large data set Flashcards
daily mean temperature units
degrees Celsius
daily mean temperature
average of the hourly temperature readings during a 24 hour period
daily total rainfall units
mm
daily total rainfall
includes solid precipitation such as snow or hail, which is melted before being included in any measurements
what are rainfall amounts less than 0.05mm recorded as
tr - trace
daily total sunshine
recorded to the nearest tenth of an hour
daily mean wind direction and speed
averaged over 24 hours from midnight to midnight.
what are mean wind directions given as
bearings and as cardinal directions
how is mean windspeed categorised
the beaufort scale
what is windspeed measured in
knots (kn)
1kn=1.15mph
beaufort scale
0 = calm = <1 knot
1-3 = light = 1-10 knots
4 = moderate = 11-16 knots
5 = fresh = 17-21 knots
what is daily maximum wind gust measured in
knots
daily maximum wind gust
highest instantaneous wind speed recorded
direction from which maximum gust was blowing is also recorded
daily maximum relative humidity
given as a % of air saturation with water vapour
relative humidities above 95% give rise to misty and foggy conditions
what is daily mean cloud cover measured in
oktas or eighths of the sky covered by cloud
