Antarctic Ice Discussion

[Tasboy]

12 August 2015 - first below average net sea ice extent (based on 1981-2010 climatology) since Dec 2012.

[Gray-Wolf]

I see it Tas??? over 200,000km below 'average' now???

 

With PDO giving a return to stronger positive values are we see the results of the 'tweaks' this places on teleconnections ( along with the I.P.O.) or is it just Nino impacts?

 

EDIT: Crandles over on the sea ice forum gives us a gain  of less than 7.5km/day for the past 31 days!!!!!

 

Mid winter Growth????

Edited August 14, 2015 by Gray-Wolf

[stewfox]

I notice that there is a tendency for this to be called a blip in the Antarctic and a trend in the Arctic. I assume it's those damn Polar asymmetric responses at work again

 

To be fair last week it was the wind that causes all the issues for these record extents. Has the wind now changed direction or is it just changes in the weather that causes theses recent declines ?

[Woollymummy]

Some data on energy generation in Australia, in case anyone is interested.

I have no idea on the validity of the data, I just found it on the internet.

http://reneweconomy.com.au/nem-watch

[Tasboy]

At this time of the year it's quite unusual for sea ice extent to swap from being above average to below average, based on historical data.

 

And yes, it certainly has a lot to do with the wind stewfox.

In general, in the Northern Hemisphere you would find:

Wind blows from the south = nice to be in a beer garden.

Wind blows from the north = nice to be beside a fire with a pint.

That wind has a lot to answer for!

 

Standing by for the chocolate cake

Some data on energy generation in Australia, in case anyone is interested.

I have no idea on the validity of the data, I just found it on the internet.

http://reneweconomy.com.au/nem-watch

 

Interesting, but not really part of this discussion?

[Woollymummy]

 

Interesting, but not really part of this discussion?

Tasboy, I was directly replying to posts #1465 and #1466, as there was a quibble about data between GW and MIA, I thought to save them the bother and to allow a better discussion I would try and find some information 😠- whether or not the emissions from Oz would affect Antarctic ice directly is another matter.

[Tasboy]

Tasboy, I was directly replying to posts #1465 and #1466, as there was a quibble about data between GW and MIA, I thought to save them the bother and to allow a better discussion I would try and find some information - whether or not the emissions from Oz would affect Antarctic ice directly is another matter.

Cool.

Being from Oz myself – albeit one of the states that use less coal than most – I’m embarrassed by our poor environmental record. I was at a conference recently where research was presented that showed coal and uranium dust in Antarctic ice core samples (glacial ice, not sea ice).

 

I sat there and cringed!

[Styx]

^ I second that.

[knocker]

Century-scale simulations of the response of the West Antarctic Ice Sheet to a warming climate

 

Abstract. We use the BISICLES adaptive mesh ice sheet model to carry out one, two, and three century simulations of the fast-flowing ice streams of the West Antarctic Ice Sheet, deploying sub-kilometer resolution around the grounding line since coarser resolution results in substantial underestimation of the response. Each of the simulations begins with a geometry and velocity close to present-day observations, and evolves according to variation in meteoric ice accumulation rates and oceanic ice shelf melt rates. Future changes in accumulation and melt rates range from no change, through anomalies computed by atmosphere and ocean models driven by the E1 and A1B emissions scenarios, to spatially uniform melt rate anomalies that remove most of the ice shelves over a few centuries. We find that variation in the resulting ice dynamics is dominated by the choice of initial conditions and ice shelf melt rate and mesh resolution, although ice accumulation affects the net change in volume above flotation to a similar degree. Given sufficient melt rates, we compute grounding line retreat over hundreds of kilometers in every major ice stream, but the ocean models do not predict such melt rates outside of the Amundsen Sea Embayment until after 2100. Within the Amundsen Sea Embayment the largest single source of variability is the onset of sustained retreat in Thwaites Glacier, which can triple the rate of eustatic sea level rise.

 

Open access

 

http://www.the-cryosphere.net/9/1579/2015/tc-9-1579-2015.html

 

Public Release: 18-Aug-2015

Most comprehensive projections for West Antarctica's future revealed

European Geosciences Union

 

http://www.eurekalert.org/pub_releases/2015-08/egu-mcp081315.php

[knocker]

How El Nino is impacting the sea ice.

 

What’s going on? As we’ve found with past trends and seasonal variability², it’s the winds that are driving the pattern of sea ice departures from normal. What’s different this year is that we have an El Niño in the tropical Pacific, and El Niño events drive changes in the winds all the way to the Antarctic coast, causing strong cold southerlies near the Peninsula (where we are seeing more ice than normal) and warm northerlies over the Ross Sea (where we’re seeing less ice than normal). A classic El Niño response pattern is developing outside the Tropics³, with a big high over the central south Pacific (Figure 4). This brings the anomalous northerlies to the west and the anomalous southerlies to the east.

 

http://hot-topic.co.nz/antarctic-sea-ice-the-end-of-the-trend/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+co%2FRbRF+%28Hot+Topic%29

 

Figure 4: Southern Hemisphere circulation difference from normal, averaged over 1-14 August 2015. Red contours show higher than normal pressures, blue show lower than normal, and black is zero difference from normal. The arrows show the sense of the wind differences from normal, warm northerlies towards the Ross Sea region, cold southerlies closer to the Antarctic Peninsula. Data obtained from the NCEP/NCAR reanalysis.

 

[BornFromTheVoid]

6th lowest on record now on CT http://arctic.atmos.uiuc.edu/cryosphere/antarctic.sea.ice.interactive.html

 

A new trend or just a blip? I think the last time Arctic sea ice was 6th highest for any date was 2003

[knocker]

6th lowest on record now on CT http://arctic.atmos.uiuc.edu/cryosphere/antarctic.sea.ice.interactive.html

 

A new trend or just a blip? I think the last time Arctic sea ice was 6th highest for any date was 2003

 

Pretty amazing stuff. If this is down to El Nino a couple of observations. The 1997 event didn't have a similar impact and it suggests more credence to the upward trend (beginning around the same time as the discovery of the Ozone hole) being down to the vortex and wind anomaly.

Edited August 21, 2015 by knocker

[Relativistic]

Pretty amazing stuff. If this is down to El Nino a couple of observations. The 1997 event didn't have a similar impact and it suggests more credence to the upward trend (beginning around the same time as the discovery of the Ozone hole) being down to the vortex and wind anomaly.

The ozone hole was still pretty large back then though, with ozone concentations still very low. Surely it would have had some impact on the ice extent? Both 1997 and 1998 saw no sudden changes in ice growth like 2015 has.

This has got me thinking. 2006 saw the largest Antarctic ozone hole on record. Would we not expect then that the wind anomalies would have been strongest in 2006, with the consequence that the ice extent would have reached its highest on record? Why the sudden burst of record high years recently (barring 2015) when the ozone hole is said to be starting its slow recovery?

Are we seeing lower SSTs now around Antarctica due to the increased ice extent from previous years, allowing sea ice to expand more readily? That's all I can come up with.

(If any of the facts I have given above are incorrect then please point it out.)

Edited August 22, 2015 by 22nov10blast

[BornFromTheVoid]

The ozone hole was still pretty large back then though, with ozone concentations still very low. Surely it would have had some impact on the ice extent? Both 1997 and 1998 saw no sudden changes in ice growth like 2015 has.

This has got me thinking. 2006 saw the largest Antarctic ozone hole on record. Would we not expect then that the wind anomalies would have been strongest in 2006, with the consequence that the ice extent would have reached its highest on record? Why the sudden burst of record high years recently (barring 2015) when the ozone hole is said to be starting its slow recovery?

Are we seeing lower SSTs now around Antarctica due to the increased ice extent from previous years, allowing sea ice to expand more readily? That's all I can come up with.

(If any of the facts I have given above are incorrect then please point it out.)

 

I guess like anything weather related, there are loads of factors having an influence at once. The winds are considered just part of the sea ice growth, and even the winds themselves will have numerous different influences upon them, the ozone hole being just one.

So the record large ozone hole 2006 increases the chances strong circumpolar winds, but doesn't guarantee it. And even if the winds did increase, other factors would still have to play along to allow notable sea ice growth.

 

The winds that blow the sea ice north there would also send the colder surface waters north too, might be part of the SST situation? There has been an awful lot of cold down air there in recent months too. All very interesting anyway!

 

[knocker]

Ah I was just going to reply but I see Born has already done so. Just to add that although pressure distributions in certain parts of the world during El Ninos are well understood it is very unlikely that the 2015 pattern (as seen above) would be replicated exactly in 1997. Even slight changes in the position of the anticyclones and low pressure areas would impact the wind field and would affect the ice differently. Thus caution is advisable when comparing the two.

[Relativistic]

Cheers for the informative replies, really fascinating stuff.

:)

Edited August 22, 2015 by 22nov10blast

[BornFromTheVoid]

An AMA today that might interest a few. https://www.reddit.com/r/science/comments/3hylyw/science_ama_series_we_are_living_in_concordia/

 

 

Science AMA Series: We are living in Concordia station, Antarctica, researching glaciology, climate and physiology. We haven’t seen the Sun for 4 months and 4 months to go before fresh supplies are flown in. The temperature outside is –67.8°C. AMA!

 

We are based at the French-Italian research station Concordia on the east high Antarctic plateau (75°S, 123°E, 3233m). It is one of the remotest, coldest, driest places on Earth, we are 1200 km from the coast and our nearest neighbour is 600 km away: the Russian station Vostok. The landscape is an immense white, flat surface of compacted snow extending 1000 km in all directions. The snow and ice on which we walk is more than 3 km thick. Living here is like living on another planet, ‘Planet Concordia’ or ‘White Mars’. During the nine months of winter from February to November, the station is completely isolated from the rest of the world. No plane or vehicle can reach us, even in an emergency as the harsh weather conditions make all travel impossible. We have experienced temperatures down to –80°C and three months of complete darkness. The multicultural crew is consists of 13 people: seven for logistics and six scientists. We are five Italians, one Swiss, one English and six French. This year we are three women and ten men from 24 to 56 years old. We must rely on our own skills and teamwork while being prepared to face any kind of emergency through training, fire, rescue and medical exercises. Antarctica is the largest, most extreme, multi-disciplinary, open-air scientific laboratory that helps us understand the mechanisms that regulate our planet, its climate, its history and offers a platform to observe and understand the structure of the universe, as well as charting the adaptation of humans to harsh environments. Thanks to the Antarctic Treaty, nations worldwide collaborate peacefully with respect for this environment in the name of science. We are one of very few stations at the heart of the Antarctic continent, so Concordia stands as an important node in the Earth Observatory Grid, for fields such as meteorology, seismology, geomagnetism and atmospheric chemistry. Lorenzo Moggio: 30 years old, Italian physicist, research fellow at the Bologna Institute of Atmospheric Sciences and Climate of the Italian National Research Council. This is my second winter spent at Concordia, I was here in 2010 as well.

Giampietro Casasanta: 35 years old, Italian physicist with a PhD in Remote Sensing and research fellow at the Rome Bologna Institute of Atmospheric Sciences and Climate of the Italian National Research Council. I am in charge of the Italian glaciology and remote sensing experiments.

Our tasks are to maintain and assure the scientific instruments work, retrieve the data run a first analysis and send it to Europe on a daily basis. We measure radiative balances at Earth’s surface, Meterological variables, optical and physical properties of aerosols, properties of clouds. We have at our disposal broadband and spectral radiometers in the shortwave, longwave and ultraviolet part of the electromagnetic spectrum, particle counters and sizers, lidar, sodar, sonic anemometers, automatic weather stations and sounding stations equipped with: barometers, anemometers, thermo-hygrometers, GPS and radio transmitters/receivers. Beth Healey: British medical doctor. I am running studies for the European Space Agency on the crew and myself to see how we adapt to living in this extreme environment. Our nine-month isolation living completely cut off from the world with low air pressure is similar in many ways to the stress astronauts will endure during a long spaceflight. I am running experiments on morale, eyesight, blood pressure and even searching for new life! http://www.esa.int/concordia[1] We will be back at 1pm ET to answer your questions, Ask Us Anything about life here and the science we do!

[stewfox]

6th lowest on record now on CT http://arctic.atmos.uiuc.edu/cryosphere/antarctic.sea.ice.interactive.html

 

A new trend or just a blip? I think the last time Arctic sea ice was 6th highest for any date was 2003

 

Its just the weather , we are seeing a up rise as well now as NSIDC predicted.

[BornFromTheVoid]

Its just the weather , we are seeing a up rise as well now as NSIDC predicted.

 

I agree it's just weather, for now. Were the records in recent years weather too?

 

They claimed it could increase, but that was weeks ago. Since then, the area has dropped and extent has flat lined.

In fact, the latest data shows it as 4th lowest now. Another 2 or 3 days of this and we will be lowest on record.

[knocker]

Its just the weather , we are seeing a up rise as well now as NSIDC predicted.

 

You say it's just the weather as if that makes uninteresting which is bit odd considering this is a weather/meteorological forum.

[stewfox]

I agree it's just weather, for now. Were the records in recent years weather too?

 

They claimed it could increase, but that was weeks ago. Since then, the area has dropped and extent has flat lined.

In fact, the latest data shows it as 4th lowest now. Another 2 or 3 days of this and we will be lowest on record.

 

Its interesting for sure running around 5% below average , given all the recent years and the records broken.

 

Lets see what happens in the next few weeks.

[stewfox]

I agree it's just weather, for now. Were the records in recent years weather too?

 

They claimed it could increase, but that was weeks ago. Since then, the area has dropped and extent has flat lined.

In fact, the latest data shows it as 4th lowest now. Another 2 or 3 days of this and we will be lowest on record.

 

Deleted

Edited August 23, 2015 by stewfox

[BornFromTheVoid]

We have seen another large increase today and given the cooler then average water around the periphery and suppressed temperatures I'm still going with the NSIDC predicted.

 

Hope casting for record lows needs to be based on some form of evidence, i don't see it.

 

 

https://ads.nipr.ac.jp/vishop/vishop-extent.html?S

 

EDIT:CT area is now 2nd lowest on record, and without a substantial increase tomorrow, it will be lowest on record.

http://arctic.atmos.uiuc.edu/cryosphere/antarctic.sea.ice.interactive.html

 

Edited August 23, 2015 by BornFromTheVoid

[stewfox]

I was clearly referring to area, not extent, which you know well are different metrics. Your baseless accusations of hopecasting and misrepresentation of the NSIDC, while typical for AGW "sceptics", are unnecessary.

 

EDIT: In fact, CT area is now 2nd lowest on record, and without a substantial increase tomorrow, it will be lowest on record.

http://arctic.atmos.uiuc.edu/cryosphere/antarctic.sea.ice.interactive.html

 

 

 

I apologize and have removed my post

 

You have referred to area before.

 

Regardless its certainly been interesting re whats happened down there, I fear my tag line is under threat.

Edited August 23, 2015 by stewfox

[BornFromTheVoid]

I apologize and have removed my post

 

You have referred to area before.

 

Regardless its certainly been interesting re whats happened down there, I fear my tag line is under threat.

 

Ok

 

Is your signature referring to Antarctic ice in general or sea ice?