Data Analysis and Interpretation

Data analysis and interpretation focuses on May 4, 2016, for Ft. McMurray, AB and the area

that surrounds it.

1. Obtain the hourly data set of weather observables here.

2. Regarding the temperature data:

a. Plot temperature (°C) vs. local time (hours) for the full 24­hour period.

b. When (local time of day) are the minimum and maximum temperatures attained?

How does the timing of these values in the data compare/contrast with the

textbook example of Figure 1 below? (In reporting times, it is important to

account for DST when applicable.)

3. UV index data serves as a proxy for incoming solar energy. Obtain hourly data for the

forecasted UV index here; regarding this data:

a. When (local time of day) are the minimum and maximum UV index values

expected? How does the timing of these values in the data compare/contrast with

the textbook example of Figure 1 below? (In reporting times, it is important to

account for DST when applicable.)

b. Which mechanism of heat transfer does the UV index represent?

c. Why is a lag between maximum incoming solar energy and maximum

temperature expected?

d. Estimate the UV index at 7 pm local time.

4. The interaction between fuel, heat and oxygen are the ‘fire essentials’ modelled by The

Fire Triangle. Suppose there is ample fuel (e.g., smouldering wood from partially burned

forest) and oxygen, so that the only variable is heat.

a. At the edge of the fire, fire responders are in close proximity with smouldering

wood. In this location, how might they observe conduction and convection?

Which types of processes are these?

b. Heat is required to raise the fuel to its ignition temperature; suppose that this

ignition temperature is 28 °C. When is this ignition temperature (of 28 °C) first

reached according to the data?

5. Regarding the visibility data:

a. Define visibility as a weather observable.

b. Plot visibility (km) vs. time for the full 24­hour period.

c. Based on the visibility data, when does smoke (from the wildfire) start to appear?

For how long is this state of reduced visibility present? (Assume that this smoke

is the only element responsible for decreased visibility. Also assume that once

the fire reaches its ignition temperature, it burns, and continues to burn for the

remainder of the day.)

6. Suppose that by 7 pm, the smoke from the wildfire has developed into a 1 km thick

‘cloud’.

a. State the percentage of incoming solar energy that is reflected, transmitted and

absorbed by this cloud. (Hint: Make use of Figure 2.) If this smoke cloud

continues to thicken, how will the reflective, transmissive and absorptive radiative

transfers be affected?

b. Estimate the effective UV index. Assume that the forecasted UV index (answer

3(d) above) is reduced solely by reflective capacity of the smoke cloud. (Hint: If

the reflective capacity of the cloud is 60%, then the UV index is reduced by 60% ­

i.e., only 40% of the incoming solar energy is available for transmission and/or

absorption.)

c. Why does this thickening smoke cloud have a relatively minor effect on the

maximum temperature (answer 1(c))?

7. Using Google (or a similar search service), search for “satellite imagery ft. mcmurray

alberta may 4 2016”, and then respond to the following questions:

a. Why might evidence of the Ft. McMurray wildfires be expected in satellite

imagery that focuses on the visible light portion of the EM spectrum? Illustrate

with an image. (Be certain to reference your source.)

b. Why might evidence of the Ft. McMurray wildfires be expected in satellite

imagery that focuses on the infrared (IR) portion of the EM spectrum? Illustrate

with an image. (Be certain to reference your source.)

Attachments:

• 1501888121-1589103_1_NATS1780ASummer2016Lab-TemperatureRadiationandTheFt.McMurrayWildfiresMay162016Version0.9.pdf