A Jolly Jollie – snow sampling in the Jollie catchment, Mt Cook

Definition:

Jolly: adjective. a field trip where work is done, but the enjoyment of being in the area outweighs any hardships.

A hard days travel through remote and unsympathetic country, wintery conditions, repetitive work, long hours, must be good at digging holes and not mind being in a small team likely to be made up of hairy smelly men. Voluntary. Will involve views to die for and heli-skiing!

For me it was a no brainer, for sure I would drive to Mt Cook to be part of the team of scientists laying siege to the Jollie Catchment in the annual snow survey. The National Institute of Water and Atmosphere (NIWA), over 4 consecutive years has undertaken the Jollie Snow Experiment (J-SEx), collecting hundreds of snow depth and density samples over a single day at the time of maximum snow storage.

With the boys, on the ridge. Ready for a Jolly Jollie. Photo by Jason Blair

With the boys, on the ridge. Ready for a Jolly Jollie. Photo by Jason Blair

In hydrological models, snow has traditionally been treated simply as ‘snow’. Anyone who has spent any time in the mountains knows full well that all snow is not created equally. Firstly snow does not layer onto the mountains like Christmas cake icing in perfect uniform thickness. Rather it billows around under the force of the storm, accumulating in some areas and being stripped in others perhaps like trying to ice a head of broccoli while someone holds a hair dryer next to it. Strangely I’ve never tried to do this, but I’m sure you would end up with variable icing cover. Secondly as any skiers will know, some snow is like icing powder, some like porridge and some like sheet ice, all which have very different densities. Therefore from a water storage point of view, snow is variable.

Satellite images that gather snow data for hydrological models have the ability to measure more than just the presence of snow. As the Inuit peoples of the Arctic know, snow is not just white. The Inuit people have many different words for what we simply call snow. Satellite images have the ability to measure more parameters but to ensure accuracy this requires ground truth points. In other words, if I can tell the satellite that the “pixel” I am standing on is x, and the pixel that Fred is standing on is y, and the pixel that Charlie is standing on is z, it can then work out the values for all the pixels between me and the boys. This is called extrapolating the data, and is a powerful remote sensing tool for obtaining data for large areas that could never be covered by foot. In fact, remote sensing has changed the way people do modern earth science.

No description required. Photo by Jason Blair

No description required. Photo by Jason Blair

The Jollie catchment is a contributor to Lake Pukaki, one of New Zealand’s major hydroelectricity dams, and it is a relatively small and simple catchment with a water flow gauge on the stream. There is good satellite coverage but little was understood about snow depth and density and the environmental drivers of this. In order to understand what the satellite can measure, ground data has to collected, and this is where the siege comes in. One day, and as many people as possible to take as many samples as possible. And the quickest way to get people around the mountains – helicopter to the top, ski to the bottom. Simple.

Helicopter with GPR strapped underneath. Photo by Jason Blair

Helicopter with GPR strapped underneath. Photo by Jason Blair

So in teams of 4 were dropped in by helicopter along the ridges bounding the catchment. We all skied down into the valley, stopping every 100m in elevation to take snow samples. Now don’t get me wrong, a bit of hard labor was done at every 100m, but it was between beautifully carved fresh turns.

Digging. Photo by Jason Blair

Digging. Photo by Jason Blair

We did a bit of digging! At each location we dug a snow pit, either to the base, or until the snow became isothermic (so the pits were all at least 2m deep). Down the snow pit we measured the temperature, the permeability, noted the depth of all the layers, and took snow density measurements every 10cm. While two people were doing this the other two did a snow depth transect, probing the depth of the snow every meter along the contour for 100m.

Snow pack analysis. Photo by Jason Blair

Snow pack analysis. Photo by Jason Blair

As well as the ground teams, a Ground Penetrating Radar (GPR) was strapped underneath the helicopter. This was able to measure the depth of the snow, and was verified by the ground measurements. The airborne GPR was successfully tested and into the future will be used over ground sampling as a greater area can be covered increasing the spatial resolution for catchment wide sampling for snow storage estimates.

Snow depth probing

Snow depth probing

Jolly good!

 

 

8th Hydrological Wonder of the World: Onxy River, Antarctica

Puffed chest, I knowledgably looked at the map and in my, ‘I’m so at home in the mountains’ voice proclaimed,

“it’s on the true left”

I then stuttered, paused, looked utterly confused and stuttered,

“which bloody side IS the true left”

The orientation of the valley from high ice plateau to ocean would pronounce the north side of the valley as the true left, but the river wasn’t flowing out to sea. Therefore by using the river as the reference, the south side of the valley is the true left.

“What the blimen heck is that river up to? It’s flowing the wrong way – where does it think it is going? Into Lake Vanda? But where does the lake flow out? Nowhere!”

Intriguing. I love maps and geomorphology, and this is a fantastic quirk.

Onxy River, Wright Valley

Onxy River, Wright Valley

I finally got there, the mystical Dry Valleys. It was a bit like my first time to Antarctica. Before my first trip south, my mind became a creative but uncontrollable pessimistic monster. I couldn’t foresee past the crazy things that WOULD prevent me from getting to Antarctica. Maybe I would be the victim of a “you’ve been punked” episode on the flight down, arriving back on the tarmac in Christchurch, movie cameras focusing on my beetroot face as I exited the airplane. Of course this didn’t happen, but it was touch and go for a long period. Getting to the Dry Valleys were much simpler, I got in the helicopter on a beautiful calm day, and 45 minutes later I was at Lake Vanda, Wright Valley.

Arriving by Helo - James Bond Style

Arriving by Helo – James Bond Style

Lyrics in my head….

Let’s have bizarre celebrations, let’s forget who forget what forget where.

Let’s pretend we don’t exist, let’s pretend we’re in Antarctica.    Of Montreal

Nothing remains of the old Vanda Station, although stories and nostalgia roll through my mind. In fact the old site is almost completely under the lake, which I suppose isn’t surprising seeing there is no lake outlet. It must be a sensitive hydrological system – certainly not prime lakeside real estate. Beside the newer hut is the old tinny, an overturned memory of lakeside summers from days gone by.

For me, there was the novelty of natural noise after 3 months of almost none!  A noise so homely and soothing, the cascading Onxy River. On the river bank I set up my Trango tent, a 4m3 cocoon of warm, glowing space. My own space (the only all season, having shared a room at Scott Base).  Time out! Bliss!

Camp at Lake Vanda

Camp at Lake Vanda

The Onxy River is the largest and longest river in Antarctica (40km). It was flowing at approximately 1 cumec, which with a little problem solving was just rock hopable. According to the stream gauging crew who helicoptered in to gauge the river, it can reach around 10 cumecs. In 1984 back in Vanda Station days, the Onxy River was rafted. Bloody good year 1984. First raft descent of the Onxy River (up valley???), Poi Eh was written by the Patea Maori Club, and I was born!

After a hard days scientific research, while the sun circled overhead, we ate our packet curry dinner and listened to the crackly news bulletin broadcasted from Scott Base. The bulletin was finished with a flourish – a static infused rendition of Poi E! Beaming out of the wee handheld radio, Lake Vanda’s links to NZ were a million miles away but as strong as steel.

Onxy River, liquid for a few weeks of the year

Onxy River, liquid for a few weeks of the year

Rere atu taku poi ti ta’ taha ra

WHAKARUNGA WHAKA RARO TAKE POI E!   Patea Maori Club