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b_lumenkraft

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Re: "Stupid" Questions :o
« Reply #2200 on: July 06, 2019, 11:27:34 AM »
More on this one:

The surface has a dirty blue tint (which i interpreted as rather thin ice

Meaning, if you use the "return [B8A*2,B03*1,B02*1]" setting in Sentinel you will see liquid water on ice as bright blue and white ice as pink.

I think the dirty blue colour indicates thin/weak ice. I found further evidence for this claim today.

In this GIF you see a floe like that (which i think is a piece of fast ice originating in Kane Basin) decomposing just by being pushed around by currents.

I guess my question is,

is this dirty blue colour indicating wet/soaked ice,

or is it so thin that it's translucent and we see the ocean darkness through it?

johnm33

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Re: "Stupid" Questions :o
« Reply #2201 on: July 06, 2019, 03:57:26 PM »
binntho on July 05, 2019, 03:06:44 PM

    "But I doubt very much if the ice stays in the air when the tide goes out."

I saw a documentary where the Inuit made a hole in the ice and went foraging along the shore beneath the ice whilst the tide was out. So it can.
now with added link
« Last Edit: July 07, 2019, 12:23:00 PM by johnm33 »

Sebastian Jones

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Re: "Stupid" Questions :o
« Reply #2202 on: July 06, 2019, 07:30:13 PM »
binntho on July 05, 2019, 03:06:44 PM

    "But I doubt very much if the ice stays in the air when the tide goes out."

I saw a documentary where the Inuit made a hole in the ice and went foraging along the shore beneath the ice whilst the tide was out. So it can.
It happened to me once: I was breaking trail up the Yukon in December and my dogs got on the trail of a wolverine. Wolverines leave a wonderful trail for a dog- a compacted trench. The trail went along the shore, where the ice was sloped, because the river level had dropped since freeze up (kinda like the tide went out). At one point, the shelf ice had cracked and fallen down The wolverine simply went on into the space beneath the ice. So too did my dogs. The trouble was that the space was only about a metre high. Plenty for a wolverine, plenty for a dog. But not even close enough for a dogsled, or its driver. So I got stuck and had the "interesting" exercise of extricating a string of nine dogs from the cave in which they were convinced they should travel. It's funny now, in retrospect....

jdallen

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Re: "Stupid" Questions :o
« Reply #2203 on: July 07, 2019, 12:33:22 AM »
<sigh> that's not Ice staying in the air. <face palm>  ;)
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kynde

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Re: "Stupid" Questions :o
« Reply #2204 on: July 07, 2019, 10:40:19 AM »
Since the GAC has been a topic today, I'm going to pop up a question that's been bothering me for ages.

The GAC formed over Siberia and moved over to the Arctic and intensified. As someone only slightly acquainted with tropical cyclone formation I'm curious how does that happen exactly? How does an extratropical cyclone strengthen over the arctic sea? With all the heat in the arctic going into the melting ice and SSTs as a result being quite steady and low what does it feed on? Or do they just run that much colder that some open sea having gained even a little bit of dew point is enough?

Also are there some features to look for that might favour their generation and intensification like we have with tropical cyclones?

oren

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Re: "Stupid" Questions :o
« Reply #2205 on: July 07, 2019, 10:56:03 AM »

Oscillidous

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Re: "Stupid" Questions :o
« Reply #2206 on: July 07, 2019, 06:04:16 PM »
Hey all, I've been a long time lurker, but I've had some rather silly questions I can't seem to get a definitive answer on.

Firstly, it was recently determined that the effect of aerosol masking has been underestimated by double, but I don't see any paper which gives any temperature value as to how much warming has been avoided. This paper: https://rmets.onlinelibrary.wiley.com/doi/abs/10.1002/joc.4613 says we have avoided 2.6K, this is equivalent to degrees C right? And if this is the case, would that mean that 4C or more is in the cards when we lose aerosol masking?

Also, many this year are saying we will tie 2012 or surpass it, but it seems to my ignorant eyes that the ice is overall much poorer in terms of overall rigidity to even really matter if it does or not, because it seems like so much energy is going into the ice that refreeze will start later and melt will start early next season, with nothing but poor ice. Are any others feeling this way, or would it be too early to speak about?

In the event that we do lose sea ice, it would seem to me that there wouldn't be a rebound of the pack as a whole, but rather there would be seasonal diminishing returns of small areas having bits of ice until there is no longer a refreeze. Is this assumption also incorrect?

Finally, to what degree would this bring in terms of warming and how fast do we estimate the warming will occur?
When the ice moves it cuts deep grooves
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Sterks

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Re: "Stupid" Questions :o
« Reply #2207 on: July 07, 2019, 06:42:26 PM »
Since the GAC has been a topic today, I'm going to pop up a question that's been bothering me for ages.

The GAC formed over Siberia and moved over to the Arctic and intensified. As someone only slightly acquainted with tropical cyclone formation I'm curious how does that happen exactly? How does an extratropical cyclone strengthen over the arctic sea? With all the heat in the arctic going into the melting ice and SSTs as a result being quite steady and low what does it feed on? Or do they just run that much colder that some open sea having gained even a little bit of dew point is enough?

Also are there some features to look for that might favour their generation and intensification like we have with tropical cyclones?

This is a valid question for me as well. The initial, moderate storms come from the periphery both in 2012 (Siberia) and 2016 (Kara),  and then have a surge in strength as they locate at the center in the Arctic. 2016 GAC restrengthens by merging with other lows several times. I don't know, in both cases a disruption of the normal atmosphere due to the anomalous warmth of the Arctic regions might have played a role, but I am not expert on that. 2016 was also a very warm year even when it didn't show on top of the ice until July.

AmbiValent

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Re: "Stupid" Questions :o
« Reply #2208 on: July 10, 2019, 05:08:18 PM »
I'm not sure if we currently have an active transpolar drift, pushing Fram export. Which sources and graphs would be best to consult?
Bright ice, how can you crack and fail? How can the ice that seemed so mighty suddenly seem so frail?

oren

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Re: "Stupid" Questions :o
« Reply #2209 on: July 10, 2019, 06:52:40 PM »
The best source IMHO is OSI SAF sea ice drift, which is actual movement calculated from satellite sensors.
If you bookmark this, it will always give you the most recent two days.

http://osisaf.met.no/p/osisaf_hlprod_qlook.php?year=2019&month=07&day=09&action=Today&prod=LR-Drift&area=NH&size=100%25

crandles

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Re: "Stupid" Questions :o
« Reply #2210 on: July 10, 2019, 07:14:36 PM »
Hey all, I've been a long time lurker, but I've had some rather silly questions I can't seem to get a definitive answer on.

Firstly, it was recently determined that the effect of aerosol masking has been underestimated by double, but I don't see any paper which gives any temperature value as to how much warming has been avoided. This paper: https://rmets.onlinelibrary.wiley.com/doi/abs/10.1002/joc.4613 says we have avoided 2.6K, this is equivalent to degrees C right? And if this is the case, would that mean that 4C or more is in the cards when we lose aerosol masking?

Also, many this year are saying we will tie 2012 or surpass it, but it seems to my ignorant eyes that the ice is overall much poorer in terms of overall rigidity to even really matter if it does or not, because it seems like so much energy is going into the ice that refreeze will start later and melt will start early next season, with nothing but poor ice. Are any others feeling this way, or would it be too early to speak about?

In the event that we do lose sea ice, it would seem to me that there wouldn't be a rebound of the pack as a whole, but rather there would be seasonal diminishing returns of small areas having bits of ice until there is no longer a refreeze. Is this assumption also incorrect?

Finally, to what degree would this bring in terms of warming and how fast do we estimate the warming will occur?

Welcome to the forum.

Far from best qualifies for this but:

easy question first
K is equivalent to degrees C right?
yes.

Says we have avoided 2.6K And if this is the case, would that mean that 4C or more is in the cards when we lose aerosol masking?

If we lost aerosol masking that would be 2.6K and perhaps you are adding 1.5C that seems pretty much unavoidable to get to 4C?

Not sure we are going to lose the masking completely even if we completely give up coal mining there will still likely be other mining and other sources of aerosols. So not sure we will really get the full 2.6K. However increases in GHG while reducing aerosol forcing should be considered highly likely to give a faster rate of temperature rise than GHG increases while aerosols are also increasing.

>effect of aerosol masking has been underestimated by double
I assume this is Rosenfeld et al 2019. I haven't seen much in the way of review that I would trust. I have seen headlines like

Quote
We need to rethink everything we know about global warming
New calculations show scientists have grossly underestimated the effects of air pollution
which I don't trust - looks like a clickbait heading to me.

If I read the paper, I wouldn't trust me to critique the paper, but I will point out:
The paper's title is
Rosenfeld, D.; et al. (2019): Aerosol-driven droplet concentrations dominate coverage and water of oceanic low level clouds
looks like it has appeared in Science so very reputable journal and if I had criticisms of the paper definitely trust the peer review rather than me.

However, note that this paper is only about part of the effects of aerosols.
Second it is one paper.
I am noting these things because there are other ways to assess aerosol effects. For example volcanoes have massive effect on aerosol levels compared to what humans do and we can see the temperature effect. From one eruption, you couldn't tell much but from 3 or 4 significant volcanoes in the last several decades you can start to judge if the models have aerosols about right. If the models are way out, there would be noticeable problems with other efforts at assessing aerosol effects.

I am not saying it is impossible that ghg warming and aerosol cooling have both been underestimated such that the errors largely cancel out. However if we were way out, it would likely show up elsewhere.

With that size difference, a more likely possibility might be that we have underestimated aerosol effects in one place but also overestimated them somewhere else.

'rethink everything we know about global warming' just isn't the way things work. It is not a long chain that is only as strong as the weakest link. It is much more like a mesh where even if you cut one wire then not much happens other than nearby wires taking up some of the strain.

Sorry this is not a more expert answer.

Tor Bejnar

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Re: "Stupid" Questions :o
« Reply #2211 on: July 10, 2019, 09:38:14 PM »
I'm not sure if we currently have an active transpolar drift, pushing Fram export. Which sources and graphs would be best to consult?
The strong evidence of an active transpolar drift from October 2018 into late April or early May 2019 is via A-Team's May 23 post here.  The 'visual' structures 'collapsed' around the first of May, so drift directions were much harder to follow afterwards.  Read A-Teams version of events! (and his images/GIFs)
Arctic ice is healthy for children and other living things.

Rich

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Re: "Stupid" Questions :o
« Reply #2212 on: July 11, 2019, 07:41:54 PM »
Is there a thread on the forum related to Prepping?

I'm becoming increasingly convinced that the current edition of human civilization is fucked and I'd like to improve the odds of some people I care about.

If not at ASIF, other sources would be welcome.

b_lumenkraft

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Re: "Stupid" Questions :o
« Reply #2213 on: July 11, 2019, 07:52:37 PM »
Is there a thread on the forum related to Prepping?

Accumulating knowledge is the best way to prepare IMHO. When the big catastrophe hits, you want to know how to rebuild a community.

Learn how power grids work for example. Or learn how you can build a radio and a transmitter. Or learn how TCP-IP works and how to set up a data network. Or learn how to do agriculture in your area and how to improve it. Or learn how to teach such things.


Rich

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Re: "Stupid" Questions :o
« Reply #2214 on: July 11, 2019, 08:19:05 PM »
 >:(
Is there a thread on the forum related to Prepping?

Accumulating knowledge is the best way to prepare IMHO. When the big catastrophe hits, you want to know how to rebuild a community.


I agree. Now I'm trying to find a community of people dedicated to sharing that knowledge.

If it doesn't exist at ASIF, I could start a thread or look elsewhere.

Not wanting to start a thread unnecessarily, I thought I would ask here first.


kassy

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Re: "Stupid" Questions :o
« Reply #2215 on: July 11, 2019, 08:24:04 PM »
What would come closest? There is interesting stuff on gardening if you have a garden.

Prepping only takes you so far. It is nice to have supplies when you can shelter in place but those are different scenarios. Storms, quakes , a pandemic.

Prepping for this is harder.

Your old folks live at the beach at some soon to be disaster area. Do you urge them to move and where too?

Having a good social net helps very much.

And of course there are basic supplies which are sensible (i can always make some simple food).

You could open one in The Rest. State what scenarios you would want to prep for (time wise).
 

HapHazard

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Re: "Stupid" Questions :o
« Reply #2216 on: July 11, 2019, 08:50:39 PM »
Is there a thread on the forum related to Prepping?

I'm becoming increasingly convinced that the current edition of human civilization is fucked and I'd like to improve the odds of some people I care about.

If not at ASIF, other sources would be welcome.

https://www.reddit.com/r/preppers/

Plenty of overlap on other subs, too, such as /r/Homesteading and /r/SelfSufficiency

But the most important preps are always your mental and physical robustness.

be cause

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Re: "Stupid" Questions :o
« Reply #2217 on: July 11, 2019, 10:01:07 PM »
here in Ireland we would have to have the Green Preppers and the Red Preppers ..
2007 + 5 = 2012 + 4 = 2016 + 3 = 2019 ...

petm

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Re: "Stupid" Questions :o
« Reply #2218 on: July 12, 2019, 02:24:40 PM »
Why does a cyclone centered at a pole spin?

crandles

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Re: "Stupid" Questions :o
« Reply #2219 on: July 12, 2019, 02:30:40 PM »
Why does a cyclone centered at a pole spin?

Because it was spinning when it arrived at the pole and conservation of angular momentum?

petm

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Re: "Stupid" Questions :o
« Reply #2220 on: July 12, 2019, 04:37:28 PM »
Because it was spinning when it arrived at the pole and conservation of angular momentum?

True. But I also realized that I had it backwards -- the Coriolis effect is maximum at the poles, not zero. Could make for some interesting storms in a few decades, or whever we have long enough periods of blue ocean...

Rich

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Re: "Stupid" Questions :o
« Reply #2221 on: July 14, 2019, 05:40:53 AM »
I'm trying to interpret something.

There are regions along the coast with warm SST's and no adjacent ice. What prevents the heat from diffusing into the surrounding water until it reaches equilibrium with the surrounding water?

One potential answer is that the diffusion is happening, but that the shallow coastal water is constantly having it's heat replenished through the earth (either below or adjacent to it).


binntho

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Re: "Stupid" Questions :o
« Reply #2222 on: July 14, 2019, 08:43:35 AM »
I'm trying to interpret something.

There are regions along the coast with warm SST's and no adjacent ice. What prevents the heat from diffusing into the surrounding water until it reaches equilibrium with the surrounding water?
I don't think anything is stopping the heat from "diffusing". It just takes a hell of a long time. The three ways of "diffusing" heat are through radiation, conduction and convection. The first two are very slow and I guess it would take several years for a large body of water with small temperature differences to reach equilibrium.

Thermal convection can work very quickly, i.e. when the water moves and mixes. But that requires kinetic energy. Vertical convection creates it's own kinetic energy (basically through gravity and density differences) but lateral convection doesn't. I.e. the heat does not convect from side to side without any external influences.

One potential answer is that the diffusion is happening, but that the shallow coastal water is constantly having it's heat replenished through the earth (either below or adjacent to it).

That is not a potential answer.

Pragma

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Re: "Stupid" Questions :o
« Reply #2223 on: July 14, 2019, 04:19:01 PM »

Thermal convection can work very quickly, i.e. when the water moves and mixes. But that requires kinetic energy. Vertical convection creates it's own kinetic energy (basically through gravity and density differences) but lateral convection doesn't. I.e. the heat does not convect from side to side without any external influences.


I think you need to tighten up your terminology here.

AFAIK, by definition, convection is a function of gravity, (you said it yourself) so lateral i.e. 90 degrees from the direction of gravity, convection does not exist.

Any side to side transfer of heat would be a function of radiation, conduction, currents or mixing.
[/quote]

binntho

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Re: "Stupid" Questions :o
« Reply #2224 on: July 14, 2019, 06:00:01 PM »

Thermal convection can work very quickly, i.e. when the water moves and mixes. But that requires kinetic energy. Vertical convection creates it's own kinetic energy (basically through gravity and density differences) but lateral convection doesn't. I.e. the heat does not convect from side to side without any external influences.


I think you need to tighten up your terminology here.

AFAIK, by definition, convection is a function of gravity, (you said it yourself) so lateral i.e. 90 degrees from the direction of gravity, convection does not exist.

Any side to side transfer of heat would be a function of radiation, conduction, currents or mixing.

Well I'm not too sure. Convection certainly happens when heat rises due to the combined efforts of expansion and gravity. But what do you call it when warm currents move heat laterally, as is happening all the time in the world's oceans - isn't that also a form of convection?

I've certainly never thought of convection as being tied exclusively to vertical movement, according to Wikipedia it is defined as:

Quote from: Wikipedia
Convection is the heat transfer due to the bulk movement of molecules within fluids such as gases and liquids, including molten rock. Convection includes sub-mechanisms of advection, and diffusion.

EDIT: Reading the excellent Wikipedia entry, I found this:

Quote from: Wikipedia
Heat is transferred by convection in numerous examples of naturally occurring fluid flow, such as wind, oceanic currents, and movements within the Earth's mantle.
So the author of the entry seems to agree with me, that wind and oceanic currents are examples of convection.

Klondike Kat

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Re: "Stupid" Questions :o
« Reply #2225 on: July 14, 2019, 06:54:54 PM »

Thermal convection can work very quickly, i.e. when the water moves and mixes. But that requires kinetic energy. Vertical convection creates it's own kinetic energy (basically through gravity and density differences) but lateral convection doesn't. I.e. the heat does not convect from side to side without any external influences.


I think you need to tighten up your terminology here.

AFAIK, by definition, convection is a function of gravity, (you said it yourself) so lateral i.e. 90 degrees from the direction of gravity, convection does not exist.

Any side to side transfer of heat would be a function of radiation, conduction, currents or mixing.

Well I'm not too sure. Convection certainly happens when heat rises due to the combined efforts of expansion and gravity. But what do you call it when warm currents move heat laterally, as is happening all the time in the world's oceans - isn't that also a form of convection?

I've certainly never thought of convection as being tied exclusively to vertical movement, according to Wikipedia it is defined as:

Quote from: Wikipedia
Convection is the heat transfer due to the bulk movement of molecules within fluids such as gases and liquids, including molten rock. Convection includes sub-mechanisms of advection, and diffusion.

EDIT: Reading the excellent Wikipedia entry, I found this:

Quote from: Wikipedia
Heat is transferred by convection in numerous examples of naturally occurring fluid flow, such as wind, oceanic currents, and movements within the Earth's mantle.
So the author of the entry seems to agree with me, that wind and oceanic currents are examples of convection.

You are correct.  Oceanic currents are examples of convection.  The Gulf Stream and East Australian are examples of fast moving oceanic currents, capable of transporting significant amounts of warm water long distances.  The fastest transfer of heat through the Arctic is also via ocean currents, including those which can transport large ice floes.

Pragma

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Re: "Stupid" Questions :o
« Reply #2226 on: July 14, 2019, 07:06:31 PM »
Well I'm not too sure. <snip>

Quote from: Wikipedia
Heat is transferred by convection in numerous examples of naturally occurring fluid flow, such as wind, oceanic currents, and movements within the Earth's mantle.
So the author of the entry seems to agree with me, that wind and oceanic currents are examples of convection.

I see your point. Some parts of the article do exactly that.

I read the article several times, and the more I read it, the less clear it became. It could be this and it could be that but generally this means this and not that, etc, etc.

Part of the problem, IMHO is that it is poorly written. I am now thinking of one of my profs that would savage this Wiki entry.

For example it starts off:

"Convection is the heat transfer due to the bulk movement of ...."

and then two paragraph later it says:

"Thermal convection can be demonstrated..."

As opposed to what other kind of convection?

And then there is this little gem:

"Sometimes the term "convection" is used to refer specifically to "free heat convection" (natural heat convection) where bulk-flow in a fluid is due to temperature-induced differences in buoyancy, as opposed to "forced heat convection" where forces other than buoyancy (such as pump or fan) move the fluid. However, in mechanics, the correct use of the word "convection" is the more general sense, and different types of convection should be further qualified, for clarity."

I'm not sure of what context he is using the term "mechanics" but personally, I would never use a pump or fan as an example of convection. That is like saying if you put a Canada Goose in a box and ship him somewhere via an airplane, he is migrating.

I don't think I am being picky here. When one is trying to learn, this sort of vague discussion, filled with ambiguity and redundancy is a student's nightmare.

I found this from Machine Design:

Quote
Convection

When a fluid, such as air or a liquid, is heated and then travels away from the source, it carries the thermal energy along. This type of heat transfer is called convection. The fluid above a hot surface expands, becomes less dense, and rises.

At the molecular level, the molecules expand upon introduction of thermal energy. As temperature of the given fluid mass increases, the volume of the fluid must increase by same factor. This effect on the fluid causes displacement. As the immediate hot air rises, it pushes denser, colder air down. This series of events represents how convection currents are formed. The equation for convection rates is calculated as follows:

Q = hc ∙ A ∙ (Ts – Tf)

where Q = heat transferred per unit time; hc = convective heat transfer coefficient; A = heat-transfer area of the surface; Ts = temperature of the surface; and Tf = temperature of the fluid.

A space heater is a classic convection example. As the space heater heats the air surrounding it near the floor, the air will increase in temperature, expand, and rise to the top of the room. This forces down the cooler air so that it becomes heated, thus creating a convection current.

It very much aligns with what I was taught, but I don't want to get involved with duelling quotes or be accused of cherry picking.

Is there a thermodynamicist in the house?  :D

kassy

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Re: "Stupid" Questions :o
« Reply #2227 on: July 14, 2019, 10:02:32 PM »
Isn´t the convection part of the currents where they sink or rise?

Peter Ellis

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Re: "Stupid" Questions :o
« Reply #2228 on: July 14, 2019, 10:03:43 PM »
Convection is when heat is transported by fluid flow.

If the fluid flow is itself caused by the heat (e.g. warm water rising from the bottom of a saucepan, cold water sinking from melting ice) then it is called "free heat convection".  If the fluid flow is caused by something else (e.g. I squirt a warm stream of liquid into a cold pool) then it is called "forced heat convection".

In both cases, heat is transported by moving hot molecules from one location to another, rather than by transferring energy from one molecule to another.
« Last Edit: July 14, 2019, 10:09:56 PM by Peter Ellis »

Peter Ellis

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« Reply #2229 on: July 14, 2019, 10:08:58 PM »
The clue is in the etymology: con+vection = with+movement. The molecules travel with the heat and vice versa.  This is also why a fan oven is called a convection oven.
« Last Edit: July 14, 2019, 10:15:55 PM by Peter Ellis »

Pragma

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Re: "Stupid" Questions :o
« Reply #2230 on: July 14, 2019, 10:35:34 PM »
The clue is in the etymology: con+vection = with+movement. The molecules travel with the heat and vice versa.  This is also why a fan oven is called a convection oven.

Thanks Peter,

I thought of a convection oven and then realized it had a fan. A bit of Googling tells me that "Forced Convection" is indeed a thing.

It's all in the common usage. I have a forced air heating system and if I ask a serviceman to come have a look at my forced convection heater he would ask what planet I was from. :). Convection furnaces, as they were called, used to exist. They sat in the basement and key rooms in the house had gratings in the floor, with no piping. Forced air furnaces replaced them.

My definition and perception was far too limited, but I still think "Forced Convection" sounds a lot like "all natural synthetics".

Cheers

Peter Ellis

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Re: "Stupid" Questions :o
« Reply #2231 on: July 14, 2019, 10:57:35 PM »
It's worth appreciating that even natural convection generates lateral movement as well as vertical - how could it not?  Although the "engine" for a convection current is the vertical motion of fluid due to thermal buoyancy, something has to come in from the sides to replace the rising/falling fluid.

So (e.g.) in a cyclone, air is rising in the centre by convection, forcing air at low levels to flow inwards (given a spiral twist by Coriolis effects) and air at higher levels to flow outwards (ditto).  All of these elements of the motion, whether vertical or horizontal, transfer heat.

Tor Bejnar

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Re: "Stupid" Questions :o
« Reply #2232 on: July 14, 2019, 11:28:44 PM »
One added bit:  those ocean currents moving heat here and yon are largely caused by gravity.
Quote
Ocean currents can be generated by wind, density differences in water masses caused by temperature and salinity variations, gravity, and events such as earthquakes.
reference: NOAA
Arctic ice is healthy for children and other living things.

petm

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Re: "Stupid" Questions :o
« Reply #2233 on: July 15, 2019, 12:18:19 AM »
Yeah, you just got caught up in natural vs. forced convection.

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

petm

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Re: "Stupid" Questions :o
« Reply #2234 on: July 15, 2019, 01:53:40 AM »
There are regions along the coast with warm SST's and no adjacent ice. What prevents the heat from diffusing into the surrounding water until it reaches equilibrium with the surrounding water?

Getting back to your original question, if you watch the progression of SSTs (e.g. go here and play a month's worth: http://ocean.dmi.dk/satellite/index.uk.php), I think you'll see that the heat actually is moving towards as well as melting the ice. It just takes some time.

Rich

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Re: "Stupid" Questions :o
« Reply #2235 on: July 15, 2019, 04:53:21 AM »
Getting back to the original question.

So we have warm SST's in shallow water. Iirc, The shallowest water is in the ESS, just a few meters deep.

Let's say that water is 2C today. Is there any sense that the temperature of the earth at the base of that water is significantly different than 2C?

What role does the earth below the shallow water have in the temperature equilibrium?

Tor Bejnar

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Re: "Stupid" Questions :o
« Reply #2236 on: July 15, 2019, 06:04:48 AM »
Quote
[ESS is] just a few meters deep.
Wikipedia:
Quote
(mostly less than 50 m)
I trust this is what you meant.
Arctic ice is healthy for children and other living things.

binntho

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Re: "Stupid" Questions :o
« Reply #2237 on: July 15, 2019, 06:42:46 AM »
Getting back to the original question.

Let's say that water is 2C today. Is there any sense that the temperature of the earth at the base of that water is significantly different than 2C?

What role does the earth below the shallow water have in the temperature equilibrium?

One regularly sees denier sites claiming that geothermal energy is somehow responsible for  global warming. One good example was the claim that the long-time (and spectacular) lava flow from one of the Hawaiian volcanoes into the Pacific was responsible for all the increase in ocean heat content.

Geophysicists have of course worked out the total heat transfer from the earth to the atmosphere (including the ocean), and it's generally reckoned to be in the region of 40-90 mM/m2 (milliwatt per meter squared), compared to the average solar irradiance of 1365 W/m2.

A very large proportion of geothermal energy outflow happens along the volcanically active mid-ocean ridges, as well as in terrestrial volcanoes and geothermal areas. The shallow Siberian seas have neither, so geothermal energy outflow there is far lower than the global average.

And it requires only a little bit of common sense to see that geothermal energy can only have an extremely minor effect in this area. It is unable to thaw through permafrost, as an example, and the shallow seas off Siberia are very well known for their underlying permafrost.

This has been cited as one of the biggest potential positive feedbacks in AGW, i.e. that frozen organic materials on and under the bottom of the shallow Siberian seas will start to melt due to increased global (and of course local) temperatures, releasing large amounts of CO2 and, more dangerously, methane.

So the bottom of the shallow Siberian seas is frozen solid. No change of any excess heat coming from that direction!

The world is full of exciting publications, both online and also in the form of textbooks for various grades. Self-learning is the hallmark of the adult, reflex questions belong to early childhood.

johnm33

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Re: "Stupid" Questions :o
« Reply #2238 on: July 15, 2019, 10:24:45 AM »
"What role does the earth below the shallow water have in the temperature equilibrium?"
  I wonder, Shakhova has 'up to' 20km of sediment in the ESS, which may be warming from below, http://www.geologyin.com/2014/12/geothermal-gradient.html

Rich

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Re: "Stupid" Questions :o
« Reply #2239 on: July 15, 2019, 10:31:02 AM »
I come from a space where any genuine question is a good question. I'm not going to be dissuaded by insults. I'm happy to indulge your propensity for one-upsmanship.

So..if the shallow water on the Siberian shelf is 2C at the surface (let's assume as a result of solar irradiance as you indicate is most likely) and 5M deep.

Are you saying there would be no heat exchange between the sub-sea earth and water?

I didn't come here seeking an answer to this question, but while I'm here.... what would it take to import sufficient energy to begin thawing the earth under those few meters of water ?

binntho

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Re: "Stupid" Questions :o
« Reply #2240 on: July 15, 2019, 10:59:54 AM »
I come from a space where any genuine question is a good question. I'm not going to be dissuaded by insults. I'm happy to indulge your propensity for one-upsmanship.

So..if the shallow water on the Siberian shelf is 2C at the surface (let's assume as a result of solar irradiance as you indicate is most likely) and 5M deep.

Are you saying there would be no heat exchange between the sub-sea earth and water?

I didn't come here seeking an answer to this question, but while I'm here.... what would it take to import sufficient energy to begin thawing the earth under those few meters of water ?

It's just the astounding lack of real-world knowledge mixed with the arrogance of writing long posts critisizing those that have been here for years, and talking about "customer base" and what have you ...

The Siberian shelf has an average depth of 100 meters and most of the sea floor is frozen solid down to several meters under the sea floor. This is information that I found by Googling, took me 2 seconds. Have you tried?

The permafrost there is melting, as has been pointed out several times over the years by several people and is generally considered to be the largest and most dangerous of the possible positive feedbacks, with some of the most strident alarmists talking about an impending Harmageddon.

I obvously didn't say "there would be no heat exchange between the sub-sea earth and water", that is called a straw man which is a method often used by those who have totally lost the argument. And if you think anybody here is ready to answer a question like "what would it take to import sufficient energy to begin thawing the earth under those few meters of water" then you are obviously totally understanding the customers that frequent this particular base.

Rich

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Re: "Stupid" Questions :o
« Reply #2241 on: July 15, 2019, 11:08:28 AM »
It's interesting that you frame this in terms of winning and losing an argument.

This is the stupid questions thread. I didn't come here with an argument. I came here with questions.

You are so consumed with ego that everything is framed in terms of winner and loser.

I'm just trying to learn and you're insulting someone for asking questions. How pathetic is that?

binntho

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Re: "Stupid" Questions :o
« Reply #2242 on: July 15, 2019, 11:30:28 AM »
It's interesting that you frame this in terms of winning and losing an argument.

I don't.

I'm just trying to learn and you're insulting someone for asking questions. How pathetic is that?
Yes I'm surprised at myself - I'm usually the most patient of men when it comes to people asking stupid questions.

And I've actually used a lot of time answering your stupid questions, looking things up on Google (have you ever tried that?) and trying to explain how the real world works. Which is fine by me, I actually quite enjoy that.

But when ignorance combines with arrogance in such a tenacious way, I guess even my renowned patience starts cracking around the seems.

be cause

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Re: "Stupid" Questions :o
« Reply #2243 on: July 15, 2019, 11:55:00 AM »
we should celebrate that stupid questions are making it to the stupid question thread at last ... b.c.
2007 + 5 = 2012 + 4 = 2016 + 3 = 2019 ...

Rich

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Re: "Stupid" Questions :o
« Reply #2244 on: July 15, 2019, 11:55:29 AM »
When someone asks a question, it's an acknowledgement of a certain degree of ignorance.

I'm comfortable enough acknowledging that I'm ignorant about some things to ask the question. If your belief is that people should go to Google with their questions, then you might consider not answering their questions here.

Despite your one-uppity manner with me, you seem to be knowledgeable and I consider you a good resource for learning. I think you're doing a good thing by answering people's questions and you should keep at it.

binntho

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Re: "Stupid" Questions :o
« Reply #2245 on: July 15, 2019, 12:09:31 PM »
we should celebrate that stupid questions are making it to the stupid question thread at last ... b.c.
Indeed!

Rich

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Re: "Stupid" Questions :o
« Reply #2246 on: July 15, 2019, 12:24:32 PM »

So..if the shallow water on the Siberian shelf is 2C at the surface (let's assume as a result of solar irradiance as you indicate is most likely) and 5M deep.




The Siberian shelf has an average depth of 100 meters and most of the sea floor is frozen solid down to several meters under the sea floor. This is information that I found by Googling, took me 2 seconds. Have you tried?


The Siberian Shelf is a big place. 100M sounds like a reasonably average depth.

The above zero SST's at the moment (courtesy of GFS) in the ESS are not all over. They're on the coast. Geology.com has a nice depth chart with color coding for the Arctic and much of the coast has depth of 0-10 and 10-20 meters.

I'm interested in exploring the relationship / correlation between water temp and depth. If you're game we can try that. If not, also OK.

kassy

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Re: "Stupid" Questions :o
« Reply #2247 on: July 15, 2019, 01:37:13 PM »
I'm interested in exploring the relationship / correlation between water temp and depth.

Then you need to read up on salinity too. That is basically oceanography.

You might find Shakhova et al 2019 interesting.

Quote
In the ESAS, sea water is much warmer
than air (mean annual air temperature of −10 ◦C vs. mean annual sea water temperature of −1
◦C).
Consequently, the subsea permafrost has warmed by up to 17 ◦C during the last 12 kyrs [23,32]. It
has been suggested that the following factors determine the evolution of subsea permafrost after
inundation:

https://www.mdpi.com/2076-3263/9/6/251



Rich

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Re: "Stupid" Questions :o
« Reply #2248 on: July 15, 2019, 02:03:42 PM »
I'm interested in exploring the relationship / correlation between water temp and depth.

Then you need to read up on salinity too. That is basically oceanography.

You might find Shakhova et al 2019 interesting.

Quote
In the ESAS, sea water is much warmer
than air (mean annual air temperature of −10 ◦C vs. mean annual sea water temperature of −1
◦C).


Consequently, the subsea permafrost has warmed by up to 17 ◦C during the last 12 kyrs [23,32]. It
has been suggested that the following factors determine the evolution of subsea permafrost after
inundation:

https://www.mdpi.com/2076-3263/9/6/251

Thanks for the link. I realize salinity has a role to play in density and water layers. All things being equal, salty water is denser and generally sinks below fresh water.

At this point I'm trying to keep it as simple as possible and isolate the variables. Perhaps it's incorrect, but I'm working with an assumption of 1 layer in 10m deep coastal water.


SteveMDFP

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Re: "Stupid" Questions :o
« Reply #2249 on: July 15, 2019, 03:15:13 PM »

At this point I'm trying to keep it as simple as possible and isolate the variables. Perhaps it's incorrect, but I'm working with an assumption of 1 layer in 10m deep coastal water.

Sounds reasonable to me, as long as there's a little wind and/or waves.  But even this would be seasonally variable.  In freezing season, salt is excluded from the forming ice, and sinks to the bottom.  In melting season, melting ice releases fresh water, which floats above the saltier water below.  Still, in 10 meters of depth, it won't take much wind or waves to mix the whole column of water, once the surface ice is gone or pulverized.

We have very little data for depth/salinity/temperature plots on the Russian side of the arctic.  The few buoys we periodically discuss here all get placed on the US/Canadian side.

For the submerged permafrost, degradation will be slow, because heat from the ocean waters above hasn't a strong tendency to move down--heat rises.  At the bottom surface of the submerged permafrost geothermal heat is quite weak, as the permafrost layer is insulated from the geothermal heat by great depths of ancient sediment.

It works a little differently between land and marine permafrost degradation.  Freshwater lakes tend to have a temp of +4 degrees C at the bottom, because that's the temp at which fresh water is densest. These "thermokarst" lakes keep melting permafrost at their bottoms.  This is not the case for seawater, which is densest at about its freezing point. 

So melting of submerged permafrost will be very slow.  But I think it's effectively impossible for submerged permafrost to grow in depth, it can only thin and degrade over time.  Like, apparently, thousands of years.  Of course, the submerged permafrost has had something like 10k years to get along on the process since the last glacial maximum.

Shakhova and Semiletov have published voluminously on arctic permafrost.  I've only skimmed a few of their articles.  So if you want *real* expert information, I'd suggest perhaps starting here:
https://scholar.google.com/scholar?hl=en&as_sdt=0%2C21&q=Shakhova+Semiletov