Hi,

Can anyone confirm that when the concentration of CO2 in the
atmosphere is measured in ppmv (parts per million by volume) that it
is the same value when quoted as uatm (micro atmospheres)?

TIA

Cheers, Alastair.

On Aug 16, 10:33*am, Alastair wrote:
Hi,

Can anyone confirm that when the concentration of CO2 in the
atmosphere is measured in ppmv (parts per million by volume) that it
is the same value when quoted as uatm (micro atmospheres)?

TIA

Cheers, Alastair.

Can't see why it should be any different. The partial pressure
exerted by the CO2 will be proportional to its volume concentration,
the conditions being those of an Ideal Gas, near enough.

Tudor Hughes, Warlingham, Surrey.

On Aug 16, 5:21*pm, Tudor Hughes wrote:
On Aug 16, 10:33*am, Alastair wrote:

Hi,

Can anyone confirm that when the concentration of CO2 in the
atmosphere is measured in ppmv (parts per million by volume) that it
is the same value when quoted as uatm (micro atmospheres)?

TIA

Cheers, Alastair.

* * *Can't see why it should be any different. *The partial pressure
exerted by the CO2 will be proportional to its volume concentration,
the conditions being those of an Ideal Gas, near enough.

Tudor Hughes, Warlingham, Surrey.

Thanks Tudor,

I think the reason that the two scales are used is that for CO2
dissolved in the ocean ppmv would not make sense, so oceanographers
use uatm, but everyone else uses ppmv.

Cheers, Alastair.

"Tudor Hughes" wrote in message
...

On Aug 16, 10:33 am, Alastair wrote:
Hi,

Can anyone confirm that when the concentration of CO2 in the
atmosphere is measured in ppmv (parts per million by volume) that it
is the same value when quoted as uatm (micro atmospheres)?

TIA

Cheers, Alastair.

Can't see why it should be any different. The partial pressure
exerted by the CO2 will be proportional to its volume concentration,
the conditions being those of an Ideal Gas, near enough.

Tudor Hughes, Warlingham, Surrey.

Yes, I thought about it for a bit and came to exactly that conclusion. It's
inconsequential, but I think the 'u' of uatm is probably the Greek letter
'mu', the prefix for 'a millionth', written as a 'u' for obvious reasons.

Ian Bingham,
Inchmarlo, Aberdeenshire.

On Aug 16, 9:30*pm, Alastair wrote:

I think the reason that the two scales are used is that for CO2
dissolved in the ocean ppmv would not make sense.

A litre of the gas at stp will dissolve in a litre of water. (Or is it
the other way around?)

Considering the amount of superheated carbonate and the underlying
carbon rich strata oil companies drill through it to, it doesn't make
any sense at all.