Monday, 24 March 2014

Tom Training

What's big, black and sometimes a little scary?

  and it's not this guy..'s this guy....

And I'm not talking about me with a sunburned face.  But instead about the wide fracture in the glacier ice as a result of various stresses and strains associated with it's flow down-slope.  These crevasses are amazing things to witness and staring down into the abyss is very intriguing, particularly when you can hear the fast flow of englacial/subglacial water channels.  It seems generally important to not fall rapidly to your potential death down one of these things, and its simple enough to follow that advice when you can see them all.  In the above picture on Hellstugubreen in Jotunheimen of southern Norway it seems like these crevasses are reasonably visible... but parts of the ascent up this ice mass involved some probing of snow and some worries when the ice axe disappears from you.  We were pretty lucky in this instance and pretty careful... but the greatest level of preparation can never 100% prevent a fall into an unseen crevasse, and thus its important to understand how to get yourself or another out.  

This week has been all about training for me for the coming fieldwork in less than 2 weeks.  On friday past, the task was just this... to practice crevasse rescue techniques... where else but the Lake District, home of glaciers....  True, the presence of glaciers is particularly absent in England, but the setup of this training was pretty awesome.  

A purpose built barn structure, rather cold (good to simulate conditions in some glacial instances... though not intentional) with bolts, karabiners and ropes here, there and everywhere.  The course was a full day focusing on the techniques of roping up for glacier travel, climbing up a rope yourself using prusik knots and a bit of strength and establishing a system of ropes, slings and pulleys to make lifting someones full weight a lot easier.  Having spent the last few months getting involved with some top rope indoor climbing, roping myself into harnesses was something I felt a bit more confident with... but it's clear to me that i'm someone who takes a while to engrave knots into my mind and make them second nature.  undoing knots is my true weakness! :/

Getting a little too close to another mans special area doing this, but important to be able to take charge and rope in someone else during glacier travel.  Would love to say Mark had no idea in this picture and I had to help him.... truth was my trouble with engraving knots into my brain was taking over when doing it to someone else.  

Oh yeah... log lifting! (simulating a dead weight of an unconscious crevasse victim of course! :P )

The course was fantastic, taught well with a mixture of hands on and some theory and thinking.  To anyone looking to do some training for crevasse rescue or to refresh existing knowledge, I would highly recommend Distant Horizons

Considering the cover of thick snow during the field excursion in April, and the minimal crevassing on the Miage as a whole, the requirement for conducting fieldwork was more to be able to ski...

And I can happily say I'm suitably capable for the shallow incline of the glacier following 6/7 hours of me speeding downhill with a plank on each foot at the indoor snow centre in Castleford (Xscape).  The training, which I was less willing to fork out the money for, seemed even more appealing with the payment coming from a training budget from my external funding source (necessary training... I think so! :) ).  The costly lessons were even more worthwhile considering I was one of two people for a whole day tuition (usually ~10 people) and the other went home after about an hour not feeling well... thus 1 to 1 lessons from someone who had been an instructor in Courmayeur and was familiar with the Miage Glacier.... success! 

Unfortunately I don't have a picture of me skiing like a pro... but just use your imagination.... I only fell over a few times, and only when getting into the spirit of parallel turns on the steeper upper parts of the slope.  Generally happy considering there may be some spare time in April for some recreational skiing... but that is to be determined... can call me Tomski

Sunday, 16 March 2014

The science of bad glacial tripods

The weeks are flying by! ...and among other work this last week, I have been thrown back to a task which I feel reasonably inadequate at performing... that would be metal work.  The last time I was in a workshop, clutching some small metal trinket, I was about 12 years old and in year 8 at school.  I was generally useless and D+T/metalwork/woodwork and the idea of going back to that worried me somewhat.  Flopping anxiously into a workshop of the university with departmental safety boots a size too big, not entirely sure which saw would best fit my needs.  Considering the type of mans man who tends to operate in such an environment (which I guess I'm not), I felt a little useless not knowing the name of all the tools and the best technique for using them....

However, I was saved from this by the fact that I simply had to cut some metal plates in half and was able to use a guillotine to do it in seconds.  The fact that the workshop tech squeezed my bicep afterward just reinforced my discomfort with such encounters..

The point of the whole ordeal is an attempt at stabilizing the tripods I need to hold my temperature loggers in the air, as the ones the department have would likely fall over after someone sneezes on them.  The 13 kilo steel tripods seem to have some stability on a flat surface to which it can bolted to- however, given the uneven nature of a glacier (before you pile as much as a metre or two of avalanche debris on top), it becomes a bit more tricky.

The obvious answer seems to drill the whole thing into the ice and save the hassle.  However, the idea here is to capture the temperature of the air near the surface but at a height that is the intermediate between the 'free air' and the air within the glacier boundary (see awesome drawing).  This Screen height is typically measured at 2 metres above the surface.  Because the surface of ice (assuming it is bare) cannot exceed melting point (0 degrees C ), it affects the air at the near surface that is warmer during the summer melting season.  As a result, this colder surface acts to 'dampen' the temperature changes close to the surface, which does not accurately reflect what is really changing in the air.  Therefore, looking back at our tripod: drilling it in to the ice, it will rarely remain at a constant height above the surface when the ice melts and when snow disappears.

That leaves us with option of a free-standing tripod... which sucks considering the success rate of the same tripods on a previous field season at this glacier.  Furthermore, as the surface experiences a non-uniform movement/melt, tying the tripods to something, could also act to tip it.  Annoying :/ .

As a result, I have had to make my way to a B&Q (which has proved rather challenging to get to larger stores without a car in Newcastle) in order to throw myself into more situations where I feel completely unsure of what I'm doing.  NOTE:  Informing a staff member of what you plan to do does need lead to any progress on finding something suitable when it comes to temperature tripods and glaciers.  Hopefully stabilizing the tripods with half metre strips of metal on its feet proves to be successful, but we shall see between April and June.  I'm half expecting to be rather annoyed come June when I visit the glacier to see my tripods sunbathing on the glacier surface.  An example of the type of metal strip I'm referring to can be vaguely seen in the picture below where all the tripods from the indoor calibration tests were bunched together (slacking with my photos):


But all in all.... the setup of these tripods is very simple.  The loggers can be operated by a monkey (coincidence!), the radiation shields work well the protect the thermistor probes from direct radiation to give an actual indication of air temperature (see the test below), and the stuff is mainly held together with copious amounts of sturdy tape and cable ties at the 2 metre screen height.

 One of the Tinytag loggers (TT3) was tested in the outdoors with one probe housed comfortably in a radiation shield to protect from direct heating, while the other had to bake in the clear skies that we saw during the midweek.  The upper graph shows the temperatures we are referring to until the irregularities at around 10pm on the 13th where it was brought in from the garden.  The clear skies and south facing aspect of this garden mean that conditions were ideal to test the importance of the radiation shields.  As can be seen from the bottom graph, the differences were high during the peak midday hours, showing differences in excess of 4 degrees C at times.  Considering the accuracy of these loggers in stable indoor conditions last week, the differences are significant and would severely hamper any accurate understanding of temperature differences.  Lucky we have all the radiation shields we need :) .

Therefore, I'm not too worried about the accuracy of the data at this point, more the fact if it stays in the place I want it to!

Sunday, 9 March 2014

Winter? what is that? (says the Englishman)

I'm sure we have all sat in a room at some point and tried to guess what the temperature is ... and usually a guess that's roughly within 20°C plus or minus.  Maybe it was back at school when the heating had broken and below a certain temperature, class had to be cancelled (I was this fortunate only once!).  Or maybe, you are like this guy with his funky headwear, trying to figure out how many layers you need.  

Either way, I realised I don't have too much difficulty in working out the temperature... mainly because I'm surrounded by 10 different sensors that are capable of recording data every second on air temperature and relative humidity of my little secluded hideaway.  I don't want make it sound like the Bat-Cave or anything.... but its the TomCave! (trademark).  

...ok, so it's the old boiler house at the University which has more dust than equipment... but either way its my little hideaway spot.  

Basically, in preparation for some fieldwork in the Alps next month, I need to test all of my temperature sensors and the logging systems before installing them on the glacier.  In order to accurately understand the temperature differences across a glacier when it begins to melt, I have to make sure all the sensors are reading approximately the same temperature under a (more) controlled environment.  Thus, the TomCave acts as a nice spot, sheltered from the effects of wind, but with a nice window to allow the sensors to record a daily cycle of temperature under impact of the sun (and how they all respond to this change).  

What we get is this:

The graph here shows the typical cycle of air temperature with peaks between midday and around 3-4pm as would be expected.  Interestingly during the 6th March (the fourth 'peak') the difference between the high daytime value and the night time low is very little.  This would suggest a cloudy, overcast day which persisted during the night, trapping the outgoing heat from the earths surface.  But the crazy thing to notice, is the dates and the associated temperatures... I think we should have all noticed (in the UK and over parts of Euro-Scandinavia) what a crazily mild winter we have had, with warm-ish temperatures and endless rain.  Highs of 15.5°C at the end of this graph support this early onset of spring (if winter ever came at all) assuming we ignore the start of this graph where I held my hand on the sensor just to.... test science and such (hence the 21.5°C maximum at the start).  
Fellow people from Minnesota and parts of the US that I know would argue very differently the case of the disappearing winter.  As this guy and his crazy dress sense indicates, the presence of the Polar Vortex over the US and Canada this winter has given them something to grumble about, perhaps even deny climate change on the grounds that its gone a bit colder this year.  

A brief BBC News overview in case you have been living in a hole, or perhaps you got frozen solid at the beginning of it, and having recently thawed, you are wondering what the hell happened.  .  

Either way, considering the maximum temperature between 1981-2010 at Tynemouth is recorded as 9°C, the presence of 15.5 at the beginning of the month seems pretty significant. (Historical data source: MetOffice:  

Personally, I'm waiting for a small, cold snap of winter weather before spring becomes fully incorporated into the mood and dress sense of Newcastle's population (excluding the night time experience :S ).  

I digress!.... Looking back the same graph but more zoomed in:

The air temperature during the day of March 5th (middle peak on first graph) measured at 10 minute intervals is expressed by the main black and blue lines, with the boxes showing the maximum and minimum values recorded within those 10 minute intervals.  The lines show some very minor variations between two sensors which are under near-identical conditions.  However these differences are less than one tenth of a degree, which is a reasonable similarity of measure considering the manufacturer indicates an accuracy within a twentieth of a degree (0.2) of these sensors.  

This will need to be tested under alternate conditions before being installed on the glacier in April when all the temperature loggers are in the same place (half currently being in Italy already).  But that is a job for the near future.  

I will be very interested to see the range of temperatures found during this field season in comparison with the general findings of previous studies, if this (European) winter is anything to go by.  However the differences between the air temperature measured in the TomCave and those measured above a glacier surface are something to consider... more on that next week.  


Sunday, 2 March 2014

I think I've been approved... let's do some science

What has 14 points and gives me a stupid grin?...... and its not a football team (especially as that would currently be a conference team like Hyde or similar, and that is nothing to grin about)..

The answer:

A sweet pair of new crampons for fieldwork/ playing around on ice... YEY!

Granted at this stage, they aren't 100% required, considering April fieldwork involves a lot of snow and use of skis/snowshoes... and in summer, there is mostly debris on the lower glacier area..  However, upper areas of the glacier are reasonably crevassed/I have some ambitious aims for where to put my temperature tripods/I'm looking for some recreational ascents around Mt Blanc.

Either way... I feel even more psyched for fieldwork which begins in a month.  Which brings me back to my point for this weeks blog.. project approval.  Last week, I presented a 10 minute overview to my project background and my aims for the 3 years I am studying at Northumbria and attempted to answer some questions from a small panel of staff at the University...

   ... A question about how to prevent my equipment from being stolen, I couldn't really answer to be honest...

... But either way things went alright, and while I have not had any formal confirmation, I think I'm ok to carry on with my research and all it's serious ethical implications!

Last time I was talking about some potential places where I could place my temperature sensors to capture the typical variability across the Miage Glacier in Italy.  Some places I have concluded to be ridiculously hard/impossible to reach and therefore unfeasible without having a jetpack (should see if I could get this funded somehow).  But other areas have been generally agreed upon and now I have to think about logistics with regards to getting the equipment up the glacier on a sled and where to set up the initial five stations (the rest will be established in summer when we have lots of 'willing' undergraduate students to help carry things).

One idea is the effect slope angles on temperature across a glacier.  Previous studies have highlighted that temperature can be predicted by a simple thermodynamic model, whereby temperature is controlled by the movement of energy between the surface and the air (sensible heat flux) and the adiabatic heating of the air as it descends.  A study by Ulrich Strasser and company (1) found that temperature differences were much greater when temperature was measured at the base of steeper slopes of the Haut Glacier d'Arolla in Switzerland.  A nice picture of this glacier in the snow... just 'cos I have one :)

So to test the consistency of this idea, I am planning to set up two temperature tripods a the base of two tributaries of the Miage Glacier at similar elevations, one which will be at the foot of a steeper slope/ice fall and one at a more gentle incline from the main body of the debris section.  By understanding these differences, we can gain knowledge on the relative impact of these factors.

Using an even more detailed DEM derived from LiDAR survey over the main body of the glacier, we can see the presence of much steeper terrain to test this idea.  The two most central red dots are the likely placements for this test.  The new slope angles shown in the above image (reds indicating steeper slope angles) are derived from this LiDAR data which has a spatial resolution of 2 metres (meaning that each pixel of the image corresponds to 2 m in reality).  This is an improvement from the resampled 10 m resolution that can still be seen to the left of this image.  However using this high level of detail in distributed melt modelling would require a lot of processing power which is likely to be unrealistic and unnecessary for my work.

Next job: test and calibrate the temperature sensors and get the tripods in good working order... accurate results are needed!

(1) Strasser, U., Corripio, J. G., Pellicciotti, F., Burlando, P., Brock, B. W., & Funk, M. (2004). Spatial and temporal variability of meteorological variables at Haut Glacier d’Arolla (Switzerland) during the ablation season 2001: Measurements and simulations. Journal of Geophysical Research, 109, D03103. doi:10.1029/2003JD003973