Recent Question/Assignment

• Model
A simplified model of the radiative energy transfer processes of the Earth and its atmosphere can be explained by the following diagram.
• Assumptions of Model
Incident radiant energy from the sun is mostly in the “shortwave” range (visible, near ultra-violet and near infra-red). Consider atmosphere to be transparent to this radiation. The shortwave radiation is partially reflected from surface and back to space, remainder is absorbed by the surface.
Io = Intensity of radiation arriving from the Sun at Earth’s orbit
? = albedo of the surface (fraction reflected) ˜ 0.3 PIN = Power absorbed by earth’s surface
At equilibrium temperature, surface radiates in the “longwave” range (mostly far infra-red). At these wavelengths, the surface is a black body emitter, and the atmosphere is an efficient absorber. Some small fraction of the energy radiated from the surface is directly transmitted through the atmosphere. The atmosphere absorbs the remainder of this energy and re-radiates this energy out to space and back towards the surface.
PS = Power radiated by earth’s surface
t = transmissivity of atmosphere (fraction transmitted)
PT = Power transmitted through atmosphere to space
PA = Power radiated by atmosphere
POUT = Power radiated out to space
The power radiated from the surface is either transmitted through the atmosphere or absorbed by it, so
PS = PT + PA
The total power radiated out to space is made up of the power radiated outwards by the atmosphere and the power transmitted through the atmosphere from the surface
POUT = PT + ½ ? PA
To maintain equilibrium, the power absorbed by the surface must equal the total power radiated back to space
• Problems
1. (a) Using this model, show that the mean surface temperature of the earth is given by the equation
Ts4 ? Io ?1???
2??1? t?

(b) Research an authoritative source for the current value of the average surface temperature of the earth (year 2016) and hence determine for the current longwave transmissivity of the atmosphere, t.
(c) The transmissivity of the atmosphere decreases exponentially with increasing concentration of greenhouse gasses in the atmosphere. The measured mean concentration of CO2 in the atmosphere (in ppmv = parts per million by volume) is given in the graph below. You may assume for the purposes of this assignment that the Mauna Loa station data shown here approximates the global average data.
Add your team number to the year 2040. e.g. If you are in team 10, you will analyse the year 2040 + 10 = 2150. Use the data in the graph below to determine the mean surface temperature of the Earth in that year. Assume the CO2 concentration increases at its current rate.
Illustration from
2. Estimate the rise in sea-level from year 2016 to your group’s year as a result of thermal expansion of the oceans. You may assume for simplicity that all shorelines are vertical, and that the full depth of the ocean expands.
3. A small rise in the mean surface temperature of the earth could lead to the melting of the entire Greenland ice cap. A higher surface temperature could cause the rate of melting to exceed the rate at which snow seasonally replaces the ice. Determine the contribution that the melting of the entire Greenland ice cap would make to rise in sea-level. You do not have to consider your target year, or how long this would take to occur.
4. Compare your value for the thermal sea-level rise in your year and your value for the contribution from melting of the Greenland ice cap to values predicted by a published scientific study. List any differences in the assumptions made by that study with the assumptions you have made in your calculations.
Meet with or contact the members of your group, and find out what task you can contribute towards the solution of the problem and the production of a report for submitting. If you don't know which group you're in, check under Team Lists on the PVB101 BB site.
Please use your human resources (the people in your team) effectively.
There are many roles that may be required to solve and report the problem, such as
Team Leader
Communications Officer
Number Cruncher(s)
Graphic designer(s)
One person can't be expected to do it all: divide the responsibilities among people who will contribute best in that role. We hope you will try out different roles in subsequent assignment modules to round out your team skills properly.
Ultimately, you will assess each group member (including yourself) on their contribution in that role.
Team Discussion Boards
Each team will have a group discussion board link on the left screen menu on the PVB101 BB site. It’s a good idea for someone in each group to be updating the current ideas their group has ON THE DISCUSSION BOARD FOR THEIR GROUP, even if the main discussions are held elsewhere (meetings or whatever).
It is not compulsory to do this, BUT if the ideas go on the board, then the tutors and I can keep track of where you're heading and where to go and maybe offer some contribution. This is also good evidence in case of a disputed peer mark.
The tutors will be asked to review your draft solution which you post in your team’s FILE EXCHANGE AREA a few days before the due date to offer feedback on your problem-solving strategy.
Report Format
The team assignment report may be presented as any of the following:
PowerPoint presentation
However, you will be required to submit the team assignment report as an electronic copy in pdf format via the Sea-level Rise Assignment link under Teamwork Area on the PVB101 BB site.
There is no word limit as such, simply address each question. Just keep in mind that the report should be neat, well explained, and concise (stick to the relevant points) with your methods of solving the problem, logical arguments and conclusions clearly outlined. The mode of presentation you choose is not itself assessable, and time spent producing the final report should be in accordance with the time spent by other tasks performed. i.e. don't go overboard on presentation: tell us how you solved the problem. In short… you should focus on the assessment criteria!
You will be required to cite any sources which you use in your team report for solution data or comparision results. You don’t need to cite the task sheet or lecture notes. You should choose reputable and appropriate sources for the information you are citing. (“Wikipedia”, for example is not an original source from an appropriate body, but may be helpful in finding background and links to more specific sources such as publications by universities, government bodies, professional organisations, etc.). References to information from these sources must be made both in the body of the text and in a bibliography. QUT Harvard is the preferred style for this report, but any acceptable QUT referencing style may be used. Consult QUT Cite|Write ( ) for more information about acceptable QUT referencing styles.
Due Date FRIDAY 7th Oct (Week 10) PDF upload via the Sea-level Rise
Assignment link under Teamwork Area on the PVB101 BB site
This assignment will contribute 10% to the overall assessment of the unit. This will comprise:
Final Report (Tutor’s mark) 7% Self and Peer Assessment 3%
N.B. The self and peer assessment mark for an individual student must be of sufficient value, or else overall mark the student will receive for this project is zero.
Project Plan
A project plan is not compulsory for this exercise, but is recommended best practise.
Final Report Criteria 5%
Solving Skills A. B. Appropriate physical relationships are applied correctly.
Correct data from the scene or by research is obtained and applied
C. Arguments made are relevant to the solution of problem (or the stated objectives of the project)
D. Logical links are made between previous arguments and/or results of calculations
E. All relevant information that can reasonably be deduced in the stated context of the project has been considered
Skills A. B. Nature of problem and objectives of project clearly stated
Stated arguments are based on evidence presented in the scenario or obtained by research
C. Assumptions made are clearly stated.
D. Arguments are stated clearly and concisely in a logical order, using appropriate language in correct context
E. Conclusions are clearly and concisely stated and logically follow from arguments presented in the report
Literacy Skills A. B. Any material obtained by research is clearly referenced in the report text
Data and information is relevant to the problem
C. Sources are appropriately listed in a bibliography
D. Sources consulted are reputable, reliable and appropriate
Self and peer assessment marks will be entered using the link to a Google form which will be made available on the PVB101 BB site at a time to be advised.
There will be five criteria for each assignment, based on DEMONSTRATED ABILITIES
A. Working in a team = Attitude, co-operation, supportiveness, reliability and contribution
B. Communication = Verbal and written skills, maintaining contact with team mates, listening skills and ability to provide feedback
C. Workload management = Meeting deadlines, participating and contributing equally, and communicating about workload
D. Quality of work = Problem solving ability and contributing work that is organised, complete, scientifically and academically sound
E. Overall = How would you rate this person’s contribution to your team for this task?
Peer Assessment Standards
Your will assess each team member for each criteria using the following standards:
Excellent = 5
Very Good = 4
Good = 3
Satisfactory = 2
Unsatisfactory = 1
Negative or No input = 0
In the context of this project, we ask you to interpret each standard as follows:
“Excellent” – student effectively and consistently demonstrated this ability
“Very Good” – student consistently demonstrated this ability
“Satisfactory” – student demonstrated this ability, but not consistently “Unsatisfactory” – student rarely demonstrated, or did not adequately demonstrate, this ability
“Negative or No input” – student did not demonstrate this ability
If the overall peer assessment average mark for an individual is
-unsatisfactory- or worse, then that individual will receive the ZERO for that task.
If the overall peer assessment average mark for an individual is -satisfactory- or better, then the peer assessment component of the mark for that project will equal the peer assessment numerical average out of 5, scaled to 3%.