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Messages - weatherdude88

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101
Arctic sea ice / Re: The 2017 melting season
« on: August 10, 2017, 05:09:17 PM »
From Extent Numbers and arctic.io images, the Trend seems to be that Ice is being dispersed by the Storms, thus keeping Extent Decline (relatively) lower, than expected.
But Jetstream Collapse & crossing the Equator plus Extreme Summer Events should give us the whole Picture about the State of the Ice (Slush).

Quite the Contrary.


102
The rest / Re: Do you understand the Enthalpy of Fusion of ice?
« on: September 15, 2016, 07:42:08 PM »
Since we are discussing the Enthalpy of Fusion, it is only fair we also discuss the Mpemba effect. Warm/hot water under certain conditions freezes faster than colder water.


103
Arctic sea ice / Re: 2016 sea ice area and extent data
« on: September 14, 2016, 03:00:31 PM »
I was aware of the 5 day trailing mean, however unaware it was used for the NSIDC minimum northern hemisphere sea ice extent value. It appears NSIDC does calculate their minimum/maximum values form a 5 day trailing mean. My apologies BornFromTheVoid, I  am expecting NSIDC to shortly release a press release with a minimum of  4.14*10^6 KM^2.

104
Arctic sea ice / Re: 2016 sea ice area and extent data
« on: September 14, 2016, 12:59:06 AM »
5 day NSIDC extent crept upward by 2k yesterday, so the likely minimum will be 4.137 million km2 from September 10th.

The NSIDC northern hemisphere sea ice extent minimum was September 7th, 2016 with a value of 4.083*10^6 KM^2.

ftp://sidads.colorado.edu/DATASETS/NOAA/G02135/north/daily/data/NH_seaice_extent_nrt_v2.csv

The 4.137 million KM^2 value was on September 9th, 2016. 4.083 is less than 4.137, and September 7th is before September 9th. Therefore the minimum was on the 7th.


105
Seems like many competing effects.  And thus anyone who proclaims the result is obvious, without citing precedent over a range of similar predicates, is claiming more knowledge than I would be willing to trust.

One thing it shows pretty clearly is that we have no SST's currently across the central arctic below -5C.  That indicates pretty definitively that the transfer of heat is not yet high enough to support a refreeze. 

My -5C claim is in part historical, in part from work presented elsewhere by others on these forums, and actually is shaded on the conservative side.  I've read from others here that the threshold may actually be a bit lower, at -10C. 

No need to be conservative because we have never had liquid water surface temps across the arctic at -5C as suggested by your first post. The initial map posted shows a large area of uniform 2 meter surface temperatures.

106
Arctic sea ice / Re: Home brew AMSR2 extent & area calculation
« on: August 24, 2016, 09:29:33 PM »
Find an Arctic SST map from September/October with -5 Celsius water temperature. Better yet find any map where there is arctic sea water at -5 Celsius or even an example in nature. You might be looking for a while since it does not exist.
OK, this is exactly what I was talking about  - a Troll. 

You are trying to imply that I was suggesting water wouldn't freeze at -5C or -10C.  Nonsense.  That's nothing like what I was saying.

You appear to be posting this to accomplish two things (1) distract the audience by attacking my credibility and (2) disrupt the discussion.

Just stop.

Show me any example where the liquid water temperature in the arctic is -5 Celcius?

My -5C claim is in part historical, in part from work presented elsewhere by others on these forums, and actually is shaded on the conservative side.  I've read from others here that the threshold may actually be a bit lower, at -10C. 

Show me this historical claim. Perhaps rather than continuous ad-hominems, you can address with an example or provide some scientific evidence? 

One thing it shows pretty clearly is that we have no SST's currently across the central arctic below -5C.  That indicates pretty definitively that the transfer of heat is not yet high enough to support a refreeze. 

We have never had liquid water surface temps across the arctic at -5C.


107
Arctic sea ice / Re: Home brew AMSR2 extent & area calculation
« on: August 24, 2016, 09:20:25 PM »
y, would not mean new ice, would mean melt pond freeze. Very normal on this time in the year.

Melt pond freeze over contributes to an increase in area. The argument here is "is CAB area increasing?" I am not going to get into an argument based on how much of the CAB increase is melt pond freeze over VS. new sea ice formation. These regions received significant increases the last several days based on AMSR2 from U Bremen sea ice concentration map images.

108
Arctic sea ice / Re: Home brew AMSR2 extent & area calculation
« on: August 24, 2016, 09:02:57 PM »
If so, then there was refreeze of melt ponds on the site to greenland, or what area do you mean?

The coldest regions of the arctic ocean had an extended period of anomalous cold surface temperatures based on the long term mean which is already well below freezing for 80 north and above. Here are the last three AMSR2 from U Bremen sea ice concentration map images. Look near the pole where we had anomalies. There is a significant increase in ice concentration in the last two days in this region.










109
Arctic sea ice / Re: Home brew AMSR2 extent & area calculation
« on: August 24, 2016, 08:40:51 PM »
@ weatherdude88

You make it to simple, you have to look where it was cold, not only if its be cold enough, here the past 7 days resolution anomaly: http://www.karstenhaustein.com/reanalysis/gfs0p5/ANOM2m_arctic/ANOM2m_past07_arctic.html

the cold was on the side, where ice is not open and already frozen, also is to note, that winds are also play a role by refreeze and we saw often very middle to strong winds, so therefore between the ice should be small ekman-pumping

Therefore its seem very unlikly that there was any kind of refreeze

You are proving my point. Go back and look at the sea ice area concentration maps. Some of those areas with the coldest anomalies saw an increase in concentration. Additionally, these anomalies are based on the long term mean.

110
Arctic sea ice / Re: Home brew AMSR2 extent & area calculation
« on: August 24, 2016, 08:35:32 PM »
My -5C claim is in part historical, in part from work presented elsewhere by others on these forums, and actually is shaded on the conservative side.  I've read from others here that the threshold may actually be a bit lower, at -10C.  However, I will do some additional research on it specifically.

Find an Arctic SST map from September/October with -5 Celsius water temperature. Better yet find any map where there is arctic sea water at -5 Celsius or even an example in nature. You might be looking for a while since it does not exist.

111
Arctic sea ice / Re: Home brew AMSR2 extent & area calculation
« on: August 24, 2016, 08:03:05 PM »
AMSR2 will "flip" on a daily basis.  It fails mightily when used to assert massive changes - melt or freeze - have taken place on a day to day basis.  Its best and effective use it over longer time scales. Using it as you have, you are indulging your confirmation bias and doing bad science.
 

Update 20160820.
Regional area in the CAB increased: +31k. The Laptev regions went the other way: -23k.

Update 20160821.
Same for CAB area: +63k.

The CAB area has been increasing for a number of days now according to the Home brew AMSR2 extent & area calculation. So anomalously cold below freezing temperatures at the surface for an extended period at 80 degrees north cannot cause a several day freeze up? The adjacent water that is near its freezing point cannot have a small amount of heat removed to form ice? Why do the other regions show losses under similar weather conditions? The scenario of a temporary refreezes or clouds causing false losses are more logical than false gains. This is the scenario that makes the most sense using thermodynamics/physics.


 
As one example, consider the attached DMI 2 meter temperature map for today below.  One thing it shows pretty clearly is that we have no SST's
2 meter temperature anomaly maps are for surface temperatures and are indeed not SST's.

At a fundamental level, your posts fail to demonstrate a cogent understanding at the forces in play. 

As one example, consider the attached DMI 2 meter temperature map for today below.  One thing it shows pretty clearly is that we have no SST's currently across the central arctic below -5C. 

It is well known arctic sea water freezes at around -1.8 Celsius. (Yes, this changes with salt concentration) If SST’s were -5C we would have ice at the surface. (not arctic sea water) Please elaborate on your -5 SST Celsius claim.

112
I really don't know how to get through to you. The increase is measured from AMSR2 which does not account for all clouds.

Comparing MODIS today and yesterday clearly shows why there was a sudden apparent increase in area across the CAB. Clouds increased dramatically.

I am telling you the clouds are the reason the area increased and you are telling me the area increased... you are just full of non-sequiturs today!

Update 20160820.
Regional area in the CAB increased: +31k. The Laptev regions went the other way: -23k.

Update 20160821.
Same for CAB area: +63k.

CAB area has been increasing for several days now according to the Home brew AMSR2 extent & area calculation. When did the cloud cover dramatically increase? In your above post you claim a dramatic increase comparing today and yesterday? Disregarding, comparing day to day images the cloud cover does not vary much.

https://lance.modaps.eosdis.nasa.gov/imagery/subsets/?mosaic=Arctic.2016236.terra.4km

I am still also trying to understand why we are not experiencing the same "bbr2314 phenomenon" in the other regions with similar cloud cover?


113
The CAB isn't increasing in area.

Regional area increased in the CAB : +53k. Area declined in Laptev (-26), Chukchi (-18k) and ESS (-16k).

In layman's, if the CAB really is decreasing and the satellites are "tricked" by cloud cover, why are we not seeing this same phenomenon the last several days in the above regions where there is currently the same or thicker cloud cover?


114
I would argue that cloud cover has more of an impact the less sea ice we have, but this becomes especially pronounced as area decreases relative to extent (i.e., as compactness goes down).

Consider; in 2012, things were bad, but the main pack was still cohesive. Whether or not this area was covered by clouds, it appeared entirely (or almost entirely) white to the satellites, with the uniformity in concentration aiding "steadiness" in observations. Cloud cover over open ocean is easier to reduce than cloud cover over a background that is the same color.

This year, with structure of the pack completely shattered, you have -- for the very first time -- only a small area of ice that is structurally intact. While this small triangle of area N of the CAA/Greenland falls into the same category as 2012's ice, the remainder most certainly does not.

With ice that is very dispersed, as in this year, cloud cover -- especially of the low sort -- masks much of the open water in between the ice, and the satellites have a much harder time distinguishing what is real vs. what isn't, at least when clouds are overhead. Additionally, I think open water *encourages* cloud cover this far N, especially as it gives up its latent heat from the summertime, further reducing accuracy as clouds have been nearly continuous over much of the Arctic this summer.

Again, the key is the overall structural integrity of the ice.

Updates of 2012 AMSR2 data seem to have been completed. We have complete data from the first of August to 30th September. Thanks for that.

Update 20160823.

Extent: -81.4 (-123k vs 2015, -733k vs 2014, -706k vs 2013, +784k vs 2012)
Area: -8.3 (-296k vs 2015, -976k vs 2014, -946k vs 2013, +484k vs 2012)
 
You will find the updated graphs in the top post

Regional extent declined in the CAB (-32k) and Laptev (-19k).

Regional area increased in the CAB : +53k. Area declined in Laptev (-26), Chukchi (-18k) and ESS (-16k).

The attached delta map is of the Beaufort-Chukchi-ESS corner. Lots of reds and blues confirm there is a lot of ice moving around. The detachment of the Wrangek ice progresses further.

bbr2314,

Please explain why the CAB is increasing in area, whereas the ESS and Chukchi lost area. Are you hypothesizing the ice is in better shape in these region than the CAB? (Or is there even any ice there if it is in worse shape?) Additionally, with the storminess on the Russian side surely there is thicker cloud cover currently in the Laptev. So why does the Laptev also show loses? Please help me understand your "theory" works with respect to the above regions?

115
Arctic sea ice / Re: Home brew AMSR2 extent & area calculation
« on: August 24, 2016, 03:45:43 PM »
Regardless,  AMSR2 from U Bremen sea ice concentration map shows a significant gain in ice area in the CAB. Our cyclone is long gone from the Canadian side of the arctic. 




116
Arctic sea ice / Re: Home brew AMSR2 extent & area calculation
« on: August 24, 2016, 01:27:34 AM »
MODIS shows an inordinate amount of very thick clouds today. Once those clear I would think the CAB flashes back to major red and we have a "false" drop of 150K+ to account for the "gains" that weren't really there.

Quote
A key feature of these AMSR instruments is the ability to see through clouds, thereby providing an uninterrupted view of ocean measurements

http://www.remss.com/missions/amsr

Please provide scientific evidence on where AMSR instruments show "false gains" due  to cloud cover to support your claim. If you do not provide any, most in this forum including myself will conclude this is another Dunning-Kruger-Esque statement.

If you ever followed concentration maps closely than you would have noticed plently of false sea ice detection.

Today there is ice detected in the Sea of Okhotsk and around northern Japan. These areas are probably masked out in August, but false detection remains in the Arctic basin.

Its possible that there are plenty of ice crystals in the clouds, but defenitly none in the sea.

Quote
this approach only detects the first appearance of open water so potential refill of ice is not accounted for.


Quote
Conversely, the better agreement with AMSR-E and IMS compared to QuikSCAT and IMS is likely due to the reduced sensitivity to transient weather events that can affect QuikSCAT (Howell et al., 2010 and Yu et al., 2009).

http://www.sciencedirect.com/science/article/pii/S0034425714000649

At variance with:

Quote
False ice concentrations can occur due to bad weather systems.

http://www.iup.uni-bremen.de:8084/amsr2/regions-amsr2.php

However, if we take a look at the other sea ice area models, and when we experienced moderate to strong loses the first several days of cyclonic weather, why did ASMR instruments not show "false gains"? Even though we had anomalously cold weather with snowfall? Why do the other sea ice metrics correlate closely with ASMR2 even though they use different algorithms?

Speak for yourself Weatherdude, and the others will speak for themselves. I could be wrong, but I think most will disagree with you.

Why would ASMR instruments show a 87.7 thousand square kilometers gain over 2 days with similar atmospheric conditions to the previous several days? It seems more likely from a scientific point of view that "false loses" were reality when areas were refreezing.   

I am still waiting for scientific proof that ASMR instruments show large scale "false gains" over multiple days above 70 degrees north.


117
Arctic sea ice / Re: Home brew AMSR2 extent & area calculation
« on: August 23, 2016, 11:24:10 PM »
MODIS shows an inordinate amount of very thick clouds today. Once those clear I would think the CAB flashes back to major red and we have a "false" drop of 150K+ to account for the "gains" that weren't really there.

Quote
A key feature of these AMSR instruments is the ability to see through clouds, thereby providing an uninterrupted view of ocean measurements

http://www.remss.com/missions/amsr

Please provide scientific evidence on where AMSR instruments show "false gains" due  to cloud cover to support your claim. If you do not provide any, most in this forum including myself will conclude this is another Dunning-Kruger-Esque statement.

118
Arctic sea ice / Re: The 2016 melting season
« on: August 16, 2016, 01:01:22 AM »
Plot the same graph from each source if you want to show differences, not one thing from DMI and something different from PIOMAS.

I'll leave that as an exercise for the interested reader. FTB for example?

Jim, thank you for your presentation of the US Navy HYCOM/CICE implementation against the DMI HYCOM/CICE presentation. It seems to me that in this particular case (2016 versus 2012) the US Navy HYCOM/CICE model is consistent with PIOMAS and Cryosat 2 observations, and DMI is NOT.

For example, as early as June 23, DMI still showed 3 - 4 meter ice in the Pacific section of the CAB :


None of the other ice volume product (US Navy HYCOM/CICE nor PIOMAS nor Cryosat 2) show that thick ice in that area.
 
And may I add that Richard Rathbone provides only unfounded criticism of your work, and fails to provide ANY evidence in this comparison.

PIOMAS clearly shows thicker ice than 2010,2011,2012, and 2013.



Since the last PIOMAS update was in July and weather conditions have remained favorable for slower than average ice melt, it is no surprise DMI's updated sea ice thickness shows thicker ice than 2012. (Keep in mind, in 2012 the GAC already did most of its damage in relationship to ice volume as demonstrated by the various papers posted here). Furthermore, DMI's sea ice thickness model is based on HYCOM-CICE. Lastly, your posted graph is from 2015.

119
Arctic sea ice / Re: The 2016 melting season
« on: August 12, 2016, 05:02:09 PM »
Temperatures remain anomalously cold in the arctic.
...
The upcoming storm will serve to reinforce/intensify these anomalies. A fifth place finish in sea ice extent is looking likely, with an early minimum.
...

Considering your assessment same time last year using the 925 hpa plots, when you predicted a "significant slowdown" that might lead 2015 be above 2013 and 2014,

http://forum.arctic-sea-ice.net/index.php/topic,1149.msg59717.html#msg59717

I should put all my chips this year finish record low.

might

Quote
The rapid pace of daily ice loss seen in late July 2015 slowed somewhat in August.
http://nsidc.org/arcticseaicenews/2015/09/steady-decline-summer-minimum-approaching/

Considering members here were predicting 2015 would beat 2012 I rest my case. Seaicesailor, how about you make a prediction we can judge your accuracy? (We can see who is closer and we will find out in 45 days or less) The anomalously cold weather, cloud cover, and physical forces of low pressure with regards to ice dispersion will be extremely favorable for ice preservation. 2012 featured anomalously warm weather leading up to and following the storm. (This is nothing like the 2012 GAC)

120
Arctic sea ice / Re: The 2016 melting season
« on: August 12, 2016, 04:15:05 PM »
Temperatures remain anomalously cold in the arctic.





The upcoming storm will serve to reinforce/intensify these anomalies. A fifth place finish in sea ice extent is looking likely, with an early minimum.






121
Arctic sea ice / Re: Home brew AMSR2 extent & area calculation
« on: August 09, 2016, 03:33:40 AM »
The question is, how much of this mobile, thin, shattered ice will melt out from bottom melt in the next few week.  Higher salt water is flowing in from the North Atlantic. Anomalous pockets of warmth still persist north of Canada.

I know that the HYCOM thickness maps are considered unreliable but still I suspect truth in this.  August 6 2012 vs 2016.  How much will go "poof"?

DMI sea ice thickness 2012 VS. 2016




122
Arctic sea ice / Re: The 2016 melting season
« on: July 10, 2016, 04:44:11 PM »
A study at the University of Leuven in Belgium determined that clouds are doing more to melt the surface of Greenland's ice sheet than to prevent such. Why? They concluded that it's because of white surface of the ice. Why would the same not apply to sea ice? Now surely, where the ice has already melted and left mostly open water, the clouds would hinder insolation. However, what about when they cover a nice undisturbed area of white, high albedo ice? From what I have read lately, they no longer believe the clouds to be such a protection. Of course, NASA themselves are still learning when it comes to clouds. They have concluded that not all clouds are the same in regard to whether they effectively heat or cool a surface below them. When they do heat the surface its not by much; one of us humans would much prefer to be in the shade of a cloud and be just a little warmer than say maybe that of a tree, if we had to choose that or to be in the open sunlight. The ice however, as long as it absorbs enough energy starts to melt.
Also, as of late, researchers have learned that just as the climate changes clouds, clouds can change the climate, a feedback thing.
Not trying to say this is going to melt every crystal of ice in the Arctic by September, but it may have a greater impact than previously thought.

Quote
Using an advanced snow model, we find that this warming enhances GrIS meltwater runoff in response to reduced refreezing rates at night, when cloud warming is highest compared with clear skies.

http://www.nature.com/ncomms/2016/160112/ncomms10266/full/ncomms10266.html

The arctic has near 24 hours of sunlight during the summer months. It is common sense that cloud cover at night retains more heat at the surface VS. clear night time skies. The net effect for a cloudy day with 12 hours of sunlight and 12 hours of night time is cooling. This paper says nothing new.


123
Arctic sea ice / Re: The 2016 melting season
« on: July 10, 2016, 08:36:24 AM »
I notice a lot of people aren't counting synergistic effects the different variables have on the ice when it is in this state.

The most common one is sunlight and open water, open water absorbs solar radiation and heats, which causes more open water.

But open water also releases longwave IR to the atmosphere. In this case, cloudier weather would be more beneficial overall since the massive amount of heat escaping would be partially reflected back.

Now consider that there are also sunny parts of that Arctic going on at the same time, heat absorbed by the water in those areas could be transported to the cloudy areas via currents, and then trapped by the clouds.

Tl;dr: Open water is bad regardless of the weather.

The net cloud effect is 21 W m-2 cooling on average. Cloudy conditions favor less ice melt given they reflect more radiation into space than they reradiate back down through the atmosphere to the surface.

http://www.met.reading.ac.uk/~sgs02rpa/PAPERS/Allan11MA.pdf

124
Arctic sea ice / Re: The 2016 melting season
« on: June 28, 2016, 07:58:41 PM »
I said surface temps are running warmer than 925 *not* running above normal though it is irrelevant since it is only a half-degree difference.

Please define "warmer than 925"? At first glance 2M temperatures are currently in the same or at a lower percentile than 925 MB.





"irrelevant" Considering at the surface arctic ocean water freezes at -1.8 C, freshwater at 0 C, and taking into account the proximity to and the high heat capacity of water, I would conclude it to be relevant. Just because the temperature anomaly range at 925 MB is greater, does not make the "half-degree difference" at the surface irrelevant.



 


125
Arctic sea ice / Re: The 2016 melting season
« on: June 28, 2016, 05:42:55 PM »

How about a guide to what 925mb temps mean? I am not a meteorologist so anyone with in depth knowledge in that area (thermodynamics of the atmosphere) correct me if I am wrong.
In a standard atmosphere 925mb is the air pressure 760m above sea level. If air is warmed at the ground and then rises it is colder at that height because it expands and cools from 1013mbar. In the arctic ocean where the sea ice keeps temperatures of the surface around 0 deg C temperatures are often higher at 925mbar than at the surface. This is because air from elsewhere (where land surfaces warm the air) which moves north is less dense than the cold surface air and therefore "floats" above it. If winds create enough turbulence mixing of that air down to the surface will warm the surface and cool the air. This is why surface air temperatures (at 2 meters off the ground) are never far from 0 deg. The 925mbar temps show more strongly when warm air comes into the arctic. The low average shows that despite the inflows which have occurred for short periods the overall effect has not been as strong as in other years.
What temperatures do not show strongly is the heating which goes into water from sunlight. Water is warmed through absorption over a large depth / volume of water so temperatures rise slowly.
When the spreading of the ice shown in bbr's posts opens water (which is cold) absorption is increased but surface temperatures don't rise, possibly fall.

I would add that adiabatic heating means that air at 925hp will be around 4 to 5 degrees warmer when it mixes down to the surface. In a high pressure system air from  higher in the atmosphere sinks to the surface causing substantial heating which will raise the 925hp temp.  At the same time the sinking air clears out the clouds allowing a combination of sunshine and warm sinking air to melt ice.  High pressure, high 925hp, high solar radiation and high surface melting often coincide.

You have to specify the time of year. For example: during the winter months the 925 MB temperatures on average are warmer then the surface. (Temperature Inversion) This is directly due to a lack of sunlight (thermal energy) to heat the layers of the atmosphere. There is a continuous loss of heat from the surface. The thermal energy from the sun trumps the properties of the air that rise or lower with different atmospheric conditions. When the sunlight returns across the arctic the temperature inversion returns to the standard profile we see at lower latitudes year round. The high heat capacity of liquid and frozen water at the surface keeps the surface near freezing during the summer months. You also have to specify the conditions. Over land in general there is a 7.4616 C temperature difference between 925 MB and the surface when there is sunny weather. When there is water falling through the column the temperature difference on average is 4.5797 C on average. Keep in mind sunny weather heats the water at surface as well as the air molecules in the atmospheric layers above. Cold 925 MB temperatures are an indication of cloudy weather. Less thermal energy in the lowers layer of the atmosphere and surface are significantly favorable for less ice melt.

126
Arctic sea ice / Re: The 2016 melting season
« on: June 28, 2016, 04:02:28 PM »

Can we have a guide to not posting 925mb temps? Surface temps have been running much warmer, as has been posted *numerous* times in the past few pages.

Surface Temps are currently anomalously cold at latitudes 80 degrees and north.





Additionally ice volume is now ahead of 2012 and 2015.



I am expecting PIOMAS to reflect this during the next update since they closely correlate.

127
Arctic sea ice / Re: The 2015 melting season
« on: September 06, 2015, 05:37:12 PM »
As far as I understand it, El Nino itself (which we are not in one yet)

Not yet? What definition are you using? Most would say it started at least 6 months ago.

http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_disc_feb2015/ensodisc.html
5th Feb 2015 only a watch

http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_disc_mar2015/ensodisc.html
5th March 2015 - El Nino Advisory

(El Niño or La Niña Advisory: Issued when El Niño or La Niña conditions are observed and expected to continue.)

We very clearly have not met the criterion for El Niño as of yet even though it is imminent. NOAA defines El Niño as a 3-month running average of the sea surface temperature anomalies of the NINO3.4 region that must remain at or above +0.5 degrees. Once the JJA ONI value updates we will have an official El Niño. (This update will be the fifth consecutive 3 month running average greater than .5 Celsius) NOAA El Niño conditions are defined as:

1. Departures in the Niño-3.4 index equal to or exceeding +0.5C for a single month.
2. The tropical Pacific atmosphere should be consistent with El Niño. In particular, rainfall should be enhanced near the Date Line and suppressed near Indonesia, and the surface winds across parts of the equatorial Pacific should be anomalously westerly.
3.A forecast that the ONI will equal or exceed +0.5C for several seasons in a row.

An official El Niño and El Niño conditions are different mechanisms. Please do not confuse them.

128
Arctic sea ice / Re: The 2015 melting season
« on: August 26, 2015, 03:07:25 PM »
DMI arctic sea ice volume is showing big gains.




129
Arctic sea ice / Re: The 2015 melting season
« on: August 24, 2015, 04:52:51 PM »
I've decided I want to say something.  ;)

I think what is happening, is that the melt ponds in the Central Arctic are freezing over now that temperatures are dropping below zero. This effect will show up in the area data, and not in the extent data, as those melt ponds never were counted as open water. Another reason could be that there is little compaction going on, and thus no compensation there.

Neven,

Statistically speaking of course, if we have a few more days of this the earliest arctic SIA minimum in the modern era will be likely.

130
Arctic sea ice / Re: The 2015 melting season
« on: August 24, 2015, 04:49:34 PM »
The storm is still there on the 06z ECM. Will be interesting to see what effect it has.

 ;D
There is a 0z ECMWF and a 12z ECMWF model run. This model is only initialized twice a day unlike its american cousins. The model run you posted above is the 0z ECMWF.

131
Arctic sea ice / Re: The 2015 melting season
« on: August 06, 2015, 07:04:25 PM »
The significant slowdown has begun. The last two days we lost 81830 square kilometers according to IARC-JAXA. By comparison in 2014 we lost 102286 square kilometers and 2013 we lost 130287 square kilometers during the same period. The guidance shows the weather pattern remaining entrenched through the remainder of the month. We may even have higher sea ice extent than 2013 and 2014 by the time we reach minimum. 925 Hpa temperatures over the arctic continue to plummet.






132
Arctic sea ice / Re: The 2015 melting season
« on: August 06, 2015, 02:04:57 AM »
...

Weatherdude88... Are you really arguing about the ice in Baffin Bay as if it is that significant to what is happening further North?

*And* not making that clear to me?

If so, please stop trolling.

SST's are not only colder in the eastern arctic, but also in the Greenland sea and Svalbard. You are the one claiming a late minimum based off SST's that are slightly colder than previous years. (Either way SST's are not unprecedented) It has always been assumed when talking about the eastern arctic while living in the western hemisphere is the region below:



133
Arctic sea ice / Re: The 2015 melting season
« on: August 05, 2015, 11:57:45 PM »
Excuse me? Lower SSTs?

http://polar.ncep.noaa.gov/sst/ophi/color_newdisp_anomaly_north_pole_stereo_ophi0.png
Your SST anomaly map uses the baseline 1961-1990. (Thats what gives it such a warm appearance)
SST anomalies in the eastern arctic are indeed cooler then the previous few years. Here is 2014 VS 2015.





In addition the eastern arctic has the highest ice coverage in the last 10 years. (It must be from those warm SST's  :P)

http://ice-glaces.ec.gc.ca/prods/CVCHDCTEA/20150803180000_CVCHDCTEA_0008402993.pdf

http://ice-glaces.ec.gc.ca/prods/CVCHACTEA/20150803180000_CVCHACTEA_0008402997.pdf

134
Arctic sea ice / Re: The 2015 melting season
« on: August 05, 2015, 06:39:21 PM »
That is a line on a graph.

Several of us have provided very reasonable refutations of your assertion regarding the Beaufort and Chukchi.

Explain first why the numbers you expect would be a slowdown. Then please, show us why. Where will the heat already present go, if not into the ice?

In my post regarding the Beaufort I stated "if the pattern continues". So even if you believe the hiatus in the region is due to ice export there will still be plenty of ice in the central arctic to export into the Beaufort. In reference to the slowdown, this pattern has been firmly entrenched for greater than one week now. The cloud cover has significantly reduced the solar radiation entering the system. The heat that was in the system from the above average July heat has had plenty of time to moderate over the last two weeks. Models keep below average temperatures over the Beaufort and favor any melting to be in-situ. Therefore I am fully expecting a very slow melt rate in the western/central arctic. The SST's in the eastern arctic being colder than recent years will limit the melting there. 

135
Arctic sea ice / Re: The 2015 melting season
« on: August 05, 2015, 06:08:10 PM »
More evidence of the impending significant slowdown. NORSEX Ice Area is making an early turn. I fully expect sea ice extent loss on JAXA over the next 5-10 days to average under 50,000 square kilometers per day.




136
Arctic sea ice / Re: The 2015 melting season
« on: August 05, 2015, 05:44:17 PM »
No, you can't. What you also can't do is compare apples and oranges.

Jim,

Perhaps you should work more on your reading comprehension. I was responding to David's quote below where he claims that the MASIE metric has not increased at all over the past 12 days (now 13 days) by visually eye balling a graph without looking at the raw data. 

There is nothin gin the MASIE record that  suggests that even that  measure has increased over the past 12 days.
http://nsidc.org/data/masie/masie_plots.html

137
Arctic sea ice / Re: The 2015 melting season
« on: August 05, 2015, 04:14:40 PM »
There is nothin gin the MASIE record that  suggests that even that  measure has increased over the past 12 days.
http://nsidc.org/data/masie/masie_plots.html

Sure there is. Day 204 we had 866733.79 square kilometers of MASIE sea ice extent in the Beautfort. Day 216 which was yesterday we had 868666.75 of MASIE sea ice extent in the Beautfort. We have gained now 1,932.96 square kilometers in the Beautfort over the last 13 days using the MASIE metric. (866733.79 square kilometers - 868666.75 square kilometers = -1,932.96 square kilometers) This graph was plotted with the data in the link I posted above. You cannot just ignore the raw data because your eyes are not sharp enough to see the increase.

138
Arctic sea ice / Re: The 2015 melting season
« on: August 05, 2015, 03:53:21 PM »
Weatherdude,
MASIE is not an accepted measure of extent , it  is used for completely different purposes. The accepted measures are IJIS / Ajax and NSIDC. 

https://nsidc.org/data/masie/

The accepted measures use a limit of 15% or 30% sea ice. Masie is virtually anywhere where you  might see ice which is a much  larger area and even a single ice berg is enough to  cause the area to  be counted.

http://nsidc.org/data/masie/about_masie.html

Quote
MASIE-NH stands for the Multisensor Analyzed Sea Ice Extent – Northern Hemisphere. It is similar to the Sea Ice Index (SII) product in that it is easy to use and gives a graphical view of ice extent in various formats. However, it relies more on visible imagery than on passive microwave data, so the ice edge position will generally be more accurate than that of the Sea Ice Index.

Quote
The Sea Ice Index ice extent is widely used, but the edge position can be off by 10s or in some cases 100s of kilometers. NIC produces a better ice edge product


139
Arctic sea ice / Re: The 2015 melting season
« on: August 05, 2015, 05:10:43 AM »
Quiet daily update from U. Bremen.

Confirmation that the ice in the Beaufort and Chukchi Seas is not long for this world.



The Beautfort is looking quite robust. Sea ice extent has gained over 3455.03 square kilometers in the last 12 days. If this pattern continues there will be very little melt in the Beautfort. There also has been a significant slow down in the Chukchi during this past week.

ftp://sidads.colorado.edu/DATASETS/NOAA/G02186/masie_extent_sqkm.csv

Edit: Since this is a ftp you have to copy and paste the link

140
Arctic sea ice / Re: The 2015 melting season
« on: August 03, 2015, 08:04:29 PM »
Waters approaching 10C are reaching north of Svalbard. Several other areas looking quite toasty too, including Baffin Bay.

Not all maps are created equal. The range of colors make that map impossible to interpret the SST's. A reality check shows SST's much cooler then your "10C".




142
Science / Re: Discussions on climate sensitivity at Ringberg
« on: July 30, 2015, 09:46:31 PM »
Just curious: Where does a low climate sensitivity get us temperature-wise at the end of 2100 under a business-as-usual scenario? That means a doubling around 2050, right? And then it continues, so that by 2100 we're at around 600 ppm.

Neven,

Here is a link to a climate sensitivity calculator. (However the climate sensitivity range is only from 2-5 C)

http://scied.ucar.edu/climate-sensitivity-calculator

143
Arctic sea ice / Re: The 2015 melting season
« on: July 30, 2015, 08:12:15 PM »
What a difference two weeks make.


144
Science / Re: Discussions on climate sensitivity at Ringberg
« on: July 30, 2015, 07:37:33 PM »
http://link.springer.com/article/10.1007/s00382-014-2342-y


"Using 1859–1882 for the base period and 1995–2011 for the final period, thus avoiding major volcanic activity, median estimates are derived for ECS of 1.64 K and for TCR of 1.33 K. ECS 17–83 and 5–95 % uncertainty ranges are 1.25–2.45 and 1.05–4.05 K; the corresponding TCR ranges are 1.05–1.80 and 0.90–2.50 K."

I see a general reduction in climate sensitivity estimates first in journals and then the IPCC assessments over the coming years. I would make a strong argument that climate sensitivity is most definitely on the lower end of the range (or less) given we are in a inter glacial and temperatures are suppose to rise. (This start of the years for the base period falls towards the end of the little ice age which corresponded with low solar activity) Temperatures where already rising due to an increase in solar activity.

145
Science / Response to Plinius
« on: July 30, 2015, 06:59:59 PM »
I think, weatherdude, you should stop bullshitting around about things that you do not understand. Climate models (CMIP5) with updated forcings (yes, unheard of, but somehow people failed to predict volcanic eruptions...) are fully in line with the observations (and do _NOT_ overpredict temperature rise), and they do have ECS between 2.1 and 4.5K.
http://onlinelibrary.wiley.com/doi/10.1029/2012GL051607/full

I see I hit a nerve. Perhaps you are angry because you are biased? This paper is almost the equivalent of a "sectional". Even the IPCC reduced climate sensitivity after this paper was published.

Apart from that:
Combining this paper:
http://www.nature.com/ngeo/journal/v7/n9/abs/ngeo2228.html

Here is a paper claiming half the warming in the arctic is from natural variation.
http://www.nature.com/nature/journal/v509/n7499/full/nature13260.html?WT.ec_id=NATURE-20140508

with this one:
http://onlinelibrary.wiley.com/doi/10.1002/2015GL064888/abstract

Right from this link the paper claims to only be able to account for 38% . "Applying the methodology of the HadCRUT4 record to climate model temperature fields accounts for 38% of the discrepancy in trend between models and observations over the period 1975-2014."

I suppose that one can call your unfunded blunder about low climate sensitivity in the 1.5 region pretty optimistic, given that the transient response is already above 1.8K.
Maybe some divine intervention lowers the climate sensitivity below the transient response?

For example CERES suggest a climate sensitivity of 1.3 C. (All the recent data sets I have seen imply climate sensitivity below 1.5 C.
http://ceres-tool.larc.nasa.gov/ord-tool/jsp/EBAFSelection.jsp


   

146
Arctic sea ice / Re: The 2015 melting season
« on: July 30, 2015, 06:47:05 PM »

The IPCC lowered the range of climate sensitivity from 2 -4.5 C down to 1.5-4.5 C in their last assessment. Over 95 percent of climate models have overestimated the warming trend since 1979. It has become increasingly clear that the climate is less sensitive then originally projected. (And in reality I predict it is much lower) The climate has always changed naturally and will continue to do so, and for you to claim warming from anthropogenic forcing are worse than predicted and to try and distinguish anthropogenic warming from warming in natural variation shows your unscientific bias. Here is a paper claiming CO2 has a radiative cooling effect. Am I claiming the earth is cooling? No Let's get back to logic and most importantly back on topic.
http://onlinelibrary.wiley.com/doi/10.1002/qj.2628/abstract

The paper you linked to isn't about the climate impacts of CO2. When the paper refers to positive or negative feedbacks at different temperatures, it's referring to feedbacks on self aggregating convection in the model they use.

It's best to think a little rather than blindly accepting what the climate denier blogs tell you.

EDIT: Sorry for going off topic, Neven. Is there a suitable thread for these comments elsewhere?

I read the paper. My point was there is no need to pick and choose articles/literature as one can find multiple to try and validate their point. There is no requirement for scientist to try and prove GHGs cannot warm the surface. It was already done. This paper uses the terminology  ‘positive feedback’ incorrectly. Solar energy cannot signify a positive feedback and green house gases can only represent one in a system. What is intriguing is a cooler atmosphere not being able to warm a surface. You cannot argue against thermodynamics. I will post all further responses in other thread.

147
Arctic sea ice / Re: The 2015 melting season
« on: July 30, 2015, 05:50:57 PM »
<lots of snipping by Neven>

Let's get back to logic and most importantly back on topic.

<I'm letting the only useful remark stand. Because the other 7 of your 8 comments so far have been relatively mild, I won't ban you, weatherdude88, but I don't want any more climate risk denial on this forum, okay? Thanks, N.>

148
Arctic sea ice / Re: The 2015 melting season
« on: July 28, 2015, 10:18:17 PM »
As the dipole shifts more to the NW of Greenland this week

I would suggest understanding the terminology you are using before posting.

Quote
The Arctic dipole anomaly is a pressure pattern characterized by high pressure on the arctic regions of North America, and a low pressure on the Eurasia region

https://en.wikipedia.org/wiki/Arctic_dipole_anomaly


149
Arctic sea ice / Re: The 2015 melting season
« on: July 28, 2015, 05:49:11 PM »
depends on how much ice dies on the European side. A lot of warm water appears to be driven under the ice from north atlantic and Barents. No need to export the ice if you can melt it out in situ.

And apart from this: I would not call the first week of August "End of the melt season".

plinius,

SST's in August average above -1.8 Celsius in the western and Siberian side of the arctic, so of course you will have melt throughout the month of August. (Water has a very high heat capacity and therefore will trump air temperatures) Additionally the wind profiles suggest ice transport from the eastern side to the Beaufort which is the mechanism that could increase extent in that region. Let's be realistic. If this pattern locks in place there will be a dramatic slowdown. SST's in the northern Atlantic are colder then the previous 5 melting seasons. So I fail to see how SST's from the northern Atlantic or Barents will have a significant effect.

150
Arctic sea ice / Re: The 2015 melting season
« on: July 28, 2015, 05:33:23 PM »
OUCH! The arctic dipole is forecast to be over the Arctic 5 days now. It arrived yesterday on the 27th...  This is the forecast on 8/1/15 ... Not good folks not good.. http://earth.nullschool.net/#2015/08/01/1500Z/wind/isobaric/250hPa/overlay=mean_sea_level_pressure/orthographic=-90.00,90.00,450

12Patrick,

Quite the opposite. Your link is not a dipole. A anomalously cold pattern appears to be locking in place in the arctic for the month of August. The latest guidance suggest ice retention versus ice export. We may even sea ice extent growth in the Beaufort this month. It appears to be a very boring end to the melt season.

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