Glaciers

[RWood]

Reported in a Met. Society newsletter.

Saturday March 07, 2009 ONE News

There is more grim news for South Island glaciers as scientists take to the skies to gauge their health.
Glaciers give a good reading of regional climate change and early indications are that they are still shrinking after another warm year.
Glaciologist Trevor Chinn says the glaciers "know exactly what the climate's doing".
"Where a thermometer shifts one-tenth of a millimetre, a glacier shifts tens of metres and you can see the change," he says.
Chinn discovered, by accident, that a simple snapshot of the snowline at the end of summer, before any new winter snow, can provide a weather picture for the whole year.
"If the snowline's above [a certain] height, then we're getting warmer and if it's below that height, we're getting cooler."
NIWA scientists cover 50 glaciers at 10,000 feet. Using GPS they take photographs from the same position to compare with 30 years of data.
"They've been sort of sitting more or less the same and now you can see there's bare ice sitting everywhere with hardly any new snow," Chinn says.
"So the prognosis is the glaciers are starting to look a little bit sick."

[Nev]

Yes, the item was entitled 'Glaciers reveal global warming effects'.
You can also watch the video here.

[sthguy]

"They've been sort of sitting more or less the same and now you can see there's bare ice sitting everywhere with hardly any new snow," Chinn says.
"So the prognosis is the glaciers are starting to look a little bit sick."

Well......that's the normal condition of glaciers at the end of summer.....

[Manukau heads obs]

have a look at the video link, its more clear then

[tgsnoopy]

Pretty depressing that video.

The changes in my lifetime are scary, I worry about the future of the planet for our children, grandchildren etc.

[RWood]

Ignore the troller's comment, is my advice. Chinn and other experts have been looking at this stuff for a long time.

[southernthrash]

That story is a little misleading. While the ELA or end of summer snowline may provide an indication of climate change, glacier size alone does not. In particular, those glaciers which now terminate in proglacial lakes are now largely decoupled from climate.

It would also be nice to see vertical aerials used, obliques do not provide as clear interpretation.

As far as climatic variables, temperature is not the only factor. Precipitation (type and amount) and cloud cover play a significant role.

[Manukau heads obs]

As far as climatic variables, temperature is not the only factor. Precipitation (type and amount) and cloud cover play a significant role.

I think that temperature is the underlying thing, i.e it affects the other things you mention

(e.g you could argue that the recent increases in sunshine hours are due to warmer temperatures (i.e less cloud cover, because warmer air can hold more moisture )
just as it could be argued that the increase in size and number or the tropical mangrove in the NI Harbours is due to sea water temperature increasing

[Manukau heads obs]

As far as climatic variables, temperature is not the only factor. Precipitation (type and amount) and cloud cover play a significant role.

I think that temperature is the underlying thing, i.e it affects the other things you mention

(e.g you could argue that the recent increases in sunshine hours are due to warmer temperatures (i.e less cloud cover, because warmer air can hold more moisture )
just as it could be argued that the increase in size and number or the tropical mangrove in the NI Harbours is due to sea water temperature increasing

[NZstorm]

Would be interesting to see what the long term temperature data is for the SI West Coast region. I have had a look at Hokitika Airport and no real rise in the mean temperature evident there. Long term mean is 11.7C and the mean for 2008 was 11.7C. But thats one site, would be interesting to see others. Recording began at Hokotika in 1963.

[skywatch]

Oh no, more misleading material on glaciers. It's kinda sad really:(

[Manukau heads obs]

can you elaborate?

[RWood]

Would be interesting to see what the long term temperature data is for the SI West Coast region. I have had a look at Hokitika Airport and no real rise in the mean temperature evident there. Long term mean is 11.7C and the mean for 2008 was 11.7C. But thats one site, would be interesting to see others. Recording began at Hokotika in 1963.

The "long term" temperature data trend for the West Coast is as for elsewhere - it has increased. You wouldn't have to go far back beyond 1963, possibly no further back, to show such an increase. NZ warmed by 0.9C in the 20th century - not exactly news.

[RWood]

Oh no, more misleading material on glaciers. It's kinda sad really:(

Meaning? Care to elaborate on who you are representing? You have already been taken to task earlier on this forum for sloppiness and inaccuracy, so we're entitled to know.

[sthguy]

Ignore the troller's comment

If you spend anytime in the mountains you will know that most icefields and glaciers become mostly clear of winter and spring snowcover below about 8000ft by late summer/early autumn.

The fluctuating movements of New Zealands glaciers are well documented. This includes long term shrinkages and medium term advances.

The issues refered to by southernthrash on Wed 08/04/2009 in this thread are also well documented.

If the expression 'troller' is going to redefined to include people who make legitimate points in this forum then it all a bit sad really.

[RWood]

Watching the video again and listening to the comments made there, I am justified in using that term in response to your flippant dismissal of the post. You know very well from the context in the video that "looking a bit sick" is not Chinn's description of a single-season state change.

[sthguy]

And I stand by every word of my two posts. If you survey glaciers at the end of a winter you'll find them buried in new snow. If you survey them in March, you'll see loads of bare ice. That's normal, and by using that expression in the the article implies that the lack of snow cover it is not normal, when it quite patently is.

I rather think you might fit the description of a 'troll' rather better than I, as you usually launch yourself at anybody who dare give a view differing from your own.

[Willoughby]

I think a mod needs to come in here and clean this up because it has gone way off topic!

There wouldn't be much left unfortunately - the whole thread wouldn't make sense if that happened... it's better if this thread was left alone and sunk.

Edit: On second thought I decided to clean out the thread and was easy to weed out - pretty much the last 10 posts.

[RWood]

OK.

http://www.niwa.cri.nz/pubs/wa/ma/16-3/glacier

[southernthrash]

While being a quick and easy measure of glaciers, estimating mass balance from aerial photographs (especially obliques) is not terribly scientific.

It would be nice to see vertical aerials used, at least, that way the images can be properly georeferenced and scaled, and direct interpretations are much more robust.

A number of satellite platforms are now equipped with sensors that enable much more effective and accurate estimation of mass balance than aerials. The fact remains though, that field measurements are far more accurate.

I agree re the old boys club, many people here don't seem to like new or challenging ideas, and don't seem keen to question what they read/hear from the sources they do respect.

[Manukau heads obs]

how about you guys opening your eyes and minds (i.e be more open minded) to other ideas as well
i.e that the glaciers are getting smaller and are retreating, in response to a warmer trend
(thats all thats is being discussed, nothing more, nothing less)(i.e it does not discuss if that warming trend is going to continue (global warming) or similar, its just stating that glaciers are a good barometer

also, comparing photos from the same angle and perspective is OK in my book (even if it might not be as good as some other method) (and no point in changing the method now, best to keep the same method going so can use past comparisons)
whats is important is the photo is take from the same spot, same angle, same time every year
which they have been
and they are showing a trend of decreasing ice accumulation (i.e melting earlier in spring and freezing later in autumn)

[RWood]

To repeat: if you (two) think the scientists are implying something incorrect about the "glacier status", let's see you challenge them directly by communicating with them. My pick is that you won't, among the reasons being that at least one of you is probably a cheerleader for skifield interests. You are both anonymous here, for a start. And as for sthguy - some while back you horned in on a straightforward conversation between me and another (former) member about Invercargill's climate response to a La Nina situation with totally irrelevant and irritating nonsense.

[Michael]

Watching this topic reminds of a trademe auction in the dying minutes whos going to outbid each other.

[jamie]

Watching this topic reminds of a trademe auction in the dying minutes whos going to outbid each other.

Good call. It is making for a good laugh at how silly it all is.

[tgsnoopy]

I don't know about silly?

I see a couple of people passionate about their perspective.

We are entitled to different opinions, so long as we respect each other and don't ram our opinion down others throats some debate is often a good thing.

Heck if both parties did a little research of communicating based on the others postings, how can that be a bad thing.

As for Trade Me auctions, man it's easy to get tied up in those last minute bidding wars and spend more than you intended to...

I hope no-one here makes a post they later regret