Data set variables Flashcards
What is daily mean temperature measured in?
degrees Celsius
what is daily mean air temperature?
the average of the hourly temperature readings
What is daily total rainfall?
Daily total refers to 24 hour periods commencing at 0900 Greenwich mean time on the day of entry and includes any solid precipitation
what is a ‘trace or tr’ of rain?
an amount less that 0.05mm
what is daily total rainfall measured in?
millimetres (mm)
how would you deal with a tr reading in a sample?
use the value as 0 or half of 0.05mm (0.025)
what is daily total sunshine recorded in?
hours or tenths and show the amount of bright sunshine recorded on the day of entry
what is relative humidity?
a measure of how close the air is to being saturated with water vapour
what relative humidity is associated with mist and fog?
over 95%
what is wind speed measured in?
knots (1 knot=1.15mph)
what is the maximum gust speed?
the maximum instantaneous speed that occurred during the 24 hours from 0000GMT on the date given
how is the daily mean wind direction recorded?
its averaged over 24 hours from 0000GMT on the date given and rounded to the nearest 10 degrees
what is the direction of maximum gust?
the direction from which the wing was blowing when the maximum gust during the hours commencing at the time of entry occurred, and is measured in degreed from true north
For UK locations, what are wind and gust direction measurements listed as?
cardinal directions
what is cloud cover measured in?
eighths (oktas)
