That global warming thingy

[Eeyore]

They are easy to find.

Salt water at around 0 deg C with typical salinity: 1.029 g per ml
Fresh water at 0 deg C: 0.9999 g per ml

So salt water is approx 3% more dense, which means it will push the ice
about 3% further out of the water then fresh water would.

Whilst the water level will remain the same of course !

This means the water level would increase slightly,
No.


while the average density would decrease slightly upon melting.

So what ?


Graham

 

[Eeyore]

atmosphere.

Interesting. References on the accumulating ice?

http://www.google.com/search?&q=ice+increase+antarctica

Graham

 

[Eeyore]

atmosphere.

Interesting. References on the accumulating ice?

NASA - Sea Ice May Be on Increase in the Antarctic: A Phenomenon ...
This occurrence runs counter to the paper’s new finding that sea ice in the
Antarctic’s (or South Pole) Southern Ocean appears to be on the increase. ...
www.nasa.gov/lb/vision/earth/environment/sea_ice.html - 18k - Cached - Similar
pages
Top Story - SATELLITES SHOW OVERALL INCREASES IN ANTARCTIC SEA ICE ...
.... records of sea ice around Antarctica reveal an overall increase in the ...
Parkinson examined 21 years (1979-1999) of Antarctic sea ice satellite ...
www.gsfc.nasa.gov/topstory/20020820southseaice.html - 16k - Cached - Similar
pages
World Climate Report » Antarctic Ice: A Global Warming Snow Job?
.... continent is likely to dramatically increase snowfall. Consider Antarctica.
.... “As climate shifts, Antarctic ice sheet is growing” –Los Angeles Times, ...
www.worldclimatereport.com/index.php/2005/05/27/antarctic-ice-a-global-warming-snow-job/
- 28k - 10 Mar 2007 - Cached - Similar pages
Warmer air may increase Antarctic sea ice | Science Blog
Predicted increases in precipitation due to warmer air temperatures from
greenhouse gas emissions may actually increase sea ice volume in the Antarctic's
....
www.scienceblog.com/cms/node/8305 - 20k - Cached - Similar pages
Antarctic sea ice is on the increase.(Antarctica)(Brief Article ...
Antarctic sea ice is on the increase.(Antarctica)(Brief Article) from
Geographical in Reference & Education provided by LookSmart Find Articles.
findarticles.com/p/articles/mi_hb3120/is_200310/ai_n7779396 - 29k - Cached -
Similar pages
news @ nature.com - East Antarctica puts on weight - Increased ...
Increased snowfall over a large area of Antarctica is thickening the ice sheet
and ... would trigger an increase in snowfall over the Antarctic continent, ...
www.nature.com/news/2005/050516/full/050516-10.html - Similar pages

 

[Eeyore]

overall ocean temperatures.

- Acoustical measurement practices have shown average ocean temperatures in
many areas to have risen ~0.5 deg C from recent periods such as mid 1990's
to year 2000 (generally a 5 year span).

Surface currents.

Here is some info on the arctic
ocean, for example: http://www.acoustics.org/press/144th/Mikhalevsky.htm

- The average planet temperature has risen 0.75 deg C over about the last
century: http://en.wikipedia.org/wiki/Global_warming - states "Relative to
the period 1860-1900, global temperatures on both land and sea have
increased by 0.75 °C

Surface or air temperature.

Graham

 

[Jeff L]

temps,

It does. Most of the ocean mass is at temperature where the coefficient
is a lot closer to zero. Some is at temperature where the coefficient is
negative.

http://www.windows.ucar.edu/tour/link=/earth/Water/temp.html

Interesting, I would have thought that the oceans would start to warm again
after a certain point the further you go down, like when you dig a deep hole
in the earth, it starts to heat up after a certain depth from the thermal
gradient formed from energy escaping the earths core.

4 deg C is around the peak density of pure water, so there likely is very
little change, and as you said, some in in the negative area.

However, to complicate matters, the extreme pressures involved at the deeper
depths of the ocean slightly compress the water, thus changing it's
properties a bit, and raising the freezing point a little (fraction of a
degree)!

 

[Eeyore]

However, to complicate matters, the extreme pressures involved at the deeper
depths of the ocean slightly compress the water,

Water *is* compressible ?

Graham

 

[Jeff L]

Tell me something. Did you stop to consider how long it would take the oceans to
rise in temperature by 6 degrees?

Maybe you'd like to consider that ? How many Joules would it take for

example ?

Earth intercepts: ~1300 W per M^2 at equator (~perpendicular to sun)
Area of Earth intercepting energy from sun: Pi * (6,380,000 m) ^2 =
127876644008780 m^2
Energy received by earth: 166239637211414493 W
= 598462693961092177 kj per hour

Assuming 1 L of water = 1.00 kg
Volume of ocean is 1,320,000,000 km3
Specific heat capacity of water (assuming the same for salt water - it's
close) : 4.186 kJ·kg?1·K?1

1320000000000000000000 kg of water in ocean * 4.186 kJ·kg?1·K?1* 6 deg C =
33153120000000000000000 kj to raise the ocean 6 deg C

33153120000000000000000 kj / 598462693961092177 kj per hour = 55,397 h

55,397 h / 8766 h per year = 6.3 years

To add some assumptions, this is assuming no energy is reflected back to
space, there is no loss from the dark side of the planet, the mass of the
non ocean material has zero influence, and there is no heat from consuming
millions of years worth of stored energy, and no energy is released from
nuclear sources, including natural radioactive decay.

So, after this calculation, it seems reasonable that the planet can heat up
that much in the order of 100 years.

 

[Jeff L]

Water *is* compressible ?

Yes. All matter is. You can freeze water at room temp by compressing it to
extremely high pressures.

Water is surprisingly more compressive at ocean pressures then I thought:

"Even in the deep oceans at 4000 m depth where pressures are 4×107 Pa, there
is only a 1.8% change in volume" -
http://en.wikipedia.org/wiki/Water_(molecule)

 

[Eeyore]

To add some assumptions, this is assuming no energy is reflected back to
space

Is that so ?

So, after this calculation, it seems reasonable that the planet can heat up
that much in the order of 100 years.

Bunkum. Talk about bad csience.

Graham

 

[Eeyore]

To add some assumptions, this is assuming no energy is reflected back to
space

Is that so ?

So, after this calculation, it seems reasonable that the planet can heat up
that much in the order of 100 years.

Bunkum. Talk about bad science.

Graham

 

[MassiveProng]

Water *is* compressible ?

Graham

Howard Hughes proved that all liquids are compressible on a famous
flight to prove it.

Changed the way aircraft makers work with hydraulic fluids, and
their system designs.

 

[default]

You are the source of nothing but stench, dipshit.

Watch the film, see the sources, and then come back. I DARE YOU.

Unfortunately it isn't happening. Requires I download a "player" to
view the format - it isn't a standard video file type.

Then there's the pesky other 11 videos to watch before forming an
opinion. - on dialup? Sorry, better things to do then wait for that.

 

[Homer J Simpson]

Some extremely thin one comprised mostly of CO2. They get a few dust
storms.
Put much oxygen there with its lower molecular weight especially in the
case of a thermosphere, and see how long it stays. Maybe millennia, maybe
a bit more, ???

We could get Halliburton to build a shell around Mars. How much could it
cost?

 

[Don Klipstein]

Don Klipstein wrote:

(stuff about ocean depth and my figuring that the oceans may rise a meter
from thermal expansion)

How long would it take the oceans to rise in temp by 2 degrees ?

Let me try an estimate for that...

The first graph in the Wiki article on global warming looks to me like
rising at a rate of about .035 degree C per year after 1979. Suppose this
rate gets sustained.

I somehow remember doing a calculation in the past for thermal time
constant of the ocean mass, and came up with a century or somewhat more.

Feed a .035 degree per year slope starting from 1979 into a first order
lowpass filter with a time constant of a century, and I come up with a
guess of 130 years, or 2109.
And half this warmup of the ocean mass would occur in roughly the last
50 years of this 130 year period. And with the thermal expansion
coefficient being non-constant and increasing, the halfway point of the
sea level rise of this 130 year period will be even farther into it.

==================================================================

Let me take a new stab at thermal time constant of the ocean mass...

Solar constant at sea level with sun at zenith and really clear air is
1100 watts per square meter if I remember correctly. It could be closer
to 1,000. Ratio of a sphere's surface area to cross section is 4, so
divide 1100 by 4 to get 275 watts per square meter. Half this for average
extent and opacity of cloud cover, for average insolation of 137.5 watts
per square meter. Multiply by .96 for water being about 4% reflective,
for 132 watts per square meter.

Average Earth surface temperature is nearly enough 288 K. So I will use
132 watts per square meter and 288 K.

Let's suppose the radiation absorbed takes a 1% jump from 132 to 133.32
watts per square meter. In a first order of approximation, a 1% increase
in incoming radiation will increase the surface temperature by .25%. This
is neglecting interaction of spectral shift of outgoing radiation with
ability to radiate it changing with wavelength, and this neglects feedback
mechanisms such as change of the Earth's ability to absorb radiation.

So that extra 1.32 watt per square meter in a first order approximation
is expected to warm things up by .72 degree K.

Water has a specific heat of 4.19 joules per gram per degree K, maybe a
bit less for salt water. I would guess 4.15.

A 1 square meter column of average depth sea water 3.71 km deep has a
mass of close enough to 3.75E9 grams. Multiply this by 4.15 and .72, and
it looks like about 1.12E10 joules is needed to warm a square meter of
ocean all the way down by .72 degree.
Divide that by 1.32 watts, and I get a thermal time constant of about
8.5E9 seconds, or about 270 years.

With a thermal time constant of 270 years and planet surface temperature
rising .035 degree per year, I would expect the average ocean mass
temperature to be 2 degrees warmer than it was in 1979 sometime around
2150-2170.

- Don Klipstein ([email protected])

 

[Don Klipstein]

Whilst the water level will remain the same of course !


So what ?

Suppose you have a cubic kilometer of seawater density 1.029 g/ml with a
102.9 megaton iceberg floating on it. (Combined mass is 1.1319 gigatons.)
Volume of the seawater plus the sub-waterline portion of the iceberg is
1.1 cubic kilometers.

Lets say the iceberg melts and dilutes the seawater to a density 10% of
the way from 1.029 to 1, which is 1.0261 g/ml. So we now have 1.1319
gigatons of water with a density of 1.0261 g/ml, which means a volume of
1.1031 cubic kilometers rather than 1.1.

- Don Klipstein ([email protected])

 

[Don Klipstein]

Water *is* compressible ?

Its bulk modulus is not infinite. There is a relationship (in fluids)
between bulk modulus, density and speed of sound, and the speed of sound
in water is not infinite or close to the speed of light or anything like
that.

- Don Klipstein ([email protected])

 

[Don Klipstein]

Yes. All matter is. You can freeze water at room temp by compressing it to
extremely high pressures.

I thought the freezing point of water was lowered by increasing pressure,
although I wonder if that reverses beyond some pressure. Raising of
freezing point by increasing pressure tends to occur in materials that
contract when they freeze.

- Don Klipstein ([email protected])

 

[Eeyore]

(stuff about ocean depth and my figuring that the oceans may rise a meter
from thermal expansion)


Let me try an estimate for that...

The first graph in the Wiki article on global warming looks to me like
rising at a rate of about .035 degree C per year after 1979. Suppose this
rate gets sustained.

I somehow remember doing a calculation in the past for thermal time
constant of the ocean mass, and came up with a century or somewhat more.

Feed a .035 degree per year slope starting from 1979 into a first order
lowpass filter with a time constant of a century, and I come up with a
guess of 130 years, or 2109.
And half this warmup of the ocean mass would occur in roughly the last
50 years of this 130 year period. And with the thermal expansion
coefficient being non-constant and increasing, the halfway point of the
sea level rise of this 130 year period will be even farther into it.

==================================================================

Let me take a new stab at thermal time constant of the ocean mass...

Solar constant at sea level with sun at zenith and really clear air is
1100 watts per square meter if I remember correctly. It could be closer
to 1,000. Ratio of a sphere's surface area to cross section is 4, so
divide 1100 by 4 to get 275 watts per square meter. Half this for average
extent and opacity of cloud cover, for average insolation of 137.5 watts
per square meter. Multiply by .96 for water being about 4% reflective,
for 132 watts per square meter.

Average Earth surface temperature is nearly enough 288 K. So I will use
132 watts per square meter and 288 K.

Let's suppose the radiation absorbed takes a 1% jump from 132 to 133.32
watts per square meter. In a first order of approximation, a 1% increase
in incoming radiation will increase the surface temperature by .25%. This
is neglecting interaction of spectral shift of outgoing radiation with
ability to radiate it changing with wavelength, and this neglects feedback
mechanisms such as change of the Earth's ability to absorb radiation.

So that extra 1.32 watt per square meter in a first order approximation
is expected to warm things up by .72 degree K.

Water has a specific heat of 4.19 joules per gram per degree K, maybe a
bit less for salt water. I would guess 4.15.

A 1 square meter column of average depth sea water 3.71 km deep has a
mass of close enough to 3.75E9 grams. Multiply this by 4.15 and .72, and
it looks like about 1.12E10 joules is needed to warm a square meter of
ocean all the way down by .72 degree.
Divide that by 1.32 watts, and I get a thermal time constant of about
8.5E9 seconds, or about 270 years.

With a thermal time constant of 270 years and planet surface temperature
rising .035 degree per year, I would expect the average ocean mass
temperature to be 2 degrees warmer than it was in 1979 sometime around
2150-2170.

At the surface perhaps.

Graham

 

[default]

I don't need a primer in refrigeration, chump.

Apparently you do. I stated the humidity is high and you suggest
evaporative cooling will lower it.

 

[Jim Thompson]

I thought the freezing point of water was lowered by increasing pressure,
although I wonder if that reverses beyond some pressure. Raising of
freezing point by increasing pressure tends to occur in materials that
contract when they freeze.

- Don Klipstein ([email protected])

Yep. I have no clue where Jeff L got his data.

...Jim Thompson