Suffolk Bird Report 2019
Suffolk’s weather in a changing climate: 2019 Edward Jackson It’s the first week of August and I shouldn’t keep the Editor waiting much longer for this promised annual piece! I’m prompted by the forecast that an extended period of summer heat, well over 30°C, is predicted for the week ahead and also, as if on cue, I’ve seen the Met Office has just released its own UK Weather Report for 2019. So, it feels the time is right to don the research goggles once again, summarise Suffolk’s weather story for the year just past and also to give some meteorological and also climatological context for all the records that follow these pages. How does Weather relate to Climate? Despite the oft-quoted British obsession, let’s start by being clear about the difference between weather and climate. The term weather is used to describe the state of the atmosphere at a location at any given moment. Looking outside right now at 14:30hr on August 6th 2020, here in Brantham the sky is virtually overcast with what I judge to be stratocumulus cloud (7/8 cloud cover to use the formal description); there’s no rain or other form of precipitation; the outside thermometer in the shade registers 27°C and in terms of wind, a light breeze (Force 2) is blowing from the west. There were longer periods of sunshine earlier today, but I don’t have the more sophisticated equipment needed to record the actual hours of sunshine in a day, or to measure air pressure and humidity. However, the basic variables of cloud cover and type; precipitation (rain, drizzle, sleet, snow and hail); temperature (daytime maximum and night time minimum) and wind (reflecting the speed and direction of movement of an air mass due to differences in atmospheric pressure) are simple enough for us all to observe. Our experiences of these changing characteristics are easily woven into everyday conversation. The Met Office (based in Bracknell until 2003 and now in Exeter) maintains a network of 435 observation stations across the UK. Around 265 of these are known as ‘Synoptic Stations’ and automatically report hourly readings of key variables using digital equipment. The remaining 170 or so are the ‘Climate Stations’ and rely on people rather quaintly called ‘Co-operating Observers’, who take daily readings of temperature, rainfall and other variables at 09:00hr GMT (10:00hr BST in summer), using equipment supplied by the Met Office. These data used to be transcribed from the daily weather logbook onto large format monthly return sheets and sent off in the post, but they are now reported online much more efficiently. Suffolk hosts five automated Synoptic Stations: Santon Downham on the north-west border with Norfolk; Brooms Barn Experimental Station west of Bury St Edmunds; Cavendish on the upper Stour; Wattisham north of Hadleigh and Charsfield north-east of Ipswich. The only Climate Station is on the lower Stour and officially named East Bergholt, though it is actually in the grounds on the Field Study Centre at Flatford Mill. Successive generations of Field Centre staff myself included - have ensured its continuous operation since the Centre opened in 1946. When atmospheric variables are subject to regular and systematic observations, whether manually or automatically, the data collected create a time series. Hourly and daily changes can then be analysed and averaged out over the longer timescales of months, years and decades. Although I have 30 years’ experience of changing weather patterns and therefore a sense of the climate of my home area in south Suffolk, the concept of climate is more usually applied to areas larger than this, at the scale of counties (Suffolk), regions (East of England) and countries (England and then the UK). As the size of the area under consideration increases, the changes in the atmosphere that generate weather conditions and the averaged sequences we call climate are progressively influenced by external geographic variables. The most important have traditionally been latitude 8
