1.5 Large Data Sets

Question 1

What are the two set periods of time we need to know

Answer 1

May - Oct 1987
May - Oct 2015

Question 2

What are the 5 areas studied in the UK region (in order)

Answer 2

Leuchars

           Leeming
 
               Heathrow 

       	Hurn

Camborne

Question 3

What are the 3 areas studied in the rest of the world (in order)

Answer 3

Beijing
Jacksonville
N
——————————–
S
Perth

Question 4

Daily mean temperature

Answer 4

dc - the average of the hourly temperature readings during a 24hr period

Question 5

Daily total rainfall

Answer 5

mm - Measures the amount of rainfall, including solid precipitation (snow, hail), within a 24hr period.

Question 6

What is tr

Answer 6

• rainfall is the ONLY variable with ‘tr’. Trace does not appear overseas
• Trace means values of rainfall less than 0.05mm
• If using tr in calculation, use 0.025

Question 7

Daily total sunshine

Answer 7

Recorded to the nearest tenth (1/10) of an hour

Question 8

Daily mean wind direction

Answer 8

knots - given as bearings and as cardinal (compass) directions

Question 9

Daily mean windspeed

Answer 9

kn/knots - ‘nautical mile per hour’
1kn = 1.15mph
Windspeed data is categorised according to the Beaufort scale

Question 10

What is the Beaufort scale

Answer 10

0 –> CALM = <1kn
1-3 –> LIGHT = 1-10kn
4 –> MODERATE = 11-16kn
5 –> FRESH = 17-21kn

Question 11

Daily maximum gust

Answer 11

knots - this is the highest instantaneous windspeed recorded. The direction from which the maximum gust was blowing is also recorded

Question 12

Daily maximum relative humidity

Answer 12

Given as % of air saturation with water vapour. Relative humidities above 95% give rise to misty/foggy conditions

Question 13

What are the only 4 types of data recorded for OVERSEAS LOCATIONS

Answer 13

• daily mean temp
• daily total rainfall
• daily mean pressure
• daily mean windspeed

Question 14

Daily mean cloud cover

Answer 14

oktas, meaning the eighths of the sky covered by cloud

Question 15

Daily mean visibility

Answer 15

decametres (Dm) - this is the greatest horizontal distance at which an object can be seen in daylight

Question 16

Daily mean pressure

Answer 16

hectopascals (hPa)

Question 17

what is n/a

Answer 17

• the ONLY 4 variables to have n/a are: daily total sunshine, daily mean windspeed (& Beaufort conversion) & daily maximum gust
• these 4 variables are all n/a for the first 2 weeks of May 1987
• n/a doesnt appear overseas
• should be discounted from sample

Question 18

what does high mean pressure indicate

Answer 18

calmer, clear sky

Question 19

What does high pressure in winter indicate

Answer 19

Colder, because no sky cover

Question 20

What does lower mean pressure indicate

Answer 20

Associated with more violent weather

Question 21

What does higher mean pressure in summer indicate

Answer 21

Hotter

Question 22

Patterns for the 5 UK locations

Answer 22

The more North a location, the more likely temperature will be lower, rainfall will be higher

Question 23

Patterns for 3 Overseas locations

Answer 23

Jacksonville, Florida is prone to hurricanes & Perth is the only location in the Southern hemisphere

Question 24

What is the average atmospheric pressure

Answer 24

1013

Question 25

What are the 2 discrete variables

Answer 25

• Cloud cover
• Cardinal directions

Question 26

Why is October significant

Answer 26

Oct 1987 - all UK locations experienced higher rainfall in comparison to May-Sep due to the great storm
Oct 2015 - Perth had warmest October since records began
Oct 1987 & 2015 - Beijing significantly colder relative to May-Sep