Voices of Science

My feeling is that the emphasis has not been so much on what I call dynamic meteorology and climatology. In other words, trying to determine the circulation patterns that have brought about changes in weather and climate, which I think is, you know, essential really to understanding both past, present and future climate. And perhaps that emphasis is not so strongly thought of now. I think I’ve hopefully brought that out strongly in the book, that this is really essential to understanding climatic change. You should understand, or try and find out, how the circulation patterns have varied in the past, rather than just constructing a series of temperature, rainfall, humidity. Because all these factors, elements, such as temperature, rainfall, humidity and what have you, they all depend on the circulation pattern. I mean, you hear much talk about extremes of weather today, you know, whether they’ve happened in the past or not, and you get the impression sometimes from media that these are unique events, but if you delve back into the past you find that these are not particularly unique and we’ve had them in the past even perhaps affecting areas more strongly. I don’t know if I’m right in that way, but … how else can I put it? Anyway, that’s, you know, what I feel, that in order to understand what’s going on today, rather than just thinking about the actual events themselves, why are they occurring? And one of the main themes, which I’ve taken on from Gordon Manley, is the study of the westerlies over the British Isles. And at the moment, with these cold winters and warm summers and what have you, it’s due to the decline in the westerlies. We are now living in a period when the westerlies are not so strong as they were in the early part of the twentieth century, when we had a more favourable climate. So when the westerlies go into decline you have other patterns, what we call blocking patterns, occurring and these lead to extremes of weather, dry, wet, cold and wet seasons. Whereas if you have the westerlies blowing strongly, as we’ve had quite recently in this latter part of the winter, we have these mild wet conditions, but early in the winter, in December, we had this very cold spell and that’s because the westerlies completely died out.