Severe North Atlantic cyclone strikes Ireland and UK

A very deep area of low pressure resulted in a North Atlantic cyclone (named Alexandra) which caused massive ocean surges and brought strong winds to parts of Ireland and the UK.

Met-10/Metop-B, 09 December 2014, 12:00 UTC 

Airmass RGB, with surface pressure and ASCAT winds 

Credit: EUMeTrain

Gale force gusts of more than 129 km/h (80 mph) were recorded at Tiree in Scotland and ocean waves over 15 m (50 ft) high were recorded by the K5 buoy off the north west coast of Scotland (59.10N, 11.40W)

The strong winds caused transport chaos and power outtages across the Northern parts of the UK.

The gales and ocean surges were caused by rapid or explosive cyclogenesis — an intense low pressure system with a central pressure that falls 24 hPa in a 24-hour period, referred to colloquially as a 'weather bomb'.

In EUMETSAT weather blog, ITV weather forecaster Liam Dutton explained how the jet stream caused the cyclogenesis.

The Airmass RGB image from 9 December 12:00 UTC (left side) shows the system had a central pressure of less than 950 hPa.

Met-10, 10 December 2014, 06:00 UTC.

Airmass RGB with 10 m ECMWF model winds 

Credit: EUMeTrain

The ASCAT instrument on Metop measured 60 knots (111 km/h), but the real winds were probably higher as ASCAT winds saturate at around 60 knots (higher winds than 60 knots do not produce a higher ASCAT signal).

Also striking in this image are the strong winds over the Western Mediterranean caused by Mistral winds (two storms caught in one image).

The Airmass RGB image from 10 December 06:00 UTC (right side) shows the very large fetch zone of the storm, which is ideal (conditions) for forming high (monster) waves and very large ocean surge.

NOAA's GOES-East satellite Monitoring Atlantic Hurricane Gonzalo - Video

On Oct. 15 at 11:15 a.m. EDT NOAA's GOES-East satellite saw Gonzalo had tightly wrapped bands of thunderstorms spiraling into the center of its circulation. 

Credit: NASA /NOAA GOES Project

Hurricane Gonzalo has made the jump to major hurricane status and on Oct. 15 was a Category 4 storm on the Saffir-Simpson Hurricane Scale.

NOAA's GOES-East satellite provided imagery of the storm.

According to the National Hurricane Center, Gonzalo is the first category 4 hurricane in the Atlantic basin since Ophelia in 2011.

NOAA's GOES-East satellite provides visible and infrared images of weather from its orbit in a fixed position over the Earth.

On Oct. 15 at 15:15 UTC (11:15 a.m. EDT) GOES saw Gonzalo had tightly wrapped bands of thunderstorms spiraling into the center of its circulation.

The eye of the storm was obscured by high clouds in the image.

NOAA aircraft data and microwave images clearly show concentric eyewalls, with the inner radius of maximum winds now only about 4-5 nautical miles from the center.

At 11 a.m. EDT on Oct. 15, Gonzalo's maximum sustained winds increased to near 130 mph (215 kph) and the National Hurricane Center (NHC) noted that fluctuations in intensity are expected over the next couple of days.

Gonzalo's cloud-covered eye was located near latitude 23.5 north and longitude 68.0 west, about 640 miles (1,025 km) south-southwest of Bermuda.

Gonzalo is moving toward the northwest near 12 mph (19 kph).

The minimum central pressure recently reported by an air force reconnaissance aircraft was 949 millibars.


This animation of visible and infrared images from NOAA's GOES-East satellite shows the movement and strengthening of Gonzalo from a tropical storm on Oct. 13 to a hurricane on Oct. 15 north of Puerto Rico. 

Credit: NASA/NOAA GOES Project

Tropical storm conditions are possible in Bermuda by late Thursday night, Oct. 16, and hurricane conditions are possible over Bermuda on Friday Oct. 16.

Ocean swells however, will be felt over a much larger area, reached the U.S. east coast on Oct. 16. Large swells generated by Gonzalo are affecting portions of the Virgin Islands, the northern coasts of Puerto Rico and the Dominican Republic and portions of the Bahamas. Swells will reach much of the east coast of the United States and Bermuda on Thursday.

By late Oct. 16, Gonzalo is expected to turn to the northeast and the center is expected to approach Bermuda sometime on Oct. 17.

NASA GEOS-5 Image: A Portrait of Global Winds

High-resolution global atmospheric modeling provides a unique tool to study the role of weather within Earth’s climate system. 

NASA’s Goddard Earth Observing System Model (GEOS-5) is capable of simulating worldwide weather at resolutions as fine as 3.5 kilometers.

This visualization shows global winds from a GEOS-5 simulation using 10-kilometer resolution. 

Surface winds (0 to 40 meters/second) are shown in white and trace features including Atlantic and Pacific cyclones.

Upper-level winds (250 hectopascals) are colored by speed (0 to 175 meters/second), with red indicating faster.

This simulation ran on the Discover supercomputer at the NASA Center for Climate Simulation. 

The complete 2-year “Nature Run” simulation—a computer model representation of Earth's atmosphere from basic inputs including observed sea-surface temperatures and surface emissions from biomass burning, volcanoes and anthropogenic sources—produces its own unique weather patterns including precipitation, aerosols and hurricanes. 

A follow-on Nature Run is simulating Earth’s atmosphere at 7 kilometers for 2 years and 3.5 kilometers for 3 months.

Image Credit: William Putman/NASA Goddard Space Flight Center

Amazon Founder Finds Apollo 11 Moon Rocket Engines On Atlantic Ocean Floor

This NASA file photo shows the first stage of the mighty Saturn V rocket used to launch the historic Apollo 11 moon landing mission in 1969 as the booster was being built. The five huge F-1 rocket engines were discarded into the Atlantic Ocean after the July 16, 1969 launch.

CREDIT: NASA

When NASA's mighty Saturn V rocket launched the historic Apollo 11 mission to land the first men on the moon in 1969, the five powerful engines that powered the booster's first stage dropped into the Atlantic Ocean and were lost forever.

Lost, that is, until now.

A private expedition financed by Amazon.com founder and billionaire Jeff Bezos has discovered the five F-1 rocket engines used to launch Apollo 11 into space on July 16, 1969 and is drawing up plans to retrieve one or more so they can be publicly displayed.

"I'm excited to report that, using state-of-the-art deep sea sonar, the team has found the Apollo 11 engines lying 14,000 feet below the surface, and we're making plans to attempt to raise one or more of them from the ocean floor," Bezos wrote in a statement posted to the Bezos Expeditions website.

"We don't know yet what condition these engines might be in - they hit the ocean at high velocity and have been in salt water for more than 40 years. On the other hand, they're made of tough stuff, so we'll see."

Seafloor Mountain Expedition Studied Crust's Deepest Layer

A topographical map of the Atlantis Massif, which also shows the location of its Lost City hydrothermal vents.

CREDIT: NOAA.

Scientists recently returned from an expedition to an unusual seafloor mountain, where they conducted what may be the first-ever on-site study of a type of rock that makes up a huge amount of our planet, but is largely out of reach.

Researchers aboard the research vessel JOIDES Resolution sent instruments to the Atlantis Massif, a seamount that lies near the Mid-Atlantic Ridge, a long volcanic rift bisecting the Atlantic Ocean, where two tectonic plates are being slowly shoved apart and fresh oceanic crust is created.

Seamounts are essentially a mountain that doesn't rise above the ocean's surface.

Unlike most seamounts, which are typically made of volcanic rock, geological forces essentially yanked the Atlantis Massif from the Earth's gabbroic layer — the deepest layer of the Earth's crust, which rests directly on the planet's ever-shifting mantle.

ESA ENVISAT & ERS Satellites detect abundance of fresh water in the Arctic

ESA satellites show that a large dome of fresh water has been building up in the Arctic Ocean over the last 15 years.

A change in wind direction could cause the water to spill into the north Atlantic, cooling Europe.

The results are remarkable: since 2002, the sea surface in the studied area has risen by about 15 cm, and the volume of fresh water has increased by some 8000 cubic km – around 10% of all the fresh water in the Arctic Ocean.

Researchers from the Centre for Polar Observation and Modelling (CPOM) at University College London and the UK’s National Oceanography Centre used data from ESA’s ERS-2 and Envisat satellites to measure sea-surface height over the western Arctic from 1995 to 2010.

The results were published yesterday in the online version of the scientific journal, Nature Geoscience.

	Mean sea surface

The scientists conclude that the dome could be a result of strong Arctic winds accelerating a large ocean circulation known as the Beaufort Gyre, causing the sea surface to bulge.

A change in the direction of the wind would cause the fresh water to spill into the rest of the Arctic Ocean and even reach the north Atlantic.

This could slow a key ocean current, stemming from the Gulf Stream, and subsequently cool Europe.

This current keeps the continent relatively mild compared to other areas at similar latitudes.

“When we looked at our data on a year-to-year basis, we noticed that the changes in the sea surface height did not always follow what the wind was doing, so we thought about reasons why this might happen,” said Katharine Giles, CPOM research fellow and lead author of the study.

“One idea is that sea ice forms a barrier between the atmosphere and the ocean. So as the sea ice cover changes, the effect of the wind on the ocean might also change.

“Our next step is to look into how changes in the sea ice cover might affect the coupling between the atmosphere and the ocean in more detail to see if we can confirm this idea.”

Sea ice can be measured by different types of satellite data. Radar altimeters on satellites such as the two used in the study, Envisat and ERS-2, can be particularly useful when observing inaccessible areas like the Arctic.

ESA ISS Image: The Gilbert Islands

Oceans' deepest depth re-measured

US scientists have mapped the deepest part of the world's oceans in greater detail than ever before.

The Mariana Trench in the western Pacific runs for about 2,500km and extends down to 10,994m.

This measurement for the deepest point - known as Challenger Deep - is arguably the most precise yet.

The survey, conducted by the Center for Coastal and Ocean Mapping (CCOM), was completed to help determine the exact extent of US waters in the region.

"We mapped the entire trench, from its northern end at Dutton Ridge, all the way to where it becomes the Yap Trench in the south," explained Dr Jim Gardner from CCOM, which is based at the University of New Hampshire.

"We used a multibeam echosounder mounted on a US Navy hydrographic ship. This instrument allows you to map a swath of soundings perpendicular to the line of travel of the ship. It's like mowing the grass. And we were able to map the trench at a 100m resolution," he told BBC News.

The distance to the bottom of Challenger Deep has an error associated with it of about plus or minus 40m.

The figure of 10,994m is slightly less than some other recent measurements in the modern era, but they are all broadly similar.

A location in the trench about 200km to the east of Challenger goes almost as far down. This spot, known as HMRG Deep, has a depth of 10,809m.

It is extraordinary to think that both Challenger and HMRG extend deeper below sea level than Mount Everest rises above it.

Dr Gardner said his team's survey put a huge effort into getting the "sound speed profile" of the water column correct - this measure of how the echosounding signals speed and slow as they descend is the largest source of error in the measurement.

He presented the results of the mapping here at the 2011 American Geophysical Union (AGU) Fall Meeting, the world's largest annual gathering of Earth and planetary scientists.

The US State Department funded the study because it wants to know whether the exclusive economic zone encompassing the American territories of Guam and the Northern Mariana Islands can be pushed out beyond its current limit of 200 nautical miles (370km).

This may be possible if the shape of the seafloor fulfils certain requirements under the United Nations Convention on the Law of the Sea.

But the data also has high scientific interest in that it gives geologists a clearer picture of the structures in one of the most fascinating subduction zones on Earth.

NASA Earth Observatory: Atlantic Heat Source for Hurricane Irene

As Hurricane Irene rumbles through the Atlantic Ocean, it needs fuel to sustain itself.

Warm water is the main fuel, and there is plenty of it right now, as there usually is this time of year.

The map above shows sea surface temperatures (SST) in the Atlantic Ocean, Gulf of Mexico, and the Caribbean Sea on August 23, 2011.

The measurements come from the Advanced Microwave Scanning Radiometer (AMSR-E) on NASA’s Aqua satellite and the Moderate Resolution Imaging Spectroradiometer (MODIS) instruments on both the Terra and Aqua satellites.

The satellites measure the temperature of the top millimeter of the ocean.

Waters typically need to be above 27.8 degrees Celsius (82 Fahrenheit) to properly fuel tropical storms with warm, moist air. Red, orange, and yellow colors depict waters above the 27.8 degree mark.

The warmer the water, the more intense the storm can grow, if upper level wind patterns cooperate. In the map above, such waters dominate the Gulf of Mexico and tropical Atlantic in late August 2011.

They also run up the southeastern coast of the United States, following the Gulf Stream to Cape Hatteras before giving way to slightly cooler waters (shades of blue) in the Middle and North Atlantic.

As of 5 p.m. Eastern Daylight Time on August 24, 2011, the NOAA National Hurricane Center reported Irene had maximum sustained winds of 195 kilometers (120 miles) per hour and was located at 23.1 degrees North and 74.7 degrees West, about 45 kilometers (30 miles) east-southeast of Long Island in the Bahamas.

The forecasted path had the hurricane sweeping over nearly all Bahaman islands, then turning toward the North Carolina coast and eventually New England. Forecasts are updated roughly every six hours.

Irene is the first hurricane of the Atlantic season, and potentially the first to make landfall in the United States in several years.


Further Reading

1. National Hurricane Center. (2011, August 24). Hurricane Irene. National Weather Service. Accessed August 24, 2011.
2. NASA Earth Observatory. (n.d.). Global Maps: Sea Surface Temperature. Accessed August 24, 2011.

Missing Link Between Solar Activity and The UK's Cold Winters

A link between low solar activity and jet streams over the Atlantic could explain why, despite global warming trends, people in regions North East of the Atlantic Ocean might need to brace themselves for more frequent cold winters in years to come.

A new report published in IOP Publishing's Environmental Research Letters describes how we are moving into an era of lower solar activity which is likely to result in UK winter temperatures more like those seen at the end of the seventeenth century.

Lead author Mike Lockwood of the University of Reading said: "This year's winter in the UK has been the 14th coldest in the last 160 years and yet the global average temperature for the same period has been the 5th highest. We have discovered that this kind of anomaly is significantly more common when solar activity is low."

The new paper, 'Are cold winters in Europe associated with low solar activity?', differs from previous efforts to explain the UK's recent cold winters by comparing the most comprehensive, but regionally specific, temperature dataset available (the Central England Temperature dataset) to the long-term behaviour of the Sun's magnetic field, and to trends across the entire Northern Hemisphere.

The paper is being published now as the researchers have just had the opportunity to put this year's data to the test and found that this year's results fit well with the trends they have discovered.