Much of my work on the Cow House residency has been inspired by the work taking place in the Manchester Ice Cloud Chamber (MICC) at the Centre for Atmospheric Science. I mentioned previously in my blog about a visit I made to the MICC where I spoke to Dr Clive Saunders who showed me a few experiments I could do without the need for a multi-million pound piece of lab equipment.
The basis for this experiment is that water can remain liquid at temperatures below 0°C. This is called super cooling; water at below 0°C is said to be supercooled water. Supercooled water between 0°C and -36°C will form ice crystals only if it can form around a nucleus. This is called heterogeneous nucleation. The water must form around a nucleus such as pollen, dust or even bacteria. Supercooled water below -36°C will turn to ice without the presence of an ice nucleus. This is called homogenous nucleation. The water freezes ‘automatically’. I am recreating homogenously formed ice crystals.
Clouds that form higher up in the atmosphere consist of these ice crystals. An example of such a cloud is cirrostratus. These are whitish clouds, which form a very thin layer around 5.5km high. They indicate there is a lot of moisture in the air and can later descend to form other types of rain cloud.
In my first experiment, water vapour is put into a chest freezer at between 0°C and -36°C and supercooling occurs. Air at high pressure is added with a syringe and the temperature is reduced to below -36°C. Ice crystals then form in a bubbling chain reaction. I pointed a spotlight into the freezer and this showed up the ice crystals.
After figuring out how to do this successfully in the freezer, I decided the next step was to scale it up. I hired a refrigerated transit van and built a room with fabric walls, which could be slotted into the back. I tried out a few techniques with varying success. It is very hard to keep the van cool for long enough for the ice crystals to form. Using a pressure hose and air compressor was most successful. The fabric room is now a sort of corridor in my studio.