"Smart" and "Stupid" Questions - Feel Free To Ask

[wallen]

As previously stated I am just an novice, but follow this forum with great interest. What I haven't seen though any reporting/ references regarding the increasing levels of Methane and it's potential impact on the ice.

[crandles]

It is rising again after a plateau from circa 2000 to 2007



Lots of reports of methane plumes increasing, but not really showing up in the data.

[Pmt111500]

It is rising again after a plateau from circa 2000 to 2007

Lots of reports of methane plumes increasing, but not really showing up in the data.

Yep. Oceanic Plumes not yet big enough to reach surface, my guess the general rise is from melting permafrost. At least the yearly pattern fits to it.

[gerontocrat]

As previously stated I am just an novice, but follow this forum with great interest. What I haven't seen though any reporting/ references regarding the increasing levels of Methane and it's potential impact on the ice.

Find permafrost in the cryosphere section. In there lots of threads about methane release. Note the effect is as a potent greenhouse gas, i.e. increases temperature increases and thus an indirect effect on sea ice.

[Thomas Barlow]

As previously stated I am just an novice, but follow this forum with great interest. What I haven't seen though any reporting/ references regarding the increasing levels of Methane and it's potential impact on the ice.

You can follow that in the 'Permafrost' discussion, under 'Arctic Methane Release'.
https://forum.arctic-sea-ice.net/index.php/topic,12.0.html

[wallen]

Thank you.

[gerontocrat]

The Boundaries of the Arctic Ocean Seas.

I looked for a definitive map of the Arctic Ocean with the boundaries marked in three ways - those used by the NSIDC for their regional extent and area spreadsheets, and the political boundaries.

I did not do very well.  I attach examples

Any idea where I can find them?

[Shared Humanity]

While it may be necessary to set boundaries in order to track extent and area in individual seas, the boundaries are hopelessly arbitrary and only serve to obfuscate what is going on with the sea ice. It would be far more useful to track the Arctic using the geological features (troughs and ridges, islands and shelves, ocean currents etc.)

[oren]

I think this is the NSIDC regions map.

[gerontocrat]

I think this is the NSIDC regions map.

Thanks Oren -  I guess so too. (Though St Lawrence doesn't get separated I am not going to quibble)

[Pmt111500]

The Lomonosov-ridge separating the Canadian Arctic basin from the parts very much subject to atlantification could be a dividing line but as the difference between Pacific and Atlantic warming becomes more relevant the dividing line becomes less relevant. Who suspects Greenland will shed it's ice to Pacific?? Nobody. Thus Greenland keeps the NA relatively cool compared to any other ocean save Antarctic and people still wonder why people elsewhere want to escape to the relative coolness of the lands near Greenland. In a bar so the possible later posts will be more incomprehensible.

[Tor Bejnar]

FYI, I cross-posted these maps in the Arctic Maps thread.

[wallen]

With the recent crossing of the Arctic in winter by a large ship without assistance is obviously the start of more to come.  As more  and more ships follow this path, I wonder on the extent of impact this will have on the refreezing of the ice over the winter period.

[Pmt111500]

With the recent crossing of the Arctic in winter by a large ship without assistance is obviously the start of more to come.  As more  and more ships follow this path, I wonder on the extent of impact this will have on the refreezing of the ice over the winter period.

Negligible, the ships follow the path of least resistance which usually is following the previous ship forming a convoy just by convenience. Any ice forming on the channel gets under the ice and likely gets stuck beneath the ice cover at most 2-3 miles of the channel. Well you could say it thickens the narrow borders of the clear channel. (Basing this on Baltic)

[Krakatoa]

I was wondering how much NSIDC's data on sea ice concentration is telling us about the current state of Arctic Sea ice. When I eyeball the data for day 140, to me it looks like this year the ice in the Arctic Ocean is relatively healthy. I see a lot less light blue spots compared with years like 2016, 2015 or 2012.

Can this be an indication that this year's summer minimum will be more on the high side (like last year)?

[Daniel B.]

Krakatoa,
The answer is maybe.  I know that is not giving you much, but many factors contribute to the annual minimum.  I would say you are more likely to be right than wrong, but the current state of the ice is but one factor.  Comparing to other years:  2016 witnessed much greater melt in the spring, but less so around the solstice.  The early melt gave it a head start to finish on the low side.  2014 also started out with high melt, but slowed significantly during the summer, resulting in a relatively high minimum.  Conversely, 2012 had much less spring melt, but it picked up in June, accelerating through the summer to the lowest minimum witnessed.  2015 started similar to 2012, but never had the summer acceleration.  Thus far this year, the spring melt has been somewhat average.  If this continues through the summer, you will be correct. 

[Shared Humanity]

Krakatoa-

Not sure what you are seeing when compared to last year. There is always going to be some variation when comparing years but the entire Atlantic side is far worse than last year, less ice in Greenland Sea, Barents and very weak ice north of Svalbard and around FJI.

[Krakatoa]

You're right that the Atlantic side looks worse this year that 2017. I was mostly looking at the Beaufort and Chukchi side of the Arctic basin. There 2018 looks more solid than most years. And I believe that there is also where most extend loss is happening during summer.

[Alexander555]

I think 2018 looks a little scary. Because the only year where the Chukchi  Sea  looks as bad as today, is 2017. And only 2016 looks worse for the Beaufort Sea. All in the last few years. And the only places were the ice is a little thicker than normal, are places the normaly always melt out. If i'm right. And the central arctic basin is going to get some heat in the near future.

[GoSouthYoungins]

I think 2018 looks a little scary. Because the only year where the Chukchi  Sea  looks as bad as today, is 2017. And only 2016 looks worse for the Beaufort Sea. All in the last few years. And the only places were the ice is a little thicker than normal, are places the normaly always melt out. If i'm right. And the central arctic basin is going to get some heat in the near future.

And the oceans are warmer. And the GHG concentrations are higher. As always, what happens this year is weather dependent, but it doesn't take a PhD to realize "Sooner, rather than later. Faster than Forecast"

[thejazzmarauder]

Neven has previously said that the worst possible weather for the arctic would be high pressure in June/July and then a big storm at the end of summer.

1) Does high pressure produce more surface melt than cloudy skies would at the same temp? Or do the sunny skies that accompany high pressure simply act to help increase temperatures?

2) What is a meaningful high pressure # (e.g. 1015, 1025, 1035)?

3) Is there a point where a higher pressure is no longer worse for the sea ice (e.g. 1030 is bad but 1040 is no worse)?

4) Can high pressure + slightly below freezing temps still produce melt ponding, or do temps need to be above freezing?

[Neven]

1) Does high pressure produce more surface melt than cloudy skies would at the same temp? Or do the sunny skies that accompany high pressure simply act to help increase temperatures?

Yes, it does, because the solar radiation is absorbed by the ice or open water.

2) What is a meaningful high pressure # (e.g. 1015, 1025, 1035)?

The higher, the more meaningful to the ice, especially if it is combined with a low pressure system adjacent to it. This causes strong winds that move the ice around.

3) Is there a point where a higher pressure is no longer worse for the sea ice (e.g. 1030 is bad but 1040 is no worse)?

That's difficult to say. I would think that for clear skies it doesn't matter all that much, but it does matter for the wind. The higher the pressure, the stronger the wind.

4) Can high pressure + slightly below freezing temps still produce melt ponding, or do temps need to be above freezing?

I believe it can. And humidity also plays a role.

[crandles]

4) Can high pressure + slightly below freezing temps still produce melt ponding, or do temps need to be above freezing?

I believe it can. And humidity also plays a role.

Yes, to attempt further explanation, it is the heat balance that matters not the temperature. Melt water can increase with (air) temp below zero: Due to albedo difference the water accepts more solar heat than ice not covered with water, that heat has to find a heat sink rather than raise the temp above zero but that is entirely possible as it gets used melting ice. You might object to this as patches of water have to get above zero to melt the ice, but the more general air temperature over large area can stay below zero.

Yes, humidity does play a role with latent heat being released where it condenses and absorbed where it evaporates/sublimates.

(I think)

[johnm33]

So when the pressures higher is the temp higher simply as a result of the pressure, say 1030 being 3% warmer for instance?
One more, trying to figure out ice dynamics I was struck with the thought that Amundsen tides acts like a bellows pumping the Beaufort gyre. As the water surges in it draws ice south, and towards the gulf, but the the ice resists being drawn east, when the water moves out it carries the ice west with it, rinse repeat. Any opinions?

[crandles]

So when the pressures higher is the temp higher simply as a result of the pressure, say 1030 being 3% warmer for instance?

No, high pressure generally means clear sky rather than cloudy so if it is daytime it tends to be warmer but at night colder.

[Neven]

No, high pressure generally means clear sky rather than cloudy so if it is daytime it tends to be warmer but at night colder.

And right now there's no night in the Arctic. 

[crandles]

And right now there's no night in the Arctic. 

Don't get any melt ponding in winter/night in Arctic either 

[thejazzmarauder]

Thank you for the answers. A couple more "stupid" questions:

1) Are average summer temps in the CAB typically above freezing? What about daily max temps?

2) If one of the arctic seas, e.g. the Laptev, melts out early, does it increase the likelihood of accelerated melt in the adjacent part of the CAB later in the season?

3) Are there areas of the CAB that are particularly dependent on sea ice to the south acting as a buffer against things that can harm ice like waves and warmer waters (e.g. western CAB, which depends on Chuckchi to shield it from water entering arctic through the Bering strait)?

[RoxTheGeologist]

This might seem like a stupid question: I am in the right place.

I'm going to state something that seems obvious; As far as I can tell the ice melts out from the boundary of the ice coverage. I'm going to generalize. Holes don't typically melt out in the center of the pack. The melting boundary seems to be a few miles wide, perhaps, but is pretty much always at the edge of the pack. Even as the ice warms and thins with melt ponds, the melt edge is at the point of open water. I assume that the mechanism is where energy gets transferred from water to ice.

Is there clear understanding of the mechanism of how energy gets transferred from open water to the ice pack to make it melt?

That boundary between ice and sea seems like it would be complex mix of temperatures and densities. Fresh water forming and sitting at the surface as ice melts, Insolation of the dark water, wave action. How quickly does the ice boundary melt out? Without mixing I would think slowly, the newly formed fresh water lens sits on top of salt warm water, warming up from insolation, how does this change when it's the fresh water lens itself warming? If its below 18 PSU of salinity then the density increases as it warms, generating convection with, one assumes, warm, more saline water below the pack. It seems that the mechanism of how energy from the warming water is transferred to the edge of the pack is critical to our understanding of rate of melt. It also points to Neven's observation that you need both insolation and mixing to melt the pack efficiently.

[oren]

Thank you for the answers. A couple more "stupid" questions:

1) Are average summer temps in the CAB typically above freezing? What about daily max temps?

2) If one of the arctic seas, e.g. the Laptev, melts out early, does it increase the likelihood of accelerated melt in the adjacent part of the CAB later in the season?

3) Are there areas of the CAB that are particularly dependent on sea ice to the south acting as a buffer against things that can harm ice like waves and warmer waters (e.g. western CAB, which depends on Chukchi to shield it from water entering arctic through the Bering strait)?

1) I think in general where there is still sea ice, temps are stuck to around 0^oC, as most positive heat balance gets absorbed by the ice and the snow on top of it. This is shown nicely in the DMI chart where recent years have sharp autumn and winter warming, but no summer warming.
2) I believe so. Some years where the Laptev melted early had a "Laptev bite" eating into the adjacent CAB ice.

[thejazzmarauder]

Thank you for the answers. A couple more "stupid" questions:

1) Are average summer temps in the CAB typically above freezing? What about daily max temps?

2) If one of the arctic seas, e.g. the Laptev, melts out early, does it increase the likelihood of accelerated melt in the adjacent part of the CAB later in the season?

3) Are there areas of the CAB that are particularly dependent on sea ice to the south acting as a buffer against things that can harm ice like waves and warmer waters (e.g. western CAB, which depends on Chukchi to shield it from water entering arctic through the Bering strait)?

1) I think in general where there is still sea ice, temps are stuck to around 0^oC, as most positive heat balance gets absorbed by the ice and the snow on top of it. This is shown nicely in the DMI chart where recent years have sharp autumn and winter warming, but no summer warming.
2) I believe so. Some years where the Laptev melted early had a "Laptev bite" eating into the adjacent CAB ice.

Thanks, that makes a lot of sense. I’ve always wondered what was up with that DMI chart; very interesting.

So the only way to know true heat content in the CAB is to look at speed of ice melt (meaning you can’t accurately forecast the severity of an Arctic heat wave like you can over land using temperature-based measurements)? I might be thinking about it incorrectly.

[Shared Humanity]

Thanks, that makes a lot of sense. I’ve always wondered what was up with that DMI chart; very interesting.

So the only way to know true heat content in the CAB is to look at speed of ice melt (meaning you can’t accurately forecast the severity of an Arctic heat wave like you can over land using temperature-based measurements)? I might be thinking about it incorrectly.

So long as sea ice is present, air temperatures will remain close to 0C. The heat that intrudes from the lower latitudes goes into melting the sea ice. For 2m temps to rise significantly over 0C when ice is present, the heat and moisture intrusion must be huge. Once the sea ice has melted away, 2m temps over open sea can spike dramatically as can SST's as open water soaks up sunlight.

[El Cid]

New stupid question:

on a scale of 1-10, 10 being most detrimential, how would you rate the effect on arctic ice during summer ?
- full sunlight (high pressures, clear skies)
- stormy weather (low pressure, big winds)
- heat intrusion from air
- from sea
- any other?

thanks

[gregcharles]

Another new stupid question:

Why is the melt in the Hudson Bay starting in the north and working its way down? I know it's done that before, but if I ever understood why, I've forgotten already. Something to do with rivers? Also, why is the divide between ~100% ice concentration and ~0% approximately a straight line from shore to shore of the bay?

[oren]

Another new stupid question:

Why is the melt in the Hudson Bay starting in the north and working its way down? I know it's done that before, but if I ever understood why, I've forgotten already. Something to do with rivers? Also, why is the divide between ~100% ice concentration and ~0% approximately a straight line from shore to shore of the bay?

The explanation should in principle be that the ice is typically transported south by the prevailing wind, so any melt seems to be in the north but in fact could be anywhere in the bay. Is that wind actually there? And why it prevails in that direction? I can't say...

[johnm33]

'Hudson Bay' The tides are greater in the north, sometimes the warm waters of the Irminger current or waters warmed by it get drawn in to Hudson towards Foxe, they dissipate southwards ccw. What % part this plays is anyones guess.

[thejazzmarauder]

With the current cyclone and corresponding pressure gradient on its west side, is this storm sucking warm air from Russia into the arctic (since the LP system is rotating counter-clockwise while the HP system rotates clockwise)?

[aperson]

With the current cyclone and corresponding pressure gradient on its west side, is this storm sucking warm air from Russia into the arctic (since the LP system is rotating counter-clockwise while the HP system rotates clockwise)?

Yes, wind flows mostly along the isobar contours of a sea level chart (or 500hPa geopotential height chart, or whatever height you are looking at). When wind is in geostrophic balance it is purely flowing along the isobars. To the extent that wind flow is ageostrophic it can cross the isobars. Using this in tandem with your correct understanding of the coriolis force lets one figure out where the wind is blowing. The tighter packed the isobars are, the faster the wind.

[pearscot]

Is a dipole weather pattern in the Arctic detrimental toward maintaining more ice?

Is the ice, in general, in worse condition leaving the freezing season, or is it similar to what we have seen in the subsequent years following 2012?

Thank you!

[Hyperion]

Is a dipole weather pattern in the Arctic detrimental toward maintaining more ice?

Is the ice, in general, in worse condition leaving the freezing season, or is it similar to what we have seen in the subsequent years following 2012?

Thank you!

Almost certainly yes to both questions

[Pmt111500]

Is the ice, in general, in worse condition leaving the freezing season, or is it similar to what we have seen in the subsequent years following 2012?

Thank you!

2012 crash was largely a crash for older ice setting a new limit of how much volume can be present after a regular winter. Last summer some more older ice was sent to trajectories which lead to its speedy destruction. Taking to account older ice is fresher than the new one, there should be a small difference on how fast they melt (in volume). Thus increase in the speed of melt could be expected after these have been melted at the edge of Atlantic Sub-polar Gyre.

[pearscot]

Is the ice, in general, in worse condition leaving the freezing season, or is it similar to what we have seen in the subsequent years following 2012?

Thank you!

2012 crash was largely a crash for older ice setting a new limit of how much volume can be present after a regular winter. Last summer some more older ice was sent to trajectories which lead to its speedy destruction. Taking to account older ice is fresher than the new one, there should be a small difference on how fast they melt (in volume). Thus increase in the speed of melt could be expected after these have been melted at the edge of Atlantic Sub-polar Gyre.

Great, thanks for the in depth explanation!

[Pikk_Ax]

Heya,
I've been lurking for a while and I have a question.
How do I figure out how to see what the sea ice concentration was for a particular date at the NSIDC website,
It's not very intuitive to the likes of me.
Thanks.
(Norwegians needn't bother mentioning my name, I'm aware. I've kept the name in other contexts for a long while now.)
Pikk.

[johnm33]

"how do I" NSIDC

[Alexander555]

Does it always looks like this, this  time of the year ?

[oren]

Does it always looks like this, this  time of the year ?

GFS has been very bad this year several days out, insisting on rising temps that never materialize. But in any year 10 days of GFS is generally garbage.
OTOH, it is quite warm (at least in in Siberia, maybe elsewhere too) right now, so it's still an anomalous situation, but maybe not as bad as shown in the image.

[Hyperion]

Is it normal for there to be, like what is it here, some 12 or even 13 vortexes over the northern latitudes, way up at 70hPa, about 18+ km altitude?

When I compare with 250 hPa and sealevel pressure, it looks like most all of them are above low or high pressure systems, and rotating the same direction all the way up.

Is this why there appears to be floods of water vapour heading north from so many directions at once?

Or am I just paranoid? Still as they say, just because you paranoid, don't mean the whole world ain't out to get ya.

What would you call this, a ,uni-hemispheric-trans-turbo-strato-do-deca-pole? UHTTSDDP?

Kinda got a ring to it. Makes me want to break into song.
Paraphrasing Floyd, learning to fly:

Is this nature out to make us pay?
Blown the sky right through the roof of the day!
You-aitch-tea-tea-esss...dee-deeeeee-peeeee!

[aperson]

A non-ensemble 10 day max provides so little information I'm not sure why the site would offer charts of it. Model biases after 5 days quickly become extreme.

I would stick to ensembles like GEFS or EPS and stick to mean temperatures instead of min or max.

[gerontocrat]

Does it always looks like this, this  time of the year ?

That image is deceiving. I believe it is NOT the maximum temperature at one point in time over the whole map . i.e. even if GFS was dead right you would never see that image in reality.

It looks at the maximum temp for each part of the map during the next 10 days and uses that to build the complete image, which automatically creates a bias to the high temperature for the whole map area. The opposite applies to the minimum temperature map.

The average temp map is more realistic, though even then I only look at the 3 and 5 day outlook as after that GFS goes wobbly.

[jdallen]

...that said, today's 12z run temps for today are not that far off from the temp map at the start of this discussion.