"John Hall" wrote in message ...


Ah. I've been wondering what the difference between "extent" and "area"
was, but I think that implicitly answers my question. So the "area" is
the total surface area of the frozen bits, while the "extent" is the
area that is at least partially frozen?
=============================

Yes, broadly correct I think. But a more formal answer at:

http://nsidc.org/cryosphere/seaice/d...rminology.html

In message , JohnD
writes
"John Hall" wrote in message
...

Ah. I've been wondering what the difference between "extent" and "area"
was, but I think that implicitly answers my question. So the "area" is
the total surface area of the frozen bits, while the "extent" is the
area that is at least partially frozen?
=============================

Yes, broadly correct I think. But a more formal answer at:

http://nsidc.org/cryosphere/seaice/d...rminology.html

Thanks, John.
--
John Hall
"One can certainly imagine the myriad of uses
for a hand-held iguana maker"
Hobbes (the tiger, not the philosopher!)

On 27/01/2017 16:36, John Hall wrote:
In message , N_Cook writes
I suppose when Larsen C breaks away, initially the sea-ice extent area
will show an increase, but area will be the same.

Ah. I've been wondering what the difference between "extent" and "area"
was, but I think that implicitly answers my question. So the "area" is
the total surface area of the frozen bits, while the "extent" is the
area that is at least partially frozen?

Extent includes leads and melt lakes.
It looks as though
sum [ concentration x extent (cell by cell)] = total area

Global extent total still dropping, back to what is was 10 days ago at
16.473 million sq km for 27 Jan 2017, while Wipneus is off-air for the
weekend, may have to soon amend the heading of this thread.
I see these bods
https://forum.arctic-sea-ice.net/ind...1611.2250.html
are now getting into CO2 and salinity anomalies around the Arctic

On Saturday, 28 January 2017 14:22:05 UTC, N_Cook wrote:
Global extent total still dropping, back to what is was 10 days ago at
16.473 million sq km for 27 Jan 2017, while Wipneus is off-air for the
weekend, may have to soon amend the heading of this thread.
I see these bods
https://forum.arctic-sea-ice.net/ind...1611.2250.html
are now getting into CO2 and salinity anomalies around the Arctic

This chart is a little ahead of the NSIDC one and you can see from it that the Arctic sea ice has begun to melt again.
https://ads.nipr.ac.jp/vishop/#/extent

Meanwhile the Antarctic seems to be heading for an all time low of less than 2 million sq km.

On 28/01/2017 16:21, Alastair wrote:
On Saturday, 28 January 2017 14:22:05 UTC, N_Cook wrote:
Global extent total still dropping, back to what is was 10 days ago at
16.473 million sq km for 27 Jan 2017, while Wipneus is off-air for the
weekend, may have to soon amend the heading of this thread.
I see these bods
https://forum.arctic-sea-ice.net/ind...1611.2250.html
are now getting into CO2 and salinity anomalies around the Arctic

This chart is a little ahead of the NSIDC one and you can see from it that the Arctic sea ice has begun to melt again.
https://ads.nipr.ac.jp/vishop/#/extent

Meanwhile the Antarctic seems to be heading for an all time low of less than 2 million sq km.


Are those nipr plots auto gated through? or at least outputs continue
thru weekends?
Looks like a new "all-time" global record minimum of sea-ice coming
along about Monday

On 28/01/2017 16:21, Alastair wrote:
On Saturday, 28 January 2017 14:22:05 UTC, N_Cook wrote:
Global extent total still dropping, back to what is was 10 days ago at
16.473 million sq km for 27 Jan 2017, while Wipneus is off-air for the
weekend, may have to soon amend the heading of this thread.
I see these bods
https://forum.arctic-sea-ice.net/ind...1611.2250.html
are now getting into CO2 and salinity anomalies around the Arctic

This chart is a little ahead of the NSIDC one and you can see from it that the Arctic sea ice has begun to melt again.
https://ads.nipr.ac.jp/vishop/#/extent

Meanwhile the Antarctic seems to be heading for an all time low of less than 2 million sq km.



Using NSIDC Charctic I make the , until recent, minimum to be
2.290 million sq km on 27 Feb 1997
27 Jan 2017 was 2.763 million dropping approx 0.1 million a day
so "all time" record Antarctic minimum next week looks likely

On Saturday, 28 January 2017 16:38:59 UTC, N_Cook wrote:
On 28/01/2017 16:21, Alastair wrote:
On Saturday, 28 January 2017 14:22:05 UTC, N_Cook wrote:
Global extent total still dropping, back to what is was 10 days ago at
16.473 million sq km for 27 Jan 2017, while Wipneus is off-air for the
weekend, may have to soon amend the heading of this thread.
I see these bods
https://forum.arctic-sea-ice.net/ind...1611.2250.html
are now getting into CO2 and salinity anomalies around the Arctic

This chart is a little ahead of the NSIDC one and you can see from it that the Arctic sea ice has begun to melt again.
https://ads.nipr.ac.jp/vishop/#/extent

Meanwhile the Antarctic seems to be heading for an all time low of less than 2 million sq km.


Are those nipr plots auto gated through? or at least outputs continue
thru weekends?

AIUI, the NIPR data is updated daily about midnight GMT whereas the NSIDC data is a five day running mean updated later the following day.

In message ,
Alastair writes
This chart is a little ahead of the NSIDC one and you can see from it
that the Arctic sea ice has begun to melt again.
https://ads.nipr.ac.jp/vishop/#/extent

If the amount of Arctic sea ice is reducing in JANUARY, even if it turns
out to be only for a day or two, that seems remarkable and really brings
it home just how far global warming has gone.
--
John Hall
"One can certainly imagine the myriad of uses
for a hand-held iguana maker"
Hobbes (the tiger, not the philosopher!)

On Saturday, 28 January 2017 21:56:04 UTC, John Hall wrote:
In message ,
Alastair writes
This chart is a little ahead of the NSIDC one and you can see from it
that the Arctic sea ice has begun to melt again.
https://ads.nipr.ac.jp/vishop/#/extent

If the amount of Arctic sea ice is reducing in JANUARY, even if it turns
out to be only for a day or two, that seems remarkable and really brings
it home just how far global warming has gone.

Dimwit!

Wouldn't it mean that there is something a little deeper behind it?
Or don't you use logic where you come in?

All I can think is how badly you are going to hurt when you are shown up as the clown you are. When that happens get a copy of the film Marvellous about a clown called Nello and it may help you get over yourself.