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Jim Williams

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Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #800 on: February 11, 2017, 06:05:30 PM »
Well that is what temperature scales, like Kelvin, does. 
However, it provides easier units to be able to do the math.

1 K = 0.00000000000000000000000138 Joules. = 1.38 x 10-23 Joules

The math is a bit easier using the Kelvin units ;)

Wrong Math.  The interesting Stuff is in Watts and the like.

dj

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Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #801 on: February 11, 2017, 06:54:11 PM »
The Boltzmann constant is more appropriate in discussions of ideal gases. In other cases, even those involving no phase change, say the internal energy of a crystal at low temperatures which goes as T^4 , temperature changes correspond to very nonlinear energy changes. Each increment of temperature gives nonlinear change in internal energy of a crystal. If the internal energy of a crystal at T=1K is U1, and that at 2K is U2, then the ratio U2/U1 is 2^4=16  even absent any phase change.

A deeper context for Boltzmann's constant than the ideal gas laws appears in the relationship of entropy S to number of microstates W in the formula S=k*ln(W)

Coupled with the thermodynamic definition of entropy, dS = integral(dQ/T) , one immediately sees the fundamental relation between entropy, internal states and information theory. I much prefer this as the defining relation for Boltzmann's constant, but others may differ.
 
sidd

Now you are confusing the Boltzmann constant (the measured internal kinetic energy) with the thermodynamic transfer of energy from a "black body" to its surroundings. 

This is covered by the Stefan-Boltzmann constant:
σ = 5.670367(13)×10−8 W⋅m−2⋅K−4

In which the Boltzmann constant (the internal kinetic energy of the crystal) is part of the equation determining the Stefan-Boltzmann constant.


where:




kB is the Boltzmann constant;
h is the Planck constant;
ħ is the reduced Planck constant;
c is the speed of light in vacuum.
Wikipedia  [url=https://en.wikipedia.org/wiki/Stefan%E2%80%93Boltzmann_constant]

Edit: corrected my statement as per what is being measured internally (thanks Dundee).

« Last Edit: February 11, 2017, 08:53:22 PM by dj »

dj

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Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #802 on: February 11, 2017, 07:01:05 PM »
Well that is what temperature scales, like Kelvin, does. 
However, it provides easier units to be able to do the math.

1 K = 0.00000000000000000000000138 Joules. = 1.38 x 10-23 Joules

The math is a bit easier using the Kelvin units ;)

Wrong Math.  The interesting Stuff is in Watts and the like.

The only wrong math is when something does not add up ;)

Kelvin is simply a measure of how many Watts there are at any given moment (s) = W*s.
« Last Edit: February 11, 2017, 07:37:24 PM by dj »

Dundee

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Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #803 on: February 11, 2017, 08:20:23 PM »
OK, I gotta wade into this morass . . .

Temperature very simply is a measure of hot and cold. Thermal energy flows from hot to cold, so temperature is a convenient way to track this. If you get much beyond this, it isn't simple any more.

The precise relation between temperature and energy implied from the Boltzmann constant applies to ideal gasses. Among other things, ideal gas molecules do not take up physical space and do not interact at a distance. At low pressures and high temperatures, many gasses act very like ideal gasses.

Back to the Arctic. At low temperatures, all gasses act less and less 'ideal'. And water vapor in particular (with strong intermolecular forces) is a particularly non-ideal gas.

The relation between temperature and energy in an engineering sense (with real materials) is defined as heat capacity. In an ideal gas, this is a constant, in real materials, it varies with temperature. Ice (and water vapor) has a heat capacity very roughly one-half that of liquid water. Changing one unit mass of water by one unit of temperature will change the temperature of two unit mass of ice or water vapor by the same magnitude of temperature, or twice the temperature difference in the same mass.

When matter freezes or vaporizes, energy is involved in the state change beyond that which changes temperature. In the case of water, these changes (at a constant pressure) happen at a particular temperature. Ice and water in contact (at a given temperature) will always be at the same temperature (the melting point) no matter what the proportion of ice and water. Adding energy increases the proportion of water until the ice is gone, at that point the temperature again begins to rise as thermal energy is added.

The heat capacity of ice (real ice, in real conditions) is not constant. Very roughly, ice at -40 degrees has only 90% of the heat capacity of ice at the freezing point, and heat capacity continues to fall with temperature from there. The actual thermal energy in ice is the heat capacity integrated over temperature (the area under a heat capacity graph) from absolute zero to the temperature of interest. Absolute zero is the point at which there is no thermal energy present. This is in only in a rough practical sense - it turns out that (due to quantum effects and other weirdness) things are more complicated than that, but not in a way that affect understanding of the Arctic.

As a practical matter, it is almost always the change in thermal energy (or relative amount) we care about - this is why absolute temperature scales are rarely used in everyday life. Common uses for them include calculating the efficiency (among other things) of heat engine cycles, and describing temperatures so low that the freezing point of water is no longer a meaningful reference. They are also handy for calculating heat transfer by radiation to free space (which behaves much as though it were at absolute zero.

Generally speaking, conduction and convection of thermal energy are proportional to temperature difference. This is why 'degree days' are so handy. It is critical when computing temperature differences that the same scale is used - mixing relative and absolute scales or scales with different increments (F and C, K and R) will lead to wrong answers.

So to go back to the original question from Jim Williams, Matt Strassler's explanation was not particularly helpful. While it is true temperature is a measure of mechanical energy per molecule (sort of), there are lots of modes by which a molecule can hold energy. In a (monatomic) ideal gas, it simplifies to translational motion, which is great for classroom physics. In solids, liquids, and real gasses (particularly water vapor) it is much more involved, and changes with temperature. It is not true (nor particularly significant) that  "-172.15°C is 1% more energy than -173.15°C". At 100K water is ice, and its heat capacity is about two thirds that at the freezing point and dropping somewhat faster than linearly with temperature. A quick look did not turn up properties of water ice at lower temperatures, but very roughly, it is reasonable to expect the total thermal energy of ice at -173.15C to be a bit less than 2% higher than at -172.15C.

A later question was "At what temperature is there a 1% energy increase from 0oF [~-17.77oC]?". Again, I can only extrapolate (and also establish reasonable bounds on) properties below 100K, but the answer (by integrating heat capacity with respect to temperature) looks to be very roughly -16.1C or 3F (in other words, from 0F/-17.77C, a 1% increase in total thermal energy will yield a temperature increase of about 5/3rdsC/K or 3F/R). This answer is significantly lower than you'd get by assuming constant heat capacity.

It is fair to say that to speak of a 1% (or any other proportion) change of temperature in a absolute sense on any temperature scale that is not absolute (e.g. F, C) is completely meaningless. It is also, unfortunately, true that for all but a few specific thermodynamic calculations that to speak of a particular proportional change in temperature (in an absolute sense) is also often all but meaningless. Working with proportional changes in temperature difference, over which there is no phase change and the overall span of temperature is reasonable, is perfectly fine.  It is ok for you to feel twice as cold, it is without physical meaning to say any particular temperature is twice as cold as some other temperature.

In the words of NIST (http://cryogenics.nist.gov/Papers/Cryo_Materials.pdf),

Models for specific heat began in the 1871 with Boltzmann and were further refined by Einstein and Debye in the early part of the 20th century. While there are many variations of these first models, they generally only provide accurate results for materials with perfect crystal lattice structures. The specific heat of many of the engineering materials of interest here is not described well by these simple models.

I'm not sure this makes things clearer (or will make Jim Williams or others feel better) but the fact is thermodynamics is not a simple science, and many of the simple assertions made above do not stand up to scrutiny.

The good news is, Arctic temperatures may be cold but they are not truly cryogenic. Properties of ice (and water vapor) at Arctic temperatures are well described in engineering literature (and, presumably, have been correctly applied in models heavily dependent on thermodynamics, such as PIOMAS). At some point you have to trust the experts or do a LOT of homework.

Please don't even attempt to understand the physics (or, too often, complete lack of same) behind wind chill numbers. And please don't try to apply wind chill values when calculating degree days or computing your heating bill . . .

dj

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Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #804 on: February 11, 2017, 08:58:37 PM »
OK, I gotta wade into this morass . . .

Yes, but is it not better to understand the simple "ideal" relationships first before throwing in all the caveats?   :)

Of course I understood that was only for ideal gases - but grasping that concept first is crucial, don't you think?

Tor Bejnar

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Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #805 on: February 11, 2017, 11:07:45 PM »
thanks, Dundee.
Arctic ice is healthy for children and other living things because "we cannot negotiate with the melting point of ice"

DaveHitz

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Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #806 on: February 12, 2017, 01:23:30 AM »
Yes, but is it not better to understand the simple "ideal" relationships first before throwing in all the caveats?   :)

Of course I understood that was only for ideal gases - but grasping that concept first is crucial, don't you think?

For me, it depends whether the "simple ideal relationships" have any applicability to the real world.

Physics teachers love to do problems about "friction free environments" (because the math is simpler), but in our everyday lives here on Earth, Aristotle was correct: "Objects in motion tend to come to rest." Physics types will say, "That's because there is always friction, which exerts a force." But that's exactly the point: the friction-free simple case essentially never applies. (Again, I mean here on Earth.)

Likewise, I'm not sure that this simplified concept about ideal gases has any useful relevance to the arctic which consists entirely of solids, liquids, and non-ideal gasses. Especially since much of what's interesting in the arctic is phases changes, which is where the simplified version is furthest from the truth.

Jim Williams

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Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #807 on: February 12, 2017, 02:35:02 AM »
Yes, but is it not better to understand the simple "ideal" relationships first before throwing in all the caveats?   :)

Of course I understood that was only for ideal gases - but grasping that concept first is crucial, don't you think?

For me, it depends whether the "simple ideal relationships" have any applicability to the real world.

Physics teachers love to do problems about "friction free environments" (because the math is simpler), but in our everyday lives here on Earth, Aristotle was correct: "Objects in motion tend to come to rest." Physics types will say, "That's because there is always friction, which exerts a force." But that's exactly the point: the friction-free simple case essentially never applies. (Again, I mean here on Earth.)

Likewise, I'm not sure that this simplified concept about ideal gases has any useful relevance to the arctic which consists entirely of solids, liquids, and non-ideal gasses. Especially since much of what's interesting in the arctic is phases changes, which is where the simplified version is furthest from the truth.

I'm with you and I think Dundee finally gave us a meaningful answer.

sidd

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Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #808 on: February 12, 2017, 07:03:57 AM »
"Now you are confusing the Boltzmann constant (the measured internal kinetic energy) with the thermodynamic transfer of energy from a "black body" to its surroundings. "

Not at all. But I shall bow out of the discussion now.

dj

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Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #809 on: February 12, 2017, 09:24:41 AM »
"Now you are confusing the Boltzmann constant (the measured internal kinetic energy) with the thermodynamic transfer of energy from a "black body" to its surroundings. "

Not at all. But I shall bow out of the discussion now.

I am assuming that if you're measuring the temperature of something, that you have the thermometer embedded within that material.  Thus, you are measuring the conduction or convection, not the radiation, of thermal energy.

Which leads to my own stupid question: 
How is the temperature of ice taken?  Is the temperature a measure making direct contact with the ice (conduction), or is there some space between the thermometer and the ice (radiation)?  Never done it and never thought about it before.
« Last Edit: February 12, 2017, 09:56:55 AM by dj »

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Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #810 on: February 12, 2017, 10:22:41 AM »
How the internal temperature of ice is taken? That's a good question. If i remembe correctly, one mehtod was embedding a conductive lead with resistors through the ice, letting refreeze, waiting a couple days, and start sending short elecrtical pulses down the line. The resistors conductivity changes by the temperature it's in so you get the change in local T. Bunch of calibrating happens and we get those nice ice buoy measurements of temperatures.

https://en.m.wikipedia.org/wiki/Electrical_resistivity_and_conductivity#Temperature_dependence
Someone correct that if this went horribly wrong

oren

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Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #811 on: February 12, 2017, 01:46:50 PM »
How the internal temperature of ice is taken? That's a good question. If i remembe correctly, one mehtod was embedding a conductive lead with resistors through the ice, letting refreeze, waiting a couple days, and start sending short elecrtical pulses down the line. The resistors conductivity changes by the temperature it's in so you get the change in local T. Bunch of calibrating happens and we get those nice ice buoy measurements of temperatures.

https://en.m.wikipedia.org/wiki/Electrical_resistivity_and_conductivity#Temperature_dependence
Someone correct that if this went horribly wrong
Correct, the O-Buoys have somethings called thermistors. There used to be a good explanation around the forum somewhere regarding these buoys.

dj

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Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #812 on: February 12, 2017, 03:30:32 PM »
How the internal temperature of ice is taken? That's a good question. If i remembe correctly, one mehtod was embedding a conductive lead with resistors through the ice, letting refreeze, waiting a couple days, and start sending short elecrtical pulses down the line. The resistors conductivity changes by the temperature it's in so you get the change in local T. Bunch of calibrating happens and we get those nice ice buoy measurements of temperatures.

https://en.m.wikipedia.org/wiki/Electrical_resistivity_and_conductivity#Temperature_dependence
Someone correct that if this went horribly wrong

Thank you very much!

Addendum:  If that is a "good question" is it considered OT for "Stupid questions"?  ;)
« Last Edit: February 12, 2017, 03:51:59 PM by dj »

SteveMDFP

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Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #813 on: February 12, 2017, 03:48:48 PM »

I am assuming that if you're measuring the temperature of something, that you have the thermometer embedded within that material.  Thus, you are measuring the conduction or convection, not the radiation, of thermal energy.

Which leads to my own stupid question: 
How is the temperature of ice taken?  Is the temperature a measure making direct contact with the ice (conduction), or is there some space between the thermometer and the ice (radiation)?  Never done it and never thought about it before.

Conduction, convection, and radiation are mechanisms of heat flux.  When the thermometer is in equilibrium with the thing being measured, there is no net flux by any of these mechanisms.  Any of these mechanisms can bring the thermometer into equilibrium with the thing being measured. 

Imagine you put a hollow sphere of ice in orbit.  A thermometer is suspended in the center, not touching the insides in any way.  The space inside the sphere is a vacuum.  The ice is at, say -10C and the thermometer is at +20 C.  Wait some days.  Eventually the thermometer will radiate heat into the ice, which will not radiate as much heat back to the thermometer.  Equilibrium will eventually be reached, and the thermometer will read -10 (assuming thermal mass of the thermometer is trivial in comparison to the ice). 

In more real-world situations, radiation, convection, and conduction all work together to bring equilibrium, faster than any single mechanism would.

dj

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Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #814 on: February 12, 2017, 03:56:24 PM »

I am assuming that if you're measuring the temperature of something, that you have the thermometer embedded within that material.  Thus, you are measuring the conduction or convection, not the radiation, of thermal energy.

Which leads to my own stupid question: 
How is the temperature of ice taken?  Is the temperature a measure making direct contact with the ice (conduction), or is there some space between the thermometer and the ice (radiation)?  Never done it and never thought about it before.

Conduction, convection, and radiation are mechanisms of heat flux.  When the thermometer is in equilibrium with the thing being measured, there is no net flux by any of these mechanisms.  Any of these mechanisms can bring the thermometer into equilibrium with the thing being measured. 

Imagine you put a hollow sphere of ice in orbit.  A thermometer is suspended in the center, not touching the insides in any way.  The space inside the sphere is a vacuum.  The ice is at, say -10C and the thermometer is at +20 C.  Wait some days.  Eventually the thermometer will radiate heat into the ice, which will not radiate as much heat back to the thermometer.  Equilibrium will eventually be reached, and the thermometer will read -10 (assuming thermal mass of the thermometer is trivial in comparison to the ice). 

In more real-world situations, radiation, convection, and conduction all work together to bring equilibrium, faster than any single mechanism would.

True.  I was more interested in whether or not it was via conduction or not. Allowing for the bore hole/hole to refreeze over time means it would be via conduction (not necessarily measuring the temperature of the air within the ice).  I was just curious as I had not thought about it previously.

Stupid questions are not necessarily stupid, as they do give pause to think about things not necessarily considered before.
« Last Edit: February 12, 2017, 04:43:39 PM by dj »

dj

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Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #815 on: February 12, 2017, 05:06:21 PM »
Ok, stupid questions 2-5.  And I am not a statistician, so it may take me a bit to understand any replies (in essence be prepared for additional inquiries).

There is speculation regarding as to when or if we have reached a tipping point in, for example, the Arctic in regards to ice growth/Freeze season as measured by FDDs.

So, statistically speaking:
(1) Would it be appropriate to treat each freeze season separately as a dataset, and run a Chow test on - for example - a regression analysis of the accumulation of FDDs for each freeze season, change in ice volume, extent, or area?

(2) If done, would it then be appropriate to group those freeze seasons that are not statistically different as an appropriate baseline for comparison to those that are (if any) statistically different?

(3) Would this be an appropriate method to determine whether or not a "tipping point" has been achieved?

(4) Has anyone already done an analysis of this type?  Be it on FDDs or the equivalent melt season measure or on the results, i.e. the amount of change in Volume/Extent/Area of Arctic Sea ice?

Edit: I cannot count - it should be 2-5 (given that I already asked one previously).  Thank goodness I am not a Statistician. :D
« Last Edit: February 12, 2017, 05:52:58 PM by dj »

Jim Williams

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Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #816 on: February 12, 2017, 05:20:39 PM »
Chow test: https://en.wikipedia.org/wiki/Chow_test

Interesting notion...doesn't seem to tell you anything about the underlying reasons, but it would tend to tell you if there was a catastrophe or not.

Waiting for the discussion.

dj

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Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #817 on: February 12, 2017, 05:48:13 PM »
Chow test: https://en.wikipedia.org/wiki/Chow_test

Interesting notion...doesn't seem to tell you anything about the underlying reasons, but it would tend to tell you if there was a catastrophe or not.

Waiting for the discussion.

True, but would it not allow you to tease out the potential mechanisms?  Part of what I am am thinking is that, for example, for a freeze season the Chow test for FDDs are not statistically different from other seasons but the volume/extent was - then this would be indicative of another mechanism in play (such as warmer water temperatures or stormier weather).  Just a thought.

The other part is that, given that the the baseline (ERA40 or ERA-Interm) and ice measurements appears to be constantly changing would this not allow for a determination of an appropriate "baseline" for comparisons? I am not sure I have worded that well.

Jim Williams

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Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #818 on: February 12, 2017, 06:03:08 PM »
True, but would it not allow you to tease out the potential mechanisms?
I will leave the rest of it to others that have more brain cells left, but I don't think so -- at least not directly.

What it will tell you is that if you are traversing an event surface, you have fallen at a particular point from a plane that folded under to the plane below it.   Catastrophe Theory (and game theory) are a bit hard to put into human terms.

If you are running about with one set of coefficients and suddenly you are running about with another set then you have fallen off a cliff.

oren

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Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #819 on: February 12, 2017, 06:40:54 PM »
Ok, stupid questions 2-5.  And I am not a statistician, so it may take me a bit to understand any replies (in essence be prepared for additional inquiries).

There is speculation regarding as to when or if we have reached a tipping point in, for example, the Arctic in regards to ice growth/Freeze season as measured by FDDs.

So, statistically speaking:
(1) Would it be appropriate to treat each freeze season separately as a dataset, and run a Chow test on - for example - a regression analysis of the accumulation of FDDs for each freeze season, change in ice volume, extent, or area?

(2) If done, would it then be appropriate to group those freeze seasons that are not statistically different as an appropriate baseline for comparison to those that are (if any) statistically different?

(3) Would this be an appropriate method to determine whether or not a "tipping point" has been achieved?

(4) Has anyone already done an analysis of this type?  Be it on FDDs or the equivalent melt season measure or on the results, i.e. the amount of change in Volume/Extent/Area of Arctic Sea ice?

Edit: I cannot count - it should be 2-5 (given that I already asked one previously).  Thank goodness I am not a Statistician. :D
1. If you mean compare the FDD accumulation for each freezing season, and finding whether recent years break away from a previous clustering, then yes it is appropriate.
2. Yes
3. If you find a statistically significant change then yes. But I doubt you will as of now.
4. Check out the chart showing accumulated FDD anomalies since September of each year.
https://sites.google.com/site/cryospherecomputing/degree-days-freezing

zizek

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Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #820 on: February 12, 2017, 07:11:16 PM »
I'm a first year student in a technical program with little background in climate science. Even though it's sort of unrelated to my field, I'm writing a paper about the challenges the Canadian Department of Fisheries and Oceans will face (or are currently facing) due to climate change.  I've been making great progress, and have assembled some great resources dealing with specific issues. But I'm having trouble getting some decent literature on the following topics:

As I understand it, the IPCC has been making some fairly conservative projections. But I'm having difficulty finding any pieces addressing that specifically. This would really help my argument because as far as I know, the government relies heavily on the IPCC.

Is their anything that gives an overview of recent developments in respect to record breaking high temperatures and poor arctic sea ice. I see a lot of papers being posted here, but they seem very specific and go over my head.

My goal with the paper is to describe just how exposed the department is to climate change crisis.

I apologize if this seems like I'm asking you to do my homework.  But this paper is really a thought exercise for myself.  I'm going far above and beyond what an intro to essay writing course is asking for.

If you have any literature that might help my cause, It would be much appreciated. Thanks!

And sorry if this seems like the wrong thread for it. I was gonna post in the science forum, but Stupid Questions thread seemed more suitable :)


Neven

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Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #821 on: February 12, 2017, 07:21:54 PM »
Welcome, Slavoj, your profile has been released.

Have you had a look at the latest NOAA Arctic Report Card?
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Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #822 on: February 12, 2017, 08:05:51 PM »
"My goal with the paper is to describe just how exposed the department is to climate change crisis."

 ::)
About as exposed as a piece of photographic film wrapped around a fuel rod in a candu reactor.

This planet needs periodic defrost cycles or permafrost and deepsea hydrocarbon reservoirs build up to dangerous levels that could trigger a venus style runaway greenhouse event that boils the oceans and leaves us with 100 atmospheres of pressure and temperatures that would melt lead at sea level. This has been happening on an approximately 150my cycle here for the last billion years. The worst crash, from the perspective of the critters in residence from a glaciated phase, which usually lasts around 50my to a hothouse earth where mostly reptiles and insects are happiest, in this time, was the end Permian event 250 million years ago. but at that time we had one super-continent, Pangaea, with a small icecap at one end, and potential for permafrost carbon and deepsea clathrates was undeniably much less than our current situation. And the current crop of apes have triggered a defrost far more rapid in progress than ever before. Keep your chin up  ;D its a privileged position to be around to witness such a rare event. whether its the death of a planetary biosphere or the critters with the brains to grab the reins and steer the cart away from the cliff actually doing it. Science is hamstrung by only being allowed to speak about the past with certainty. and is yet to recover from bullying by the fossil trolls, so is speaking in over conservative terms about future predictions. The Chinese write crisis with two symbols. One means danger, the other opportunity. Its a good idea to look for the silver lining that generally is hidden in most dark clouds. Order is stagnant chaos is fertile. You are either green and growing, or ripe and rotting.
 8)
Policy: The diversion of NZ aluminum production to build giant space-mirrors to melt the icecaps and destroy the foolish greed-worshiping cities of man. Thereby returning man to the sea, which he should never have left in the first place.
https://en.wikipedia.org/wiki/McGillicuddy_Serious_Party

crandles

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Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #823 on: February 12, 2017, 08:26:16 PM »

As I understand it, the IPCC has been making some fairly conservative projections. But I'm having difficulty finding any pieces addressing that specifically. This would really help my argument because as far as I know, the government relies heavily on the IPCC.

Is their anything that gives an overview of recent developments in respect to record breaking high temperatures and poor arctic sea ice. I see a lot of papers being posted here, but they seem very specific and go over my head.

My goal with the paper is to describe just how exposed the department is to climate change crisis.

You could compare IPCC report saying
Quote
Global mean sea level rise for 2081–2100 relative to 1986–2005 will likely be in the ranges of 0.26 to 0.55 m for RCP2.6, 0.32 to 0.63 m for RCP4.5, 0.33 to 0.63 m for RCP6.0, and 0.45 to 0.82 m for RCP8.5 (medium confidence). For RCP8.5, the rise by the year 2100 is 0.52 to 0.98 m, with a rate during 2081 to 2100 of 8 to 16 mm yr–1 (medium confidence).
These ranges are derived from CMIP5 climate projections in combination with process-based models and literature assessment of glacier and ice sheet contributions (see Figure SPM.9, Table SPM.2). {13.5}

with what experts predicted at similar time. eg
http://www.realclimate.org/index.php/archives/2013/11/sea-level-rise-what-the-experts-expect/
and look for similar from previous reports.

Part of the problem with this might be how you deal with statements such as
Quote
Based on current understanding, only the collapse of marine-based sectors of the Antarctic ice sheet, if initiated, could cause global mean sea level to rise substantially above the likely range during the 21st century.

Is that sufficient warming that the IPCC numbers could tend to be on the low side?

longwalks1

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Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #824 on: February 12, 2017, 08:33:26 PM »
Zizek, since I drive past it, if in Winnipeg at the UM  501 University Crescent.  If you live near any other sites in Canada

http://www.dfo-mpo.gc.ca/science/regions/index-eng.htm     - stop by and say, "Hi."

Myself, when I research I can go too large for a focus.  Possible subsets of climate impacts on Canadian fisheries are 1.  species migration  and invasive species.  2.  Since plankton is the base, impacts on plankton.  3.  Focus on the West Coast changes or East Coast changes (cod, seals) or arctic basins. 4.  If you want to bring in something novel, maybe explore "the canaries in the coal mine" - usage of marine bird species populations as in indicator of overall health of ecosystems, marine birds as the litmus test.  Yeah, #4 is myself getting a little too carried away.

If you have a technical background, but not grounded in specifics, sites like https://phys.org/  might serve as an initial search engine.   It is technical enough, but not rigorous, but does give you the direct sources.  Hey, good luck.

Dr. Barber has a new video up also about Arctic change.   

Pmt111500

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Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #825 on: February 12, 2017, 08:36:58 PM »
Part of the problem with this might be how you deal with statements such as
Quote
Based on current understanding, only the collapse of marine-based sectors of the Antarctic ice sheet, if initiated, could cause global mean sea level to rise substantially above the likely range during the 21st century.

Is that sufficient warming that the IPCC numbers could tend to be on the low side?

(sarc) But but, that is totally understandable by those whose lives it mattters the most, that is 4-14 year olds with adhd? (/sarc)


dj

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Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #826 on: February 12, 2017, 09:13:02 PM »
Ok, stupid questions 2-5.  And I am not a statistician, so it may take me a bit to understand any replies (in essence be prepared for additional inquiries).

There is speculation regarding as to when or if we have reached a tipping point in, for example, the Arctic in regards to ice growth/Freeze season as measured by FDDs.

So, statistically speaking:
(1) Would it be appropriate to treat each freeze season separately as a dataset, and run a Chow test on - for example - a regression analysis of the accumulation of FDDs for each freeze season, change in ice volume, extent, or area?

(2) If done, would it then be appropriate to group those freeze seasons that are not statistically different as an appropriate baseline for comparison to those that are (if any) statistically different?

(3) Would this be an appropriate method to determine whether or not a "tipping point" has been achieved?

(4) Has anyone already done an analysis of this type?  Be it on FDDs or the equivalent melt season measure or on the results, i.e. the amount of change in Volume/Extent/Area of Arctic Sea ice?

Edit: I cannot count - it should be 2-5 (given that I already asked one previously).  Thank goodness I am not a Statistician. :D
1. If you mean compare the FDD accumulation for each freezing season, and finding whether recent years break away from a previous clustering, then yes it is appropriate.
2. Yes
3. If you find a statistically significant change then yes. But I doubt you will as of now.
4. Check out the chart showing accumulated FDD anomalies since September of each year.
https://sites.google.com/site/cryospherecomputing/degree-days-freezing

Hmm, if a tipping point would be an ice-free summer in the Arctic, perhaps we passed that tipping point in the late-1990's early 2000's?  Unfortunately, tipping points are often unrecognized until after one has fallen out of the canoe and into the water.

Image is attached?  As a noob I am unsure as to how to embed images in a post.

Source:
Walsh, John E., et al. "A database for depicting Arctic sea ice variations back to 1850." Geographical Review 107.1 (2017): 89-107.






Hyperion

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Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #827 on: February 12, 2017, 09:27:20 PM »
Don't forget acidification making it impossible for fishes and shellfish and crustaceans  to produce shells for their eggs or the young to form skeletons. Already stopped the mussels being able to reproduce on around 1/4 of New Zealand's coastline. You need to electrify reefs to overcome it.   :(
Policy: The diversion of NZ aluminum production to build giant space-mirrors to melt the icecaps and destroy the foolish greed-worshiping cities of man. Thereby returning man to the sea, which he should never have left in the first place.
https://en.wikipedia.org/wiki/McGillicuddy_Serious_Party

Iceismylife

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Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #828 on: February 12, 2017, 09:28:15 PM »
<snip>

As I understand it, the IPCC has been making some fairly conservative projections. But I'm having difficulty finding any pieces addressing that specifically. This would really help my argument because as far as I know, the government relies heavily on the IPCC.

<snap>
For what it is worth NOAA (US) has issued a warning to the insurance companies of a possible 3m sea level rise by 2050~2060.  Looking at the ice dynamics in Antarctica this is reasonably likely.

The IPCC is smoking really good dope but don't quote me on that.  Their models are broken. Someone on this forum said they were modeling albedo as constant if at all.

For an alternative look https://forum.arctic-sea-ice.net/index.php/topic,1749.0.html this thread makes good reading.

Hyperion

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Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #829 on: February 12, 2017, 09:50:48 PM »
Anyone here suffering from Mortality Salience?  ::) Planetry MS sure is a biggy for most. they do anything to distract themselves from having to think about it. ;)

Quote https://en.wikipedia.org/wiki/Mortality_salience
"Potential to cause worldview defense[edit]
Mortality salience has the potential to cause worldview defense, a psychological mechanism that strengthens people's connection with their in-group as a defense mechanism. Studies also show that mortality salience can lead people to feel more inclined to punish minor moral transgressions. One such study divided a group of judges into two groups—one that was asked to reflect upon their own mortality, and one group that was not. The judges were then asked to set a bond for an alleged prostitute. The group that had reflected on mortality set an average bond of $455, while the control group's average bond was $50.[4]
Another study found that mortality salience could cause an increase in support for martyrdom and military intervention. Tom Pyszczynski et al. found that students who had reflected on their mortality showed preference towards people who supported martyrdom, and indicated they might consider martyrdom themselves. They also found that, especially among students who were politically conservative, mortality salience increased support for military intervention, but not among students who were politically liberal.[5] "

from Terror management theory. https://en.wikipedia.org/wiki/Terror_management_theory :

"  TMT is derived from anthropologist Ernest Becker's 1973 Pulitzer Prize-winning work of nonfiction The Denial of Death, in which Becker argues most human action is taken to ignore or avoid the inevitability of death. The terror of absolute annihilation creates such a profound – albeit subconscious – anxiety in people that they spend their lives attempting to make sense of it. On large scales, societies build symbols: laws, religious meaning systems, cultures, and belief systems to explain the significance of life, define what makes certain characteristics, skills, and talents extraordinary, reward others whom they find exemplify certain attributes, and punish or kill others who do not adhere to their cultural worldview. On an individual level, self-esteem provides a buffer against death-related anxiety."
Policy: The diversion of NZ aluminum production to build giant space-mirrors to melt the icecaps and destroy the foolish greed-worshiping cities of man. Thereby returning man to the sea, which he should never have left in the first place.
https://en.wikipedia.org/wiki/McGillicuddy_Serious_Party

Ninebelowzero

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Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #830 on: February 14, 2017, 05:40:03 AM »
According to nullschool The Norwegians appear to have nicked the Polar jetstream.





When are they going to give it back?  8)

zizek

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Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #831 on: February 14, 2017, 02:55:26 PM »
Thanks for all the great responses!

This forum is superb.  I don't think I've ever seen a forum with so much high quality content. kudos to the mods and users!

gerontocrat

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Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #832 on: February 14, 2017, 03:25:17 PM »
Norwegians have nicked the polar vortex to provide wind for electricity generation  for their electrical vehicles programme. Mind you, they are also opening up new oil fields in the Barents.
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realitybytes

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Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #833 on: February 14, 2017, 10:55:49 PM »
101 strides is merely one stride more than 100 strides -- it is no percents more.
You haven't put a smiley in there, so I can't tell if you're joking or genuinely confused.

If the standard Stride is 10 cm, then 100 Strides is 1000 cm and 101 Strides is 1010 cm, which is 1% greater.

If the standard Stride is 20 miles, then 100 Strides is 2000 miles and 101 Strides is 2020 miles, which is 1% greater.
Then this is purely a case of liars figure.  1% of which measure?  The previous stride or the current stride?

Jim, I didn't see anyone actually answer your precise question as to "which measure", so I will.

The "which measure" he is referring to as the basis for the percentage change is not the incremental measure of any individual stride, but the sum total distance represented by the starting point - "100 Strides" - and the next (incremental) Stride to get to 101 Strides is indeed exactly 1% more. (I hope this doesn't add to the confusion, but the *next* additional Stride, to get to 102, would be slightly less than 1%, as the basis distance would then be 101 Strides, and the percent increase of distance would be 1/101...)

I'm wondering if the confusion may have arose from the original statement about "-172.15 degrees Celsius" (same as 101 K) having 1% more energy than "-173.15 degrees Celsius" (same as 100 K)... in which case, the "which measure" being used as the basis is 100 K (aka -173.15 degC), and 101 K (aka -172.15 degC) measures exactly 1% more energy than the total energy at 100 K (because K is an absolute measure)

The observation that 1 is infinitely greater percentage than 0 is true, at 1 K vs. 0 K... but much like dividing by zero has no meaning, so does 0 K (other than as a limit, never reachable)

Hyperion

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Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #834 on: February 15, 2017, 06:02:09 PM »
Norwegians have nicked the polar vortex to provide wind for electricity generation  for their electrical vehicles programme. Mind you, they are also opening up new oil fields in the Barents.

If they make some Giant Seacrete ( https://en.wikipedia.org/wiki/Biorock ) or Geopolymer ( https://en.wikipedia.org/wiki/Geopolymer )
 heat exchangers instead of concrete oil rigs....

 They could make enough electricity to power all the worlds transport needs by putting turbines on heatpipes  ( https://en.wikipedia.org/wiki/Heat_pipe ) to transfer the heat from the gulfstream up to the south of Greenland meltpool. Put the brakes on this 10x anthro GG global warming effect from the meltpool reducing outgoing long wave over a large area of the earths surface and causing an accelerating runaway greenland melt. And the cyclone canon of the adjacent hot and cold surface waters building up from current ww2 bren gun level that produced 60ft swells in the north atlantic to the 100,000 year ago style revolving six barrel 100mm autogun version, (or even worse considering the much faster rate of change we have triggered) that sent 200 ft waves right across the north Atlantic Ocean to throw 10m plus boulders 6 kms inland and 50m above sea level onto ridgetops in the bahamas.
 Assuming that Hansen and Co's paper before paris had any validity of course.  ::)

I love heatpipes  8)
No moving parts and they have achieved greater per area energy fluxes than the surface of the sun with them in the lab.

 You could even electrolyse the co2 out of the sea and air into hydrocarbon fuel for transport purposes. Then shift reaction the energy into liquid hydrogen later for transport fuel, and sequester the C as char or engineering polymers.
Policy: The diversion of NZ aluminum production to build giant space-mirrors to melt the icecaps and destroy the foolish greed-worshiping cities of man. Thereby returning man to the sea, which he should never have left in the first place.
https://en.wikipedia.org/wiki/McGillicuddy_Serious_Party

binntho

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Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #835 on: February 17, 2017, 01:26:50 PM »
Probably a very stupid question:

I've been following this forum with great interest for some time now, and have accumulated a number of shortcuts to various blogs, information pages, and of course, to Nevens fabulous Arctic Sea Ice Graphs page.

But I keep seeing these interesting and fantastic images posted and far too often I've no idea where they are coming from. Would it be stupid to ask that someone more knowledgeable than me maintained a categorized list of useful sites/links?

What has triggered this question at this time is that I've been looking for the latest HadCrut numbers (an acquaintance of mine has shown me a spurious graph claiming to be from the MetOffice with January 2017 marked in), and during one of my searches I came across this page:

https://moyhu.blogspot.it/p/latest-ice-and-temperature-data.html

Perhaps everybody knows of this page, but for me it looks like a good resource for an amateur wanting to keep abreast of things.
because a thing is eloquently expressed it should not be taken to be as necessarily true
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josh-j

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Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #836 on: February 18, 2017, 05:22:56 PM »
Here is my stupid question:

DMI 80n graph page says the data is derived from the ECMWF operational model. I can see in the older graph years that ERA40 was used but I don't know what the "operational model" is now.

Basically I want to get the data behind the DMI 80N graph but am struggling to find out where to look. I'm not sure if the values calculated by DMI are available somewhere but cannot see anywhere to obtain from their site?

Thanks for any help :)

CalamityCountdown

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Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #837 on: February 18, 2017, 05:39:40 PM »
Arctic sea ice extent on an annual/biannual basis seems to have a tendency to revert to the trend line. Are there changes in the climate that reduce the likelihood that 2018 will be another bounce back year? (which would of course will lead to more alternative facts from the denial-sphere - as reported by  http://greatwhitecon.info/blog/)


Gray-Wolf

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Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #838 on: February 18, 2017, 05:50:58 PM »
Arctic sea ice extent on an annual/biannual basis seems to have a tendency to revert to the trend line. Are there changes in the climate that reduce the likelihood that 2018 will be another bounce back year? (which would of course will lead to more alternative facts from the denial-sphere - as reported by  http://greatwhitecon.info/blog/)

If the past two winters are showing us a big shift in the energy budget across the basin then 'no'!

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ko.yaa.nis.katsi (from the Hopi language), n. 1. crazy life. 2. life in turmoil. 3. life disintegrating. 4. life out of balance. 5. a state of life that calls for another way of living.
 
VIRESCIT VULNERE VIRTUS

crandles

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Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #839 on: February 18, 2017, 06:47:06 PM »
Here is my stupid question:

DMI 80n graph page says the data is derived from the ECMWF operational model. I can see in the older graph years that ERA40 was used but I don't know what the "operational model" is now.

Basically I want to get the data behind the DMI 80N graph but am struggling to find out where to look. I'm not sure if the values calculated by DMI are available somewhere but cannot see anywhere to obtain from their site?

Thanks for any help :)

See (may need to click link to go to post to get attachment)

No there's not.

Actually there is. For the 2016 numbers see:

ftp.dmi.dk/plus80N_temperatureindex/

For previous years see the attachment, which is actually a ZIP archive.

2017 numbers are now in the ftp site and the zip file doesn't have 2016. Think I can attach the 2016 numbers here
« Last Edit: February 18, 2017, 06:56:14 PM by crandles »

josh-j

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Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #840 on: February 18, 2017, 11:10:24 PM »
Thank you very much Crandles, much obliged! And thanks to Jim also. :)

Cate

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Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #841 on: February 21, 2017, 01:24:21 PM »
I have a question beyond stupid. :D

Does the term "Arctic sea ice extent" (in the data, discussions, etc) include the large area of coastal pack ice that annually makes it way from the various Arctic waterways down the Labrador coast to the "front" off NE Newfoundland?

Btw, this is the pack that provides the whelping ground for the harp seal and is the traditional ground for the much-maligned Newfoundland seal hunt---or as we call it, the seal fishery.

magnamentis

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Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #842 on: February 21, 2017, 02:05:35 PM »
yes and if you want to find out for other regions as well, just watch one of the maps that provide extent data and see whether the ice is on that map or not and whether the average bounderies include that region or not. one example would be this:

as you can see, the region you were asking is included :-)

Cate

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Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #843 on: February 21, 2017, 04:15:00 PM »
Thank you, magnamentis. It's interesting to me that that ice in Canadian waters even as far south as the Gulf of St Lawrence is counted as "Arctic" sea ice.

Jim Williams

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Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #844 on: February 21, 2017, 04:56:16 PM »
Also, since the picture on the graphs page no longer finds this page for some reason, you can even check to see how those regions are doing at the moment compared to previous years:

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

Cate

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Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #845 on: February 22, 2017, 02:28:14 AM »
Also, since the picture on the graphs page no longer finds this page for some reason, you can even check to see how those regions are doing at the moment compared to previous years:

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

Jim, thanks for this---yet another grim line on that graph for the entire NH. Looks like 2017 extent has managed to climb out of the basement only in the past couple of days.

magnamentis

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Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #846 on: February 22, 2017, 02:40:35 AM »
Thank you, magnamentis. It's interesting to me that that ice in Canadian waters even as far south as the Gulf of St Lawrence is counted as "Arctic" sea ice.
you're welcome :D

after all it's just a term because 90% of northern hemisphere "sea-ice is in the arctic as to north of the polar circle, while one could as well say "northern hemisphere sea-ice" but i don't think that this is really important as long most people understand the meaning.

Tealight

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Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #847 on: February 28, 2017, 09:22:50 PM »
Why is CO2 measured in parts per million and not in kg/m2 ? Wouldn't this give us a better comparison to other greenhouse gases like water vapour? When looking at Mars & Venus we can see that it is not the concentration that matters, but the total mass. Both planets have around 96% CO2 concentration, but only Venus is hot because it has a very thick atmosphere. Mars on the other hand has a thin atmosphere and is very cold.

Using a standard atmosphere I get the following conversion:
Pressure   1013.25   hPa
Pressure   101325   N/m2 (kg⋅m⋅s−2/m2)
accelaration:   9.81   m/s2
Atmosphere mass:   10328.74618   kg /m2
      
CO2 concentration:   405   ppm      
CO2 mass:   4.183   kg/m2

DrTskoul

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Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #848 on: February 28, 2017, 11:27:44 PM »
I am sure the ppm of CO2 are in volume. The local concentration of CO2 dictates its absorbance and emissivity of IR. You cannot do any calculations or modeling based on the integral amount above your head. And it would vary based on the local pressure.

FredBear

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Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #849 on: March 01, 2017, 01:47:21 PM »
Tealight, the first rule of the computer generation has been KISS (Keep It Simple, Stupid) for the reason that complexity breeds confusion, etc. We don't need to feed Trolls anything they can use to "justify" their attempts to say the goal-posts have been moved.

ppm CO2 as a standard is measured at one place, at altitude and could be affected by volcanic fumes (if the wind blows the wrong way?) or Asian economic activity. The standard is used as a measure of the balance between production and consumption, it cannot tell whether the ocean changes pH - but it does reflect changes in photosynthesis throughout the year! It will be measured in dried air to keep one variable out, produces a clear, simple number (especially when there are 0's in it!) and researchers can relate their discoveries in other fields to it.

In short, measured ppm CO2 is a simple, reliable, trusted, useful, visual tool, with known limitations.