1.5 Large Data Sets Flashcards
What are the two set periods of time we need to know
May - Oct 1987
May - Oct 2015
What are the 5 areas studied in the UK region (in order)
Leuchars
Leeming
Heathrow
Hurn
Camborne
What are the 3 areas studied in the rest of the world (in order)
Beijing
Jacksonville
N
——————————–
S
Perth
Daily mean temperature
dc - the average of the hourly temperature readings during a 24hr period
Daily total rainfall
mm - Measures the amount of rainfall, including solid precipitation (snow, hail), within a 24hr period.
What is tr
- rainfall is the ONLY variable with ‘tr’. Trace does not appear overseas
- Trace means values of rainfall less than 0.05mm
- If using tr in calculation, use 0.025
Daily total sunshine
Recorded to the nearest tenth (1/10) of an hour
Daily mean wind direction
knots - given as bearings and as cardinal (compass) directions
Daily mean windspeed
kn/knots - ‘nautical mile per hour’
1kn = 1.15mph
Windspeed data is categorised according to the Beaufort scale
What is the Beaufort scale
0 –> CALM = <1kn
1-3 –> LIGHT = 1-10kn
4 –> MODERATE = 11-16kn
5 –> FRESH = 17-21kn
Daily maximum gust
knots - this is the highest instantaneous windspeed recorded. The direction from which the maximum gust was blowing is also recorded
Daily maximum relative humidity
Given as % of air saturation with water vapour. Relative humidities above 95% give rise to misty/foggy conditions
What are the only 4 types of data recorded for OVERSEAS LOCATIONS
- daily mean temp
- daily total rainfall
- daily mean pressure
- daily mean windspeed
Daily mean cloud cover
oktas, meaning the eighths of the sky covered by cloud
Daily mean visibility
decametres (Dm) - this is the greatest horizontal distance at which an object can be seen in daylight
Daily mean pressure
hectopascals (hPa)
what is n/a
- the ONLY 4 variables to have n/a are: daily total sunshine, daily mean windspeed (& Beaufort conversion) & daily maximum gust
- these 4 variables are all n/a for the first 2 weeks of May 1987
- n/a doesnt appear overseas
- should be discounted from sample
what does high mean pressure indicate
calmer, clear sky
What does high pressure in winter indicate
Colder, because no sky cover
What does lower mean pressure indicate
Associated with more violent weather
What does higher mean pressure in summer indicate
Hotter
Patterns for the 5 UK locations
The more North a location, the more likely temperature will be lower, rainfall will be higher
Patterns for 3 Overseas locations
Jacksonville, Florida is prone to hurricanes & Perth is the only location in the Southern hemisphere
What is the average atmospheric pressure
1013
