NASA monitors the 'new normal' of sea ice

[Rob L 3,811]

Trigger alert : Climate Deniers, Nothing to see here

By Maria-José Viñas and Kate Ramsayer,
NASA's Goddard Space Flight Center

Walt Meier, a sea ice scientist at NASA’s Goddard Space Flight Center, said, “A decade ago, this year’s sea ice extent would have set a new record low and by a fair amount. Now, we’re kind of used to these low levels of sea ice – it’s the new normal.”

This year’s melt season in the Arctic Ocean and surrounding seas started with a bang, with a record low maximum extent in March and relatively rapid ice loss through May. The melt slowed down in June, however, making it highly unlikely that this year’s summertime sea ice minimum extent will set a new record.

“Even when it’s likely that we won’t have a record low, the sea ice is not showing any kind of recovery. It’s still in a continued decline over the long term,” said Walt Meier, a sea ice scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “It’s just not going to be as extreme as other years because the weather conditions in the Arctic were not as extreme as in other years.”

“A decade ago, this year’s sea ice extent would have set a new record low and by a fair amount. Now, we’re kind of used to these low levels of sea ice – it’s the new normal.”

In this animation, the daily Arctic sea ice and seasonal land cover change progress through time, from the prior sea ice maximum March 24, 2016, through Aug. 13, 2016. The Arctic sea ice cover likely won’t reach its yearly minimum extent until mid-to-late September. Credit: NASA Goddard's Scientific Visualization Studio/Cindy Starr. Download this video in HD at NASA's Scientific Visualization Studio.

This year’s sea ice cover of the Barents and Kara seas north of Russia opened up early, in April, exposing the surface ocean waters to the energy from the sun weeks ahead of schedule. By May 31, the extent of the Arctic sea ice cover was comparable to end-of-June average levels. But the Arctic weather changed in June and slowed the sea ice loss. A persistent area of low atmospheric pressure, accompanied by cloudiness, winds that dispersed ice and lower-than-average temperatures, didn’t favor melt.

The rate of ice loss picked up again during the first two weeks of August, and is now greater than average for this time of the year. A strong cyclone is moving through the Arctic, similar to one that occurred in early August 2012. Four years ago, the storm caused an accelerated loss of ice during a period when the decline in sea ice is normally slowing because the sun is setting in the Arctic. However, the current storm doesn’t appear to be as strong as the 2012 cyclone and ice conditions are less vulnerable than four years ago, Meier said.

“This year is a great case study in showing how important the weather conditions are during the summer, especially in June and July, when you have 24 hours of sunlight and the sun is high in the sky in the Arctic,” Meier said. “If you get the right atmospheric conditions during those two months, they can really accelerate the ice loss. If you don’t, they can slow down any melting momentum you had. So our predictive ability in May of the September minimum is limited, because the sea ice cover is so sensitive to the early-to-mid-summer atmospheric conditions, and you can’t foresee summer weather.”

Arctic sea ice has varied terrain in the summer months, as ridges and melt ponds form and floes break apart. A new NASA satellite called ICESat-2, launching in 2018, will measure the height of sea ice year-round. Credit: NASA/Kate Ramsayer.

As scientists are keeping an eye on the Arctic sea ice cover, NASA is also preparing for a new method to measure the thickness of sea ice – a difficult but key characteristic to track from orbit.

"We have a good handle on the sea ice area change," said Thorsten Markus, Goddard’s cryosphere lab chief. "We have very limited knowledge how thick it is."

Research vessels or submarines can measure ice thickness directly, and some airborne instruments have taken readings that can be used to calculate thickness. But satellites haven’t been able to provide a complete look at sea ice thickness in particular during melting conditions, Markus said. The radar instruments that penetrate the snow during winter to measure thickness don’t work once you add in the salty water of the melting sea ice, since the salinity interferes with the radar.

The Ice, Cloud and land Elevation Satellite-2, or ICESat-2, will use lasers to try to get more complete answers of sea ice thickness. The satellite, slated to launch by 2018, will use a laser altimeter to measure the heights of Earth’s surface.

In the Arctic, it will measure the elevation of the ice floes, compared to the water level. However, only about one-tenth of sea ice is above the water surface; the other nine-tenths lie below.

To estimate the entire thickness of the ice floe, researchers will need to go beyond the above-water height measurements, and perform calculations to account for factors like the snow on top of the ice and the densities of the frozen layers. Scientists are eager to see the measurements turned into data on sea ice thickness, Markus said.

"If we want to estimate mass changes of sea ice, or increased melting, we need the sea ice thickness," he said. "It’s critically important to understanding the changes in the Arctic."

For more information about ICESat-2, visit:

http://www.nasa.gov/icesat-2 or http://icesat-2.gsfc.nasa.gov/

For up-to-date measurements of Arctic sea ice, visit:

http://nsidc.org/arcticseaicenews/

[Voice of Reason 10,298]

Oh yea, spend billions on a satellite to measure ice thickness. Something which we have no control over. Money well spent.

[Boiler 43,392]

As a result of their westward explorations and their settlement of Greenland, the Vikings sailed as far north and west as Ellesmere Island, Skraeling Island and Ruin Island for hunting expeditions and trading with Inuit groups.[citation needed] The subsequent arrival of the Little Ice Age is thought to have been one of the reasons that European seafaring into the Northwest Passage ceased until the late 15th century.

[The Nature Boy 7,659]

Oh yea, spend billions on a satellite to measure ice thickness. Something which we have no control over. Money well spent.

is New York under water yet, lets ask AL Gore

[Voice of Reason 10,298]

In my lifetime, we have gone from "the sky is falling" to "the oceans are rising". Never been crushed by a column of air, nor has CA or FL been removed thus far.

[Dakine10 5,452]

We've been looking at property in Florida and there's already an issue in coastal areas where rainwater drainage systems that once worked are starting to see backwards flow because the ocean level is higher than the ground water table. It's intrinsic to human nature that we don't put off problems until tomorrow if we need to solve them today.

The complications inherent in Florida and other coastal areas being below sea level are not going to be any easier to solve when they are actually under water.

[Rob L 3,811]

We've been looking at property in Florida and there's already an issue in coastal areas where rainwater drainage systems that once worked are starting to see backwards flow because the ocean level is higher than the ground water table. It's intrinsic to human nature that we don't put off problems until tomorrow if we need to solve them today.

The complications inherent in Florida and other coastal areas being below sea level are not going to be any easier to solve when they are actually under water.

You obviously are hysterical and unscientific. The next mini ice age is around the corner. Purchase that waterfront property and skip the flood insurance

[Boiler 43,392]

We've been looking at property in Florida and there's already an issue in coastal areas where rainwater drainage systems that once worked are starting to see backwards flow because the ocean level is higher than the ground water table. It's intrinsic to human nature that we don't put off problems until tomorrow if we need to solve them today.

The complications inherent in Florida and other coastal areas being below sea level are not going to be any easier to solve when they are actually under water.

I remember when I first came over, there was a small town at the mouth of a canyon, now a semi arid area, but I am interested in history and looked up the history of the area, the original settlement had been wiped out by a flash flood so logically when the town was rebuilt they built up the side, away from the river.

Modern development comes along and they build alongside the scenic river.

No need to guess what happened next.

Reason there were not many cities in Florida.Not if, when.

[Dakine10 5,452]

You obviously are hysterical and unscientific. The next mini ice age is around the corner. Purchase that waterfront property and skip the flood insurance

I mowed my lawn the day before the super bowl last year because I was worried my wife would start bugging me on Sunday. If there was any skepticism left in me, having to mow the lawn in February in Denver would have cleared it all up.

[Dakine10 5,452]

I remember when I first came over, there was a small town at the mouth of a canyon, now a semi arid area, but I am interested in history and looked up the history of the area, the original settlement had been wiped out by a flash flood so logically when the town was rebuilt they built up the side, away from the river.

Modern development comes along and they build alongside the scenic river.

No need to guess what happened next.

Reason there were not many cities in Florida.Not if, when.

If the worlds population was still 200 million, it probably would be much of an issue. People would just move like they did for the previous few eons. But the earth is at 7.5 billion or so now and we'll be pushing 10 billion in about 40 years. It's not something that we can run and hide from.

[Boiler 43,392]

Build in flood areas and do not be surprised if it .... floods.

[Boiler 43,392]

I mowed my lawn the day before the super bowl last year because I was worried my wife would start bugging me on Sunday. If there was any skepticism left in me, having to mow the lawn in February in Denver would have cleared it all up.

I drove back from Denver that Saturday, never made it down the drive, stuck in a snow drift, plow came by Sunday morning, it also got stuck, no mowing.

[Dakine10 5,452]

Build in flood areas and do not be surprised if it .... floods.

I suppose being a hardass may lead to being technically correct, but otherwise not really that helpful. Cities like Tampa are only 3-4 feet above sea level. I have a hard time thinking that telling them they should have thought about all that 200 years ago is the best solution the human brain can come up with.

[Boiler 43,392]

I suppose being a hardass may lead to being technically correct, but otherwise not really that helpful. Cities like Tampa are only 3-4 feet above sea level. I have a hard time thinking that telling them they should have thought about all that 200 years ago is the best solution the human brain can come up with.

We could go the Canute route I suppose.

[Dakine10 5,452]

I drove back from Denver that Saturday, never made it down the drive, stuck in a snow drift, plow came by Sunday morning, it also got stuck, no mowing.

That's what happens when you live on a mountain. We were at 50 degrees that Saturday. I think we hit 60 for the superbowl parade and then 70 the next week.