Day Before HTV-8 Launch, Crew Studies Effects of Microgravity on Space-faring Humans

ISS - Expedition 60 Mission patch.

September 9, 2019

The International Space Station is abuzz as preparations heat up for the launch of the Japan Aerospace Exploration Agency HTV-8 “Kounotori” cargo craft from the Tanegashima Space Center tomorrow, Sept. 10. Launch is slated for 5:33 p.m. EDT, and can be seen live on NASA Television. 

NASA astronauts Christina Koch and Andrew Morgan spent more time practicing 30-meter approach and capture runs, followed by their own evaluations, in preparation for HTV-8’s arrival days later on Saturday, Sept. 14. The vehicle will be loaded with more than four tons of supplies, spare parts and experiment hardware for the space station residents.

Image above: At the Gagarin Cosmonaut Training Center in Star City, Russia, spaceflight participant Hazzaa Ali Almansoori of the United Arab Emirates (left), Oleg Skripochka of Roscosmos (center) and Jessica Meir of NASA (right) pose for pictures Sept. 5 as part of a pre-flight news conference. They will launch Sept. 25 from the Baikonur Cosmodrome in Kazakhstan on the Soyuz MS-15 spacecraft for a mission on the International Space Station. Image Credit: Gagarin Cosmonaut Training Center.

In the Kibo module, Morgan spoke to media out of Morgantown, West Virginia, referencing not only of NASA’s future with the Artemis program, but also the work currently underway that will benefit life on Earth and expand humanity’s reach into the solar system. Morgan referenced his early morning tasks with Fluid Shifts and his first spacewalk just weeks before, when he and NASA astronaut Nick Hague installed International Docking Adapter to usher in a new era of commercial visiting vehicles that will launch from American soil. 

Science investigations that will help develop countermeasures for humans exploring deep space, and for longer durations, rounded out the busy Monday. Commander Alexey Ovchinin of Roscosmos and crewmates Koch and Hague conducted eye exams aboard the orbiting laboratory. Since it is known that living and working in microgravity can induce vascular changes, as well as head and eye pressure, these measurements will help medical experts and scientists on the ground track crew health as Expedition 60 continues. Furthering research for Fluid Shifts, all other crewmates, with the exception of Koch and ESA (European Space Agency) astronaut Luca Parmitano, conducted venous ultrasounds in support of ongoing studies into vascular and fluid movement within space-faring human bodies.

Image above: Expedition 60 crew members Drew Morgan and Nick Hague pose with the spacesuits they wore during a recent spacewalk to install equipment that will accommodate the future arrivals of commercial crew spacecraft. Image Credit: NASA.

Parmitano, meanwhile, worked to close out Space Moss, an experiment that helps decode how microgravity affects the growth, development, gene expression and photosynthetic activity of tiny, rootless moss plants growing within the Cell Biology Experiment Facility incubator on the orbiting laboratory. 

Back on Earth, cosmonaut Oleg Skripochka, NASA astronaut Jessica Meir and spaceflight participant Hazzaa Ali Almansoori are set to depart for the Baikonur Cosmodrome in Kazakhstan tomorrow after spending the week prior taking part in ceremonial activities and mission briefings leading up to their mission start on Sept. 25, when they launch into space aboard a Soyuz MS-15 spacecraft.

Related links:

Expedition 60: https://www.nasa.gov/mission_pages/station/expeditions/expedition60/index.html

Japan Aerospace Exploration Agency HTV-8: https://www.nasa.gov/press-release/nasa-television-to-air-launch-capture-of-cargo-ship-to-space-station

Kibo module: https://www.nasa.gov/mission_pages/station/structure/elements/japan-kibo-laboratory

Fluid Shifts: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=1126

NASA Television: https://www.nasa.gov/nasalive/

Artemis: https://www.nasa.gov/artemis

Space Station Research and Technology: https://www.nasa.gov/mission_pages/station/research/index.html

International Space Station (ISS): https://www.nasa.gov/mission_pages/station/main/index.html

Images (mentioned), Text, Credits: NASA/Catherine Williams.

Best regards, Orbiter.ch

NASA Estimates Hurricane Dorian’s Massive Rainfall Track

NASA & JAXA - Global Precipitation Measurement (GPM) patch.

Sep. 09, 2019

Dorian – Atlantic Ocean

On Monday morning, September 9, Hurricane Dorian was a post-tropical storm after a mid-latitude weather front and cold seas had altered its tropical characteristics over the weekend. NASA compiled data on Hurricane Dorian and created a map that showed the heavy rainfall totals it left in its wake from the Bahamas to Canada.

Image above: At one-day intervals, the image shows the distance that tropical-storm force (39 mph) winds extended from Hurricane Dorian’s low-pressure center, as estimated by the National Hurricane Center. The Saffir-Simpson hurricane-intensity category is the number following the “H” in the label on the image. “TS” or “PT” indicate times when the storm was either at tropical storm strength or when the storm was categorized as post-tropical. Red circles over North Carolina indicate preliminary reports of tornadoes on Sept. 5. Image Credits: NASA Goddard.

On Saturday and Sunday, Sept. 7 and 8, Hurricane Dorian struck eastern Canada, causing wind damage and bringing heavy rainfall.  According to the Associated Press, a peak of 400,000 people were without power in Nova Scotia, Canada, because of Dorian.

At NASA’s Goddard Space Flight Center in Greenbelt, Maryland, a graphic was produced that shows precipitation that fell during the almost two-week period from August 27 to the early hours of Sept. 9. The near-real-time rain estimates come from the NASA’s IMERG algorithm, which combines observations from a fleet of satellites, in near real time, to provide near-global estimates of precipitation every 30 minutes.

his year, NASA began running an improved version of the IMERG algorithm that does a better job estimating precipitation at high latitudes, specifically north of 60 degrees North latitude. The post-tropical remnants of Hurricane Dorian were approaching this cold region at the end of the analysis period. While the IMERG algorithm is still unable to estimate precipitation falling over ice-covered surfaces (such as Greenland), IMERG can now give a more complete picture of the water cycle in places such as Canada, which is, for the most part, free of snow cover at this time of year.

In addition to rainfall totals, the map includes preliminary reports of tornadoes from 4:50 AM to 5:00 PM EDT on September 5 in North Carolina as provided by NOAA’s Storm Prediction Center.

IMERG showed largest rainfall amounts of more than 36 inches over the Bahamas and in an area off the coast of northeastern Florida. A large area of rainfall between 16 and 24 inches fell in many areas off the U.S. East Coast. Areas include those from South Carolina to the Bahamas, another off the North Carolina coast, a third area off the coasts of southern New Jersey, Delaware and Maryland, and the New England states.

By combining NASA precipitation estimates with other data sources, we can gain a greater understanding of major storms that affect our planet.

Global Precipitation Measurement (GPM) satellite. Image Credits: NASA/JAXA

On Monday, Sept. 9 at 0300 UTC (Sept. 8 a t 11 p.m. EDT), NOAA’s National Hurricane Center (NHC) issued the final advisory on Dorian. At that time, Dorian had moved into the Labrador Sea and its impacts on Newfoundland were beginning to subside. Post-tropical cyclone Dorian had maximum sustained winds near 50 knots (57 mph/93 kph). It was centered near 52.1 degrees north latitude and 53.4 degrees west longitude. That puts the center about 375 miles north of Cape Race, Newfoundland, Canada. Dorian was speeding to the east-northeast at 21 knots. Minimum central pressure was 980 millibars.

On Sept. 9, additional rainfall totals expected from Dorian in far eastern Quebec, Newfoundland and Labrador are expected to be less than 1 inch. Meanwhile, life-threatening rip tide and surf conditions are expected to affect mid-Atlantic and New England coasts of the U.S., as well as the coast of Atlantic Canada.

The NHC said the cyclone will continue into the open Atlantic, where it will dissipate south of Greenland.

Related articles:

NASA Finds Dorian Transitioning to an Extra-Tropical Cyclone
https://orbiterchspacenews.blogspot.com/2019/09/nasa-finds-dorian-transitioning-to.html

NASA Measures Dorian’s Heavy Rainfall from Bahamas to Carolinas
https://orbiterchspacenews.blogspot.com/2019/09/nasa-measures-dorians-heavy-rainfall.html

For updated forecasts, visit: http://www.nhc.noaa.gov/

Global Precipitation Measurement (GPM): https://www.nasa.gov/mission_pages/GPM/main/index.html

For more about NASA’s IMERG, visit: https://pmm.nasa.gov/gpm/imerg-global-image

Images (mentioned), Text, Credits: NASA’s Goddard Space Flight Center, by Owen Kelley/Rob Gutro.

Greetings, Orbiter.ch

New Models Suggest Titan Lakes Are Explosion Craters

NASA & ESA - Cassini Mission to Saturn & Titan patch.

Sept. 9, 2019

Using radar data from NASA's Cassini spacecraft, recently published research presents a new scenario to explain why some methane-filled lakes on Saturn's moon Titan are surrounded by steep rims that reach hundreds of feet high. The models suggests that explosions of warming nitrogen created basins in the moon's crust.

Titan is the only planetary body in our solar system other than Earth known to have stable liquid on its surface. But instead of water raining down from clouds and filling lakes and seas as on Earth, on Titan it's methane and ethane — hydrocarbons that we think of as gases but that behave as liquids in Titan's frigid climate.

Image above: This artist's concept of a lake at the north pole of Saturn's moon Titan illustrates raised rims and rampartlike features such as those seen by NASA's Cassini spacecraft around the moon's Winnipeg Lacus. Image Credits: NASA/JPL-Caltech.

Most existing models that lay out the origin of Titan's lakes show liquid methane dissolving the moon's bedrock of ice and solid organic compounds, carving reservoirs that fill with the liquid. This may be the origin of a type of lake on Titan that has sharp boundaries. On Earth, bodies of water that formed similarly, by dissolving surrounding limestone, are known as karstic lakes.

The new, alternative models for some of the smaller lakes (tens of miles across) turns that theory upside down: It proposes pockets of liquid nitrogen in Titan's crust warmed, turning into explosive gas that blew out craters, which then filled with liquid methane. The new theory explains why some of the smaller lakes near Titan's north pole, like Winnipeg Lacus, appear in radar imaging to have very steep rims that tower above sea level — rims difficult to explain with the karstic model.

The radar data were gathered by the Cassini Saturn Orbiter — a mission managed by NASA's Jet Propulsion Laboratory in Pasadena, California — during its last close flyby of Titan, as the spacecraft prepared for its final plunge into Saturn's atmosphere two years ago. An international team of scientists led by Giuseppe Mitri of Italy's G. d'Annunzio University became convinced that the karstic model didn't jibe with what they saw in these new images.

"The rim goes up, and the karst process works in the opposite way," Mitri said. "We were not finding any explanation that fit with a karstic lake basin. In reality, the morphology was more consistent with an explosion crater, where the rim is formed by the ejected material from the crater interior. It's totally a different process."

The work, published Sept. 9 in Nature Geosciences, meshes with other Titan climate models showing the moon may be warm compared to how it was in earlier Titan "ice ages."

Over the last half-billion or billion years on Titan, methane in its atmosphere has acted as a greenhouse gas, keeping the moon relatively warm — although still cold by Earth standards. Scientists have long believed that the moon has gone through epochs of cooling and warming, as methane is depleted by solar-driven chemistry and then resupplied.

Artist^s view of Cassini Titan flyby's. Image Credit: NASA/JPL

In the colder periods, nitrogen dominated the atmosphere, raining down and cycling through the icy crust to collect in pools just below the surface, said Cassini scientist and study co-author Jonathan Lunine of Cornell University in Ithaca, New York.

"These lakes with steep edges, ramparts and raised rims would be a signpost of periods in Titan's history when there was liquid nitrogen on the surface and in the crust," he noted. Even localized warming would have been enough to turn the liquid nitrogen into vapor, cause it to expand quickly and blow out a crater.

"This is a completely different explanation for the steep rims around those small lakes, which has been a tremendous puzzle," said Cassini Project Scientist Linda Spilker of JPL. "As scientists continue to mine the treasure trove of Cassini data, we'll keep putting more and more pieces of the puzzle together. Over the next decades, we will come to understand the Saturn system better and better."

The Cassini-Huygens mission is a cooperative project of NASA, ESA (the European Space Agency) and the Italian Space Agency. JPL, a division of Caltech in Pasadena, manages the mission for NASA's Science Mission Directorate in Washington. JPL designed, developed and assembled the Cassini orbiter. The radar instrument was built by JPL and the Italian Space Agency, working with team members from the U.S. and several European countries.

Titan's lakes: https://www.jpl.nasa.gov/news/news.php?feature=7378

More information about Cassini can be found here: https://solarsystem.nasa.gov/cassini

Images (mentioned), Text, Credits: NASA/Jon Nelson/Alana Johnson/JPL/Gretchen McCartney.

Best regards, Orbiter.ch

Monitoring air pollution from fires

ESA - Sentinel-5P Mission logo.

9 September 2019

The wildfires that have been devastating the Amazon rainforest have been international headline news over the last weeks. These fires are not only an environmental tragedy in terms of lost forest and biodiversity, but they are also leaving their mark on the atmosphere, affecting air quality and, potentially, the global climate.

Carbon monoxide from Amazon fires

In light of the climate crisis, the loss of swathes of forest is a serious concern. Everyone on Earth benefits from the health of rainforests like the Amazon. Trees acts as sinks for carbon, absorbing and storing atmospheric carbon dioxide – one of the main greenhouse gases – and therefore helping to cool the planet.

Consumed by fires in recent months, forests are releasing much of the carbon dioxide they once stored in their biomass back into the atmosphere. However, there are also a host of other pollutants entering the air. The Copernicus Sentinel-5P mission is being used to closely monitor the changes in air quality.

The satellite carries the state-of-the-art Tropomi instrument to map a multitude of trace gases such as nitrogen dioxide, ozone, formaldehyde, sulphur dioxide, methane, carbon monoxide and aerosols – all of which affect the air we breathe.

Formaldehyde

Using data from Copernicus Sentinel-5P, the first image shows the difference in carbon monoxide in the air between July and August. This pollutant is often associated with traffic, but here we see the increase in atmospheric concentrations following the fires. Naturally, once in the air, it can cause problems for humans by reducing the amount of oxygen that can be transported in the bloodstream.

Sentinel-5P

The next image shows how much formaldehyde was released from fires this year compared to 2018. The image also features Africa, which has also experienced more fires than last year. Formaldehyde is an important intermediate gas in the oxidation of methane and other hydrocarbons. While it is short-lived in the atmosphere, it reacts chemically to become a major source of carbon monoxide – another harmful pollutant as just noted.

Aerosols over São Paulo

The animation shows smoke and aerosols over Brazil. When breathed in these small particles can lead to cardiovascular conditions and lung problems. Aerosols also affect the climate by scattering and absorbing of incoming sunlight and trapping of outgoing long-wave radiation – and hence warming the planet. On 19–20 August, the smoke from fires got so bad that the day appeared to be turned into night as São Paulo was plunged into darkness.

With both air pollution and climate change major global concerns, satellites play a key role in monitoring the constituents of the atmosphere so that authorities have access to accurate information to help respond to incidents such as these recent fires and, ultimately, formulate environmental policies.

Fires August 2018-19

While Copernicus Sentinel-5P monitors air quality, one of the satellite missions in the same Copernicus family, Sentinel-3, is used to detect fires around the world. Data show that in August 2019, there were 79000 fires around the world compared to 16632 in August 2018.

Josef Aschbacher, ESA’s Director of Earth Observation programmes, said, "Over the last months, we have observed more and more vegetation fires on our planet, in Brazil, Siberia, Greenland, Africa, Spain, Greece and many other places. Our Earth observation satellites keep a close eye on them in order to inform people and politicians with undisputed facts about our changing planet."

Related articles:

Fires ravage the Amazon
https://orbiterchspacenews.blogspot.com/2019/08/fires-ravage-amazon.html

NASA's AIRS Maps Carbon Monoxide from Brazil Fires & Cross Country Smoke
https://orbiterchspacenews.blogspot.com/2019/08/nasas-airs-maps-carbon-monoxide-from.html

Uptick in Amazon Fire Activity in 2019
https://orbiterchspacenews.blogspot.com/2019/08/uptick-in-amazon-fire-activity-in-2019.html

NASA's ECOSTRESS Detects Amazon Fires from Space
https://orbiterchspacenews.blogspot.com/2019/08/nasas-ecostress-detects-amazon-fires.html

El Niño Could Drive Intense Season for Amazon Fires
https://orbiterchspacenews.blogspot.com/2016/06/el-nino-could-drive-intense-season-for.html

Related links:

Copernicus Atmosphere Monitoring Service: http://atmosphere.copernicus.eu/

Netherlands Space Office: http://www.spaceoffice.nl/

Royal Belgian Institute for Space Aeronomy: http://www.aeronomie.be/en/index.htm

SRON: http://www.sron.nl/

DLR: http://www.dlr.de/dlr/en/desktopdefault.aspx/tabid-10002/

Sentinel-3 World Fires Atlas: https://s3worldfireatlas.esa.int/

Space for our climate: http://www.esa.int/Our_Activities/Observing_the_Earth/Space_for_our_climate

Sentinel-5P: http://www.esa.int/Our_Activities/Observing_the_Earth/Copernicus/Sentinel-5P

Images, Animations, Text, Credits: ESA/Contains modified Copernicus data (2019), processed by SRON/Contains modified Copernicus data (2018/2019), processed by BIRA-IASB/Contains modified Copernicus data (2019), processed by KNMI/Contains modified Copernicus Sentinel data (2019), processed by ESA on ONDA Copernicus DIAS.


Greetings, Orbiter.ch

ISRO Just Found Its Lost Vikram Lander on the Moon

ISRO - Chandrayaan-2 Moon Mission logo.

Sept. 8, 2019

India's Chandrayaan-2 orbiter circling the moon has spotted the country's lost Vikram lander on the lunar surface, but there is still no signal from the lander, according to Indian media reports.

Images of Lunar Surface captured by Terrain Mapping Camera -2 (TMC-2) of Chandrayaan 2

K Sivan, chief of the Indian Space Research Organisation, said today (Sept. 8) that the Vikram lander was located by Chandrayaan-2 and efforts to restore contact the probe will continue for at least 14 days, according to a Times of India report.

"We have found the location of Lander Vikram on [the] lunar surface and Orbiter has clicked a thermal image of Lander," Sivan told the ANI news service in an interview, adding that attempts to communicate with the lander are ongoing.

Image Above: The Indian Space Research Organisation's Chandrayaan-2 moon orbiter is shown studying the lunar surface from above in this still image from a video animation.

Chandrayaan-2 mission was a highly complex mission, which represented a significant technological leap compared to the previous missions of ISRO, which brought together an Orbiter, Lander and Rover to explore the unexplored south pole of the Moon.

Since the launch of Chandrayaan-2 on July 22, 2019, not only India but the whole world watched its progress from one phase to the next with great expectations and excitement. This was a unique mission which aimed at studying not just one area of the Moon but all the areas combining  the exosphere, the surface as well as the sub-surface of the moon in a single mission.

Chandrayaan - 2 About Vikram Lander

The Orbiter has already been placed in its intended orbit around the Moon and shall enrich our understanding of the moon’s evolution and mapping of the minerals and water molecules in the Polar Regions, using its eight state-of-the-art scientific instruments. The Orbiter camera is the highest resolution camera (0.3m) in any lunar mission so far and shall provide high resolution images which will be immensely useful to the global scientific community. The precise launch and mission management has ensured a long life of almost 7 years instead of the planned one year.

Chandrayaan 2 - About Pragya Rover

The Vikram Lander followed the planned descent trajectory from its orbit of 35 km to just below 2 km above the surface. All the systems and sensors of the Lander functioned excellently until this point and proved many new technologies such as variable thrust propulsion technology used in the Lander. The success criteria was defined for each and every phase of the mission and till date 90 to 95% of the mission objectives have been accomplished and will continue contribute to Lunar science , notwithstanding the loss of communication with the Lander.

Related articles:

Chandrayaan-2 Vikram Moon lander lost signal
https://orbiterchspacenews.blogspot.com/2019/09/chandrayaan-2-vikram-moon-lander-lost.html

Chandrayaan-2 managed to get into lunar orbit
https://orbiterchspacenews.blogspot.com/2019/08/chandrayaan-2-managed-to-get-into-lunar.html

GSLV MkIII-M1 Successfully Launches Chandrayaan-2 spacecraft
https://orbiterchspacenews.blogspot.com/2019/07/gslv-mkiii-m1-successfully-launches.html

Moon mission for an Indian probe
https://orbiterchspacenews.blogspot.com/2019/07/moon-mission-for-indian-probe.html

GSLV-Mk III - M1 / Chandrayaan-2 Mission: https://www.isro.gov.in/launcher/gslv-mk-iii-m1-chandrayaan-2-mission

Related link:

India Space Research Organisation (ISRO): https://www.isro.gov.in/

Images, Videos, Text, Credits: ISRO/Orbiter.ch Aerospace/Roland Berga.

Greetings, Orbiter.ch

Hubble Spots a Swarm of Stars

NASA - Hubble Space Telescope patch.

Sept. 8, 2019

This image from the NASA/ESA Hubble Space Telescope shows a dwarf galaxy named UGC 685. Such galaxies are small and contain just a tiny fraction of the number of stars in a galaxy like the Milky Way. Dwarf galaxies often show a hazy structure, an ill-defined shape, and an appearance somewhat akin to a swarm or cloud of stars — and UGC 685 is no exception to this. Classified as an SAm galaxy — a type of unbarred spiral galaxy — it is located about 15 million light-years from Earth.

These data were gathered under Hubble’s LEGUS (Legacy ExtraGalactic UV Survey) program, the sharpest and most comprehensive ultraviolet survey of star-forming galaxies in the nearby universe.

LEGUS is imaging 50 spiral and dwarf galaxies in our cosmic neighborhood in multiple colors using Hubble’s Wide Field Camera 3. The survey is picking apart the structures of these galaxies and resolving their constituent stars, clusters, groups and other stellar associations. Star formation plays a huge role in shaping its host galaxy. By exploring these targets in detail via both new observations and archival Hubble data, LEGUS will shed light on how stars form and cluster together, how these clusters evolve, how a star’s formation affects its surroundings, and how stars explode at the end of their lives.

Hubble Space Telescope (HST)

For more information about Hubble, visit:

http://hubblesite.org/

http://www.nasa.gov/hubble

http://www.spacetelescope.org/

Text Credits: ESA (European Space Agency)/NASA/Rob Garner/Image, Animation,  Credits: ESA/Hubble & NASA; the LEGUS team, B. Tully, D. Calzetti; Acknowledgment: Judy Schmidt (Geckzilla).

Greetings, Orbiter.ch

NASA Finds Dorian Transitioning to an Extra-Tropical Cyclone

NOAA & NASA - Suomi NPP Mission patch / NASA - EOS Aqua Mission logo.

Sept. 8, 2019

Dorian – Atlantic Ocean

NASA satellites provided forecasters at the National Hurricane Center with infrared data and cloud top temperature information for Hurricane Dorian. Infrared data revealed that Dorian was becoming an extra-tropical cyclone as it moved northeast along the U.S. east coast and the area of strong storms had diminished around the storm.

Suomi NPP satellite. Image Credits: NOAA/NASA

NASA researches tropical cyclones and infrared data is one of the ways NASA uses. Cloud top temperatures provide information to forecasters about where the strongest storms are located within a tropical cyclone. The stronger the storms, the higher they extend into the troposphere, and they have the colder cloud temperatures.

On Sept. 6, at 2:23 p.m. EDT (1823 UTC), NASA’s Aqua satellite analyzed the storm using the Atmospheric Infrared Sounder or AIRS instrument. AIRS found coldest cloud top temperatures as cold as or colder than minus 80 degrees Fahrenheit (minus 62.2 degrees Celsius) circling around the center  (eye) and in a thick band of thunderstorms northeast of the center. NASA research has shown that cloud top temperatures that cold indicate strong storms that have the capability to create heavy rain.

Image above: On Sept. 6, at 2:23 p.m. EDT (1823 UTC) the AIRS instrument aboard NASA’s Aqua satellite analyzed cloud top temperatures of Hurricane Dorian in infrared light. AIRS found coldest cloud top temperatures (purple) of strongest thunderstorms were as cold as or colder than minus 80 degrees Fahrenheit (minus 62.2 degrees Celsius) around the center and in a thick band of thunderstorms northeast of the center. Image Credits: NASA JPL/Heidar Thrastarson.

On Sept. 7 at 3 a.m. EDT (0700 UTC), it was NASA-NOAA’s Suomi NPP satellite that provided an infrared view of Hurricane Dorian as it was transitioning into an extra-tropical storm. Strongest storms had cloud top temperatures as cold as or colder than minus 80 degrees Fahrenheit (minus 62.2 degrees Celsius) where the heaviest rain was falling over the open waters of the Atlantic Ocean. Those storms were now limited to the southern side of the storm, unlike the previous day, when they circled the eye.

Image above: NASA-NOAA’s Suomi NPP satellite provided an infrared view of Hurricane Dorian as it was transitioning into an extra-tropical storm on Sept. 7 at 3 a.m. EDT (0700 UTC). Strongest storms (red) had cloud top temperatures as cold as or colder than minus 80 degrees Fahrenheit (minus 62.2 degrees Celsius) where the heaviest rain was falling over the open waters of the Atlantic Ocean. Image Credits: NASA/NOAA/NRL.

NOAA’s National Hurricane Center’s (NHC) discussion said “Satellite imagery this morning [Sept. 7] indicates that Dorian is starting extratropical transition, with cold air clouds entraining [moving] into the southwestern side of the cyclone and a developing warm front to the north and east.”

EOS Aqua satellite. Image Credit: NASA

What is an Extra-Tropical Cyclone?

When a storm transitions into an extra-tropical cyclone, it means that a tropical cyclone has lost its tropical characteristics. The National Hurricane Center defines “extra-tropical” as a transition that implies both poleward displacement (meaning it moves toward the north or south pole) and the conversion of the cyclone’s primary energy source from the release of latent heat of condensation to baroclinic (the temperature contrast between warm and cold air masses) processes. It is important to note that cyclones can become extratropical and still retain winds of hurricane or tropical storm force.

Warnings and Watches in Effect on Sept. 7

NOAA’s National Hurricane Center’s (NHC) continued to issue warnings and watches as Dorian makes its way toward Canada today. A Hurricane Warning is in effect for eastern Nova Scotia from lower east Pubnico to Brule, and for western Newfoundland from Indian Harbour to Hawke’s Bay, Canada. A Hurricane Watch is in effect for Prince Edward Island and the Magdalen Islands.

A Tropical Storm Warning is in effect from east of Bar Harbor to Eastport, ME, and for Prince Edward Island, Canada. It is also in effect for southwestern Nova Scotia from Avonport to north of Lower East Pubnico, Fundy National Park to Shediac, Stone’s Cove to Indian Harbour, Hawke’s Bay to Fogo Island and from Mutton Bay to Mary’s Harbour, Canada.

Status of Hurricane Dorian on Saturday, September 7, 2019

On Saturday, September 7, 2019 at 11 a.m. EDT (1500 UTC), the center of Hurricane Dorian was located near latitude 42.0 degrees north and longitude 66.0 degrees west.

Dorian’s center is about 205 miles (330 km) south-southeast of Eastport, Maine and about 215 miles (350 km) southwest of Halifax, Nova Scotia, Canada.

The NHC said Dorian is moving toward the northeast near 29 mph (46 kph), and a general motion toward the northeast is expected to continue through Sunday night. Maximum sustained winds are near 85 mph (140 kph) with higher gusts.  Dorian is expected to become a hurricane-force post-tropical cyclone as it moves across eastern Canada tonight or on Sunday, Sept. 8. The estimated minimum central pressure is 953 millibars.

What’s Next for Dorian?

Dorian is expected to finish transition into an extratropical cyclone over the next day as it merges with a strong mid- to upper-level trough (elongated area of low pressure) and its associated surface front.

On the NHC forecast track, the center of Dorian is expected to move across central or eastern Nova Scotia this afternoon or this evening, pass near or over Prince Edward Island tonight, and then move near or over portions of Newfoundland and Labrador on Sunday.

For updated forecasts, visit: http://www.nhc.noaa.gov/

NASA-NOAA’s Suomi NPP satellite: http://www.nasa.gov/mission_pages/NPP/main/index.html

NASA’s Aqua satellite: https://www.nasa.gov/mission_pages/aqua/index.html

Images (mentioned), Text, Credits: NASA’s Goddard Space Flight Center, by Rob Gutro.

Greetings, Orbiter.ch