UK climate change from historical records Flashcards
(19 cards)
why do we need long climate records?
Humans have been affected by decadal and centennial climate cycles, need records to understand these
what are contemporary rain gauges?
they are a bucket with a known diameter, that gives an absolute measure of precipitation, the spatial coverage depends on network of gauges
rain gauge errors?
wetting losses, evaporation, splash in and out, wind and snowfall
Tipping bucket rain gauges?
can provide continuous measurements, bucket fills and then tips sending data, account for 1/2 of gauges, blockages lead to misreading, wetting and evaporation, tipping time can miss readings
radar rainfall estimates?
provides spatial coverage, emits a pulse of electromagnetic radiation reflected off of an obstacle e.g. rain, measuring the time back estimates the distance of the rain, 15 radars in the UK each with 200km range, scan every 5 mins
historical observation?
you cant expect the same level of detail
what are direct observations?
documents that contain direct observations of meterological parameters often biased towards socio-economic disasters
what are indirect or proxy observations?
physical and biological indicators that are significantly related to meterological parameters
what are discontinuous observations?
individual events that have been recorded, made by individuals for their own sake
what are continuous observations?
done continually, product of administrative routine
what occurred in Carlisle?
earliest climate records went back to 1677, records were needed to be bridged to get a complete record
what is the England and wales precipitation series?
regional reconstruction, initially constructed in 1920s, has been extended back to 1727
what is british rainfall?
major source of data for EWP, by early 20th century, there was enough data to produce major rainfall maps,
precipitation and temperature in UK last 250 yrs
noticeable positive trend in summer/ winter temp + precipitation over last 200 years, summer and winters are getting wetter and warmer
constructing a long temperature record?
many problems occur, site changes, instruments change, development of heat islands can have an effect all these can lead to problems with data set homogeneity
CET record
1859 - present shows very strong warming periods but also periods of cooling e.g.1950s
value of long records?
can see past events and variability allowing for planning, can also use it to see if extreme events are being affected by climate change
effects of volcanic eruptions on climate
short term impacts around 1-3 yrs, sulphur dioxide is ejected into atmosphere, conversion to sulphate aerosols, extremely effective at backscattering SW radiation, eruption style has to be explosive, tropical eruptions can spread sulphate into both hemispheres
how does sulphate appear in ice cores?
as acid spikes
