Category Archives: Glaciology

The Project

So a brief explanation as to why I’m here is required.

I’ve come to Vancouver to start a research project examining the relationships between the atmosphere and glaciers. I had been working as a research meteorologist for Met Éireann (Irish national weather service), when the opportunity arose to  take up a PhD in Atmospheric Sciences at the University of British Columbia (UBC).

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Evening view looking north over UBC, Vancouver.
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The Department of Earth, Ocean, and Atmospheric Sciences, UBC (snowfall is actually a relatively rare occurrence in urban Vancouver).

In a nutshell, my project aims to examine all the ways in which energy enters and exits the surface of a glacier, and how the balance between incoming and outgoing energy affects the melting or cooling of a glacier’s snow and ice.  On a broader scale, my hope is to put this work towards improving our understanding of how glaciers will respond to changes in our climate. The initial plan is to install a weather station on a glacier in the Selkirk mountains in British Columbia, beginning this summer.

So, what’s required for the design?

  1. The station needs to have sensors to measure each of the variables relevant to glacier energy balance. These include air temperature and humidity, radiation (for example, the incoming energy from sunlight), wind speed, and the transfer of heat and moisture by local air currents or ‘eddies’.
  2. It needs to be robust and reliable enough to operate in a remote mountain environment, unsupervised for several months.
  3. It needs to have its own independent power source.

 

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Initial design and set up stage. Despite extensive testing, no interesting weather was detected in the lab.

 

The first step was to assemble and test all of the individual components in the lab, and to set up a method to automatically record and save the measurements made by each sensor. The lab is where you want to make your mistakes, and where you want things to go wrong.  The more problems that present themselves in the warm, dry lab, the fewer that will come as a surprise when you’re struggling with cold fingers on the side of a mountain, or worse, when you’re already hundreds of kilometers away, oblivious to the fact that your PhD is falling into a metaphorical or very literal crevasse.

With things up and running in the lab, thoughts turned to how all the components will be brought together and mounted on the glacier, and on how to reliably power the station in such a remote setting. The plan is to rig the sensors on to a wide, stable tripod, with power provided from two marine batteries (like rugged car batteries for boats). The batteries will be recharged using a solar panel mounted nearby.

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From sketches, to nuts and bolts.

A test rig has been put together, and is now running at an outdoor site on campus. The main issues I’ll be keeping an eye on during this test include insuring the system records all the data it’s supposed to, when it’s supposed to, that the data makes sense and the sensors aren’t interfering with each other, and that a few cloudy days don’t cause my power system to flat line. Below are some images of the sensors I’m using and what they are for. For anyone interested, I intend to go into a little more detail on the science behind the project in future posts. I’m no expert though, so it should all be fairly readable!

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Above and below views of the four component radiometer. This sensor measures incoming short and long wave radiation (from the sun, clouds etc) using the two instruments on top, and also outgoing short and long wave radiation reflected or emitted by the glacier using the bottom facing instruments. The balance of incoming and outgoing radiation is one of the most important controls of glacier surface energy.

 

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The sensors for measuring air temperature and humidity are housed in beehive-like enclosures known as radiation shields. These white shields protect the sensors from direct heating by the sun or excessive cooling at night (which would cause inaccurate readings), while still allowing the air to flow past the sensor and be measured.

 

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The snow depth sensor (also known as a sonic ranger) measures the time it takes for a sound wave to travel from the sensor down to the surface and back. Changes in the length of time taken equate to changes in the height of the snow/ice surface. In this study, it will be used to measure the rate of surface melting on the glacier, and it will be mounted on a separate fixed mast to the other sensors.

 

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The wind sensor measures wind speed by the rate at which the propeller at the front is rotated by the wind, and the wind direction by which way the wind turns the sensor (it is designed so that the propeller end will always turn to face the direction of the oncoming wind).

 

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This is a combined sensor which measures both the movement of air (wind), and its water content. The two claw-like structures make up the wind sensor, which is known as a 3D sonic anemometer. It measures wind speed or air movement in three dimensions. The two lenses in between this sensor make up the gas analyser, which uses an infrared beam to estimate the water content of the air flowing past. This sensor will be used to observe the the air currents or eddies which can transport heat and water to and from a glacier surface. These measurements are one of the more unique aspects of this project, know as the eddy covariance technique, and will be explained in greater detail in future posts.

 

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The brains of the operation: the data logger (top right) has been programmed to communicate with each sensor, telling it how and when to take measurements, and saving the data produced. The white box to its left controls how power from the solar panel (below) recharges the batteries.

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All going to plan, we will travel to the glacier and install the weather station this July. There will be some modifications and additions leading up to this, including a new custom made 4 legged ‘tripod’ (quadpod?), and a timelapse camera system which I will be building in the meantime. Many more hours in the lab and office will be required to get everything ready, but from this campus, reminders for why we are doing this are never far away.

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Looking north from UBC campus towards the peaks of Tetrahedron Provincial Park.