With Cyclone Fantala, the Indian Ocean experiences its strongest storm on record

By Tom Yulsman | April 19, 2016 9:33 pm
Cyclone Fantala

NASA’s Aqua satellite acquired this natural-color image of Cyclone Fantala at 1:25 p.m. local time on April 18, 2016. (Source: NASA Earth Observatory)

It’s now the Indian Ocean’s turn.

After record setting cyclones in the Northeast Pacific (Hurricane Patricia, Oct. 2015), and the Southwest Pacific (Tropical Cyclone Winston, Feb. 2016), the Indian Ocean has now experienced its strongest storm on record.

Say hello to Cyclone Fantala, as seen in the satellite image above. Fantala’s wind speeds reached an estimated 170 miles per hour on April 18, according to the Joint Typhoon Warning Center.

Modern, reliable records of storm strength in the Indian Ocean extend back only to 1990, according to NASA’s Earth Observatory, source of the image above. But still, I think it’s an achievement worth marking.

Cyclone Fantala

An animation of enhanced infrared satellite images shows Cyclone Fantala swirling in the Indian Ocean off the coast of Madagascar, ending early in the morning local time on Wednesday, April 20, 2016. (Source: CIMSS)

Fantala has since weakened considerably, with winds subsiding to just shy of 100 miles per hour as I’m writing this on April 20th local time. The cyclone is expected to make a nearly 180-degree to the southeast and possibly head towards Madagascar — likely in a much weakened state.

CATEGORIZED UNDER: select, Top Posts, Tropical Cyclones

A thunderstorm blowing its top, as seen from space

By Tom Yulsman | April 17, 2016 9:25 pm
Updrafts from a strong thunderstorm punch through the boundary between troposphere, the lowest region of the atmosphere, and into the stratosphere above, as seen in this photograph made by an unidentified astronaut aboard the International Space Station toward the end of March 2016. (Source: NASA)

Updrafts from a strong thunderstorm punch through the boundary between the troposphere, the lowest region of the atmosphere, and into the stratosphere, as seen in this photograph made by an unidentified astronaut aboard the International Space Station toward the end of March 2016. The boundary between the two atmospheric layers is marked by the broad anvil-shaped cloud. (Source: NASA)

When I saw this sweet piece of eye candy, produced recently by an astronaut aboard the International Space Station, I felt it was time to come out of blogging hibernation.

Over the past couple of weeks, my day job as a journalism professor at the University of Colorado has held me back from posting regularly here at ImaGeo. But thanks in part to this image, I’m back. I hope you find it to be as spectacular as I do.

You’re looking at a thunderstorm as photographed by an unnamed astronaut aboard the International Space Station some time in late March. It’s a great example of a phenomenon called “overshooting tops.”

Here’s what the phenomenon looks like from an airplane: Read More

CATEGORIZED UNDER: Atmosphere, select, Top Posts, Weather

Ocean warming threatens stability of Antarctic ice shelves by carving ‘upside-down rivers’ into their undersides

By Tom Yulsman | March 29, 2016 1:24 pm
Antarctic ice shelves

The Getz Ice Shelf extends several miles into the ocean along the western Antarctic coast. The vertical face of the ice shelf is almost 200 feet high and is estimated to extend another 1,000 feet below the ocean surface. This photo was taken from a NASA DC-8 by Ted Scambos, Lead Scientist at the National Snow and Ice Data Center.

Note: Thanks to a spring-break getaway, I’m just now catching up to this new research showing that warming ocean waters are threatening the stability of giant, floating shelves of ice fringing Antarctica. The post that follows offers a summary of the new findings, followed by a Q&A with the study’s main author. 

By carving giant channels into the undersides of Antarctica’s ice shelves, warming sea water is leaving some of them more vulnerable to disintegration — and raising new concerns about sea level rise.

“We found that warm ocean water is carving these ‘upside-down rivers,’ or basal channels, into the undersides of ice shelves all around the Antarctic continent,” says lead researcher, Karen Alley, a graduate research assistant at the National Snow and Ice Data Center, and a Ph.D. student at the University of Colorado in Boulder. (See note at the end of this post about my own connection to the University of Colorado.)

These shelves form over thousands of years as ice flows off the mighty ice sheets of Antarctica and into the ocean through outlet glaciers. They can extend over the water for many miles, with bergs calving from their faces. They are, in essence, floating extensions of the grounded ice on the continent.

Antarctic ice shelves

The cross-section above shows the transition from the grounded ice of an Antarctic ice sheet to a floating ice shelf. New research shows that warming Circumpolar Deep Water is carving channels into the undersides of Antarctic ice sheets, potentially weakening them and making them more vulnerable to disintegration. (Source: Bethan Davies, Antarcticglaciers.org. CC BY-NC-SA 3.0)

The ice shelves also act like dams that impound the glaciers behind them, slowing their movement to the sea. Read More

A “warm, crazy winter” leaves the Arctic with a record-breaking low extent of sea ice

By Tom Yulsman | March 28, 2016 7:26 pm
Warm Arctic

This animation shows the evolution of Arctic sea ice from September 7, 2015, when the ice reached its minimum summer extent, to March 24, 2016, when it reached its wintertime maximum extent. (Source: NASA Goddard’s Scientific Visualization Studio/C. Starr)

Thanks to dramatically warm conditions, more of the Arctic’s sea surface seems to have remained unfrozen this winter than ever before in the era of satellite monitoring, the National Snow and Ice Data Center announced today.

This year’s low extent of wintertime Arctic sea ice breaks the previous record set just last year. (Satellite monitoring began in 1979.)

Warm Arctic

Arctic sea ice on March 24, 2016, spread across 5.607 million square miles, beating last year’s record low of 5.612 million square miles. (Source: National Snow and Ice Data Center.)

Arctic sea ice, which expands during the 24-hour darkness and frigid temperatures of winter, reached its maximum annual extent on March 24, topping out at 431,000 square miles shy of the long-term average.

That’s an area of open water equal in size to nearly two thirds of Texas.

“I’ve never seen such a warm, crazy winter in the Arctic,” said NSIDC director Mark Serreze in the announcement from the center. “The heat was relentless.” Air temperatures over the Arctic Ocean between December and February were 4 to 11 degrees Fahrenheit above average in most areas. (Please see the end of this post for a note about my connection with the University of Colorado, where the NSIDC is based.) Read More

Reliable, official numbers now in for February 2016 show that it smashed the previous record for the month

By Tom Yulsman | March 12, 2016 7:49 pm

What is the significance of reaching this new milestone? And now that El Niño is waning, what might the future bring?

February

Pattern of temperature anomalies across the globe in February 2016. The month was the warmest on record. (Source: NASA GISS)

| Please see important correction at end |

Earlier this month, a spate of headlines proclaimed that February 2016 was the warmest such month on record for the globe. At that time, I wrote that we should wait until official, reliable analyses were in before drawing any final conclusions.

SEE ALSO: February may have been the warmest on record, but we don’t know for sure — despite reports to the contrary

The first of those reliable analyses has just been released, and it shows that this past month did indeed set a new record for warmest February in a record extending back to 1880.

According to the analysis by NASA’s Goddard Institute for Space Studies, this past month was 1.35 degrees C (2.43 F) warmer than the month’s long-term average (measured between 1951 and 1980).

February’s spike was not just a one-off. January also set a record. In fact, we’ve now experienced a string of five record-setting months in a row.

But the increase temperature anomaly spike seen last month was particularly steep. As Gavin Schmidt, head of NASA GISS, put it on Twitter today: “Normally I don’t comment on individual months (too much weather, not enough climate), but last month was special.”

According to Gerald Meehl, a research scientist at the National Center for Atmospheric Research, the odds of monthly records being set are raised right now, thanks to “the juxtaposition of a large El Niño and ongoing human-caused warming.”

A spike of El Niño warmth has, in fact, occurred atop the long-term global warming trend-line. But as the string of recent monthly records suggests, that trend line also seems to be angling sharply upward now, after what many climate scientists regard as a multi-year period of slower warming.

But Meehl also cautions that we should not expect each successive month necessarily to be warmer than the preceding one. That’s in part because El Niño’s fade — as this one appears to be doing. And they often transition into La Niña, the opposite of an El Niño, resulting in cooling.

Moreover, climate can be quite labile, with natural variation causing lots of ups and downs.

Read More

Here’s what a total eclipse looks like from 22,236 miles away in space as the moon’s shadow crosses Earth’s face

By Tom Yulsman | March 12, 2016 12:54 pm

Also check out the view from a million miles away!

eclipse

As the shadow of a total solar eclipse moved across the Pacific on March 9, 2016, the Himawari-8 satellite was watching from geostationary orbit. (Source: Cooperative Institute for Meteorological Satellite Studies.)

This past Wednesday, March 9, 2016, the Moon blotted out the Sun in a total eclipse, turning day to dusk starting in Sumatra, moving east across many other Indonesian islands, and then out into the wide Pacific Ocean.

In paces with clear skies, the view from the surface was spectacular. So was the view from an airliner high above the Pacific.

But how did it look from geostationary orbit —22,236 miles out in space — looking down on Earth? Have a look by watching the animation above. Read More

CATEGORIZED UNDER: Astronomy, select, Sun, Top Posts

Curiosity Mars rover: ‘Look ma, no hands!’

By Tom Yulsman | March 7, 2016 10:35 am
Curiosity self portrait

Self portrait: Curiosity Mars rover. (Source: NASA/JPL-Caltech/MSSS)

The Curiosity Mars rover took this selfie — actually, 57 of them stitched into one mosaic — as it was exploring a feature on the Red Planet known as the “Namib Dune.”

The rover used its Mars Hand Lens Imager, or MAHLI, instrument at the end of its robotic arm to snap the images on Jan. 19, 2016, during the 1,228th Martian day, or sol, of its work on Mars. (A Mars solar day has a mean period of 24 hours 39 minutes 35.244 seconds.)

This is the sixth such self portrait for Curiosity. But as luck would have it, I had never seen one of these before. So for me, this was a totally fresh perspective.

My second reaction (after, “A rippled dune on Mars! I want to go!) was puzzlement: How did the rover produce a stand-off selfie like this without its robotic arm getting into the image? Curiosity certainly did not set up a camera on a tripod, hit the self-timer button, and then back up for the portrait.

I’ll get to the answer in a minute. But first, take a close look at this beautiful image. Make sure to click on it, and then click on it again to enlarge it. Check out the stunning details, including some damage to one of the rover’s wheels — which for scale are 20 inches in diameter and about 16 inches  wide. (The wheels actually have developed punctures, tears and other signs of damage, but Curiosity manages to soldier on…) Read More

Blessed blast of moisture now streaming into California from the Pacific comes from as far away as the Philippines

By Tom Yulsman | March 5, 2016 7:18 pm
Atmospheric moisture

Animation of total precipitable water in the atmosphere March 2-5, 2016. (Source: Space Science and Engineering Center, University of Wisconsin)

As I’m writing this, rain and snow has finally arrived in California — and as the animation above shows, some of that moisture has traveled an exceedingly long distance.

As in all the way across the Pacific Ocean.

The animation shows the evolution of total precipitable water, or TPW, in the atmosphere for 72 hours between March 2 and 5. If you could convert all the water and water vapor contained in the atmosphere, from top to bottom, into the liquid phase, TPW is what you’d wind up with. The deepest reds in the animation above show TPW amounts in excess of 2.4 inches.

This is the feedstock for storms, including the one now hitting California. Read More

Enjoy some Jovian eye candy on the anniversary of Voyager 1’s closest approach to the planet on March 5, 1979

By Tom Yulsman | March 5, 2016 3:33 pm
Voyager approach

A time-lapse movie uses images taken from Jan. 6 to Feb. 3 1979 by the Voyager 1 spacecraft as it was heading toward it’s closest approach to the planet on March 5, 19979. (Source: NASA Planetary Photojournal)

It has been 37 years since the Voyager 1 spacecraft began sending back glorious, up-close imagery of Jupiter and its coterie of moons. And today, March 5th, marks the actual anniversary of the spacecraft’s closest approach to the giant gaseous planet.

So I thought I’d share this animation of images taken by the spacecraft as it was making its final approach to Jupiter. It’s known as the Voyager “Blue Movie,” because it was built from images acquired through a blue filter.

The sequence consists of 66 images taken each time Jupiter rotated once on its axis. (Each of these Jovian days lasted about 10 hours.) At the start of the approach documented in the animation, on Jan. 6, 1979, the spacecraft was 36 million miles from Jupiter. At the end of the animation it was 19 million miles away, on Feb. 3.

A little over a month later, Voyager 1 came within 128,400 miles of Jupiter during its closest approach. It finally left the Jovian system in early April, having taken almost 19,000 images. Read More

February may have been the warmest such month on record, but we don’t know for sure — despite reports to the contrary

By Tom Yulsman | March 3, 2016 8:21 pm

A cautionary tale about accuracy in science journalism, and jumping the gun on official climate reports

Earth, the planet, as seen in an animation images acquired by the Himawari-8 satellite on Feb. 18, 2016. Note Cyclone Winston swirling on the right. (Source: NOAA/RAMMB/RAMSDIS)

Portrait of a warming planet. (Animation of false-color images acquired by the Himawari-8 satellite on Feb. 18, 2016. Note Cyclone Winston swirling on the right. Source: NOAA/RAMMB/RAMSDIS)

This past February was plenty warm, and the Arctic was particularly so. In fact, measurements taken at Earth’s surface may ultimately show that last month was warmer than any previous February in records stretching back more than a hundred years.

But unlike what you may have read in recent days, we don’t really know that yet. And claims that this shows global warming has gone into overdrive are overblown.

Source: Roy Spencer/University of Alabama

Source: Roy Spencer/University of Alabama

True, February apparently was the warmest such month ever in the satellite record. (See thumbnail at right.) And as my colleague Andrew Freedman points out at Mashable, this deals a setback to people, including some presidential candidates, “who frequently cite the satellite record of atmospheric temperatures as evidence that human-caused global warming either doesn’t exist or is far smaller than scientists claim.”

But this record stretches back only to 1979. And satellites monitor temperatures up in the troposphere, not on the surface where we live.

Official analyses of data collected during February at the surface of the Earth — traditionally the scientific gold standard for measuring global warming — have not yet been completed.

That did not stop Slate from claiming in an article widely circulated on social media that surface warming in February broke all records, showing that “global warming is going into overdrive.”

Maybe. But maybe not. Read More

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ImaGeo

ImaGeo is a visual blog focusing on the intersection of imagery, imagination and Earth. It focuses on spectacular visuals related to the science of our planet, with an emphasis (although not an exclusive one) on the unfolding Anthropocene Epoch.
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