large data set: measurements

what are the 4 measurements for international locations?

• daily mean temperature

• daily total rainfall

• daily mean pressure

• daily mean windspeed

how many measurements for the uk?

• 11

what are the measurements for the uk?

• the 4 for the international, as well as

• daily mean wind direction

• daily maximum gust

• daily max gust direction

• daily total sunshine

• daily maximum relative humidity

• daily mean total clouds

• daily mean visibility

info for:

daily mean temperature?

• every hour of the day, they measure the temp, and find the mean at the end of the day

• units= celsius (rounded to 1dp)

• range = 4-33C

  • MUST KNOW THE RANGES

• seasonal trends: hottest in summer, coldest in autumn

  • seasons flipped in perth

• UK trends: colder in the north

• non-UK trends: beijing, jacksonville hot. beijing wide temperature range. perth isn’t hot

daily total rainfall?

• units: millimetres (mm) rounded to 1dp

• measure rainfall in a measuring cylinder over the day (including precipitation like snow and sleet)

• range: 0-60mm

• tr values = trace

  • trace means rainfall was < 0.05mm

  • say tr = 0 if working with data

• seasonal trends: driest in summer

• UK trends: wetter in north

• non-UK trends: perth is very wet as the seasons are flipped (winter months)

  • perth has some days with really heavy rainfall (102mm, 104mm)

  • jacksonville is wet

daily mean windspeed?

• record windspeed throughout the day, find mean at the end

• units: knots (rounded to integers in the UK, but decimals in international

• range: 3-19 kn

• some N/A values, probably equipment error

• when working with data, ignore these values, don’t include in calculations

• seasonal trends: less windy in summer, windiest in autumn

• UK trends: coastal towns typically windier

• non-UK trends: beijing, jacksonville not that windy

  • perth is the same as the UK

what is the beaufort scale?

• as well as being given in knots, it can also be converted to the beaufort scale (light, moderate, fresh)

• most values are light or moderate

daily max gust (UK only)?

• similar to daily mean windspeed, but the maximum windspeed in a day instead of mean

• units: knots (rounded to integer)

• range: 8-52kn

• same trends as daily mean windspeed

daily mean windspeed direction (UK only)?

• the direction the daily mean windspeed is coming from

• 2 units given:

  • angle: given as a bearing to the nearest 10, range: 0-360

  • cardinal point: compass point, abbreviated to N, NE, E, SE, etc

  • also has ESE, etc

• no trends here

daily max gust direction (UK only)?

• the exact same as the daily mean windspeed direction, but for the max gust instead

• mean windspeed direction and max gust direction are normally the same

daily mean pressure?

• record pressure throughout the day, find mean at the end of the day

• units: hectopascal (hPa), rounded to integer

• range: 988- 1038 hPa

• no trends

total sunshine (UK only)?

• how many hours of sunshine there were in a day

• units: hours, rounded to 1dp

• range: 0-14 hours

• seasonal trends: more sunshine in the summer

• UK trends: less sunshine in the north

daily max relative humidity (UK only)?

• max humidity recorded in the day

• units: %, rounded to integer

• range: 80 -100%

• no trends

• if humidity > 95%, this gives rise to mist and fog

daily mean total clouds (UK only)?

• divide sky into 8 sections. number of sections with clouds = number of oktas

• units: oktas, can be any integer between 0 and 8, no decimals

• no trends

daily mean visibility (UK only)?

• furthest distance they can see an object

• units: Dm (1Dm=10m), rounded to nearest 100 Dm

• range: 200 - 5000 Dm, some values lie outside this range though

• no trends

temp and windspeed range for cambourne?

• temp: 10-20

• windspeed: 3-18

temp and windspeed range for heathrow?

• temp: 8-29

• windspeed: 3 -19

temp and windspeed range for hurn?

• temp: 6-24

• windspeed: 2-19

temp and windspeed range for leeming?

• temp: 4-23

• windspeed: 3-17

temp and windspeed range for leuchars?

• temp: 4-19

• windspeed: 3-23

temp and windspeed range for beijing?

temp: 8-33

windspeed: 2-9

temp and windspeed range for jacksonville?

• temp: 15-31

• windspeed: 1-12

temp and windspeed range for perth?

• temp: 8-25

• windspeed: 4-14

what do you need to remember?

• the 11 measurements

• where the locations are

• range of values a measurement can have

• units and possible values

• have data varies through seasons

• how data varies in the UK

• how data varies internationally

• 1987 vs 2015 (global warming)

• ‘cleaning’ the data ‘tr’ and N/A values

  • say trace values = 0

• what months are not included (LDS only records may-october)

*things to note

• in the north, it is colder, wetter and darker

• places near coast = windier