Geology Essay Assignment on Weather and Climate

NATS 1780 A (Fall 2018): Assignment 1 – Version 1.0, October 3, 2018
Due: November 7, 2018 by 11 pm EST via Moodle
The assignment is comprised of two questions.
(Late Penalty: 10% per day – including weekends; 100% deduction after solutions are posted.)
Instructions:
● You are expected to provide answers for every question. You are encouraged to show all
of your work so that marks can be awarded for partially correct answers.
● Although you are encouraged to collaborate with your classmates, each of you is
expected to submit a separate and distinct assignment.
1. Abercromby and Hildebrandsson’s scheme classifies clouds into ten forms; with practice,
it is possible to differentiate between these forms. You are required to photograph clouds
that are representative of six of the total of ten forms, subject to the following constraints:
a. You must have taken these pictures, and you must be able to prove this. Use of
the same photograph by more than one student, or use of a photograph that you
cannot prove to be your own (e.g., one obtained via the Internet), will be
considered an inappropriate display of academic integrity. The consequences
of such inappropriate displays of academic integrity can be quite serious.
b. Along with the picture, you must be able to provide the weather conditions
(please see Table 1 below) for the day the picture was taken, as well as the
classification of the cloud you photographed. (A screenshot from a weather app,
at the time and place where you took your photograph, would be ideal!)
c. All digital photographs must be capable of supplying a date – either directly on the
photograph itself or indirectly via the photograph’s metadata. (Metadata is data
about data. In this case, it is possible to extract data about a digital photograph
that states items such as the date, camera make and model, etc. You are not
required to submit metadata for your photographs.)
d. All photographs must convey a sense of perspective (e.g., include building, tree,
field, etc.) to allow for size and distance approximations.
© L. I. Lumb – Sharing prohibited. Violators subject to legal/academic consequences. 1
e. You may substitute for one or two cloud forms with pictures that capture optical
effects in Earth’s atmosphere. Examples include rainbows, sundogs, halos,
mirages, etc. Anything related to the content in the section on “Atmospheric
Optics” is acceptable. Pollution-induced optical effects are also acceptable –
anything related to the content in the section on “Air Pollution” is acceptable.
Picture # Cloud Classification
Date of Photograph
Location of Photograph (including Elevation)
Temperature & Dew Point
Cloud Base Estimate (Relative to MSL)
General Weather Conditions
Identifying Features Used to Classify the
Cloud
Table 1. Observational data required in support of each picture depicting a separate cloud for
classification.
2. From the UV Index to irradiance to temperature, in Earth’s atmosphere, relationships
exist. The purpose of this question is to expose these relationships on a day of your
choosing.
a. Use the UV Index calculator here to:
i. Estimate the maximum value of the UV Index for day you have chosen.
ii. Estimate the time of day when this maximum is reached.
iii. Keep this Web page open, as you will need it again for Question 2(d).
b. Use the EMOS archives for your chosen day to locate the corresponding
irradiance versus time graph. (Note: A copy of this graph must be included with
your submission.)
i. Estimate the maximum value of the downwelling shortwave irradiance in
W/m2
. State the time of day when this maximum is reached.
ii. How closely in time do your answers for 2(a)(ii) and 2(b)(i) match?
iii. Why might you expect your answers for 2(a)(ii) and 2(b)(i) to match
closely in time?
iv. Estimate the maximum value of the upwelling longwave irradiance in
W/m2
. State the time of day when this maximum is reached.
v. Estimate the time of day when the value of the downwelling shortwave
© L. I. Lumb – Sharing prohibited. Violators subject to legal/academic consequences. 2
irradiance (in W/m2
) is equal to the value of the upwelling longwave
irradiance (in W/m2
). State the common value of irradiance at this time of
day in W/m2
.
c. Use the EMOS archives for your chosen day to locate the corresponding
temperature versus time graph. (Note: A copy of this graph must be included with
your submission.)
i. Estimate the maximum value of temperature in °C. State the time of day
when this maximum is reached.
ii. How closely in time do your answers for 2(b)(i) and 2(c)(i) match?
iii. How closely in time do your answers for 2(b)(iv) and 2(c)(i) match?
iv. How closely in time do your answers for 2(b)(v) and 2(c)(i) match?
v. Why would you expect a closer match in 2(c)(iv) than in 2(c)(ii) or 2(c)(iii)?
vi. In simple terms, what does this tell us about the way in which Earth’s
atmosphere is heated?
d. In the irradiance-versus-time data from EMOS for the day you chose, locate an
event that you can assume corresponds to the passage of a cloud. (Passage of
clouds typically appears as a ‘negative’ spike in the irradiance-versus-time data.)
i. Estimate the reduction in downwelling shortwave irradiance as a
percentage, and the time at which this event occurred.
ii. Assuming the estimated percentage reduction is completely due to
reflection of downwelling shortwave irradiance by a cloud, estimate the
thickness of the intervening cloud cover. (Hint: Make use of Figure 19.3
below.)
iii. Using the calculator (Question 2(a)), estimate the UV Index at the time
the cloud passes. Capture this Web page, and submit it as a component
of your assignment.