Stats Large Data Set Flashcards
What does the data set consist of
Weather data samples provided by the ent office for five UK weather stations and three overseas weather stations in the time period October 1987 and may to October 2015
What 5 weather stations in the UK
Camborne, Heathrow, Huron, Leeming and Leuchars
What three locations over seas
Beijing, Jacksonville and Perth
How many data variable are recorded across the weather stations
Eleven
How are air temperatures recorded
By thermometers in a louvred screen 1.25m above short grass except some places where observations are made from a nonstandard roof top exposure
What units are daily mean temperature recorded in
Degrees Celsius
What is the daily mean air temperature
Average of the hourly temperature readings during this period
When for daily mean air temperature
0900-0900 GMT
What does the daily total rainfall refer to
24 hour periods commencing at 0900 GMT on the day of entry and included any solid precipitation such as snow or hail which is melted and measure the same was as rainfall
What is daily total rainfall measure in
mm
What does a trace or tr mean for daily total rainfall
Rain is an amount less than 0.05 mm
How is daily total sunshine measured
By an instrument that measure the amount of solar radiation exceeding a threshold recorded in hours and tenths
What’s daily maximum relative humidity
Measure of how close the air is to being saturated with water vapour
Which Latrobe humidities are associated with mist and fog
Above 95%
What is daily mean wind speed
Averaged over 24 hours from 0000GMT and given in knots ( 1 knot= 1.15 mph)
What’s the daily maximum gust
Maximum instantaneous speed that occurred during the 24 hours
What’s the daily mean wind direction
Averaged over 24 hours from 0000GMT on the date given in degrees /360
What’s the daily maximum gust directions
Direction from which the wind was blowing when the maximum gust during the hour commencing at the time of entry occurred and is measured in degrees from true north
What’s cloud cover
Fraction of the celestial dome covered by cloud measured in eighths (Oktas)
What is visibility
Defined as the greatest distance at which an object can be seen and recognised in daylight or at night could be seen and recognised if the general illumination were raised to daylight level
How’s visibility measured
Using Visiometer at automatic sites but used to be done differently
Measured horizontally
Units for visibility
Decametres (dam)
What’s pressure measured with
Previously with the millibar but replaced by SI unit of pressure the pascal (Pa)
