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Post by thermostat on Oct 6, 2012 1:53:18 GMT
Just one more comment; it is important to make a distiction between the recent increase in Antarctic Sea Ice maximum extent and the loss of ice mass from the Antartcic Ice sheet.
These two contemporary events are being driven by interconnected, but distinct physical processes.
Added heat is melting the ice sheet while changes in wind strength and patterns are expanding maximum sea ice extent.
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Post by sigurdur on Oct 6, 2012 2:07:32 GMT
thermostat: The main Antarctic Ice sheet is not loosing mass. Where in the world did you read that it is?
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Post by sigurdur on Oct 6, 2012 2:08:51 GMT
The WP portion is loosing mass, but the eastern portion is gaining mass. The net effect is that the Antarctic Ice Mass has a positive bias to it. Meaning, mass is approx flat within error bars, but approaching the upper range of the error bars.
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Post by thermostat on Oct 6, 2012 2:25:38 GMT
thermostat: The main Antarctic Ice sheet is not loosing mass. Where in the world did you read that it is? Nature Geoscience, 2008, for one (just posted above.) "Recent Antarctic ice mass loss from radar interferometry and regional climate modelling" But warming and mass loss in Antartica is described in a number of publications (since 2006). What contemporary references indicate that this is not the case?
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Post by thermostat on Oct 6, 2012 2:30:35 GMT
The WP portion is loosing mass, but the eastern portion is gaining mass. The net effect is that the Antarctic Ice Mass has a positive bias to it. Meaning, mass is approx flat within error bars, but approaching the upper range of the error bars. It is a question whether Eastern Antarctica is gaining mass. Fair enough. Meantime, other analyses show rising temperatures. This factor is important for mass balance down there, since it is generally too cold to snow and rising temperatures provide a mechanism to add mass to the ice sheet.
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Post by icefisher on Oct 6, 2012 12:41:44 GMT
Just one more comment; it is important to make a distiction between the recent increase in Antarctic Sea Ice maximum extent and the loss of ice mass from the Antartcic Ice sheet. These two contemporary events are being driven by interconnected, but distinct physical processes. Added heat is melting the ice sheet while changes in wind strength and patterns are expanding maximum sea ice extent. I would suggest the biggest factor are the massive and consistent cold anomalies we are seeing in the entire antarctic/southern Pacific/southern Altlantic/Indian oceans. Combine that with the cold water pumping out of the Bering Strait and we have something not seen in a long time. Note the La Nina emerging west of Ecuador! Hansens predictions for a super El Nino appear to be headed for the trash can yet again. And whats ahead? Solar dimming as we enter into the solar decline phase? I have to agree though with Astromet that there is yet another El Nino spurt in the system. But it does appear the loss of ice in the Arctic is having an effect on ENSO as I predicted a couple of months ago.
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Post by sigurdur on Oct 6, 2012 14:36:52 GMT
Thermostat: There was a paper published in 2010 that showed earlier mass readings by Grace and other mechanisms were wrong.
The consensus currently is that Eastern Antarctica is about flat with a positive bias. The mass is so huge that the error bars result in large, as in giga tons, variation. The bias, using the corrected Grace data, is positive. However, as I said it is within the error bars so for all intents it has remained flat for years.
The WP is warmer, but it seems it has gotten even colder over the large sheet.
Clearly, Antarctica is not in any type of trend one way or the other.
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Post by thermostat on Oct 9, 2012 4:48:09 GMT
Thermostat: There was a paper published in 2010 that showed earlier mass readings by Grace and other mechanisms were wrong. The consensus currently is that Eastern Antarctica is about flat with a positive bias. The mass is so huge that the error bars result in large, as in giga tons, variation. The bias, using the corrected Grace data, is positive. However, as I said it is within the error bars so for all intents it has remained flat for years. The WP is warmer, but it seems it has gotten even colder over the large sheet. Clearly, Antarctica is not in any type of trend one way or the other. Sigurdur, Just a few comments. You wrote, "There was a paper published in 2010 that showed earlier mass readings by Grace and other mechanisms were wrong." It is common practice when citing the literature to include the citation. "The consensus currently is that Eastern Antarctica is about flat with a positive bias." This assertion requires literature support. "Clearly, Antarctica is not in any type of trend one way or the other." Clearly? clearly based on what scientific evidence? The literature indicates that Antarctica is warming, eg. "First, climate is warming over much of the Antarctic continent, as shown in several recent studies (e.g., Chapman and Walsh, 2007, Monaghan et al., 2008, Steig et al., 2009) and is related to Pacific Ocean warming (Ding et al., 2010) and circumpolar winds." see 'Poles apart: A record-breaking summer and winter'; nsidc.org/arcticseaicenews/"
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Post by nonentropic on Oct 9, 2012 8:01:45 GMT
Not sure that it says to much other than the south grew in spite of warming while the north shrunk because of warming.
Is that heads I win tales you loose.
Sounds like a run at funding needs ie more study will resolve to your preference.
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Post by icefisher on Oct 9, 2012 14:17:59 GMT
Sigurdur, Just a few comments. You wrote, "There was a paper published in 2010 that showed earlier mass readings by Grace and other mechanisms were wrong." It is common practice when citing the literature to include the citation. WTF!!! We are still waiting for your Milankovitch cycle correlation to ice levels of 8,000 years ago citatation tstat!! What is this the pot calling the kettle black?
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Post by sigurdur on Oct 9, 2012 14:26:00 GMT
Tstat: Someplace on this forum I have already posted that paper concerning the errors in the earlier ice mass on Antarctica.
We all know the Stieg paper is rubbish concerning Antarctica temps.
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Post by icefisher on Oct 9, 2012 15:09:30 GMT
The literature indicates that Antarctica is warming, eg. "First, climate is warming over much of the Antarctic continent, as shown in several recent studies (e.g., Chapman and Walsh, 2007, Monaghan et al., 2008, Steig et al., 2009) and is related to Pacific Ocean warming (Ding et al., 2010) and circumpolar winds." see 'Poles apart: A record-breaking summer and winter'; nsidc.org/arcticseaicenews/"You wanted references? Well once again tstat you are guilty of not reading the actual references. They all support Sigurdur's statement. The fact that warming is detectable in the antarctic has been shown sensitive to start dates and a 2009 Corregidum(correction) by Steig to his 2009 study acknowledges that warming detected in the antarctica by his study may be attributable to muliti-decadal variation or in other words there may be no warming trend in Antarctica. Anyway I will cut and paste some relevant statements to highlight what you have obviously not read. Highlights mine. Chapman and Walsh, 2007 Trends computed using these analyses show considerable sensitivity to start and end dates, with trends calculated using start dates prior to 1965 showing overall warming, while those using start dates from 1966 to 1982 show net cooling over the region. Because of the large interannual variability of temperatures over the continental Antarctic, most of the continental trends are not statistically significant. Monaghan et al., 2008 Statistically insignificant (p > 0.05) positive trends occur over most regions and months during 1960�2005. By contrast, 1970�2005 trends are weakly negative overall. Subtle near-surface temperature increases during winter from 1970 to 2000 are consistent with tropospheric warming from radiosonde records and a lack of winter SAM trends. Widespread but statistically insignificant (p > 0.05) warming over Antarctica from 1992 to 2005 coincides with a leveling off of upward SAM trends during summer and autumn since the mid-1990s. Weakly significant annual trends (p < 0.10) of about +1 K decade−1 are found at three stations in interior and coastal East Antarctica since 1992. The subtle shift toward warming during the past 15 years raises the question of whether the recent trends are linked more closely to anthropogenic influences or multidecadal variability.Eric J. Steig1, David P. Schneider, Scott D. Rutherford, Michael E. Mann, Josefino C. Comiso & Drew T. Shindell (Corregidum) Assessments of Antarctic temperature change have emphasized the contrast between strong warming of the Antarctic Peninsula and slight cooling of the Antarctic continental interior in recent decades1. This pattern of temperature change has been attributed to the increased strength of the circumpolar westerlies, largely in response to changes in stratospheric ozone2. This picture, however, is substantially incomplete owing to the sparseness and short duration of the observations. Here we show that significant warming extends well beyond the Antarctic Peninsula to cover most of West Antarctica, an area of warming much larger than previously reported. West Antarctic warming exceeds 0.1 �C per decade over the past 50 years, and is strongest in winter and spring. Although this is partly offset by autumn cooling in East Antarctica, the continent-wide average near-surface temperature trend is positive. Simulations using a general circulation model reproduce the essential features of the spatial pattern and the long-term trend, and we suggest that neither can be attributed directly to increases in the strength of the westerlies. Instead, regional changes in atmospheric circulation and associated changes in sea surface temperature and sea ice are required to explain the enhanced warming in West AntarcticaSo in correction Steig recognized that the warming must be regional in nature. Here he attributes the warming to ozone variations. Perhaps explaining both loss of west arctic ice and the west arctic warming while the remainder of the continent has slight cooling. I am favoring the idea that west antartica is being affected by the AMO being in positive phase since the peninsula is surrounded by surface thermohaline currents of the AMO. And of course in this study Mannian statistics were used to exaggerate warming. this was refuted by O'Donnell et all 2010. O'Donnell et al 2010 found a minor statistically insignificant warming trend in antarctic over the Steig period of choice which in itself was biased as noted in Chapman and Walsh, 2007. The 1957 start date was probably biased to a warming trend with later dates in the late 60's showing cooling. So your references here do not support your viewpoint Tstat but in fact support Sigurdur's. Since you did the same thing with Polyak etal 2011 one has to wonder if you have any research skills whatsoever. You can spew out references but what do you do? Take garbage straight off Think Progress or SKS without applying an ounce of effort to determine if what they write is in any supportive of your claims? So now that you have been humored how about a reference to support your claim that this years ice minimum had not been duplicated for 8,000 years? p.s. Opps I forgot you backed off that claim.
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Post by magellan on Oct 9, 2012 16:25:17 GMT
Tstat: Someplace on this forum I have already posted that paper concerning the errors in the earlier ice mass on Antarctica. We all know the Stieg paper is rubbish concerning Antarctica temps. It must have been good, after all it was on the cover of the so called "prestigious" 'Nature" journal. Oh wait, didn't they also elevate Mann to divinity status more than once even after the hockey stick was thoroughly debunked? O’Donnell et al 2010 Refutes Steig et al 2009Do you think Thermostat actually reads anything? This was NASA's rendition of the Antarctic before Steig and co. doctored it. Neither UAH or RSS show warming at the South Pole. Thermostat, please explain. Next thing you know he'll post about a new paper from 1998 that shows a hockey stick shape temperature profile indicating present day temperatures are warmer than at any time in the past 1000+ years. We'll even get to see the spaghetti graphs "validating" it. ROFL
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Post by sigurdur on Oct 10, 2012 2:20:12 GMT
One thing that I do do, is read the literature. I am way behind at the moment, have a large batch of current literature to read.
When I state something concerning climate, it is backed by published literature.
I am not writing a paper when I comment, so if I have posted the paper at a previous time, I will not repost it as I have many varied interests.
Magellan and Icefisher both point out that what I wrote concering Antarctic temperatures is correct.
I enjoy this forum, as a lot of literature is posted here and discussed quite well. It is evident that I am not the only one who actually reads the literature. What a great thing it is!
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Post by nonentropic on Oct 10, 2012 3:20:28 GMT
Right on Sig, love your comments on farming far from here and in a different hemisphere.
Us old bastards have time to read stuff and discuss without an agenda, but I can tell when I hear the word unprecedented one more time I will explode. It has to be the word of the decade and it means in round terms I am lying because without a time or place constraint it cannot be anything but a lie. Should you because you seem good at set up a new page here for the biggest distortion intended when the word is used the media.
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