Chapter 1 Large Data Set (AS) Flashcards
What is daily mean temperature measured in?
degrees Celcius (°C) to 1 d.p
What is daily total rainfall measured in?
millimetres (mm) to 1 d.p
What is daily total sunshine measured in?
hours (hr) to 1 d.p
What is daily maximum relative humidity measured in?
percentage (%) to the nearest integer
What is daily mean windspeed measured in?
- knots (kn) to the nearest integer
- Beaufort Conversion (calm, light, moderate etc…)
What is daily mean wind direction measured in?
- degrees (°) to the nearest 10
- cardinal direction (N, S, SE, NSN, etc..)
What is daily maximum gust measured in?
knots (kn) to the nearest integer
What is daily maximum gust direction measured in?
- degrees (°) to the nearest 10
- cardinal direction (N, S, SE, NSN, etc..)
What is cloud cover measured in?
oktas, where one okta = one eighth of the sky covered
What is daily mean visibility measured in?
decametres (Dm / dam) to the nearest 100
1 Dm = 10m
What is daily mean pressure measured in?
hectopascals (hPa) to the nearest integer
1hPa = 100 Pa = 1 millibar
What is a trace (tr) value?
A trace value is less than 0.05mm of daily total rainfall. In calculations it can be rounded to 0.
How can you estimate if a given day is misty or foggy?
A daily maximum relative humidity of over 95% indicates mist or fog.
Where is missing data (‘n/a’ or ‘-‘) found in the data set?
- The first half of May 1987 has missing values in UK locations for total daily total sunshine, mean windspeed and maximum gust.
- Other ‘n/a’ and ‘-‘ values can also be found haphazardly around the data set.
What four variables are recorded for the three international locations?
The three international cities only contain data for daily mean temperature, daily total rainfall, daily mean pressure and daily mean windspeed.