Snow Depth, stupid question???

I'm not sure where you are taking your figures from, but I assure you that the resorts quoted figures in those resorts have differed substantially from the figures shown by the SLF data stations. I know for a fact that I have seen early season figures that were a long way above the seasons accumulated snowfall given by SLF. Where or how they measure it is a different issue but the glacier resorts that I have experience of tend to embelish their snow figures on the glacier. I've seen the figures on both the Engelberg and Laax sites, on the my Switzerland site and in local newspapers which drastically differ from what is on the SLF site. I also happen to be up close to those altitudes in non glacier areas as late as mid November and can see what the new accumulation is. The fact that its snowing down to 1500m today doesn't have anything to do with it, the weather can get warm again and the newly fallen snow could melt away to about 3000m within a couple of weeks.

I've been here in Switzerland for winters for 10 years and year round for 6 years. I know what I have experienced and the truth differs from the reality at a number of resorts that I have visited.

I'll agree that the resort reporting cleared up quite a bit a few years back when MySwitzerland.com apparently threatened to drop resorts if they falsely reported snow depths on their resorts. Now at least in my area it only appears to be glacier resorts that have this exageration and only on the glacier. Funnily enough a neighbouring resort that goes nearly to the same altitude can have 2m less snow the only difference being no glacier! :-o

ise wrote:

ir12daveor wrote:
That very much depends on the glacier. Engelberg and Laax post 3-4m of snow at the start of the season every year and there is no way that much snow has accumulated yet. In these cases they are measuring on the glacier. Whether they are measuring right down to rock or not I don't know, but it is certainly glacier and not new accumulated snow.

Average glacier depths in their accumulation zones around Switzerland are 70m as I already pointed out. From that you know for certain a snow report of 3m isn't the glacier depth.

I'm not able to speculate what a hypothetical snow report may or may not be measuring but if I saw a report in December for, as an example, Zermatt, telling there was 2m of snow on the glacier I would know that was new snow from that winter.

So when you see Engleberg reporting depths in December of around a 1.5m (that's the actual recorded, reported historical figure) you're seeing new snow that's fallen in that winter.

I can't see why that's surprising, it's snowing right now, the zero isotherm is beginning to settle below 3000m so higher glaciers are accumulating snow. It would surprising if there wasn't a couple of metres of snow accumulated by December. In fact, that relatively low figure of 1.5m for Engelberg reflects a fairly poor start to the last season. It's the same for the 1.7m that Laax reported in December last year. In point of fact, neither Engelberg nor Laax ever reported more than 3m for the whole of the previous season, the highest measure was 3m or so in April which represents the season accumulation.

And, physically, practically, how is it measured? By putting a pole in the snow of the glacier at the start of the winter, or more likely around now, and seeing how far up the pole the snow goes.

The first reports for Engelberg last season were 0cm lower and 45cm upper in November then 48cm/123cm in December, there's nothing I find surprising about that.

ir12daveor wrote:I'm not sure where you are taking your figures from, but I assure you that the resorts quoted figures in those resorts have differed substantially from the figures shown by the SLF data stations.

Early season reported snow depths on glaciers are for accumulated snow that winter, that's why they're the sort of numbers you'd expect at around the one or two metre mark.

I can tell you why SLF figures aren't really relevant to glaciers if it helps you though, it's simply because they don't place monitoring stations on the glaciers. You'd not really get too much data relevant to avalanche forecasting so it's not something they systematically do.

If you want extend your knowledge of what's happening on glaciers with snow depths and the glacier depth then I can recommend the work done by Zurich University who've pioneered some laser technology to measure depths and density and give better ideas about what we call glacier mass balance which is a better measurement of how well glaciers are doing. There's also the ETHZ glacier monitoring service which has some good data available publicly. The University in Fribourg also publish analysis of snowfall, depth and duration.

But these are academic resources and likely of interest only to professionals and you don't really need them to understood what I'm trying to explain to you. You're telling us that you see reports of 4m of snow on a glacier in the early season. I think you're correctly realising this isn't likely which is why you were helpful in warning people to treat them with caution. I'm sure you do understand that glaciers are more than 3 or 4m deep so you know it's not the depth of the glacier you're seeing. Without getting too farfetched then you must see your 3 or 4m figure is :

a) measured from an arbitrary point and just means "oh boy, there's a lot of snow up there"
b) accumulated snow
c) (sorry) not true.

And, again correctly, you're sensibly eliminating that it's accumulated snow either because it's too early in the season and/or you appreciate that would be the entire season accumulation at current averages.

Obviously ski stations aren't really going to get away with just picking figures out of the air, you know they're not reporting glacier depth because you'd see figures of 5000cm and more so you must see that they're trying to accurately report the actual accumulated snow depth on their glaciers and that's why they report figures around 1 or 2m for glacier snow depths early in the season.

And they go on right through the season reporting the amount of that's fallen on the glacier. And we can test this quite easily. We know there's going to be 1 to 2m of new snow on the glacier on December because it is accumulating right now, we expect to see some 3 or 4m by the end of the season and values in between of those during the season.

So, here's the report filed by Engelberg on 23.05 this year :

Actual weather sunny Last snow resort 04.04.2010
Temperature at 1200 noon -2 °C Last snow area 18.05.2010
Depth of snow in resort/valley
1050 m 0 cm New-fallen snow (last 24h)
1050 m 0 cm
Depth of snow on upper runs
3020 m 342 cm New-fallen snow (last 24h)
3020 m 0 cm
Depth of snow on lower runs
1050 m 0 cm
Erste Bergfahrt um 8.15

And here, by comparison is one filed in March 2008 :

Actual weather cloudy Last snow resort 05.03.2008
Temperature at 1200 noon -14 °C Last snow area 12.03.2008
Depth of snow in resort/valley
1050 m 35 cm New-fallen snow (last 24h)
1050 m 0 cm
Depth of snow on upper runs
3020 m 260 cm New-fallen snow (last 24h)
3020 m 0 cm
Depth of snow on lower runs
1800 m 135 cm
Erste Bergfahrt um 08.30 Uhr

So what's the depth going to be in late December? Around 1.5m, the same as last year I'd expect.

I cannot possibly comment on hypothetical snow reports, I can simply tell you what the snow reports I do have sight of actually say and why figures of 3 or 4m bear no relation to anything that could be measured. If, as the season kicks off, you have an actual copy of a report that says 4m of snow on a glacier somewhere than post it (or it send via my website as I don't always have time to read this) and we'll see if we can work out what they're measuring.

ir12daveor wrote:I've been here in Switzerland for winters for 10 years and year round for 6 years. I know what I have experienced and the truth differs from the reality at a number of resorts that I have visited.

I'm sure it's not a competition :) I spend a few days in the mountains each year myself )

Ok Ise, lets get your unique view on this one.

Currently Saas-Fee is reporting 186cm of snow at 3500m. Interestingly they are reporting 0cm at 3100m.
http://www.saas-fee.ch/en/snowrep.cfm

If we look at the webcams for Gornergrat or Rothorn in Zermatt we can clearly see that there is nowhere near that level of snow 400m lower then that. Now I'd expect a bit of difference in snowfall over about 400m of altitude, but based on the weather we've been having lately I find somewhere in the region of 1.5m difficult to accept. Granted I know the glacier up there is very thick (can't remember the exact figures)

The snowsport report for Zermatt says 173cm at 2900m (Even if the 2900m is a mistake and they mean 3900m its a big diffence) when we can clearly see on the webcams 200m higher that there is nowhere near that amount of snow!

I accept your point that at these locations they are not measuring overall glacier thickness. I do realise how thick these glaciers are but there is a some degree of playing with the figures involved here somehow.

http://www.zermatt.ch/de/page.cfm/service/Wispo
http://www.zermatt.ch/en/page.cfm/interactive/webcams

ir12daveor wrote:Ok Ise, lets get your unique view on this one.

Currently Saas-Fee is reporting 186cm of snow at 3500m. Interestingly they are reporting 0cm at 3100m.
http://www.saas-fee.ch/en/snowrep.cfm

If we look at the webcams for Gornergrat or Rothorn in Zermatt we can clearly see that there is nowhere near that level of snow 400m lower then that. Now I'd expect a bit of difference in snowfall over about 400m of altitude, but based on the weather we've been having lately I find somewhere in the region of 1.5m difficult to accept. Granted I know the glacier up there is very thick (can't remember the exact figures)

The snowsport report for Zermatt says 173cm at 2900m (Even if the 2900m is a mistake and they mean 3900m its a big diffence) when we can clearly see on the webcams 200m higher that there is nowhere near that amount of snow!

I accept your point that at these locations they are not measuring overall glacier thickness. I do realise how thick these glaciers are but there is a some degree of playing with the figures involved here somehow.

http://www.zermatt.ch/de/page.cfm/service/Wispo
http://www.zermatt.ch/en/page.cfm/interactive/webcams

I think all I tried to point out was that glaciers were a bit more than 3m deep! You were saying that stations were reporting 3 or 4m of snow at the start of a season and I tried to explain that wasn't quite true.

So, it's the start of the season and you're asking about Saas Fee. I used the historical snow reports from Engelberg as it was your first chosen example and we saw that in fact they weren't reporting 3 or 4m at all and it was 1.5m to 2.0m as expected as this would be new snow accumulation since last winter. We also saw that they weren't reporting 3 or 4m until the end of the season. That's all what I suggested you'd expect.

During October alone around 45cm of new snow fell, so far in November there's been around 55cm adding to the snow fallen September and earlier. That's at the point around 3400m in Saas Fee where the most accurate measurement is taken. The surface temperature of the glacier is about zero degrees so what falls as snow basically stays there and consolidates. Away from the glacier the ground temperatures still aren't consistently at zero so although there's been a couple of metres of snow since the spring obviously none of that snow hung around in any measurable quantity, there's the odd patch as you'll have seen on your webcams.

I haven't looked at the webcams but I have been to the places you're talking about so I have actually seen with my own eyes that snow falling although I did cheat a little and ask the Bergbahnen in Saas Fee for you what had fallen for the last two months.