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chubbs

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Everything posted by chubbs

  1. Grabbed this chart from ASIF. Despite the different enso and NHemi temp and circulation, 2017 isn't far from 2016.
  2. Yes I posted a link to that paper earlier. This is an area of increasing research following up on Jennifer Francis' work. Here is a recent paper on jet stream meandering with further support for Francis' ideas. Open source and with a video (second link) from the author giving an overview. " The most robust changes are detected for autumn which has seen a pronounced increase in strongly meandering patterns at the hemispheric level as well as over the Eurasian sector. " http://iopscience.iop.org/article/10.1088/1748-9326/11/9/094028/meta http://bcove.me/zccol3mi
  3. This freezing degree day chart, from ASIF, integrates the DMI above 80 temperature curve. This freezing year is unique and to this date much warmer than last year. We are roughly one month behind recent years with two months of hard winter to go.
  4. Will be interesting to see the studies to come on this years pattern. Open water and/or nino can't be the full explanation because they haven't triggered this behavior in the past and conditions are even worse so far this year despite the switch to nina.
  5. PIOMAS data for December is in. In January, 2016 started with higher sea ice volume than 2011, 2012 and 2013 but ended with record low December volume. Eyeballing the chart, it looks like 2016 is the worst year ever in terms of sea ice volume lost. Very unusual, in that lack of gain in the non-summer months drove the the decline instead of big summer losses.
  6. Here is a chart of global ice volume from Wipneus. Roughly 5000 cubic kilometers of ice has been lost this year. That is 5 trillion tons of ice. It took 4 times 10 to the 20th power calories to melt that ice or roughly 4% of the earth's typical energy gain from GHG. Considering that it has happened in less than half a year that is a significant heat loss for atmosphere and ocean surface waters this fall.
  7. I don't buy the pre-1940 infilled data either. There just isn't enough data available. My main point is that you can't use Hadcrut to support an argument that the 1930s were as warm as present because HADCRUT doesn't have enough 1930s data coverage. Even now 70-90N coverage is not much more than 50% and the infilled series shows that the data void areas are likely to be warming the most.
  8. Here is hadcrut 70-90N infilled per cowtan+way
  9. Here is Hadcrut 70-90N with a requirement that 25% of the grids have valid data.
  10. NSIDC have a nice discussion on Antarctica in the Nov monthly summary. Winds and temperatures both contributed to the unusual ice losses. http://nsidc.org/arcticseaicenews/
  11. I posted some rough numbers on another blog. S Hemi sea ice has been running 2500000 sq km lower than last year. That is roughly 0.7% of earth's surface. Sea ice albedo impact vs open water is roughly 0.2 after accounting for clouds. Insolation at 70S is 50% above the global average on the Dec solstice. So currently there is roughly 0.2% more solar being absorbed at the earth's surface due to the change in SHemi sea ice vs. last year. Of course the impact decreases off the solstice and disappears completely once the sun sets. Integrating over a season the impact is about the same magnitude as going from peak to bottom of a solar cycle.
  12. S Hemi ice is highly variable and gets a reset every year since most of the ice melts so we will need to see several years to confirm any change in the sea ice trend. Biggest concern is surface melt on ice shelves that are already under pressure from bottom melting. One unusually warm year could speed things up.
  13. November volume at record low with roughly 25% less sea ice than last November.
  14. Yup, I am more optimistic about our winter than 75-90N. Here is Nov 2009.
  15. This chart illustrates how 2016 compares to the range of extent in previous years. The extreme outer edge represents the coldest years from the early portion of the satellite record. Note that 2016 is not the least expansive year in all areas.
  16. Currently Antarctic sea ice is even more unusual.
  17. Looks like 2016 volume caught-up to 2012 by late October. Record low volume likely in Nov.
  18. The climate feedback maybe smaller this time of year but the mid-latitude impact is greatest through warming of the Arctic leading to a weaker jet stream. Could be another good I95 snow year.
  19. As long as the Arctic Ocean completely freezes in winter, record melt extent will always produce record re-freeze. With all the open water in the Arctic Ocean this year, we will get a record late Fall/early Winter re-freeze at some point.
  20. Global sea ice extent has moved far outside the historical envelop in the past 3 weeks. Unlikely to get much better in the next week or so with PV splits at both poles.
  21. NSIDC extent for Oct 29 from Mohyu blog. (1000 of square km) Arctic Antarctic Total 2015 8444 17748 26192 2016 7111 16620 23731 2016 has 2461 x 1000 sq km or 9.4% less sea ice than this date last year. This is roughly 0.5% of the earth's surface.
  22. This just out (behind a paywall) . Timely for this fall's unusual arctic circulation. Note positive feedback between sea ice loss and circulation changes leading to increased heat transport to arctic. On the atmospheric response experiment to a Blue Arctic Ocean Tetsu Nakamura1,2,*, Koji Yamazaki1,2, Meiji Honda3, Jinro Ukita3, Ralf Jaiser4, Dörthe Handorf4 and Klaus Dethloff4 Abstract We demonstrated atmospheric responses to a reduction in Arctic sea ice via simulations in which Arctic sea ice decreased stepwise from the present-day range to an ice-free range. In all cases, the tropospheric response exhibited a negative Arctic Oscillation (AO)-like pattern. An intensification of the climatological planetary-scale wave due to the present-day sea ice reduction on the Atlantic side of the Arctic Ocean induced stratospheric polar vortex weakening and the subsequent negative AO. Conversely, strong Arctic warming due to ice-free conditions across the entire Arctic Ocean induced a weakening of the tropospheric westerlies corresponding to a negative AO without troposphere-stratosphere coupling, for which the planetary-scale wave response to a surface heat source extending to the Pacific side of the Arctic Ocean was responsible. Because the resultant negative AO-like response was accompanied by secondary circulation in the meridional plane, atmospheric heat transport into the Arctic increased, accelerating the Arctic amplification. http://onlinelibrary.wiley.com/doi/10.1002/2016GL070526/abstract
  23. Per Jaxa, looks like antarctic extent is also at a record low. First time ever for both poles at same time?
  24. Saw this Wipneus plot of PIOMASS minimum volume at the ASIF. This year ended up close to 2010 and 2011 and not far below the linear trendline. If we follow the linear trend, 2012 will be a normal year by 2022.
  25. The figure below from a recent paper below shows how glacier discharge (D) has increased and surface mass balance has decreased since 1990 causing an increasingly negative Greenland mass balance (MB). Comparing the SMB estimates in the chart below to the chart posted above, the long term trends are similar but there are some differences in the relative ranking of individual years. http://www.the-cryosphere.net/10/1933/2016/
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