This is John Christensen's Typepad Profile.
Join Typepad and start following John Christensen's activity
Join Now!
Already a member? Sign In
John Christensen
Recent Activity
Given the outlook, there seems to be a chance the record could be broken again 3-4 days from now..
Yes, the uptick on Arctic SIA came a day late, with 106K. This is a significant milestone; a warming world means less sea ice.
Hi Neven, Agreed, but one index cannot go down for long, when all other main indices are going up, I am not suggesting CT should change their numbers. Then you said: They'll probably be quiet until Antarctic SIA shoots up again, which it probably will after the El Niño is gone, because there seems to be something wrong with the southern system as well (and AGW may very well be the cause; think of changes in wind and ocean patterns, run-off from the continent, etc). The Antarctic is such a challenging place, I agree, mostly because it seems we don't know too much about what is going on down there. For the past few years the increase in Antarctic sea ice has been attributed to changes in wind and ocean patterns, and especially to an estimated increase in run-off from the continent. And these changes are then attributed to AGW. I would therefore be cautious to speculate that AGW for this particular year still is the cause of the change, but that the change is reversed compared to prior years. AGW is impacting the climate system for sure, but cannot be the mother of all change..
Hi Ac A, Who made that documentary, it does not seem very accurate in a number of places. About 7.30 into the movie, they state that Antarctica holds 70% of all fresh water on the planet. Interesting, since about 70% of all fresh water is found in ice and snow in total.. ;-) Next they show the 18-20 feet sea level rise as a consequence of melting the western Antarctic Peninsula, where I watched the entire peninsula of Jutland disappear, where hills reach about 500 feet.. ;-) But yes, we would get the point even if they had made it more factual.
NSIDC SIE and Daily Roos area and extent are all showing increases in the last two days, so Cryosphere seem to need an adjustment..
Finally, weather changes to a pattern, which is more conducive to ice formation on the Atlantic side: The high in the central Arctic combined with the low in southern Barents pull cold air masses from northern Siberia across Kara, Atlantic parts of the Arctic Ocean and Barents. DMI SIE as of 06.02.2016 has gone up significantly in the past two days (I believe there is one day delay so those two last days would be 04.02 and 05.02), most likely as a consequence of the change in weather on this side of the Arctic:
A great entry by Jeff Masters (Wunderground) on the Arctic January ice extent and weather analysis:
Somewhat off-topic (Sorry!), but I wanted to share an experience of what may be a minor SSW event: Flying over the north Atlantic today (Sorry again!), I noticed that the jet stream was south of Iceland and that on the east end of Iceland the wind speed was near 0km/h. At 11,200meters altitude the temperature was -57/-58C just when reaching Iceland, which is normal, but when I had reached the middle of the area of low wind at altitude about 50km later, the temperature had dropped to -70C. Shortly after the temperature started rising again, and in the middle of the Denmark Strait it was at -56C. Is this in principle a minor SSW event, or just what occurs with very low wind speed at altitude?
The highest winter temperature in 80N I have seen before 2000 was in 1976, where it reached 264K in March, a full nine degrees warmer than the current peak (Average for that time of year being 2-3 degrees warmer than for January). 1974 saw a peak of 260K in January, 5 degrees warmer than this event.. I just signed up at ECMWF and am waiting to be acknowledged. Once I have access I will try to obtain more detailed data and will share.
Thanks for the update Jim! Looking at the DMI 80N chart, it doesn't look like this invasion of heat will reach a top 5 spot compared to earlier years.
Hi Rob, Considering the length of the NW passage from the Baffin Bay to the Chuckchi Sea, the brief period of low ice extent late Aug/early Sep, the area that must have been covered with 20-60% ice concentration, and lastly the speed of the ship at the time, it would be impossible to make the journey in one season, even if the steady ice pack seemed to leave the passage open at the peak of the minimum.
Very nice berg and views, thanks for sharing jgnfld!
You are right, sorry Neven. The best thread may be this one, which I guess I killed with all the AO numbers a while back: P-maker, Please see my comments there.
Kevin said: Increasing CO2 leads to a warmer globe. This is amplified in the arctic. A warmer arctic leads to less sea ice. Less sea ice leads to changes in synoptic weather; including a jet stream that moves slower and with increased waviness. If you mean the jet stream is the tail, yes she's looking at the tail, but not because she's ignoring the rest of the elephant. Kevin, seriously, this is non-sense. This is what James Hansen has to say about the AO and the jet stream: "The degree to which Arctic air penetrates into middle latitudes is related to the AO index, which is defined by surface atmospheric pressure patterns. When the AO index is positive, surface pressure is low in the polar region. This helps the middle latitude jet stream to blow strongly and consistently from west to east, thus keeping cold Arctic air locked in the polar region. When the AO index is negative, there tends to be high pressure in the polar region, weaker zonal winds, and greater movement of frigid polar air into middle latitudes." (Hansen, James; Reto Ruedy; Makiko Sato; Ken Lo (2009). "If It’s That Warm, How Come It’s So Damned Cold?") The cold spell in 2010 explained by the NCDC: "Cold arctic air gripped western Europe in the first three weeks of December. Two major snowstorms, icy conditions, and frigid temperatures wreaked havoc across much of the region...The harsh winter weather was attributed to a negative Arctic Oscillation, which is a climate pattern that influences weather in the Northern Hemisphere. A very persistent, strong ridge of high pressure, or 'blocking system', near Greenland allowed cold Arctic air to slide south into Europe. Europe was not the only region in the Northern Hemisphere affected by the Arctic Oscillation. A large snow storm and frigid temperatures affected much of the Midwest United States on December 10–13...." ( If I should provide a hypothesis of how the AO (and therefore the jet stream) could be impacted in a warmer world with less Arctic sea ice, then the increase in open water in the Arctic should cause an increase in fall and winter low pressure in the Arctic. This would lead to a positive AO index becoming more prominent, which again would move the jet stream further north and keep the jet stream strong. Dr. Jennifer Francis to my knowledge is not tackling the challenge of whether we will see slow, meandering jet stream paths in AO positive conditions, or if we will see AO negative conditions becoming more prominent, as they were prior to 1987. But if AO negative becomes more prominent, as it was until 30 years ago, what then caused it to change: Ocean circulations or global warming? Dr. Jennifer Francis is looking at a limited geographic area over a limited period of time, and her conclusion therefore seems to miss the broader influence of the AO in our NH atmospheric patterns.
Hi Kevin, IMO Jennifer Francis is looking at the tail of the elephant.
From Kris: Incidentally, do you have something to substantiate the AO is all that important!??? That is a very curious comment, since the jet stream is defined by the AO.. Think about that for a minute.
And from Kris also: As we all know, in the past few years the anomalously warm Arctic air weakened considerably the Polar Jet, triggering this Polar Jet to meander in giant meanders. Resulting in large pockets of cold air moving to the South. Last Winter the East North America had been struck for weeks by this phenomena. Well, yes the jet stream caused the cold in East North America in 2015, but it was caused by the negative AO index. Considering the history of the AO and jet stream during winter months, it is interesting to note that the AO was primarily negative from 1950 to 1987 and then turned positive until 2011. And yes; in 2015 it was negative, so nothing unusual about that: When you compare the temperature in the state of NY in 2015 to the longer record, you also note that while it was cold in 2015, the anomaly was not at all extreme: In other words, the jet stream has been meandering many times in the past, and much more forcefully than in the past few years. The relative dominance of positive AO during winter from 1987-2011 could have created a false impression that Arctic temperatures are impacting the jet stream.
Kris said: As we all know, in the past few years the anomalously warm Arctic air weakened considerably the Polar Jet, triggering this Polar Jet to meander in giant meanders. Resulting in large pockets of cold air moving to the South. Do you have something to substantiate this hypothesis Kris? As you seem to be cognizant of the works of the jet stream, you will also know that when the AO index is positive, then the jet stream moves further north and strengthens, while when the AO index is negative, the jet stream moves further south and slows down, following a more wobbly path. Do you have anything substantial showing that: - The jet stream has slowed down under AO positive or negative conditions compared to 'normal' jet stream speed? - Or that negative AO (causing slower, meandering jet stream) has become more frequent than 'normal' occurrence of negative AO index?
I would agree with Neven; the anomalous events do not appear to be that far off compared to the historic record, at least when looking at DMI 80N. The spike in December peaked for 80N at 257K, which is -16C. The DMI 80N record from 1958-2002 seems to show 13 similar or more significant temperature peaks during winter months - although the incredible spike in early January 2000 looks like an error - maybe Y2K related..;-). In January 2016 the 80N temp is hovering at -19 to -26C, compared to the normal temp of -29 to -31C. However, you cannot really understand the temperature readings in a meaningful way, unless you consider the weather that caused the temperature. The weather in the past weeks seems to have been influenced in a major way by the clashing of the pool of warmer than normal water south of Nova Scotia and Newfoundland with the pool of cooler than normal water south of Iceland and Greenland. This natural breeding ground of winter storms has therefore been more active than usual, causing stronger than usual storms to enter the Denmark Strait pounding both Iceland and south east Greenland with much more snow than usual, and also causing equally higher than usual foehn in south west Greenland. And finally, due to more lows than usual climbing up the east coast of Greenland, winds around Svalbard and the Fram Strait, have been primarily from the south, causing warm, moist air to get near the Pole and cause the consistently high 80N temp readings. However, with the AO turning positive again, it seems the next low lingering in the Denmark Strait will move east with the jet stream, and a high will develop over the Arctic causing the gyre to get started and the 80N temp to move closer to normal. Makes me wonder if the ice during peak winter months prefers the 'not bird nor fish' style of weather that also seems preferable in peak summer months..
Hi Jim, I have lurked a bit on the forum thread, but does not have the time. However, for southern Greenland you see that this freezing season has seen a far higher amount of storms and resulting precipitation from the east, so that the foehn has been equally much higher than normal:
Toggle Commented Jan 21, 2016 on PIOMAS January 2016 at Arctic Sea Ice
And Rob; is back online
Toggle Commented Jan 21, 2016 on PIOMAS January 2016 at Arctic Sea Ice
AbbottisGone and Kris, There is really nothing to be scared about with the high temps at Illulisat.. Check out the phenomenon of foehn and sublimation: Here you see the foehn and how snow is accumulating on the east coast, while sublimation (and high temps at sea level) is visible on the western slope of southern Greenland: And luckily we are not being overwhelmed with hurricanes and typhoons: 2015 had the 4th lowest level of tropical storm activity since 1970 measured by the ACE index: The curious fact, which I have alluded to on another thread, is that only 2012, 2013, and 2014 had lower tropical storm activity - something few had anticipated with a warming and more humid atmosphere.
Toggle Commented Jan 21, 2016 on PIOMAS January 2016 at Arctic Sea Ice
Let me correct my statement above: Looking at the Climate reanalyzer, it seems like a massive low is going to wrap itself around Greenland and then moving to the CAA, causing cold temperatures at the center of the CAA, but causing yet again lots of warmer, humid air to drive into the Arctic from the Norwegian Sea.
Toggle Commented Jan 20, 2016 on PIOMAS January 2016 at Arctic Sea Ice
Hi Rob, While the guy maintaining the Arctic section of is taking a break, you can see the current and forecasted temps on this DMI site, which is still updated: Select 'ice temperature' to get the best view in lieu of the DMI 60N weather and 80N temp charts. It appears that a high is expected to arrive from northern Siberia, which will drive warm air towards Svalbard from the south, but ensure overall lower temps across the pack and ice convergence towards Beaufort.
Toggle Commented Jan 19, 2016 on PIOMAS January 2016 at Arctic Sea Ice
Somewhat off topic regarding Greenland melt water run-off in years following the strong melt of 2012: AN ICE LID - more greenland meltwater into the oceans: