402 total views
The word ‘snow’ conjures images of a world blanketed in its pristine embrace, a world where the imperfections of not only the landscape, but life, is forgotten for the sake of making a snowman, sledging, or simply hurling the wondrous material at each other. Evidence of this was seen all over the campus at the end of the first week in the new term, when we were visited by a brief flurry of snow, prompting the production of many carrot-nosed men, and many bruises, too!
However, for those living in the North West, especially close to the coast, snow is often a rare blessing, often with news of snow-drifts elsewhere in the UK being received with snorts of laughter, swiftly followed by questions about ‘where all the snow went.’ In fact, we seem to receive more rain than anything else, so the question is, why so?
Our weather is far from regular; however, one of the centres aiming to reduce this uncertainty is the Hazelrigg weather station, ‘the UK Meteorological Office’s Climatological Station Number 7236’, according to the University host-page. Dr James Heath explained how geographical air temperature changes and sea temperature significantly affects our weather.
‘For a start, it’s where our weather is coming from…the jet stream’, (which is a global current of high temperature winds) ‘which effectively steers the Atlantic storms was coming straight across the Atlantic and over the UK…and it stayed like that for the whole two months.’ He further elaborated, ‘it’s that strong contrast in sea surface temperatures and air temperatures that actually creates the weather systems themselves,’ which the jet stream subsequently steers. So we know that a stagnant jet stream and warm air causes bad weather, but how could the recent flooding be explained?
The El Niño event is a period of unusually high sea temperatures in the Eastern Pacific, which subsequently affects weather all around the world. Sea temperatures are a primary factor in the influence of global weather patterns, and with a significant warming effect being measured in the Pacific, what results is an increase in turbulent weather systems, due to greater temperature differences in the upper atmosphere. As a result, weather becomes more extreme, leading to storm systems.The effects of the El Niño event has been felt all around the world, with the subsequent atmospheric fluctuations being linked also to increased tornado activity in the US.
Furthermore, global warming could slowly worsen this process, as it slowly raises the sea temperatures further. It was found that for every 1°C increase in the surface temperature of the oceans, the moisture content of the atmosphere increases by 6%, which subsequently results in weather systems that draw more moisture than normal, producing abnormally heavy rainfall. A higher atmospheric temperature causes more water to condense than usual, producing a much heavier downpour than usual. Measurements from the Hazelrigg centre highlight this, with the centre receiving 556.2mm of rainfall in Novemeber and December; a significant leap from an average of 227.4mm over the same period, translating to a 245% increase in rainfall!
Focussing back on the effects of climate change however, it turns out that airborne particulate pollutants, have had the effect of counteracting the sea temperature rise, as it reduces the intensity of the sunlight that reaches the surface of the Earth. As a result, we are now in a Catch-22 situation; if the world actively reduced carbon emissions, the environmental impacts could theoretically worsen before the full benefits are reaped. We may potentially see more severe weather to come in the following years, which is why research into these patterns is important; the December rains were successfully predicted three months in advance, due to nationwide research and data analysis. This analysis not only helps predict future weather patterns, but also (theoretically speaking) allows targeted flood defences to be installed and planned.
In relation to our lack of snowfall, the northwest has an ‘unusually high sea surface temperature for our latitude’, meaning that compared to the other seaside regions of the UK, the temperature is much higher than usual. As such, when snow forms in the cloud layer, by the time it reaches the ground, it becomes the marmite of weather; rain.
So, does it mean we’re cursed to never see snow again? Of course not! However, it simply means that the northwest receives less than its fair share than the rest of the country. In a way, I suppose that’s what makes it so special; not only is the idea of snowflakes being born and falling from the skies fantastic, but also its rarity makes it that most special of times when you wake up, to find yourself gazing out at a pristine winter wonderland.
Doctor James Heath is a fieldwork support technician from the department of science and technology, who oversees the daily data collection of the Hazelrigg weather station. The statistics quoted have been provided by the Hazelrigg station, as part of the Met Office.
The LEC are looking for enthusiastic volunteers to work at the Hazelrigg research centre, primarily to perform a rota-based daily monitoring of the information. The role is open to anyone with a keen interest in meteorology. If you would like to learn more about the research station, visit http://www.lancaster.ac.uk/lec/about-us/facilities/hazelrigg-weather-station/