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Posted

Hi all

 

I was watching a post which based most of the effects of global sea change on melting ice caps or ice melting in general.

 

My objection might be correct , or I may get educated. I thought water expanded according to increased temperature , therefore a change in global temperature would increase the volume of the oceans as a whole long before the icecaps really came into play. I haven't really heard or read much about the water which is already contained in the oceans having an impact on rising sea levels ,So this is the reason for my comment.

 

Cheers

Iseason

Posted

Your intuition that water expands as it warms is correct. That is certainly part of the challenge before us. The thing to remember is that oceans can expand AND melting land ice runoff can flow in them to further raise sea levels. Both occur, in parallel. They are not mutually exclusive.

 

More here >> http://oceanservice.noaa.gov/facts/sealevel.html

and here (in the Causes of sea level rise section) >> http://www.climate.org/topics/sea-level/

  • 2 months later...
Posted

Hijack how? We were all talking about the topic. Ice caps, last I checked it was Antarctic. Cited a paper from 2012 and all according to Hoyle, not that Hoyle was one of the authors, of course.

 

But do as you please, most worthy adversary. You always have before.

Posted

Hijack how? We were all talking about the topic. Ice caps, last I checked it was Antarctic. Cited a paper from 2012 and all according to Hoyle, not that Hoyle was one of the authors, of course.

But do as you please, most worthy adversary. You always have before.

Perhaps it's because this discussion was about the effects of water expansion. Not that i was worried as my initial thoughts on the subject were confirmed.

However , since the opportunity arrises , how would the calculations work when placed in tandem with the ice cap melts. Surely the volume of the oceans trumps the icecaps big time. Naturally the effect would be staggered by depth .

For instance , the surface few metres would expand first. But surely this is a major amount of water.

 

Also iceburgs wouldn't increase water volume . They are already suported by the water, so displacement is already taking place by weight. If they melt , then wouldn't they simply occupy the same space they disperse.

I'm looking at ice floating as a result of it's increased volume compared to water, the extra volume is above the water to offset this difference.

So floating ice means no change until it gets above zero , when it simply joins the rest of the oceanic water , which is my original point. The greater ocean will increase in temperature and therefore volume well ahead of any region losing all it's fresh water ice into the sea. But much of the focus is on the fresh water entering the ocean and making it rise.

 

So i guess my current question would be.....if the top one meter raises it's temperature by one degree, how much oceanic rise is this? I certainly couldn't do the math. But i would also expect the next four meters (collectively)to increase by the same as the top meter. Naturally it could only be an average as curents and regional tempatures would vary.

 

But then i have another question . Does water increase evenly?does the volume increase by the same amount from zero to ten degrees as from 10 degrees to 20 degrees. This question is relevant as the tropics would have a different initial temperature to polar regions.

 

Cheers

Iseason

Posted

Don't forget that floating sea ice won't melt in isolation of land ice. When land ice melts, that will flow into the ocean and have an appreciable affect on sea level. Will let someone else address your other questions.

Posted (edited)

Hi all

 

I was watching a post which based most of the effects of global sea change on melting ice caps or ice melting in general.

 

My objection might be correct , or I may get educated. I thought water expanded according to increased temperature , therefore a change in global temperature would increase the volume of the oceans as a whole long before the icecaps really came into play. I haven't really heard or read much about the water which is already contained in the oceans having an impact on rising sea levels ,So this is the reason for my comment.

 

Cheers

Iseason

 

I think thermal expansion of water is less of a worry than melting of land ice. Say, heating water from 4oC (maximum density) by 6 degrees only results in decrease in density by 0.02%. And 6 degrees is a lot given the total amount of water in oceans. I've seen graphs for worst-case scenario of water level rise due to thermal expansion (see below) and it was just around 0.5 m by the year 2250. On the other hand, melting of Greenland glaciers can result in water level rise of several meters.

 

SeaLevelThermal.jpg

Edited by pavelcherepan
Posted

Fantastic! That's the sort of answer that is helpful.

 

What sort of difference does it make as you get away from seas level though. ? Say at the snow line . Would large expances of antartica still be unaffected due to thier hieght above sea level , or is the rate of freezing for altitude affected as well?

 

Cheers Iseeson

Posted

Fantastic! That's the sort of answer that is helpful.

 

What sort of difference does it make as you get away from seas level though. ? Say at the snow line . Would large expances of antartica still be unaffected due to thier hieght above sea level , or is the rate of freezing for altitude affected as well?

 

Cheers Iseeson

It is all about the CO2, never forget that. CO2 being heavier than air should concentrate at lower altitudes, but according to doctrine will have proportionally greater effect at the dry poles, since the effect of water vapor will be less. Also, with less ice in the way, the creep of inland ice to sea level should increase, if that makes sense.

Posted

Hi all

 

I was watching a post which based most of the effects of global sea change on melting ice caps or ice melting in general.

 

My objection might be correct , or I may get educated. I thought water expanded according to increased temperature , therefore a change in global temperature would increase the volume of the oceans as a whole long before the icecaps really came into play. I haven't really heard or read much about the water which is already contained in the oceans having an impact on rising sea levels ,So this is the reason for my comment.

 

Cheers

Iseason

A lot of the ice is on land and therefore runs into the sea when melted hence raising the sea levels. That's how I imagine it to be.

Posted (edited)

A lot of the ice is on land and therefore runs into the sea when melted hence raising the sea levels. That's how I imagine it to be.

I think you are correct in saying so. And keeping in mind that the warmest waters are at the surface generally and isolated from the frigid depths, thermal expansion of the entire volume of the liquid seas will be negligible in the short term at the very least, as pavelcherepan's post above demonstrates. Edited by Harold Squared
Posted

Less ice at the surface means more light penetration. More light penetration means more biomass. More biomass means more polar bears, who are supposedly having a hard go of it.

 

?

Posted (edited)

Less ice at the surface means more light penetration. More light penetration means more biomass. More biomass means more polar bears, who are supposedly having a hard go of it.

 

?

They need the sea-borne ice to get to the fish and seals. If the ice gaps are too big, they will drown trying to swim across them. Sea Ice + Holes = Food. Rather difficult to do that on land, is it not?

Edited by StringJunky
Posted (edited)

Eat stuff on land? I personally do it all the time, I imagine bears do as well.

Well, they aren't hard-wired to behave that way, in the main, and where's most of the food? The Artic isn't exactly the Isle of Plenty. Your scepticism is without substance. You are clearly religiously entrenched in your viewpoint.

Edited by StringJunky
Posted

Dude, I have BEEN THERE. The North Slope, Deadhorse AK. Where the polar bears roam. And you know what? They eat walruses on the beach all the time. Walruses eat shellfish all the time. Shellfish eat plankton continuously. That ain't no religion, it is called the food chain.

The Artic isn't exactly the Isle of Plenty.

Which is why more photosynthesis is a good thing.
Posted

Dude, I have BEEN THERE. The North Slope, Deadhorse AK. Where the polar bears roam. And you know what? They eat walruses on the beach all the time. Walruses eat shellfish all the time. Shellfish eat plankton continuously. That ain't no religion, it is called the food chain.

Which is why more photosynthesis is a good thing.

It will be interesting , if you could be around that long, to observe the counter that nature inflicts on the carbon imbalance. Is there enough evidence to suggest that this has happenned without mans intervention.

 

Are deposits of carbon such as oil and coal any proof? Or does such an event have to be evenly distributed rings around the globe. ?

 

Cheers iseeson

Posted

Eat stuff on land? I personally do it all the time, I imagine bears do as well.

 

Then you have pretty good internet connectivity up there in the arctic. That is where you are, right? Because otherwise this is a meaningless observation. Polar bears don't do a lot of shopping at the Foodway.

Posted

 

Then you have pretty good internet connectivity up there in the arctic. That is where you are, right? Because otherwise this is a meaningless observation. Polar bears don't do a lot of shopping at the Foodway.

Indeed and they don't, sir!

 

Polar bears, like other bears, are opportunistic feeders, pretty much out of necessity. They interbreed freely with grizzly AKA "brown bears" and produce fertile offspring. In many Alaskan communities bears of all kinds are notorious dumpster divers, so, not picky eaters.

Posted (edited)

Indeed and they don't, sir!

 

Polar bears, like other bears, are opportunistic feeders, pretty much out of necessity. They interbreed freely with grizzly AKA "brown bears" and produce fertile offspring. In many Alaskan communities bears of all kinds are notorious dumpster divers, so, not picky eaters.

It seems to me you are increasingly 'scraping the barrel' to try and salvage your arguments. Dumpster-diving Polar bears is your idea of an acceptable destiny for those animals is it?

Edited by StringJunky
Posted

They interbreed freely with grizzly AKA "brown bears" and produce fertile offspring.

 

"Evidence", he requested (not expecting to get any, because that would break the streak)

Posted (edited)

It seems to me you are increasingly 'scraping the barrel' to try and salvage your arguments. Dumpster-diving Polar bears is your idea of an acceptable destiny for those animals is it?

Lol...they especially like dirty diapers according to my sources in Ketchikan. Or fish guts, road kill, unwary drunks, they are aaalll pretty smelly, but edible. Evidently these Majestic Creatures of the Northern Wilds have no clue how noble they are. In Churchill, Manitoba, the town dump had to be closed because the bears were eating car batteries and Styrofoam, among other delicacies.

 

"Evidence", he requested (not expecting to get any, because that would break the streak)

"Wikipedia."

 

He replied laconically.

Edited by Harold Squared
Posted

"Wikipedia."

 

He replied laconically.

I checked wikipedia. It doesn't agree with your claim that they interbreed freely. It's not common at all.

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