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Northern Hemisphere Ice and Snow Advance 2019/20

  • 13-09-2019 3:27pm
    #1
    Registered Users Posts: 21,800 ✭✭✭✭ Kermit.de.frog


    It's that time of year again...

    In the last week the annual fall in sea ice has been plateauing and the ice will soon start it's advance again for this coming winter and will continue to do so right through until around the end March.

    cursnow.gif

    cursnow_alaska.gif

    cursnow_asiaeurope.gif

    sea_ice_only.jpg

    Let's keep tabs here. :cool:


«134

Comments

  • Registered Users Posts: 6,032 ✭✭✭ Oneiric 3


    A little surprised that melt is easing off a little considering the unprecedented warmth (for the time of year) going on up the Arctic at the moment.

    New Moon



  • Registered Users Posts: 8,195 ✭✭✭ Gaoth Laidir


    It looks like this year's extent will bottom out about the same as 2007, the first year we heard the alarm bells being rung about ice-free Septembers within a decade or two. In actual fact, the trend in annual minima since then has been practically flat. That's 13 years (the latest one third) of the total satellite era with a flat trend. The annual MAXima, however, do show a decreasing trend.

    Data from here. The 2019 minimum was taken as 4.238 million for now, which is probably the lowest it will get to, give or take.

    490580.JPG

    490581.png

    490582.png


  • Registered Users Posts: 8,195 ✭✭✭ Gaoth Laidir


    Just for completeness, here are the past four 10-year trends, starting at 1980. The greatest rate of decrease was 2000-09, but the most recent dedcade has actually shown a slight upward trend.

    490588.png

    490589.png

    490590.png

    490591.png


  • Registered Users Posts: 6,032 ✭✭✭ Oneiric 3


    As I said, all this is surprising given that Arctic temps (North of the 60th) are at their warmest for this period in the Climate Reanalyser record at least. This chart shows the temperature anomaly in this region for the first half of September going back to 1979 up to the present:

    SukTw0Q.png

    I'll have a look at the DMI database later if I can be arsed to see how temperatures within the 80th are doing. Perhaps they are cooler within this smaller region when compared other years that is allowing ice melt to be relatively tame this time around.


    Edit: NOAA reanalysis of September SST temp anomalies in the Arctic (C/O C.R) for between 1854 and 2018. September this year is already continuing this more recent trend.

    qaRpV2D.png

    New Moon



  • Registered Users Posts: 6,032 ✭✭✭ Oneiric 3


    Had a quick look at the DMI daily Arctic temp (N of 80 Deg) set for this period of the year - 1st to 15th Sept, which I think tends to be when the ice melt has reached its peak, and while we are once again seeing very high temps up there for the period, they are not without precedent.

    Top 5 warmest first half of Septembers up there since 1958. Anomaly figure are from the 1981-2010 average, and not the more nontraditional and to be frank, quite odd 1979-2000 bench which C.R/NOAA seems to favour.

    Year Temp Anom
    1991 -1.96 2.83
    2012 -2.26 2.53
    1984 -2.37 2.42
    2019 -2.86 1.93
    1972 -2.95 1.84

    This year's actual mean temp for this period up there is standing at -2.86c, ranking it the 4th highest in this longer term data set. 1987 saw the coldest temps up there in this part of the year, with a mean temp of -8.02c.

    New Moon



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  • Registered Users Posts: 8,195 ✭✭✭ Gaoth Laidir


    Oneiric 3 wrote: »
    Had a quick look at the DMI daily Arctic temp (N of 80 Deg) set for this period of the year - 1st to 15th Sept, which I think tends to be when the ice melt has reached its peak, and while we are once again seeing very high temps up there for the period, they are not without precedent.

    Top 5 warmest first half of Septembers up there since 1958. Anomaly figure are from the 1981-2010 average, and not the more nontraditional and to be frank, quite odd 1979-2000 bench which C.R/NOAA seems to favour.

    Year Temp Anom
    1991 -1.96 2.83
    2012 -2.26 2.53
    1984 -2.37 2.42
    2019 -2.86 1.93
    1972 -2.95 1.84

    This year's actual mean temp for this period up there is standing at -2.86c, ranking it the 4th highest in this longer term data set. 1987 saw the coldest temps up there in this part of the year, with a mean temp of -8.02c.

    It could be down to the actual regions that are above average and how large an ice pack they enclose. A small ice area being very warm will affect the average temperature but not so much the overall total ice.

    For example, the latest anomalies for the second half of August below shows the main warm anomalies over land. September may have continued on this pattern.

    490770.png


  • Registered Users Posts: 8,378 ✭✭✭ Danno


    Oneiric 3 wrote: »
    Had a quick look at the DMI daily Arctic temp (N of 80 Deg) set for this period of the year - 1st to 15th Sept, which I think tends to be when the ice melt has reached its peak, and while we are once again seeing very high temps up there for the period, they are not without precedent.

    Top 5 warmest first half of Septembers up there since 1958. Anomaly figure are from the 1981-2010 average, and not the more nontraditional and to be frank, quite odd 1979-2000 bench which C.R/NOAA seems to favour.

    Year Temp Anom
    1991 -1.96 2.83
    2012 -2.26 2.53
    1984 -2.37 2.42
    2019 -2.86 1.93
    1972 -2.95 1.84

    This year's actual mean temp for this period up there is standing at -2.86c, ranking it the 4th highest in this longer term data set. 1987 saw the coldest temps up there in this part of the year, with a mean temp of -8.02c.

    Interesting. 1984 was the second lowest of the 1980s for ice extent with 6.74 million square kilometres. 1985 was the lowest with 6.71m

    1991 meanwhile equaled 1998 with 6.43m whilst 1990 (6.07m); 1993 (6.20m); 1995 (6.06m) and 1999 (5.84m) were all lower. Source: JAXA.

    I don't think there is a strong link between ice and temperature anomaly.


  • Closed Accounts Posts: 3,502 Ariyah Crooked Banker


    My second favourite thread of the year !


  • Registered Users Posts: 6,032 ✭✭✭ Oneiric 3


    CR/NOAA Arctic anomaly for Sept (1st-22nd) now down to 2nd place (behind 2016) in its records since 1979 but could rise back into 1st place again this week as temps likely remain in and around 2.0c above the average for a good while yet.

    New Moon



  • Registered Users Posts: 21,800 ✭✭✭✭ Kermit.de.frog


    Sea ice formation and snow cover will be taking off witnin the next week across Siberia.

    gfsnh-1-114.png?0


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  • Registered Users Posts: 8,195 ✭✭✭ Gaoth Laidir


    The minimum extent bottomed out at 4.15 million on September 18th, the 2nd lowest in the satellite era. With that figure now in the graph for the past 10 years the trend is practically flat, if not slightly rising at 0.08 per decade.

    491765.png

    September's monthly volume is not in yet, but taking the August figures the past decade, the trend is slightly downward at 0.16 per decade, 34 times less than the 2000-09 trend of 5.66 per decade.

    At the risk of getting more abuse, I think it's safe to say that for now at least, the runaway loss has leveled off.

    491766.png

    491767.png


  • Registered Users Posts: 8,195 ✭✭✭ Gaoth Laidir


    5-yr running means

    491788.png

    491787.png


  • Registered Users Posts: 6,032 ✭✭✭ Oneiric 3


    Is it possible to get hold of that data? Might be interesting to compare and contrast with the actual running temperatures up there to see if there is a strong correlation (or not) between both.

    New Moon



  • Registered Users Posts: 8,195 ✭✭✭ Gaoth Laidir


    Oneiric 3 wrote: »
    Is it possible to get hold of that data? Might be interesting to compare and contrast with the actual running temperatures up there to see if there is a strong correlation (or not) between both.

    All data are in Excel files here

    https://nsidc.org/arcticseaicenews/sea-ice-tools/


  • Registered Users Posts: 6,032 ✭✭✭ Oneiric 3


    Cheers mon!

    New Moon



  • Registered Users Posts: 21,800 ✭✭✭✭ Kermit.de.frog


    The cross Arctic channel for shipping closed in with the ice pack yesterday approaching the Laptev Sea. A real pace now to the increase in the sea ice.

    cursnow_alaska.gif

    cursnow_asiaeurope.gif

    Not long now fella

    b71e4ac0ecade621412212ef6fed0821.gif


  • Registered Users Posts: 8,195 ✭✭✭ Gaoth Laidir


    Arctic sea ice volume charts now updated with the September (annual minimum) figures. Flat trend over the past decade, the most prolonged of the satellite era, but you won't read that anywhere.

    493339.png

    493341.png


  • Registered Users Posts: 5,847 ✭✭✭ pauldry


    Yes but its lowest JAXA on record currently by over 300k. Id say the reason its stayed flat in the past decade has been that a lot of the final multi year ice has been thinning. It will be interesting to see if it flatlines in the following decade. I severely doubt it and it will probably settle in the 3s in that decade


  • Registered Users Posts: 8,195 ✭✭✭ Gaoth Laidir


    pauldry wrote: »
    Yes but its lowest JAXA on record currently by over 300k. Id say the reason its stayed flat in the past decade has been that a lot of the final multi year ice has been thinning. It will be interesting to see if it flatlines in the following decade. I severely doubt it and it will probably settle in the 3s in that decade

    Thinning would be accounted for in the volume figures. It remains to be seen what happens next.

    On another note, the total annual Greenland melt area has shown a similar hiatus, with in fact a notable decrease in melt area over the past decade. Figures from here.

    493427.png


    493428.png


  • Registered Users Posts: 276 ✭✭ wing52


    Where is the "heat energy " going to then if the sea ice is stabilised? Is that why we ( in ireland anyway) are getting mildish winters, because of the gulf stream holding more of its "heat"? Do you think the polar vortex is getting more stable as well at this time of the year on a decade by decade timeframe?


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  • Registered Users Posts: 5,847 ✭✭✭ pauldry


    I think its rubbish to suggest the Arctic is stable. There are scarier facts behind the figures. As I said the Jaxa extent is the lowest on record and in many months over the past 5 years it has been the lowest on record. Its just that when September has come a lot of melt out is done and we are left with similar extent figures as before. This year was the 2nd lowest extent on record but in the record year there was a cyclone. The trend is down and by 2050 there will likely be little or nothing ice wise in the arctic in Summers end


  • Registered Users Posts: 8,195 ✭✭✭ Gaoth Laidir


    pauldry wrote: »
    I think its rubbish to suggest the Arctic is stable. There are scarier facts behind the figures. As I said the Jaxa extent is the lowest on record and in many months over the past 5 years it has been the lowest on record. Its just that when September has come a lot of melt out is done and we are left with similar extent figures as before. This year was the 2nd lowest extent on record but in the record year there was a cyclone. The trend is down and by 2050 there will likely be little or nothing ice wise in the arctic in Summers end

    So are you saying that the annual extent curve has changed shape and we're reaching the minimum earlier?Because we haven't. I posted the graphs before and 2019 is not the lowest.

    Extent is one thing, the actual amount of ice there is another. Where 2019 falls is neither here nor there. If it's close to the record low (volume or extent) is not surprising, as a flat trend means that any year within that period could be close to the minimum. The fact still remains that the trend is flat (for now, anyway) but not one report I've seen has mentioned that. They're now down to quoting each year's rank instead of the trend. The AMO appears to be the main driver of Arctic ice changes.


  • Registered Users Posts: 1,545 droidus


    pauldry wrote: »
    I think its rubbish to suggest the Arctic is stable. There are scarier facts behind the figures. As I said the Jaxa extent is the lowest on record and in many months over the past 5 years it has been the lowest on record. Its just that when September has come a lot of melt out is done and we are left with similar extent figures as before. This year was the 2nd lowest extent on record but in the record year there was a cyclone. The trend is down and by 2050 there will likely be little or nothing ice wise in the arctic in Summers end

    Agreed, but these are not linear systems. There is a significant possibility of an ice free summer before 2030, maybe as soon as 2025, resulting in a massive spike (as much as 0.6 degrees) in warming due to an increase in permafrost methane. Once that happens the climate dominos start to fall.


  • Registered Users Posts: 6,032 ✭✭✭ Oneiric 3


    Arctic temperatures for October (full month except for 2019 which is up only up to the 27th) as per the Danish Met Office (DMI)

    jmPNXxa.png

    As of yesterday, the 2019 October mean stands at -10.98c, which ranks it the 4th warmest in the series (warmest was 2018). Another point to note is that there is missing data from between the 2nd and 8th this year on the data set, so this was filled in with a computed linear progression between the 6.04c on the 1st to -8.63c on the 9th. Not perfect but unlikely to distort the overall mean value from what it would have been if the data was available.

    Data in graph is centered on the 1961-1990 October average. Black line represents the 10 year rolling average.

    Source: DMI.

    New Moon



  • Registered Users Posts: 6,032 ✭✭✭ Oneiric 3


    A couple of days data yet to go, but looking increasingly probable that this October's Arctic sea ice extent will come in the lowest on record, or at least since 1979, when records seemed to begin.

    yUNn57y.png

    Chart source: DMI

    New Moon



  • Registered Users Posts: 6,032 ✭✭✭ Oneiric 3


    Interesting. Parts of Denver could potentially achieve it lowest October temperature before the month is out:

    https://www.denverpost.com/2019/10/28/denver-coldest-october/

    The still standing record of 1.0f occurred back on October 29th 1917. Looking at the reanalysis maps. the Arctic, the source of the intense cold back then, just as it is this time around, was much colder back then than it currently is now.

    Current map (850 hPa temps)

    GFSOPNH06_6_2.png


    Reanalysis map back on October 29th 1917:

    NOAA_2_1917102918_2.png

    Not only was the source of the cold outbreak over N. America much deeper back in 1917, but it was also far closer to the north of the Continent.

    Yet back to the present, we have these potentally record breaking low temps coming from a source that potentially record breaking high for the time of year. Current temp anomaly map from C.R:
    gfs_nh-sat1_t2anom_1-day.png

    Something does not really add up here.

    New Moon



  • Closed Accounts Posts: 3,502 Ariyah Crooked Banker


    Currently -14c there at 6.30am, I live in the wrong place.


  • Registered Users Posts: 6,032 ✭✭✭ Oneiric 3


    Daily sea ice concentration for October 2019 from NISDC/NASS. Orange line represents the 1981-2010 median extent.
    (Large gif file so may take a short while to load)

    9rM6qDZ.gif

    New Moon



  • Registered Users Posts: 16,684 ✭✭✭✭ silverharp


    What is the significance of an average to 2010? Why not just have the average to last year?

    A belief in gender identity involves a level of faith as there is nothing tangible to prove its existence which, as something divorced from the physical body, is similar to the idea of a soul. - Colette Colfer



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  • Registered Users Posts: 21,800 ✭✭✭✭ Kermit.de.frog


    Impressive ice formation in to the artic sea. This should continue for some weeks yet.


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