Support the Arctic Sea Ice Forum and Blog

Author Topic: Southern Ocean Cold Spots  (Read 16992 times)

AbruptSLR

  • Multi-year ice
  • Posts: 17691
    • View Profile
  • Liked: 884
  • Likes Given: 242
Southern Ocean Cold Spots
« on: May 20, 2016, 11:10:40 PM »
I am starting this thread with the attached CCI-Reanalyzer SH 5-day SAT Anom forecast issued May 20 2016 as it clearly indicates that the: Ronne-Flichner, the Ross, and the Amery, ice shelves are already making significant ice meltwater contributions to the Southern Ocean without making any contribution to SLR.  This ice shelf meltwater is already clearly contributing to the Hansen's ice-climate feedback and is suppressing the measures Surface Air Temperatures (SAT) in the Southern Hemisphere (SH):
« Last Edit: May 21, 2016, 11:40:16 AM by AbruptSLR »
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

Sigmetnow

  • Multi-year ice
  • Posts: 15889
    • View Profile
  • Liked: 500
  • Likes Given: 233
Re: Southern Ocean Cold Spots
« Reply #1 on: May 20, 2016, 11:21:23 PM »
I am starting this thread with the attached CCI-Reanalyzer SH 5-day SAT Anom forecast issued May 20 2016 as it clearly indicates that the: Ronne-Flichner, the Ross, and the Avery, ice shelves are already making significant ice meltwater contributions to the Southern Ocean without making any contribution to SLR.  This ice shelf meltwater is already clearly contributing to the Hansen's ice-climate feedback and is suppressing the measures Surface Air Temperatures (SAT) in the Southern Hemisphere (SH):

A striking image, indeed.  Has this not been seen before?
People who say it cannot be done should not interrupt those who are doing it.

AbruptSLR

  • Multi-year ice
  • Posts: 17691
    • View Profile
  • Liked: 884
  • Likes Given: 242
Re: Southern Ocean Cold Spots
« Reply #2 on: May 20, 2016, 11:37:21 PM »
I am starting this thread with the attached CCI-Reanalyzer SH 5-day SAT Anom forecast issued May 20 2016 as it clearly indicates that the: Ronne-Flichner, the Ross, and the Avery, ice shelves are already making significant ice meltwater contributions to the Southern Ocean without making any contribution to SLR.  This ice shelf meltwater is already clearly contributing to the Hansen's ice-climate feedback and is suppressing the measures Surface Air Temperatures (SAT) in the Southern Hemisphere (SH):

A striking image, indeed.  Has this not been seen before?

The cold spots have been seen before but are now becoming much more pronounced (as the meltwater volume increases).

Also, I provide a link to the ACME Southern Ocean modeling (which seems to me to be missing the ice meltwater)

http://www.livescience.com/50831-incredible-antarctica-currents-image.html

See also:
http://phys.org/news/2015-06-ocean-reveals-insight-climate.html
&
http://www.lanl.gov/newsroom/picture-of-the-week/pic-week-9.php

And for a Youtube video see:


“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

AbruptSLR

  • Multi-year ice
  • Posts: 17691
    • View Profile
  • Liked: 884
  • Likes Given: 242
Re: Southern Ocean Cold Spots
« Reply #3 on: May 21, 2016, 11:29:23 AM »
For those who are wondering why large quantities of basal ice meltwater would be coming out from beneath three major Antarctic ice shelves, I provide the first image that shows the past protective circulation pattern beneath a cold ice shelf that helps to keep warm, Circumpolar Deep Water, CDW out from beneath as cold ice shelf, as indicated in this first accompanying image for the Flichner-Ronne Ice Shelf, FRIS (at the Filchner Trough, which is where the meltwater is existing from beneath the FRIS) per Hellmer et al 2012.  It appears likely that due to climate induced changes in the CDW circulation patterns, that CDW currents are now penetrating beneath portions of the FRIS, the Ross Ice Shelf, RIS, and the Amery Ice Shelf; thus abruptly increasing the amounts of basal ice melting as when these were cold ice shelves.

I am concerned that it such probable recent changes in warm CDW circulation patterns that has induced NOAA to notify the insurance industry of new information (see linked article) indicating that sea level could rise by 3m in the 2050-2060 timeframe due to instabilities in the West Antarctic Ice Sheet, WAIS:

http://www.insurancejournal.com/news/national/2016/04/12/405089.htm
 
The second attached image show a 2013 figure showing the preliminary multi-nation effort to monitor the CDW circulation pattern that was then only beginning to penetrate beneath the FRIS.  Such a monitoring program would give NOAA plenty of information on such a change in CDW circulation and associate basal ice melting.

Finally, I note that the linked 2015 research on local basal melting rates of the Ross Ice Shelf, RIS, indicates that channelized drainage water from adjoining marine glaciers can form grooves at a measured rate of over 2500% faster than the overall background basal melt rate.  Some decades in the future the presences of such basal grooves could reduce the stability of the ice shelf w.r.t. major iceberg calving and hydrofracturing, assuming continued global warming:

Oliver J. Marsh, Helen A. Fricker, Matthew R. Siegfried, Knut Christianson, Keith W. Nicholls, Hugh F. J. Corr & Ginny Catania (2015), "High basal melting forming a channel at the grounding line of Ross Ice Shelf, Antarctica", Geophysical Research Letters, DOI: 10.1002/2015GL066612

http://onlinelibrary.wiley.com/doi/10.1002/2015GL066612/full
« Last Edit: May 21, 2016, 11:40:47 AM by AbruptSLR »
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

AbruptSLR

  • Multi-year ice
  • Posts: 17691
    • View Profile
  • Liked: 884
  • Likes Given: 242
Re: Southern Ocean Cold Spots
« Reply #4 on: May 21, 2016, 11:38:48 AM »
With a hat-tip to Laurent, I re-post the following from the "What's new in Antarctica?" thread:

Big data reveals glorious animation of Antarctic bottom water
http://nci.org.au/2015/11/24/big-data-reveals-glorious-animation-of-antarctic-bottom-water/



Ice-climate feedback (ala Hansen et al 2016) in these AABW circulation patterns are likely also changing the CDW circulation patterns that are likely contributing to the recent intensification of the Southern Ocean cold spots, and also to the upwelling of warm CDW into the Bellingshausen and Amundsen Seas (thus also accelerating ice melt in these two areas in addition to the FRIS, RIS and Amery Ice Shelf)
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

AbruptSLR

  • Multi-year ice
  • Posts: 17691
    • View Profile
  • Liked: 884
  • Likes Given: 242
Re: Southern Ocean Cold Spots
« Reply #5 on: May 21, 2016, 08:26:06 PM »
I provide the following comparison between the Global, NH & SH GISS Land & Ocean temperature departure values for: (a) the 2015 Mean values, (b) the approximate force adjusted CMIP5 2016 RCP 8.5 (and 95% CL range per Steven) and (c) the Jan./Feb./March/April 2016 12-month running average GISS temp departures (from 1951-1980).  This data shows that as compared to the RCP 8.5 CMIP5 2016 average mean value the April 2016 12-month running average Global, NH running much hotter than for the SH; which supports that idea that the Southern Ocean Cold Spots are masking the true rate of increase of GMST departures.  It will be interesting to see if this trend continues through Dec 31 2016:

GISS Land & Ocean Temp Departure degrees Celsius, base period: 1951-1980

Year                             Global         NHem        SHem
2015 Mean                      0.86         1.13          0.60 
2016 RCP 8.5/CMIP5        0.85         1.05           0.65
RCP 8.5 95% CL Range (0.5–1.2)   (0.6–1.5)    (0.3–1.0)

12-mo. running ave.
April 2016:                    0.99           1.30            0.69
March 2016:                  0.96           1.27           0.66
Febr. 2016:                   0.93            1.22            0.64
Jan. 2016:                     0.89            1.16            0.62
(To convert 1951-1980 temp departures to pre-industrial add: + 0.256 Celsius)

http://data.giss.nasa.gov/gistemp/tabledata_v3/NH.Ts+dSST.txt
http://data.giss.nasa.gov/gistemp/tabledata_v3/GLB.Ts+dSST.txt
http://data.giss.nasa.gov/gistemp/tabledata_v3/SH.Ts+dSST.txt

“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

jimbenison

  • New ice
  • Posts: 13
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: Southern Ocean Cold Spots
« Reply #6 on: May 21, 2016, 11:32:15 PM »
That link to the insurancejournal article was particularly disturbing. But unfortunately it may be worse than changing circulation and your typical "new field data".

In a discussion that ironically tries to downplay new predictions of greatly accelerated sea level rise, Margaret Davidson, the NOAA executive that presented the preliminary findings, had this to say:

Quote
current work re cryosphere and mass water balance which is a more recent area of science work

and reports regarding current field observations as mentioned and discussed by experts at various scientific mtgs in presentation rooms and corridors within past 6 months

WA deteriorating rapidly...
portions of shelf are now ungrounded with a lens of water underneath like greenland but different

https://climatecrocks.com/2016/04/21/caution-new-sea-level-story-may-be-a-step-too-far/

The part that should put the fear of god in you (even if you're an athiest):

Quote
portions of shelf are now ungrounded with a lens of water underneath

So while it appears that some of the numbers are still speculative, the disintegration of WA has begun.

Rather than a catastrophic possibility, destabilization of the WAIS looks to be a forgone conclusion.

AbruptSLR

  • Multi-year ice
  • Posts: 17691
    • View Profile
  • Liked: 884
  • Likes Given: 242
Re: Southern Ocean Cold Spots
« Reply #7 on: May 22, 2016, 06:20:12 PM »
That link to the insurancejournal article was particularly disturbing. But unfortunately it may be worse than changing circulation and your typical "new field data".

In a discussion that ironically tries to downplay new predictions of greatly accelerated sea level rise, Margaret Davidson, the NOAA executive that presented the preliminary findings, had this to say:

Quote
current work re cryosphere and mass water balance which is a more recent area of science work

and reports regarding current field observations as mentioned and discussed by experts at various scientific mtgs in presentation rooms and corridors within past 6 months

WA deteriorating rapidly...
portions of shelf are now ungrounded with a lens of water underneath like greenland but different

https://climatecrocks.com/2016/04/21/caution-new-sea-level-story-may-be-a-step-too-far/

The part that should put the fear of god in you (even if you're an athiest):

Quote
portions of shelf are now ungrounded with a lens of water underneath

So while it appears that some of the numbers are still speculative, the disintegration of WA has begun.

Rather than a catastrophic possibility, destabilization of the WAIS looks to be a forgone conclusion.

jimbensison,

Thank you for the helpful links.

While I know that the CCI-Reanalyzer 5-day SH Surface Temp Anom forecasts do not definitively define the cold spots, they do provide valuable data to identify trends, therefore I provide the attached image issued May 22 2016 (that can be compared with earlier such images).
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

AbruptSLR

  • Multi-year ice
  • Posts: 17691
    • View Profile
  • Liked: 884
  • Likes Given: 242
Re: Southern Ocean Cold Spots
« Reply #8 on: May 22, 2016, 08:54:30 PM »
For what is worth, Steven provided that the force corrected 2016 RCP 8.5/CMIP5 land only values (baselined to 1951-1980) are about: 1.21C (with a 95% CL range of 0.7 to 1.7C)

While the following NOAA 12-month running Average GLOBAL Land Temp Anom in degrees Celsius with a base period of 1901-2000, indicate that thru April the 12-month running average (of 1.5179C) is already well above the force corrected RCP 8.5/CMIP5 projected mean value of 1.21C.  It will be interesting to watch the trends develop through the end of 2016:
Year   Jan    Feb    Mar    Apr     
'16       
run 1.3474 1.3968 1.4592 1.5179
ave       

However, Steven also provided that the force corrected 2016 RCP 8.5/CMIP5 land and ocean values (baselined to 1951-1980) are about 0.85C (with a 95% CL range of 0.5–1.2C)
While the following NASA 12-month Average Global Land and Ocean Anom in degrees Celsius with a base period of 1951-1980, indicate that thru April the 12-month running average (of 0.99C) is much closer to the force corrected RCP8.5/CMIP5 projected mean value of 0.85C.  Again it will be interesting to see whether the Land Temp Anom accelerates away from the Land & Ocean Temp Anom by the end of 2016; which might confirm that cold spots in both the North Atlantic, and the Southern, Oceans are suppressing the GMST departures from those projected by RCP 8.5/CMIP5:

GLOBAL Land and Ocean Temp Anom in degrees Celsius base period: 1951-1980
Year      Jan   Feb   Mar  Apr   
2016     1.11 1.33 1.29 1.11   
12-mo.       
running: 0.89 0.93 0.96 0.99
average                 
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

theoldinsane

  • New ice
  • Posts: 66
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: Southern Ocean Cold Spots
« Reply #9 on: May 22, 2016, 09:56:05 PM »
For what is worth, Steven provided that the force corrected 2016 RCP 8.5/CMIP5 land only values (baselined to 1951-1980) are about: 1.21C (with a 95% CL range of 0.7 to 1.7C)

While the following NOAA 12-month running Average GLOBAL Land Temp Anom in degrees Celsius with a base period of 1901-2000, indicate that thru April the 12-month running average (of 1.5179C) is already well above the force corrected RCP 8.5/CMIP5 projected mean value of 1.21C.  It will be interesting to watch the trends develop through the end of 2016:
Year   Jan    Feb    Mar    Apr     
'16       
run 1.3474 1.3968 1.4592 1.5179
ave       

However, Steven also provided that the force corrected 2016 RCP 8.5/CMIP5 land and ocean values (baselined to 1951-1980) are about 0.85C (with a 95% CL range of 0.5–1.2C)
While the following NASA 12-month Average Global Land and Ocean Anom in degrees Celsius with a base period of 1951-1980, indicate that thru April the 12-month running average (of 0.99C) is much closer to the force corrected RCP8.5/CMIP5 projected mean value of 0.85C.  Again it will be interesting to see whether the Land Temp Anom accelerates away from the Land & Ocean Temp Anom by the end of 2016; which might confirm that cold spots in both the North Atlantic, and the Southern, Oceans are suppressing the GMST departures from those projected by RCP 8.5/CMIP5:

GLOBAL Land and Ocean Temp Anom in degrees Celsius base period: 1951-1980
Year      Jan   Feb   Mar  Apr   
2016     1.11 1.33 1.29 1.11   
12-mo.       
running: 0.89 0.93 0.96 0.99
average               


We have cold spots AND hot spots in the oceans. And the land temperature is rising faster that the oceans. To me it implies superstorms beyond Hansens predictions. But I hope I have missed something?


AbruptSLR

  • Multi-year ice
  • Posts: 17691
    • View Profile
  • Liked: 884
  • Likes Given: 242
Re: Southern Ocean Cold Spots
« Reply #10 on: May 22, 2016, 11:29:35 PM »
We have cold spots AND hot spots in the oceans. And the land temperature is rising faster that the oceans. To me it implies superstorms beyond Hansens predictions. But I hope I have missed something?

theoldinsane,

Of course you are correct that I have (for the sake of brevity) grossly over-simplified the why's, and what's, associated with the identified trend that measured land temp anom's are accelerating faster away from model projections than are the measured land & ocean temp anom's.  Also, you are correct that currently there are many hot spots in most of the worlds oceans as indicated both by the very positive PDO and by the extremely high SSTA's in the Indian Ocean; and I concur that this fact likely means that Hansen et al (2016)'s projections may likely err-on-the-side-of-least-drama, ESLD, for reasons including:

1. The ocean heat content may be upwelling more previously sequestered (during the faux hiatus) heat than Hansen et al's privately-financed model forecast (& I note that almost all CMIP5 models also underestimate such upwell).  Such higher upwelling not only results in more hot spots but also conveys more ocean heat to the grounding-line of Greenland and Antarctic marine glaciers (and associated ice shelves), which amplifies ice meltwater and the associated cold spots in the North Atlantic, and Southern, Oceans.

2. Hansen et al model assumes that ECS is about 3C, while ECS is likely higher (which would impact land temp anoms more than the land & ocean temp anoms because of ocean thermal inertia); which would imply that Hansen et al (2016) ESLD w.r.t. projections.

3.  The changing of ocean currents in both the North Atlantic, and Southern, Oceans may likely be occurring sooner than assumed by Hansen et al (and essentially all other climate scientists) for reasons, including their model(s): (a) underestimate the importance of the ozone hole over Antarctica and the damage to the ice that the associate increase in westerly winds have caused; (b) underestimated the importance of the ENSO cycle on Antarctic currents, weather trends and associated ice melting; (c) RCP 8.5 95% CL may likely underestimated the forcing associated with increased atmospheric methane concentrations (due largely to increase agricultural and fracking operations) and aerosol concentration reductions (due to reductions in coal-fired power plants around the world); and (d) marine glacial ice may be more sensitive to collapse/melting than assumed by Hansen et al 2016 (and consequently essentially all other climate scientists).

4. Otherwise, slower (than ECS) positive feedback mechanisms are being activated faster than Hansen et al (and consequently faster than essentially all other climate scientists) w.r.t. to such considerations as: (a) Arctic Amplification (including snow cover and ASIE); and (b) carbon feedback sensitivity to the ENSO cycle (including wildfires and damage to the tropical rainforests).

Sometimes, I tend to oversimplify, but that doesn't mean that I don't appreciate that Hansen et al (2016) may be ESLD as I have pointed-out in other threads (both in the Science, and Consequences, folders)

Best regards,
ASLR
« Last Edit: May 22, 2016, 11:36:26 PM by AbruptSLR »
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

theoldinsane

  • New ice
  • Posts: 66
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: Southern Ocean Cold Spots
« Reply #11 on: May 23, 2016, 07:21:53 AM »
Thank you very much for your answer. It seems to me that the only one who don't ESLD is Gaia himself.

AbruptSLR

  • Multi-year ice
  • Posts: 17691
    • View Profile
  • Liked: 884
  • Likes Given: 242
Re: Southern Ocean Cold Spots
« Reply #12 on: May 23, 2016, 09:06:02 AM »
Thank you very much for your answer. It seems to me that the only one who don't ESLD is Gaia himself.

First, I appreciate your point about Gaia as conveyed in the first attached image (with Rush Limbaugh interviewing a female version of Gaia).


Second, the linked Aquarius satellite data provides the second attached image of the sea surface density for April 2015, indicating how fresh both the North Atlantic and the Southern Ocean are becoming relative to the other oceans of the world; which is a clear sign that the Hansen et al (2016) ice-climate feedback mechanism has already begun (sooner than Hansen postulated):

http://aquarius.umaine.edu/cgi/gal_density.htm
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

theoldinsane

  • New ice
  • Posts: 66
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: Southern Ocean Cold Spots
« Reply #13 on: May 23, 2016, 10:36:09 AM »
Thank you very much for your answer. It seems to me that the only one who don't ESLD is Gaia himself.

First, I appreciate your point about Gaia as conveyed in the first attached image (with Rush Limbaugh interviewing a female version of Gaia).


Second, the linked Aquarius satellite data provides the second attached image of the sea surface density for April 2015, indicating how fresh both the North Atlantic and the Southern Ocean are becoming relative to the other oceans of the world; which is a clear sign that the Hansen et al (2016) ice-climate feedback mechanism has already begun (sooner than Hansen postulated):

http://aquarius.umaine.edu/cgi/gal_density.htm

Yes, one of the best cartoons of it´s kind IMO.

About the salinity. I think the anomalies over time are important for determine the development of the fresh water lenses but I can not find any anomaly map or graph in your link. Am I to lazy or isn't there any?

Otherwise an informative homepage with a short introduction movie for newbies. I am still learning...

http://aquarius.umaine.edu/cgi/overview.htm

AbruptSLR

  • Multi-year ice
  • Posts: 17691
    • View Profile
  • Liked: 884
  • Likes Given: 242
Re: Southern Ocean Cold Spots
« Reply #14 on: May 23, 2016, 10:58:19 AM »
About the salinity. I think the anomalies over time are important for determine the development of the fresh water lenses but I can not find any anomaly map or graph in your link. Am I to lazy or isn't there any?

I have not found any anomaly maps either, but links to other relevant pages on the Aquarius website include:


http://aquarius.umaine.edu/cgi/gal_latitudes_sss.htm

http://aquarius.umaine.edu/cgi/gal_salinity.htm

“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

Blaine

  • New ice
  • Posts: 7
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: Southern Ocean Cold Spots
« Reply #15 on: May 24, 2016, 05:04:07 AM »
@AbruptSLR:
That's a beautiful shot of a very stong Antarctic Circumpolar 3-Wave in the usual phase, with almost no other noise.
Quote
This ice shelf meltwater is already clearly contributing to the Hansen's ice-climate feedback and is suppressing the measures Surface Air Temperatures (SAT) in the Southern Hemisphere (SH).
I remember thinking that when I first noticed it, but, no, it's been there more often than not for decades, and we've had plenty of time to measure both ice disappearance rates and deeper water temperatures. This phenomenon mostly has to do with the rate of wind-driven advection of warm water from beyond the continental shelf onto the shelf, although that may be just the reinforcement mechanism and not the driving mechanism.  The intermediate water temperature is in the same phase as the surface water temperature, which is the opposite of the mostly 0-wave (same regardless of longitude) salinity-driven phenomenon.  In the phase shown, we get slight ice accumulation in both large ice shelves and very fast melting of the Amundsen Sea glaciers (Pine Island, Thwaites).  Sound familiar to anyone here?

Look at wikipedia, and it's still strictly a wavenumber 2 traveling phenomenon, but

http://link.springer.com/article/10.1007%2Fs00376-011-1143-z#page-2link
Quote
Christoph et al. (1998) found that wavenumber 3 is the dominant pattern around the Antarctic, while the wavenumber 2 pattern occurs only in ~20% of cases.  The wavenumber 3 pattern was also identified as the dominant pattern in other models (e.g., Cai et al., 1999).  By analyzing the reanalysis data for the period 1968-1999, Connolley (2003) suggested that the atmosphere and ocean around the Antarctic exist in two modes.  One is the classic ACW... characterized by a wavenumber 2 pattern and 4-year period at any location.  The other is the wavenumber 3 pattern, which shows little propagation is is more like the standing oscillation found in the coupled general circulation model.  Other analyses indicate the the ACW might have interdecadal oscillations.
I kind of wonder how much longer it's going to take the mainstream modeling community to start postdicting this change.  It's kind of getting obvious now that the prediction of uniform melting around Antarctica was a miss, isn't it?

AbruptSLR

  • Multi-year ice
  • Posts: 17691
    • View Profile
  • Liked: 884
  • Likes Given: 242
Re: Southern Ocean Cold Spots
« Reply #16 on: May 24, 2016, 05:50:56 PM »
@AbruptSLR:
That's a beautiful shot of a very stong Antarctic Circumpolar 3-Wave in the usual phase, with almost no other noise.

...

I kind of wonder how much longer it's going to take the mainstream modeling community to start postdicting this change.  It's kind of getting obvious now that the prediction of uniform melting around Antarctica was a miss, isn't it?

Blaine,
Thank you very much for your insightful/helpful observations, on the episodic, and complex, nature and  influence of ice-atmosphere interactions on the freshening/cooling of the surface waters of the Southern Ocean, both locally and throughout the Southern Ocean.

First, I am aware of (but I did not previously emphasize) the influence of wind on the 3 cool spot pattern shown in the ICC Reanalyser SH 5-day 2m SAT departure forecast images, as indicated by the following link from Steven in the "Global Surface Air Temperatures" thread which shows the katabatic winds over Antarctica on May 22 2016, that were contributing to the 3 cool (2m air) spots over the Southern Ocean:
https://earth.nullschool.net/#2016/05/22/1800Z/wind/surface/level/orthographic=-360,-90,300

While you clearly seem to be well informed about what is going on in the Southern Ocean (with regard to ice-climate interaction as discussed by Hansen et al 2016, and associated modeling efforts and/or lack of effort); I suspect that I have confused some/many readers about what I am trying to convey by the name "Southern Ocean Cold Spots", as I am indeed trying to say that while the cooling is concentrated in several locations (both by wind and by ice melting), the localized cool effect somewhat rapidly distributed by both the thermohaline circulation (see the first attached image that shows that the wind-driven cooling of the AABW is concentrated near the FRIS, RIS and Amery Ice Shelves) and by surface currents and vortices for the surface meltwaters (see the second attached Jan 1 2012 image of Southern Ocean surface elevation anom patterns which are driven by steric [thermal and salinity] patterns).

In this regards, I provide the third attached image of the CCI Reanalyzer SH 5-day SAT departure forecast issued May 24 2016, showing that the Amery and FRIS cold spots are weaker than earlier this week while the RIS/ASE cold spot is more pronounced.  Which emphasizes the wind-dominated nature of these SAT departure cold spots.

The fourth attached image, shows the Nullschool SH SSTA and Ocean Current Map for May 22 2016, where the ice cover masks the SAT departure cold spots (shown by the recent CCI Reanalyzer images), but clearly shows the anomalously cold average nature of the entire surface of the Southern Ocean (which now varies seasonally with the oceans) and which (together with the increased sea ice extent) reduces the radiation of Outgoing Longwave Radiation, OLR, to space as identified by portions of Hansen's ice-climate feedback.

Most readers are likely only interested in these complex ocean-atmosphere-ice interactions/pattern because of their possible implications to what Margaret Davidson, the NOAA executive (and non-scientist) that presented the Antarctic preliminary findings to the insurance industry, had this to say about recent changes to these patterns identified by field observations in the past 6-months, e.g.:
"current work re cryosphere and mass water balance which is a more recent area of science work

and reports regarding current field observations as mentioned and discussed by experts at various scientific mtgs in presentation rooms and corridors within past 6 months

WA deteriorating rapidly...
portions of shelf are now ungrounded with a lens of water underneath like greenland but different."

As I am limited to four attached images per post, I will address the topic of changes to the "lens of water" (or subglacial cavities) in subsequent posts in this thread.
Best,
ASLR
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

AbruptSLR

  • Multi-year ice
  • Posts: 17691
    • View Profile
  • Liked: 884
  • Likes Given: 242
Re: Southern Ocean Cold Spots
« Reply #17 on: May 24, 2016, 06:29:34 PM »
This post is a follow-up to my last post, where I promised to elaborate on possible implications of recently identified changes to "lens of water" or subglacial cavities, upstream of the grounding lines of key marine glaciers in West Antarctica.

The first image shows a figure showing the location of recently active subglacial cavities in Antarctica, where "active" means that sufficient water has either entered or been discharged from the subglacial cavity to be measured by satellite altimetry since the satellite data became good enough (circa mid-1990's).  Thus these subglacial cavities naturally/normally discharge water downstream (or to the ocean) and accumulate basal glacial meltwater from upstream.  However, limited model findings indicate that with continued global warming that not only will the grounding lines migrate upstream but that these subglacial cavities will become more active, and will grow until these merge with the grounding lines (see the second attached image).

Now I note that with continued global warming the Antarctic ice shelves both cold (like FRIS, RIS and Amery) and warm (like PIIS and Thwaites) will continue to thin (due both to basal ice melting and acceleration of the ice flow velocities) which will markedly increasing their susceptibility to abrupt ice mass loss events both now and in the next few decades due to events that might increase the hydrodynamic, and hydrostatic, pressure within the sub-ice-shelf cavities.  Sources of hydrodynamic & hydrostatic pressure that could destabilize the Pine Island Ice Shelf, PIIS (or other marine glaciers with rapidly retreating grounding lines), include:

(a) Large El Nino events, could temporarily raise eustatic sea level by 6 to 8mm (due to increased rainfall over the ocean and concurrent increased drought over land) over a one or two year period, and could also induce the ABSL to direct more wind and ocean currents into the ASE,
(b) Accelerated land water mining due to increasing anthropogenic water demand;
(c) The fingerprint effect associate with ice mass loss from Greenland.  Note that several Greenland marine terminating glaciers appear to be primed for rapid grounding line retreat over the next approximately twenty years;
(d) Storm surge & storm tide could increase due to increased storm activity in the Amundsen Sea.
(e) King tide (high astronomical tides) amplitudes can increase with increasing regional sea level;
(f) Local steric sources: The Southern Ocean is freshening rapidly, resulting in regional steric SLR.
(g) Winds (such as that associate with the ABSL) and ocean currents (such as the CDW) re-directed into the ASE, which would increase ocean elevation in the embayment, and stagnation pressure beneath the PIIS, Thwaites Ice Tongue base cavity, etc.;
(h) Tsunamis have been proven to induce cracking in Antarctic ice shelves (see Walker et al. 2013, DOI: 10.1002/2013JF002742), and a large Pacific seismic event could readily direct a large tsunami into the ASE and from there into the PIIS cavity, Thwaites Ice Tongue base cavity, etc.
(i) Hydraulic connections (jokulhlaup or glacial outburst flood) of the sub-ice-shelf cavity to the pressurized basal meltwater subglacial hydrological system underneath the PIG.  The second attached image shows red dots where satellites have measured rapid changes in the ice surface elevation, which indicate a rapid movement of pressurized basal meltwater (ie. subglacial drainage events).  This image indicates that there is a significant amount of subglacial basal meltwater periodically being released from beneath the PIG into the sub-ice-shelf cavity.  Note that the build-up of hydrostatic pressure from say storm surge, or a tsunami, could serve to trigger a jokulhlaup event; so the simultaneous increase of hydrostatic, and increase of hydrodynamic, pressure is not improbable.
(j) Passing high pressure atmospheric systems, could temporarily increase the hydrostatic pressure in the sub-ice shelf cavities.
(k) Continuing eustatic SLR contributions from mountain glaciers.
(l) Local seismic activity could temporarily increase hydraulic pressure within the partially confined sub ice shelf cavities.
(m) Tidal amplification due to funnel effect within a sub-ice-shelf cavity that narrows upstream.

Next the linked Discover Magazine article about the Pine Island Bay glaciers includes a nice video of the use of ESA's SAR satellite radar interferometry use to estimate the retreat of the PIG grounding line (see third attached image and the YouTube link below).  I note that 2010-11 was a strong La Nina event, so we will need to wait & see whether the rate of grounding line retreats accelerates during the current possible 2014-15 El Nino event:

http://blogs.discovermagazine.com/imageo/2014/04/24/antarctic-glaciers-flow-faster-iceberg-drifts-toward-sea/

Quote related to the following video: "In the visualization, based on data from radar instruments on European Space Agency satellites, the Pine Island Glacier is seen where it empties into Pine Island Bay. Past what’s known as the “grounding line,” where the glacier rests on bedrock, the ice floats and is part of a giant, permanent ice shelf that fringes the coast and tends to hold back the flow of the glaciers.
In the visualization, the ice shelf can be seen flexing up and down from tidal action. And as sea water, which has become warmer at least in part from human-caused global warming, circulates under the ice, it causes the shelf to thin. With less of a buttress to hold things back, the glacier speeds up. This, in turn, causes the grounding line to retreat."

http://www.esa.int/spaceinvideos/Videos/2014/03/Pine_Island_retreat

Next, I note that other surging marine glaciers already exhibit "hydro-thermodynamic" feedback as discussed in the following linked reference (and fourth attached image).  While in this case the marine terminating glacier was in the NH and had summer icemelt that leaked to the bottom of the glacier to accelerate its motion; nevertheless, in the Antarctic which is currently too cold for significant surface melt water, the basal water in the subglacial cavities can increase due to acceleration of the ice flow, and more significantly (w.r.t. Margaret Davidson's comments to the insurance industry) tidal/barometric fluctuations can pump ocean water in and out of subglacial cavities that are located near the grounding lines.  Also, when GMST departures above pre-industrial, reach between 2 to 2.7C (which could occur as soon as 2030 to 2060), then per DeConto & Pollard 2016, surface ice melting in Antarctica could lead to hydrofracturing of such low elevation ice shelves as: PIIS, FRIS and RIS:
 
Dunse, T., Schellenberger, T., Hagen, J. O., Kääb, A., Schuler, T. V., and Reijmer, C. H.: Glacier-surge mechanisms promoted by a hydro-thermodynamic feedback to summer melt, The Cryosphere, 9, 197-215, doi:10.5194/tc-9-197-2015, 2015.

http://www.the-cryosphere.net/9/197/2015/tc-9-197-2015.html

Also see:
Per johnm33 in the Jakobshavn thread, the following link shows the local bed topology near several key marine (terminating) glaciers both in Greenland and Antarctica, indicating the close relationship between bathymetry and tides (hydrostatic pressure), bottom gradients and ice-ocean interactions (including local calving, water (fresh & brackish) lens upstream of the grounding line).   As a side note, there is growing evidence that Jakobshavn calves more frequently on high tides, so in a few decades, key WAIS marine glaciers (Thwaites, PIG, etc) may have cliff faces and may contribute to cold spots in the Southern Ocean by major calving events to produce fleets of icebergs that slowly move out from coastal areas to circulate around the Southern Ocean in great armadas (ala Hansen).
http://nholschuh.com/glaciers.html
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

AbruptSLR

  • Multi-year ice
  • Posts: 17691
    • View Profile
  • Liked: 884
  • Likes Given: 242
Re: Southern Ocean Cold Spots
« Reply #18 on: May 24, 2016, 06:47:17 PM »
As a follow-up to my last two posts, I turn to paleo evidence, and the first linked reference (and the first two associate attached images) compares paleo ice core data with a coupled climate model projections to that Southern Ocean deep convection can drive Antarctic multidecadal warming events.  The projections indicate that such convection driven warming events must be preconditioned by: (1) heat accumulation in the depth Southern Ocean (which is occurring now); (2) changes in wind and/or sea ice patterns (which are both occurring now and are have been projected in the near future); and (3) fast sea-ice-albedo feedback.

While Hansen et al (2016) projects this type of deep convective ocean behavior, most AR5/CMIP5 model projections do not; thus it is possible that in the future that: (a) initially the forecast increase in snow will fall more on sea ice than on land, where it will contribute to SLR; and (b) after a few decades of the warming event the sea ice extent will be reduced and the increased precipitation will fall more frequently as rain (rather than snow) that contributing the hydrofracturing and abrupt SLR.

J.B. Pedro, T. Martin, E. J. Steig, M. Jochum, W. Park & S.O. Rasmussen (20 February 2016), "Southern Ocean deep convection as a driver of Antarctic warming events", Geophysical Research Letters, DOI: 10.1002/2016GL067861

http://onlinelibrary.wiley.com/doi/10.1002/2016GL067861/abstract

Next, the following reference (and third attached image which shows associated/projected warming of deep ocean waters offshore of the Bellingshausen/Amundsen/Ross Seas area that will accelerate future image mass loss from these areas) considers the case of artificially introducing relatively high volumes of ice meltwater discharge from Antarctic glacial ice (see also the fourth attached image showing the observed ice meltwater discharge from Antarctic ice shelves from 1994 to 2012, indicating that this is already a substantial discharge).

C. J. Fogwill, S. J. Phipps, C. S. M. Turney & N. R. Golledge (2015), "Sensitivity of the Southern Ocean to enhanced regional Antarctic ice sheet meltwater input", Earth's Future, Volume 3, Issue 10, Pages 317–329, DOI: 10.1002/2015EF000306

http://onlinelibrary.wiley.com/doi/10.1002/2015EF000306/full

This concludes a series of three related posts, however, for more discussion on the possible implication of Southern Ocean Cold Spots, see the linked thread:
http://forum.arctic-sea-ice.net/index.php/topic,1327.0.html
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

AbruptSLR

  • Multi-year ice
  • Posts: 17691
    • View Profile
  • Liked: 884
  • Likes Given: 242
Re: Southern Ocean Cold Spots
« Reply #19 on: May 24, 2016, 08:02:11 PM »
While it may be a few decades before the relevance of the linked reference (and associated image) is clear w.r.t. to cooling of the Southern Ocean; nevertheless, the linked reference discusses field research documenting the manner in which the Ross Ice Sheet/Shelf retreated during the Holocene in a series of relatively abrupt stair-steps that periodically sent armadas of icebergs across the continental shelf, gouging furrows as they moved into the open ocean.  While this information has some relevance to projecting the potential future break-up of the existing Ross Ice Shelf; it also has a good degree of relevance to projecting the armadas of icebergs that are likely to exit out of the Amundsen Sea Embayment if/when the adjoining marine glaciers break-up (see associated image)

Yusuke Yokoyama, John B. Anderson, Masako Yamane, Lauren M. Simkins, Yosuke Miyairi, Takahiro Yamazaki, Mamito Koizumi, Hisami Suga, Kazuya Kusahara, Lindsay Prothro, Hiroyasu Hasumi, John R. Southon, and Naohiko Ohkouchi (2016), "Widespread collapse of the Ross Ice Shelf during the late Holocene", Proceedings of the National Academy of Sciences, DOI: 10.1073/pnas.1516908113


http://www.pnas.org/content/early/2016/02/09/1516908113.abstract
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

AbruptSLR

  • Multi-year ice
  • Posts: 17691
    • View Profile
  • Liked: 884
  • Likes Given: 242
Re: Southern Ocean Cold Spots
« Reply #20 on: May 26, 2016, 05:58:56 PM »
Here is a pretty picture of the CCI Reanalyzer SAT departure for today Thursday May 26 2016, clearly showing the measured (as opposed to forecast) cold spots in the Southern Ocean.
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

Laurent

  • Young ice
  • Posts: 2536
    • View Profile
  • Liked: 6
  • Likes Given: 24
Re: Southern Ocean Cold Spots
« Reply #21 on: May 26, 2016, 06:17:44 PM »
Cold ? I am seeing a very hot spot !!! the winter is coming but still there is a lot of heat up there ! Sounds the winter will be hotter in the southern hemisphere like this past winter in the high latitudes !? ;)

AbruptSLR

  • Multi-year ice
  • Posts: 17691
    • View Profile
  • Liked: 884
  • Likes Given: 242
Re: Southern Ocean Cold Spots
« Reply #22 on: May 27, 2016, 01:23:57 AM »
Cold ? I am seeing a very hot spot !!! the winter is coming but still there is a lot of heat up there ! Sounds the winter will be hotter in the southern hemisphere like this past winter in the high latitudes !? ;)

Cold spots superimposed on a global warming trend  ;)
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

Pmt111500

  • Nilas ice
  • Posts: 1886
  • Yes, I do not always bicycle
    • View Profile
  • Liked: 95
  • Likes Given: 28
Re: Southern Ocean Cold Spots
« Reply #23 on: May 27, 2016, 08:14:58 PM »
Thank you very much for your answer. It seems to me that the only one who don't ESLD is Gaia himself.

First, I appreciate your point about Gaia as conveyed in the first attached image (with Rush Limbaugh interviewing a female version of Gaia).

OT, does the lack of gender-neutral pronouns make religions always biased toward one sex? Eyrself itself and various other options could be used of natural deities maybe?

[sarc]Antarctica looks so big in Mercator how could it warm? [/sarc]
Cooling the outside by heat pump.

theoldinsane

  • New ice
  • Posts: 66
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: Southern Ocean Cold Spots
« Reply #24 on: May 27, 2016, 09:19:29 PM »
Thank you very much for your answer. It seems to me that the only one who don't ESLD is Gaia himself.

First, I appreciate your point about Gaia as conveyed in the first attached image (with Rush Limbaugh interviewing a female version of Gaia).

OT, does the lack of gender-neutral pronouns make religions always biased toward one sex? Eyrself itself and various other options could be used of natural deities maybe?

[sarc]Antarctica looks so big in Mercator how could it warm? [/sarc]

More OT

Gaia is not he or she. Gaia is....Gaia. And Gaia has developed capabilities during billions years. As a result there is humans lately (a couple of hundred years) who are trying to understand Gaia. That is not an easy task. In the same time are we humans performing a test of Gaias competence (geoengineering via release of carbondioxide) and have so far only beginning to understand Gaias response.

One surprise is the cold spots a la Hansen et al (at least to me). Much more to come...
 

AbruptSLR

  • Multi-year ice
  • Posts: 17691
    • View Profile
  • Liked: 884
  • Likes Given: 242
Re: Southern Ocean Cold Spots
« Reply #25 on: May 28, 2016, 08:21:13 PM »
The linked reference and associate following article indicates that the thermohaline circulation is slowing-down faster than models forecast.  While the current extent of slow-down is within the range of uncertainty, it is most likely that instead of being natural variability, the observed recent slow-down is most likely associate with the cold spots in both the North Atlantic, and Southern, Oceans, and if so this slowdown could accelerate abruptly if the WAIS begins to collapse beginning around 2040 (per DeConto & Pollard 2016); which would have major impacts on both the US Eastern seaboard and on Western Europe, ala Hansen et al (2016):

Hand, E. (2016). New scrutiny for a slowing Atlantic conveyor. Science, 352(6287), 751-752. doi:10.1126/science.352.6287.751

http://science.sciencemag.org/content/352/6287/751.full

See also:
https://news.mongabay.com/2016/05/scientists-concerned-slowing-atlantic-conveyor-warn-abrupt-climate-change/

Extract: "Scientists are increasingly warning of the potential that a shutdown, or even significant slowdown, of the Atlantic conveyor belt could lead to abrupt climate change, a shift in Earth’s climate that can occur within as short a timeframe as a decade but persist for decades or centuries.

Scientists in the Labrador Sea recently made the first retrieval of data from one of 53 lines moored to the sea floor and studded with instruments that have been monitoring the ocean’s circulatory system since 2014.
Held taut by submerged buoys, these moorings are arrayed from Labrador to Greenland and Scotland. In total, five research cruises are planned for this spring and summer to fetch the data the moorings are busy collecting.
The instrument array, known as the Overturning in the Subpolar North Atlantic Program (OSNAP), measures salinity, temperature, and current velocity of the surrounding water, data that is vital to understanding a set of powerful currents with far-reaching effects on the global climate. These currents are known as the Atlantic Meridional Overturning Circulation (AMOC) — or, more popularly, “the Atlantic conveyor belt” — and they have “mysteriously” slowed down over the past decade, according to Eric Hand, author of a Science article published this month.

But we’d be wise to include in our forecasts the potential for relatively sudden, possibly localized climate change induced by thermohaline shutdown, Gagosian argued. “Such a change could cool down selective areas of the globe by 3° to 5° Celsius, while simultaneously causing drought in many parts of the world.”
These abrupt changes could occur even while other regions of the globe continue to warm more gradually, Gagosian said, making it “critical to consider the economic and political ramifications of this geographically selective climate change. Specifically, the region most affected by a shutdown — the countries bordering the North Atlantic — is also one of the world’s most developed.”"
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

AbruptSLR

  • Multi-year ice
  • Posts: 17691
    • View Profile
  • Liked: 884
  • Likes Given: 242
Re: Southern Ocean Cold Spots
« Reply #26 on: June 14, 2016, 06:00:51 PM »
The linked article by Scribbler provides the attached NASA (GISS) Global Zonal Temperature Anoms for May 2016, clearly indicating that the Southern Ocean is much cooler than the global warming trend, which is probably due to a combination of the upwelling of cool deep water & surface ice meltwater:
 
https://robertscribbler.com/2016/06/13/may-marks-8th-consecutive-record-hot-month-in-nasas-global-temperature-measure/

“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

theoldinsane

  • New ice
  • Posts: 66
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: Southern Ocean Cold Spots
« Reply #27 on: June 14, 2016, 10:31:32 PM »
Slightly OT:

There is also a "cold spot" anomaly in the northern Pacific Ocean at about the same latitude as the nothern Atlantic cold spot south of Greenland. What is this about? Is it caused by El Nino or the RRR or what? I have not seen any explanation of this fenomen. Have you AbruptSLR (or someone else) an explanation?

AbruptSLR

  • Multi-year ice
  • Posts: 17691
    • View Profile
  • Liked: 884
  • Likes Given: 242
Re: Southern Ocean Cold Spots
« Reply #28 on: June 14, 2016, 11:28:45 PM »
Slightly OT:

There is also a "cold spot" anomaly in the northern Pacific Ocean at about the same latitude as the nothern Atlantic cold spot south of Greenland. What is this about? Is it caused by El Nino or the RRR or what? I have not seen any explanation of this fenomen. Have you AbruptSLR (or someone else) an explanation?

theoldinsane,

I believe the attached image shows the cold area in the northern Pacific Ocean that you are referring to.  Unfortunately, I do not have a specific answer to you except to say that it appears to me to be likely due to a combination of global warming and a multi-decadal cycle such as the Mega ENSO (which you can learn about at the thread linked below); which might mean that it is associated with the upwelling of cooler deep water due to changes in ocean circulation patterns.

http://forum.arctic-sea-ice.net/index.php/topic,1492.0.html

Best,
ASLR

See also:
http://cas.nuist.edu.cn/TeacherFiles/file/20150526/6356826228963596382609035.pdf
« Last Edit: June 14, 2016, 11:39:37 PM by AbruptSLR »
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

AbruptSLR

  • Multi-year ice
  • Posts: 17691
    • View Profile
  • Liked: 884
  • Likes Given: 242
Re: Southern Ocean Cold Spots
« Reply #29 on: June 18, 2016, 09:10:37 PM »
While, I am aware of the influence of wind on the 3 cool spot pattern shown in the attached ICC Reanalyser SH 5-day 2m SAT departure forecast issued June 18 2016, this image shows a typical pattern repeated this year which is driving anomalously cold SAT departures over the Southern Ocean, while driving anomalously warm SAT departure for the Bellingshausen Sea area.  This is a pattern clearly projected by Hansen's ice-climate feedback mechanism, and society (including scientists and policy makers) can discount this pattern at its own risk.
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

AbruptSLR

  • Multi-year ice
  • Posts: 17691
    • View Profile
  • Liked: 884
  • Likes Given: 242
Re: Southern Ocean Cold Spots
« Reply #30 on: June 21, 2016, 05:41:45 PM »
The attached plot from Karsten Haustein indicates just how atypically cold the SAT-departures is in the SH (in the top panel the blue line represents the SH and in the bottom panel the purple line does), and I note that this cold is concentrated over the Southern Ocean:

http://www.karstenhaustein.com/climate.php
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

Adam Ash

  • Frazil ice
  • Posts: 306
    • View Profile
    • The 100 metre line
  • Liked: 8
  • Likes Given: 20
Re: Southern Ocean Cold Spots
« Reply #31 on: June 22, 2016, 09:57:53 AM »
Given the present location of the ice edge around Antarctica (first image) and the direction of currents (second image) it would seem that a lot of this cold surface water could be due to run off of meltwater.  A lot of run off...?


AbruptSLR

  • Multi-year ice
  • Posts: 17691
    • View Profile
  • Liked: 884
  • Likes Given: 242
Re: Southern Ocean Cold Spots
« Reply #32 on: June 22, 2016, 06:40:35 PM »
Given the present location of the ice edge around Antarctica (first image) and the direction of currents (second image) it would seem that a lot of this cold surface water could be due to run off of meltwater.  A lot of run off...?

For what it is worth, I note that at this time of year there is no surface meltwater anywhere in Antarctica, so any meltwater contributing to cooling of the Southern Ocean at this time of year is coming from sub-glacial, sub-ice-shelf and sub-iceberg melting (due to ocean heat).

Edit: I note that anomalously high sea ice extent can reduce the emission of OLR from the Southern Ocean into space, thus leaving more warm water in the ocean to accelerate the sub-glacial, sub-ice-shelf, sub-iceberg melting.
« Last Edit: June 22, 2016, 08:48:13 PM by AbruptSLR »
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

Adam Ash

  • Frazil ice
  • Posts: 306
    • View Profile
    • The 100 metre line
  • Liked: 8
  • Likes Given: 20
Re: Southern Ocean Cold Spots
« Reply #33 on: June 23, 2016, 05:06:04 AM »
True!  -26C at Scott Base.. hopefully liquid water is only found in the bathrooms!
https://www.wunderground.com/personal-weather-station/dashboard?ID=ISCOTTBA1
 
You couldn't make this stuff up could you... ' More sea ice = warmer ocean = more melt.'  Sigh.

AbruptSLR

  • Multi-year ice
  • Posts: 17691
    • View Profile
  • Liked: 884
  • Likes Given: 242
Re: Southern Ocean Cold Spots
« Reply #34 on: July 29, 2016, 12:49:38 AM »
Antarctic winds have put us back into the 3 cool spot pattern shown in the first attached ICC Reanalyser SH 5-day 2m SAT departure forecast issued July 28 2016.  The second attached image shows that these Southern Hemisphere cool spots are serving to suppress the forecast global mean surface air temperature departures.
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

Iceismylife

  • Frazil ice
  • Posts: 281
    • View Profile
  • Liked: 1
  • Likes Given: 1
Re: Southern Ocean Cold Spots
« Reply #35 on: August 02, 2016, 03:23:29 AM »
Some musings about the cold spots.

For every 1 deg. C temp above local melting for sea water temp you loose 10m of ice a year that works out to 1 inch a day.  Where you have channels formed you have 25X the melt rate or two feet a day ice loss.  If an ice shelf is 1,000 it takes 500 days to get it to zero.  probably much sooner than that for failure.

With a 10% duty cycle it would take 14 years to go to zero on a 1,000 foot thick ice shelf.  Seven years if it fails at 50% thickness.

Just something to think about.

AbruptSLR

  • Multi-year ice
  • Posts: 17691
    • View Profile
  • Liked: 884
  • Likes Given: 242
Re: Southern Ocean Cold Spots
« Reply #36 on: August 02, 2016, 04:21:21 AM »
Some musings about the cold spots.

For every 1 deg. C temp above local melting for sea water temp you loose 10m of ice a year that works out to 1 inch a day.  Where you have channels formed you have 25X the melt rate or two feet a day ice loss.  If an ice shelf is 1,000 it takes 500 days to get it to zero.  probably much sooner than that for failure.

With a 10% duty cycle it would take 14 years to go to zero on a 1,000 foot thick ice shelf.  Seven years if it fails at 50% thickness.

Just something to think about.

The attached plot shows that for "warm" ice shelves like the Pine Island Ice Shelf, PIIS, the potential temperature near the grounding line may get as high as 1C but the associated basal meltwater is much cooler as it avects upward along the underside of the ice shelf. Many other Antarctic ice shelves are considered "cool" with much lower basal water potential temperatures.
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

Iceismylife

  • Frazil ice
  • Posts: 281
    • View Profile
  • Liked: 1
  • Likes Given: 1
Re: Southern Ocean Cold Spots
« Reply #37 on: August 02, 2016, 05:59:07 PM »
The cold plume says to me, melting and lots of it.  I may very well be wrong, but...  Cold on the surface and lots of it.  That cold came from a concentrated area under the ice.  Local high water flows rates.

The plume coming out from under Ross Ice Shelf corresponds to where it has failed in the past if my understanding is correct.

Has this circulation pattern been modeled in depth?  It appears to be new.  Up this thread a bit you said something about warmer water getting at the ice because of the pattern changing?

AbruptSLR

  • Multi-year ice
  • Posts: 17691
    • View Profile
  • Liked: 884
  • Likes Given: 242
Re: Southern Ocean Cold Spots
« Reply #38 on: August 02, 2016, 06:18:58 PM »
The cold plume says to me, melting and lots of it.  I may very well be wrong, but...  Cold on the surface and lots of it.  That cold came from a concentrated area under the ice.  Local high water flows rates.

The plume coming out from under Ross Ice Shelf corresponds to where it has failed in the past if my understanding is correct.

Has this circulation pattern been modeled in depth?  It appears to be new.  Up this thread a bit you said something about warmer water getting at the ice because of the pattern changing?

Here is a re-post from Reply #185 of the "Hazard Analysis for PIG/Thwaites ..." thread that addresses some of your issues (note that FRIS & RIS are current contributing relatively small amounts of ice meltwater from ice shelves):

The accompanying images come from the linked World Meteorological Organization's Polar Space Task Group (PSTG) reports.  The second link provides the first two images.  The first image indicates that thru 2012 most of the ice mass loss in Antarctic Ice Shelves has been concentrated in West Antarctica; which means that the associated marine glaciers are losing buttressing faster than other Antarctic marine glaciers.  The second image indicates that from 2010 to 2013 the WAIS contributed 0.45mm/yr to SLR.  The last two images come from the third link.  The third image indicates that the ice velocities for the PIG accelerated during the period when the groundling was retreating down the negative slope of the seafloor and then stabilized thru August 2015.  The fourth image shows that while the grounding line for the Thwaites Glacier has not yet reached the negative slope of the seafloor; nevertheless, its ice velocities have accelerated since 2006 as it has progressively lost buttressing from the Thwaites Ice Tongue:

http://www.wmo.int/pages/prog/sat/pstg_en.php


http://www.wmo.int/pages/prog/sat/meetings/documents/PSTG-5_Doc_06_EC-PHORS-ppt.pdf


http://www.wmo.int/pages/prog/sat/meetings/documents/PSTG-5_Doc_13-01_BScheuchl-Ice-Sheets-Final.pdf
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

sidd

  • Young ice
  • Posts: 4976
    • View Profile
  • Liked: 379
  • Likes Given: 0
Re: Southern Ocean Cold Spots
« Reply #39 on: August 02, 2016, 08:18:57 PM »
"Has this circulation pattern been modeled in depth?"

Some authors come to mind: Hellmer, Dutrieux,Sergienko. I  cannot immediately trace all the papers, but look at doi:10.1038/nature11064 and the earlier doi:10.1029/2004GL019506 by Hellmer.

AbruptSLR

  • Multi-year ice
  • Posts: 17691
    • View Profile
  • Liked: 884
  • Likes Given: 242
Re: Southern Ocean Cold Spots
« Reply #40 on: August 02, 2016, 10:38:56 PM »
"Has this circulation pattern been modeled in depth?"

Some authors come to mind: Hellmer, Dutrieux,Sergienko. I  cannot immediately trace all the papers, but look at doi:10.1038/nature11064 and the earlier doi:10.1029/2004GL019506 by Hellmer.

The linked thread provides many other associated reference; however, I would say that it would be better to wait until the ACME (Accelerated Climate Modeling for Energy) project published some results before placing too much faith in earlier model findings for the Southern Ocean:

http://forum.arctic-sea-ice.net/index.php/topic,281.100.html
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

sidd

  • Young ice
  • Posts: 4976
    • View Profile
  • Liked: 379
  • Likes Given: 0
Re: Southern Ocean Cold Spots
« Reply #41 on: August 03, 2016, 09:47:32 PM »
Re: Hellmer

The transition of the cavity under Filchner-Ronne from cold to warm as in Hellmer is underway.

doi:10.1038/ncomms12300

" ...  pulses of warm water already arrive as far south as the ice front."

Read all bout it, including instrumented seals. open access.

AbruptSLR

  • Multi-year ice
  • Posts: 17691
    • View Profile
  • Liked: 884
  • Likes Given: 242
Re: Southern Ocean Cold Spots
« Reply #42 on: August 08, 2016, 05:54:27 PM »
I provide the attached Nullschool SH SSTA image for August 8 2016, to remind people that with regards to SSTA the entire Southern Ocean is one large (& permanent) cold spot:
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

FishOutofWater

  • Grease ice
  • Posts: 745
    • View Profile
  • Liked: 281
  • Likes Given: 109
Re: Southern Ocean Cold Spots
« Reply #43 on: August 09, 2016, 03:16:52 PM »
Concerning the cold anomaly in the north Pacific, look at the temperature map and you will see it is not a cold area, it is an eastward extension of the cool water normally in the north Pacific. It is likely associated with faster than normal currents from Japan to the Pacific northwest. The strong El Niño intensified the westerlies across the Pacific. Moreover, the Pacific Decadal Oscillation (PDO) has flipped to its positive phase. This cool anomaly is consistent with the strongly positive PDO.

The cold spot in the Atlantic was started by the very cold, stormy winter of 2013-2014 that cooled the waters of the Atlantic subpolar gyre. It is fading now because deepwater formed and began moving south towards Bermuda. Warmer, salty water is now covering the surface layers of the gyre.

AbruptSLR

  • Multi-year ice
  • Posts: 17691
    • View Profile
  • Liked: 884
  • Likes Given: 242
Re: Southern Ocean Cold Spots
« Reply #44 on: August 09, 2016, 06:19:58 PM »
Concerning the cold anomaly in the north Pacific, look at the temperature map and you will see it is not a cold area, it is an eastward extension of the cool water normally in the north Pacific. It is likely associated with faster than normal currents from Japan to the Pacific northwest. The strong El Niño intensified the westerlies across the Pacific. Moreover, the Pacific Decadal Oscillation (PDO) has flipped to its positive phase. This cool anomaly is consistent with the strongly positive PDO.

cold spot in the Atlantic was started by the very cold, stormy winter of 2013-2014 that cooled the waters of the Atlantic subpolar gyre. It is fading now because deepwater formed and began moving south towards Bermuda. Warmer, salty water is now covering the surface layers of the gyre.

FishOutofWater,

Thanks for this contrasting information, as most people like to focus on the North Atlantic and/or the North Pacific; which is why I opened this thread focused on the Southern Ocean; the surface of which will remain abnormally cool for centuries to come due to AGW together with the ice-climate feedback mechanism delineated by Hansen et al (2016).

Best,
ASLR
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

FishOutofWater

  • Grease ice
  • Posts: 745
    • View Profile
  • Liked: 281
  • Likes Given: 109
Re: Southern Ocean Cold Spots
« Reply #45 on: August 10, 2016, 01:04:19 AM »
Based on studying a large amount of data and reading many papers combined with my training as a geoscientist, I am convinced that the reduction in heat release in the southern hemisphere, as outlined in the recent Hansen paper, will inevitably bring warming to the tropics and the northern hemisphere. I just reviewed a research paper that showed that the winter of 2013-2014 formed very cold water in the subpolar gyre.

There was a slowdown in northern hemisphere subpolar gyre deep water formation and the Gulf Stream in 2010 that is well documented in research reports. It may have led to the recovery of Arctic sea ice in 2013 and 2014. There is a lag time of several years between the subpolar gyre and the Arctic ocean.

All of the ocean circulations are connected but there are major lags. In some cases atmospheric teleconnections speed up the transfer of ocean heat from one region to another. I try to follow all of it, but I don't recommend that anyone else does. It might drive you over the edge.

Hansen's paper points out that the southern hemisphere could recover pretty quickly if the forcing mechanisms stopped but CO2 is rising at a record rate so that's not going to happen any time soon.

Check out sea level in the Gulf of Mexico right now. It's about a foot, (30 cm ) above baseline.

The heat build in the GoM up is off the charts right now.

Conditions are building for devastating hurricanes starting in a few weeks.

It's all connected.

AbruptSLR

  • Multi-year ice
  • Posts: 17691
    • View Profile
  • Liked: 884
  • Likes Given: 242
Re: Southern Ocean Cold Spots
« Reply #46 on: August 10, 2016, 03:22:13 AM »
Based on studying a large amount of data and reading many papers combined with my training as a geoscientist, I am convinced that the reduction in heat release in the southern hemisphere, as outlined in the recent Hansen paper, will inevitably bring warming to the tropics and the northern hemisphere. I just reviewed a research paper that showed that the winter of 2013-2014 formed very cold water in the subpolar gyre.

There was a slowdown in northern hemisphere subpolar gyre deep water formation and the Gulf Stream in 2010 that is well documented in research reports. It may have led to the recovery of Arctic sea ice in 2013 and 2014. There is a lag time of several years between the subpolar gyre and the Arctic ocean.

All of the ocean circulations are connected but there are major lags. In some cases atmospheric teleconnections speed up the transfer of ocean heat from one region to another. I try to follow all of it, but I don't recommend that anyone else does. It might drive you over the edge.

Hansen's paper points out that the southern hemisphere could recover pretty quickly if the forcing mechanisms stopped but CO2 is rising at a record rate so that's not going to happen any time soon.

Check out sea level in the Gulf of Mexico right now. It's about a foot, (30 cm ) above baseline.

The heat build in the GoM up is off the charts right now.

Conditions are building for devastating hurricanes starting in a few weeks.

It's all connected.

All very good points that I concur with.

Thanks for the post.
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson