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Tasboy

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  1. It's nice to have you back Stew. I was missing you! I don't know that I would call it (2015 Antarctic sea ice extent pattern) natural variability - perhaps it might be best described as a sudden response (it was quite a sudden slowdown in growth) to lower latitude forcings. But then again, that is part of natural variability...
  2. Yep, agree. It's been quite variable. My take is that sea ice distribution has been responding over the last few months to the El Nino (via synoptic wind pattern), after having been free from ENSO constraints for the last few years. The build up of sea ice in the Bellingshausen and Amundsen seas late in the season (it's the only place where sea ice is beyond it's climatological mean at the moment - http://www.cawcr.gov.au/staff/preid/seaice/gsfc_extent_hov_anom.html) often means that there is a chance that this "excess" sea ice may break over the Peninsula (much like a wave) as it is caug
  3. Happens! 15% is counted as ice edge. And yes, there's lots of break up around the edge, pretty much right around the continent. Unusually, there's a lot of relatively sparse ice around the Peninsular and B&A seas at the moment.
  4. Speaking of interesting... Sea-ice extent seems to have had a late rally. The annual daily maximum is now in late September, rather than on the 5th September as previously mentioned. http://www.cawcr.gov.au/staff/preid/seaice/sea_ice_table_extent.html (It should be noted that there is a small problem with the satellite data for the 29th)
  5. I think you are misinterpreting what GW has expressed. Nevertheless, a loss of a protective sea ice barrier does leave the shelves vulnerable. Given the sub-surface warming of the ocean and subsequent weakening of the shelves, perhaps even "normal" sea ice conditions over summer months may be something to be concerned about.
  6. Agree GW. Sea ice acts as an effective barrier for ice shelves against ocean processes - and hence also protects the ice sheets themselves. I coined a term "coastal exposure index" that keeps track of the broad-scale sea ice barrier. You can see it plotted in real time here: http://www.cawcr.gov.au/staff/preid/seaice/gsfc_sh_coastal_exposure.html. It's mostly interesting in summer months. A higher the coastal exposure index means trouble!
  7. No probs. Yes, the growth in areal extent did slow quite quickly. But it's not an unusual event - not unusual enough to perhaps make it "odd", but we won't worry about semantics. The sea ice distribution (and seasonality) is responding to one of its main drivers - ENSO. A similar thing happened in 2008 as the Pacific went from being cool (La Nina) to neutral. Right through January to early May the net sea ice extent was at (for then) record levels but dropped over the next few months to be at below average in September. See the chart here: http://www.cawcr.gov.au/staff/preid/seaice/gsfc_sh
  8. I don't know that it is all that odd. Interesting, but not odd. Yes. 1994 had the earliest annual daily maximum (based on data since 1979) - on 31st August. See colour coding at http://www.cawcr.gov.au/staff/preid/seaice/sea_ice_table_extent.html Note that the 2015 data are based on the NASA Team near-real-time data and will be updated once their final data are available.
  9. 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!
  10. 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 Interesting, but not really part of this discussion?
  11. 12 August 2015 - first below average net sea ice extent (based on 1981-2010 climatology) since Dec 2012.
  12. You guys are funny! The link between Pacific SSTs and the regionality of sea ice extent is well known.
  13. While SAM was close to neutral during May 2015 it has been continually positive since October 2014, and set a new positive record during those months (Feb 2015). Today's sea-ice extent is just a snapshot of sea ice that has retreated and advanced over the previous few months. So it's not very accurate to say that "because the winds are low today then the sea ice should be close to average or below average". Your mistake is fairly typical of someone who wants to make a quick judgement against science. Besides, winds are just one variable (although an important one) that influences s
  14. Since you asked… If it was scientifically interesting it probably could go in there. However statements like this are pretty useless – particularly when they are wrong - like the one I quoted. Scientists aren’t so much interested in a useless statistic (such as this and many similar statistics on this list) but more interested in “why†or “what are the ramifications or the broader context of this statisticâ€. And they certainly aren’t interested in people’s “feelings†about long-term outlooks: eg “I have a feeling we will smash the global sea ice records this yearâ€. Wha
  15. Alarmingly, in 2015 the Antarctic sea-ice extent grew only 0.026 million square kms between the 4th and 5th April. That is the third lowest growth in extent ever recorded between those dates (behind 2009 and 1988). See http://www.cawcr.gov.au/staff/preid/seaice/gsfc_sh_extent_anom.html.
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