Antarctic Ice Shelf Vista (2009 Feb 15)

[Chris Peterson]

Science is a search after knowledge, Chris.

That's where you are wrong- or at least, imprecise. In the modern sense, science is the search for knowledge using a specific, rational process. Philosophy is a search for knowledge as well, but it isn't remotely scientific.

There are many routes to knowledge, and I'm not offering any comparisons (although I obviously have my own opinions about how effective or useful different methods are). I'm just pointing out that this forum is about modern science, and that means that arguments that don't follow the dictates of the modern scientific approach are, by definition, unscientific. And for the most part, they don't belong here.

[BMAONE23]

Why don't you show the current image instead of the summer image?

OK here you go
current winter ice levels vs last year and 10 years prior
Per your request,
Current ice conditions in the arctic region

Vs the same day last year

Note Hudson bay ice is appx ½ last years level
And 10 years prior

[bhrobards]

BMAONE23- Thanks, better images than I hoped for. Very interesting. Sea ice is less in later years compared to 1998. But, wow check out the snow cover, last Feb and this almost normal. High albedo, heat reflected out, dare I say cooling. Check out the solar scientists it is sobering. Bill

[BMAONE23]

Here are the last 3 years indicating Snow Coverage (2005 feb is missing, 2004 and prior don’t indicate snow coverage)
Feb 2006

Feb 2007

Feb 2008

Today


2006 seems to have less snow coverage than today but today still has less sea ice coverage.

[tomrich67000]

Oops....looks like this photo belongs on EPOD (Earth Picture of the Day). What is it doing here???

[neufer]

I have a selfish reason too for believing that we are responsible for the climate change, and it is to hope that we wake up and do something to stop it, or at least not make it worse, for my children and grandchildren's sake.

Move your family to high ground, Gary, because we can't do anything about the sun's effect.

Well..., yes, we can and, yes, we have already:"

<<Global dimming is the gradual reduction in the amount of global direct irradiance at the Earth's surface that was observed for several decades after the start of systematic measurements in the 1950s. The effect varies by location, but worldwide it has been estimated to be of the order of a 4% reduction over the three decades from 1960–1990. It is thought that global dimming was probably due to the increased presence of aerosol particles in the atmosphere caused by human action. Aerosols and other particulates absorb solar energy and reflect sunlight back into space. The pollutants can also become nuclei for cloud droplets. Water droplets in clouds coalesce around the particles. Increased pollution causes more particulates and thereby creates clouds consisting of a greater number of smaller droplets (that is, the same amount of water is spread over more droplets). The smaller droplets make clouds more reflective, so that more incoming sunlight is reflected back into space and less reaches the earth's surface.

Some scientists have suggested using aerosols to stave off the effects of global warming as an emergency geoengineering measure. Russian expert Mikhail Budyko understood this relationship very early on. In 1974, he suggested that if global warming became a problem, the planet could be cooled by burning sulfur in the stratosphere, which would create a haze. According to Ramanathan (1988), an increase in planetary albedo of just 0.5 percent is sufficient to halve the effect of a CO2 doubling. In a weblog posting, Gavin Schmidt stated that "Ideas that we should increase aerosol emissions to counteract global warming have been described as a 'Faustian bargain' because that would imply an ever increasing amount of emissions in order to match the accumulated greenhouse gas in the atmosphere, with ever increasing monetary and health costs.">>

[bhrobards]

Here are the last 3 years indicating Snow Coverage (2005 feb is missing, 2004 and prior don’t indicate snow coverage)

BMAONE23-So why in the 1998 image is Greenland white? Bill

[bhrobards]

My conclusion after much study is that anthropogenic global warming is a taxing strategy for the elites. I think a lot of bigwig scientists need that grant money. I don't think the human race is competently capable of adjusting the earth's thermostat. The idea of dumping iron in the ocean or burning sulphur in the stratosphere to solve a problem many orders of magnitude more complex than is understood is agressively insane. I do think the luddites are capable of destroying the US and world economy. I don't think you are going to like being poor. Of course non-polluting is desireable. Technological advancement is the answer, not Ludditism. The number of variables is enormous. Natural forces and quantities are staggering. I'm not saying they can't be measured and studied but the models have little predictive value. CO2 is not a pollutant, we couldn't live without it. Some of my best friends occasionally exhale it. Even Chris does, but the difference is he holds CO2 in contempt. And finally what is this doing in APOD?

[BMAONE23]

Here are the last 3 years indicating Snow Coverage (2005 feb is missing, 2004 and prior don’t indicate snow coverage)

BMAONE23-So why in the 1998 image is Greenland white? Bill

The white area in Greenland is residual Ice Cap as opposed to annual snow cover.

[9tronium]

That, of course, is utter nonsense. Scientifically, the case for global warming is stronger than ever, and the percentage of climate scientists who think otherwise is very small.

Your comment, however, wonderfully demonstrates the grave risk we face having such a scientifically illiterate populace. We no longer live in a world where a lack of understanding of science (in its true sense, as a method of understanding) can be tolerated.

As does your lack of a basic understanding of scientific principles, Chris.

Here's the problem with the rising waters theory; the ice shelf is already floating (says so in any research you run across on the ice shelf. ) Therefore there can be no rising of sea levels any more than the level of water in your glass changes just because your ice melts in your drinking glass. The ice already displaced all of the volume it's going to. This proof is over 2000 years old (research Archimedes, it's a hoot!)

Here's the problem with global warming theory. If there were warming of any significance happening, just like a spinning skater, the earth's rotation would be slowing down as the equator grew from rising sea levels. As of this date there have been no additional changes to the times, tables or calculations for sun rises or sun sets. The explanation can only be that there is no growth at the equator and therefore no appreciable warming. Again, this type of proof is well over 2000 years old.

We could also discuss the right ascension and declination calculations astronomers use (The only changes they make are for precession), but let's keep it simple for your sake.

Much like everyone else, I'm wondering what this pic is doing on an astronomy page - unless the person posting it just wanted to make their point on "global warming"

[BMAONE23]

The concern about GreenHouse Gases comes IMO from studies of Venus. Venus is very similar to earth in size and gravity. So the concern of GreenHouse Gasses on Earth comes from the fact that Venus can not sustain our type of life. Both Venus and Mars have atmospheres containing more than 95% Carbon Dioxide. Mars though isn't warm because 1 it is further from the sun and 2 it doesn't have the gravity to support a thicker atmosphere but Earth does have a Gravity capable of supporting an atmosphere similar to Venus.

Venus’ atmospheric facts
http://www.daviddarling.info/encycloped ... atmos.html
Mars’ atmospheric facts
http://www.daviddarling.info/encycloped ... atmos.html

So the worry is allowing a runaway scenereo that leads Earth to transform into Venus.

[bhrobards]

Here are the last 3 years indicating Snow Coverage (2005 feb is missing, 2004 and prior don’t indicate snow coverage)
BMAONE23-So why in the 1998 image is Greenland white? Bill

The white area in Greenland is residual Ice Cap as opposed to annual snow cover.

So, whats up with the western mountains in Canada and Alaska, ice cap as well?

[BMAONE23]

(snip)
So, whats up with the western mountains in Canada and Alaska, ice cap as well?

In a sence, glaciers and permanently snow/ice covered mountain tops due to altitude and latitude.
You see the same thind in the Chilean Andes during their summer months

[bhrobards]

The concern about GreenHouse Gases comes IMO from studies of Venus. Venus is very similar to earth in size and gravity. So the concern of GreenHouse Gasses on Earth comes from the fact that Venus can not sustain our type of life. Both Venus and Mars have atmospheres containing more than 95% Carbon Dioxide. Mars though isn't warm because 1 it is further from the sun and 2 it doesn't have the gravity to support a thicker atmosphere but Earth does have a Gravity capable of supporting an atmosphere similar to Venus.

Venus’ atmospheric facts
http://www.daviddarling.info/encycloped ... atmos.html
Mars’ atmospheric facts
http://www.daviddarling.info/encycloped ... atmos.html

So the worry is allowing a runaway scenereo that leads Earth to transform into Venus.

Dude, you're channeling Carl Sagan. You are quite right about snow cover, I was so exhuberant I just jumped off the cliff. Very embarassing being wrong. But, I feel better now that I've confessed.Bill PS you're wrong about Venus. I don't mean that people don't believe that just that its not nearly so clean cut.

[Chris Peterson]

As does your lack of a basic understanding of scientific principles, Chris.
Here's the problem with the rising waters theory; the ice shelf is already floating (says so in any research you run across on the ice shelf. ) Therefore there can be no rising of sea levels any more than the level of water in your glass changes just because your ice melts in your drinking glass. The ice already displaced all of the volume it's going to. This proof is over 2000 years old (research Archimedes, it's a hoot!)

You're making a bit of a fool of yourself here. A little knowledge (emphasis on little) is a dangerous thing. Read the previous posts explaining the error in what you're saying here. Or, do the experiment... it isn't hard. I do it every year for middle school students. Take a beaker and put some ice cubes in it, then fill to the brim with saltwater, 3.5% w/w. Let the ice melt. I guarantee, the beaker will overflow.

Here's the problem with global warming theory. If there were warming of any significance happening, just like a spinning skater, the earth's rotation would be slowing down as the equator grew from rising sea levels. As of this date there have been no additional changes to the times, tables or calculations for sun rises or sun sets. The explanation can only be that there is no growth at the equator and therefore no appreciable warming. Again, this type of proof is well over 2000 years old.

Again, bad physics, or bad data (or both). It's easy to estimate the effect of rising sea levels on the Earth's rotation rate. Since angular momentum is conserved, you can solve for the change in angular velocity as a function of the change in radius. Taking the observed increase in sea level since 1993 of 3.2 cm, you can calculate that the day has gotten shorter by about 600 microseconds (actually, a bit less, since the sea level rise isn't quite equivalent to the radius of the Earth increasing by that amount). And indeed, this is included in the model for delta-T, the rate variation in Earth's rotation. The effect of increasing sea level is offset by the continuing rebound of northern and southern land masses because of the loss of polar ice after the last period of glaciation. In short, your argument holds no water. (Nothing affects the Earth's rotation rate fast enough to show up in sunrise/sunset times- those calculations are not made to the necessary precision.)

[neufer]

Take a beaker and put some ice cubes in it, then fill to the brim with saltwater, 3.5% w/w. Let the ice melt. I guarantee, the beaker will overflow.

It's a darn good thing that we don't live on a flat earth then!
-----------------------------------
Might also be explained by a drop in Surface tension

dyne/cm
82.55 : Sodium chloride 6.0M aqueous solution 20°C
71.97 : Water 20°C
-----------------------------------
http://www.youtube.com/watch?v=xpcUxwpOQ_A

[apodman]

Take a beaker and put some ice cubes in it, then fill to the brim with saltwater, 3.5% w/w. Let the ice melt. I guarantee, the beaker will overflow.

I think we can settle the question of who is a scientist and who isn't.

Scientist: "Take a beaker ..."

Non-scientist: "I checked my cabinet, and all I have is glasses and cups. Will one of them work?"

---

Back when I enjoyed an oceanography course, everything was in parts per thousand or parts per million (35 ppt for the NaCl in sea water) rather than percent. Every subject likes its little trademarks.

[BMAONE23]

The concern about GreenHouse Gases comes IMO from studies of Venus. Venus is very similar to earth in size and gravity. So the concern of GreenHouse Gasses on Earth comes from the fact that Venus can not sustain our type of life. Both Venus and Mars have atmospheres containing more than 95% Carbon Dioxide. Mars though isn't warm because 1 it is further from the sun and 2 it doesn't have the gravity to support a thicker atmosphere but Earth does have a Gravity capable of supporting an atmosphere similar to Venus.

Venus’ atmospheric facts
http://www.daviddarling.info/encycloped ... atmos.html
Mars’ atmospheric facts
http://www.daviddarling.info/encycloped ... atmos.html

So the worry is allowing a runaway scenereo that leads Earth to transform into Venus.

Dude, you're channeling Carl Sagan. You are quite right about snow cover, I was so exhuberant I just jumped off the cliff. Very embarassing being wrong. But, I feel better now that I've confessed.Bill PS you're wrong about Venus. I don't mean that people don't believe that just that its not nearly so clean cut.

I for one might be inclined to agree with you about the Venus effect. I don't think that the Earth could support the atmospheric pressure needed to create that environment unless all of the oceans boiled (evaporated) into water vapor.

I think that the Earth has a built in cooling mechanism, much like air conditioning, that turns itself on once the atmosphere gets to a certain temperature. I think that the key to the operation of the natural air conditioning lies in the Ice that lies in the Arctic Circle (AC). Once the AC's ice is exhausted the A.C. turns on and an ice age insues.

The process would involve dumping the icy cold fresh water locked up in the AC's ice into the cold salty ocean interrupting the gulf stream current. This interruption in turn forces the warm gulf stream waters to turn, drop and their return circulation further south than it regularly does during temperate times. This then denies the warmer currents from reaching the northern waters to bring about the more temperate climate we enjoy today. The northern regions then begin to cool and continue to cool down until the gulf stream current stops moving south and has re-established itself in its current position. The time that it takes to shift south, then relocate north is the length of time the Ice Age is in control. Once it has sifted back to the northern waters, it would depend on the thickness of the ice which has built up over the cold period that would control the years needed before temperate times returned.

[StACase]

Chris Peterson wrote:

Yearly records are completely useless. The shortest time scale that is used in models and predictions is decadal ...

We're expected to believe that the ten year projection is good when the one year isn't? That doesn't make any sense.

Besides, if you look at figure 10.5 of the IPCC AR4 it sure looks like the resolution is much finer than your ten year claim.

I'm sorry, but you clearly don't understand how any of this works. I don't think you're qualified to have an opinion. Decadal analysis and prediction isn't the same as predicting for ten years (although yes, I do think that we can make reasonable predictions about the climate decades into the future). You don't seem to understand the difference between weather (which is basically what a one year projection would be) and climate (which is what a ten year projection deals with). And you can make a plot with any time scale resolution- days if you want- where every point is a 10-year average- and that's what most of the IPCC trend plots are doing.

Study some statistics, learn how to properly analyze these reports and papers, and then come back with a well-founded opinion.

Here's what the IPCC AR4 says about figure 10.5

10.3.1 Time-Evolving Global Change

The globally averaged surface warming time series from each model in the MMD is shown in Figure 10.5, either as a single member (if that was all that was available) or a multimember ensemble mean, for each scenario in turn. The multi-model ensemble mean warming is also plotted for each case. The surface air temperature is used, averaged over each year, shown as an anomaly relative to the 1980 to 1999 period ...

[9tronium]

You're making a bit of a fool of yourself here. A little knowledge (emphasis on little) is a dangerous thing. Read the previous posts explaining the error in what you're saying here. Or, do the experiment... it isn't hard. I do it every year for middle school students. Take a beaker and put some ice cubes in it, then fill to the brim with saltwater, 3.5% w/w. Let the ice melt. I guarantee, the beaker will overflow.

Again, bad physics, or bad data (or both). It's easy to estimate the effect of rising sea levels on the Earth's rotation rate. Since angular momentum is conserved, you can solve for the change in angular velocity as a function of the change in radius. Taking the observed increase in sea level since 1993 of 3.2 cm, you can calculate that the day has gotten shorter by about 600 microseconds (actually, a bit less, since the sea level rise isn't quite equivalent to the radius of the Earth increasing by that amount). And indeed, this is included in the model for delta-T, the rate variation in Earth's rotation. The effect of increasing sea level is offset by the continuing rebound of northern and southern land masses because of the loss of polar ice after the last period of glaciation. In short, your argument holds no water. (Nothing affects the Earth's rotation rate fast enough to show up in sunrise/sunset times- those calculations are not made to the necessary precision.)

Boy, a twofer of bad info and bad experiments on your part, Chris. The reason your ice experiment overflows is because you allow the ice to touch the bottom of the beaker and don't achieve full displacement because the ice is still making contact with the vessel. Hint: pour the water in first, and then add the ice for full displacement. Heck, even Mister Wizard performed this one correctly. Now I know why my middle schooler comes home confused. How can you screw-up an experiment that’s been performed correctly countless hundreds of thousands of times?

Ok, we've got the bad experiment out of the way - now let's work on your poor data.

Read my paragraph slowly and you'll see that warming requires that the earth rotate slower, not faster - as your paragraph states - in the presence of global warming. When seas rise, the mass is further from the axis, so the moment of inertia gets larger. You're simply supporting my theory of global cooling (less liquid water = smaller equator = faster rotation: apparently by 600MS).

Furthermore, as sea levels are averaged from a number of sources (none of which are capable of determining 3.2 CM averages with any accuracy whatsoever due to tides, waves, storms, etc - and some even conflicting,) I'm not sure where your data is coming from.

And lastly, I notice you didn’t even try to comment on right ascension and declination calculations. I think you already know, deep down that you might be able to confuse middle schoolers with this info, but I walk with Archimedes and Newton on this one.

[Chris Peterson]

Boy, a twofer of bad info and bad experiments on your part, Chris. The reason your ice experiment overflows is because you allow the ice to touch the bottom of the beaker and don't achieve full displacement because the ice is still making contact with the vessel. Hint: pour the water in first, and then add the ice for full displacement. Heck, even Mister Wizard performed this one correctly. Now I know why my middle schooler comes home confused. How can you screw-up an experiment that’s been performed correctly countless hundreds of thousands of times?

You didn't do very well in school science, did you? Because you didn't listen, and you didn't follow directions. You're thinking about what happens when you melt freshwater ice cubes in fresh water. But sea surface ice is fresh, and it's floating in brine. And that's the experiment you need to do- as I suggested. The rise in water level has nothing to do with the ice touching the bottom (it isn't); the rise is caused because the density of freshwater is less than salt water.

Read my paragraph slowly and you'll see that warming requires that the earth rotate slower, not faster - as your paragraph states - in the presence of global warming. When seas rise, the mass is further from the axis, so the moment of inertia gets larger. You're simply supporting my theory of global cooling (less liquid water = smaller equator = faster rotation: apparently by 600MS).

My poor wording. The day length is increased by 600 us from a 3.2 cm increase in sea level (what, you never got a sign wrong? <g>). But that's not the only thing affecting the Earth's rotation rate, so this isn't the observed value. Rather, the observed value is close to the sum of all the effects that are modeled.

BTW, your theory of "global cooling" is not a theory. Neither is global warming. Global warming is an observation, which few scientists doubt. The theories have to do with what's causing it.

And lastly, I notice you didn’t even try to comment on right ascension and declination calculations.

Because I have no idea what you're talking about. The only thing that seems remotely relevant is that the RA of reference objects are regularly compared against their measured hour angles to determine how the rotation rate of the Earth is changing (because it isn't predictable over short periods). Is that what you're talking about? What's the issue?

[9tronium]

Boy, a twofer of bad info and bad experiments on your part, Chris. The reason your ice experiment overflows is because you allow the ice to touch the bottom of the beaker and don't achieve full displacement because the ice is still making contact with the vessel. Hint: pour the water in first, and then add the ice for full displacement. Heck, even Mister Wizard performed this one correctly. Now I know why my middle schooler comes home confused. How can you screw-up an experiment that’s been performed correctly countless hundreds of thousands of times?

You didn't do very well in school science, did you? Because you didn't listen, and you didn't follow directions. You're thinking about what happens when you melt freshwater ice cubes in fresh water. But sea surface ice is fresh, and it's floating in brine. And that's the experiment you need to do- as I suggested. The rise in water level has nothing to do with the ice touching the bottom (it isn't); the rise is caused because the density of freshwater is less than salt water.

Read my paragraph slowly and you'll see that warming requires that the earth rotate slower, not faster - as your paragraph states - in the presence of global warming. When seas rise, the mass is further from the axis, so the moment of inertia gets larger. You're simply supporting my theory of global cooling (less liquid water = smaller equator = faster rotation: apparently by 600MS).

My poor wording. The day length is increased by 600 us from a 3.2 cm increase in sea level (what, you never got a sign wrong? <g>). But that's not the only thing affecting the Earth's rotation rate, so this isn't the observed value. Rather, the observed value is close to the sum of all the effects that are modeled.

BTW, your theory of "global cooling" is not a theory. Neither is global warming. Global warming is an observation, which few scientists doubt. The theories have to do with what's causing it.

And lastly, I notice you didn’t even try to comment on right ascension and declination calculations.

Because I have no idea what you're talking about. The only thing that seems remotely relevant is that the RA of reference objects are regularly compared against their measured hour angles to determine how the rotation rate of the Earth is changing (because it isn't predictable over short periods). Is that what you're talking about? What's the issue?

Chris, I'm not really sure you have the qualifications to continue this discussion, so you should probably let it end here. But before you continue befuddling middle schoolers everywhere, let’s point out a couple of facts that are well documented about your experiment and sea-ice.

Unless you’re talking about continental glaciers, sea-ice is saltwater ice. You simply said you put an ice cube in salt water; you neglected to mention anywhere that it was freshwater. Because true sea ice is saltwater, I thought you were using saltwater ice. My mistake. So, yes, you can melt a freshwater cube into saltwater and watch the level rise a negligible amount, but you're not teaching anyone about anything except density. As sea-ice is saltwater (not glacial ice, but true sea-pack) there is no density difference, and so there is no rise in sea level to even discuss. In fact, the entirety of the northern sea pack can melt with little or no effect on the ocean levels due to this fact.

[Chris Peterson]

Unless you’re talking about continental glaciers, sea-ice is saltwater ice. You simply said you put an ice cube in salt water; you neglected to mention anywhere that it was freshwater. Because true sea ice is saltwater, I thought you were using saltwater ice. My mistake. So, yes, you can melt a freshwater cube into saltwater and watch the level rise a negligible amount, but you're not teaching anyone about anything except density. As sea-ice is saltwater (not glacial ice, but true sea-pack) there is no density difference, and so there is no rise in sea level to even discuss. In fact, the entirety of the northern sea pack can melt with little or no effect on the ocean levels due to this fact.

This APOD, and its discussion, is about Antarctic shelf ice, not seasonally frozen northern oceans. Most of the floating ice in the world is found in Antarctic ice shelves, and that ice is fresh water. If it all melted, there would be a rise in sea level of several centimeters, which is significant, even if it's dwarfed by the likely consequence of massively increased glacial runoff.

BTW, I know exactly what I'm teaching with the ice in salt water exercise. As you say, it's a density experiment. I teach it when the kids are in their chemistry/physics rotation, not their Earth science rotation. The full experiment is to run four tests side by side, with all combinations of fresh and salty ice and water, and also to experiment with mixing fresh and salty water that have been dyed. The experiment is run very scientifically, starting with the observations, then attempting to explain them, then coming up with ways of testing the explanations.

[aristarchusinexile]

This APOD, and its discussion, is about Antarctic shelf ice...

The thread either broadened considerably Chris, or originally touched on global warming, I'm not sure which at this point, so its logical to include all kinds of ice. Ah .. here's the answer, quoted from the script under the photo. "The cause is the local high temperatures of recent years, part of a planet wide climate change called global warming." Seeing as how the topic included global warming, it is necessary to consider all kinds of ice.

[aristarchusinexile]

Science is a search after knowledge, Chris.

That's where you are wrong- or at least, imprecise. In the modern sense, science is the search for knowledge using a specific, rational process. Philosophy is a search for knowledge as well, but it isn't remotely scientific.

There are many routes to knowledge, and I'm not offering any comparisons (although I obviously have my own opinions about how effective or useful different methods are). I'm just pointing out that this forum is about modern science, and that means that arguments that don't follow the dictates of the modern scientific approach are, by definition, unscientific. And for the most part, they don't belong here.

So, does your definition, Chris, of the type of science acceptable to this forum include astrophysics which wasn't considered acceptable by astronomers a mere few years ago? Does your definition include synthetic biology, which has become a recognized form of research investigating potential life forms on other planets but perhaps not recognized as such by you here and now (I just read about it this week)? Plus - how much more "specific and rational" can science get than by touching, seeing, feeling, hearing, smelling, examining, uprooting, cutting open, removing bark from, cooking, observing ingested effects on wild animals, tasting, classifying, testing balistically, shaping aerodynamically (is the Boomerang an invention of science?) etc .. all there aspects of science used by aboriginals everywhere, allowing them to thrive in conditions in which you and I would find ourselves dead in in a few days, despite scientific applications of DEET and anti-malaria potions and hi-tech camp stoves. Your idea of science allows you to speculate on the nature of a virtual world, while their true science allows them to live in a real world.