sensors such as the Atmospheric Infrared Sounder (AIRS) on the Aqua satellite and the Ozone Mapping Profiler Suite (OMPS) on Suomi NPP make frequent observations of sulfur dioxide. The map above shows concentrations of sulfur dioxide in the middle troposphere at an altitude of 8 kilometers (5 miles) as detected by OMPS on June 3.

Upon seeing data collected by AIRS several hours after the eruption that showed high levels of sulfur dioxide in the upper troposphere, Michigan Tech volcanologist Simon Carn tweeted that this appeared to be the “highest sulfur dioxide loading measured in a Fuego eruption in the satellite era.”

NASA Earth Observatory images by Joshua Stevens, using VIIRS data from the Suomi National Polar-orbiting Partnership and OMPS data from the Goddard Earth Sciences Data and Information Services Center (GES DISC). Story by Adam Voiland.

Suomi NPP – OMPS


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