Large Data Set

What are the possible values for cloud cover in the LDS?

0, 1, 2, …, 8 (measured in eighths)

What does 'tr' mean in rainfall data?

Trace rainfall (a small value between 0 and 0.05)

Why is rainfall data often skewed rather than symmetric?

It often contains many 0 or near

Is daily mean wind speed in Beaufort form qualitative or quantitative?

Qualitative. It is therefore not meaningful to fit a regression line or look for a linear relationship between Beaufort conversion and a QUANTITATIVE variable like temperature

What is the unit of measurement for daily mean visibility in the LDS?

Metres, recorded to the nearest 100 m

What is the unit of measurement for pressure in the LDS?

hPa

What is the relative north south order of Leuchars, Heathrow, Camborne, Leeming and Hurn?

Is Leuchars north or south of Camborne?

North

Why is the seasonal logic for Perth reversed in the LDS?

It is in the southern hemisphere so seasons are reversed to those in Northern Hemisphere. So if it is summer in UK, it is winter in Australia

Why are easterly winds relatively uncommon for Camborne and the UK?

Prevailing winds are more from the west or south

What is the valid range for wind direction in degrees?

0 to 360 degrees (others are invalid)

Is consecutive day cloud cover independent?

Yes

What is the data coverage for the 1987 weather data?

May to October only

How should 'less than 50%' be interpreted for cloud cover?

C < 4

What happens if a wind direction value is outside the 0

360 degree range?

High humidity relates to high or low visibility

low visibility

In the LDS which month is coldest for Beijing

October

LDS number of days data collected

184

Camborne wind speed is measured in

knots

Camborne is windier in

autumn/winter

A sensible LDS pressure range is roughly around

990 to 1040 hPa.

Which months and year are covered in LDS

May

The overseas locations (Beijing, Jacksonville, Perth) only contain data for which 4 variables: (Q

explain why a variable is n/a for an overseas location)

Explain why process may not generate a sample of size 20' from May/June/July 1987 data

For UK locations, Daily Total Sunshine, Daily Mean Windspeed, and Daily Maximum Gust are missing (n/a) for the first half of May 1987 (approximately the first 15 days)

Does The LDS contain gaps

Yes there are unavailable values (u should know that gaps exists)

For data cleaning tr should be replaced by

A numerical value between 0 0.05

Daily Mean Windspeed and Daily Maximum Gust are recorded as

Integers (whole number of knots).

Wind direction values are always multiples of

10 degrees. A direction not divisible by 10 in a question would therefore indicate a mistake

1 knot = ? mph

1.15 mph

Cloud cover measured in

Oktas

Cloud cover Oktas Values are

integers from 0 to 8. 0 oktas = clear sky, 8 oktas = fully overcast

Daily mean temperature measured in

degree Celsius to 1 dp

Negative value of Daily mean temp indicates

Below freezing

A value above 30°C would only be plausible for which 2 places

Beijing or Jacksonville.

Daily Total Sunshine is in

hours given to 1 decimal place.

Daily total sunshine Maximum physically possible is approximately

16

Wind direction means

FROM not TO

Wind direction is given in degrees from

true North (rounded to nearest 10°) and as a cardinal direction (N, NE, E, SE, S, SW, W, NW)

Relative Humidity is measured as

a percentage (%).

Relative Humidity Values above 95% are associated with

mist or fog

Relative Humidity value of 100% means

the air is fully saturated.

Why Rainfall is not suitable for normal distribution

Rainfall is right skewed because there are lots of very low values

leuchars location

Scotland on coast

Hurn location

(Dorset, south coast),

Leeming

(North Yorkshire) inland

Heathrow

Near London, inland

Camborne

Cornwall, coastal

Why is Leuchars windier

East coast of Scotland so close to sea so windier than inland locations and cooler

Which UK city has the highest temperatures of the UK station

Heathrow due to the urban heat island effect of being near a major city and airport.

Leuchars or Cambourne recorded more rainfall?

Cambourne

Coastal or inland have more wind speed?

coastal

Beijing location

Northern China, inland

Jacksonville location

East coast of USA (similar latitude to Beijing) in Florida

Compare Beijing and Jacksonville data

Beijing is inland so less wind speed than Jacksonville. It has high summer temperatures (roughly 15 degrees), high temperature AND higher windspeed indicates Jacksonville

Perth winter months

June, July, August

'suggest a month' for Perth with a high mean temperature

October

UK temperatures are higher in which months and lower in which months?

Higher in summer months (June, July, August) and lower in May and September/October.

Low outlier temperatures in a UK dataset are most likely from which months?

May or October.

Order months in terms of windy and wet (low to high)

Summer months, autumn(Sep/Oct), winter (Nov/Dec/ Jan

Why is annual rainfall estimate from LDS an underestimate for UK

Coz Winter months which have the most rain are omitted in the data

For Perth which month in the LDS is warmest

October around 19 degrees C

Perth Location

West coast of Australia, southern hemisphere

In the LDS for Perth 2015, a variable with mean around 5.3 and SD around 12.4 could be

Daily Total Rainfall (Cant be Temperature. Temp over May-Oct in Perth has a mean around 13 - 15 degrees celsius with a much smaller sd

Anomalous data in the LDS period

August 1987 was an exceptionally dry and warm period in the UK (a notable drought). June 2015 had abnormally high average temperatures across the UK

For Beijing 2015, Daily Mean Pressure covers what range of hPa

roughly 990 - 1030 hPa

State two variables from the large data set for Beijing that are not suitable to be modelled by a normal distribution

Daily Total Rainfall (highly right skewed)

Using summary statistics from May - October data to estimate an annual rainfall would be

Not accurate as it does not cover the winter months

explain why B(14, 0.27) might not be a reasonable model' for rainfall??? dont understand

The probability of rain (or no rain) is unlikely to be constant across a 14

How does High pressure affect wind direction

High pressure → clockwise winds in UK north station (eg Leuchars) gets westerly, south (Eg Canborne) gets easterly