In these tutorials you will be assessed on three pieces of work.
The purpose of the first 2 tutorials is for us all to get to know each other a bit more, by learning about what you are interested in scientifically. The topic you choose is unimportant, but it is best if you choose something you are genuinely interested in so that you are enthusiastic about it, which will give you a better chance of getting a good mark.
In this tutorial we will discuss how you will prepare a short writing assessment. You should do the following:
In this tutorial we will discuss your writing assignments. You will briefly explain it to me and the rest of your group and I will give you some feedback. In the week you should:
In the exercise you will set up and test a simple climate model that considers solar radiation, greenhouse gases and clouds. For an overview of how the model works visit this webpage.
MATLAB is available on the University clusters. Do not worry if you are unsure how to use it: by week 4 you will have been introduced to it in the data analysis course.The following MATLAB files can be downloaded and put into your working directory in MATLAB:
Once downloaded, open up the files and look at the code. Try to understand what each part of the code does, with reference to the climatesim page. To run the albedo01.m type batch_albedo01 on the MATLAB command line.
If you really prefer not to use MATLAB a simpler version of the climate model has been written in Excel:
Once downloaded, open up the file and look sheet 1 and 2. Sheet 1 is a basic climate model with one type of clouds, whereas sheet 2 is similar but containing a fraction of clouds that have been geoengineered. Try to understand what each part of the Excel file does, with reference to the climatesim page. The idea is you change some of the variables in the file and use the results to generate plots.
MATLAB users
Now type batch_albedo01a in MATLAB and you will get two figures: one of the Global Temperature vs the Cloud albedo and CO2 mixing ratio and the other of the Radiative Forcing vs the same variables. Print out your figures, produced in MATLAB, and write down what they show. Bring the figures and your descriptions to the next tutorial for discussion
Take a look at the latest IPCC report (the bit on radiative forcing). Radiative forcing can be expressed as the amount of energy going into the earth-atmosphere-ocean system due to a specific component (e.g. CO2, or clouds).
batch_albedo01a.m, save, and run again. Excel warriors
You should use sheet 1 to calculate the surface temperature for a range of values of CO2 mixing ratio (decide the range yourself). Plot this out. On the same graph do the same plot but for an increase in the cloud albedo. Repeat this for a few different cloud albedo values, so you have 4 line plots of surface temperature on the y-axis against CO2 mixing ratio on the x-axis and bring it to the next tutorial for discussion
Take a look at the latest IPCC report (the bit on radiative forcing). Radiative forcing can be expressed as the amount of energy going into the earth-atmosphere-ocean system due to a specific component (e.g. CO2, or clouds).
We will discuss your results and what they mean as part of the tutorial.
MATLAB users
Take a look at chapter 12 of the IPCC report (the bit on long-term climate change). Find the plot of global surface warming for different emissions scenarios (zero emissions and constant emissions).
albedo01.m file to reproduce a plot of surface temperature vs year for different sets of emissions scenarios and compare it to the plots in the IPCC report (to do this you will need to know the CO2 concentration in a particular year).
\[ CO_2=1.71\times 10^{-12}\exp\left(1.5916\times 10^{-2}\times year \right)+255 \]
You could then type the following into the MATLAB commandline: years=1960:1:2100;
N=length(years);
CO2=1.71e-12.*exp(1.5916e-2.*years)+255;
for i=1:N
tsurface(i)=albedo01(0.38,0.7,CO2(i),1.75);
end
plot(years,tsurface)
Excel warriors
Take a look at chapter 12 of the IPCC report (the bit on long-term climate change). Find the plot of global surface warming for different emissions scenarios (zero emissions and constant emissions).
\[ CO_2=1.71\times 10^{-12}\exp\left(1.5916\times 10^{-2}\times year \right)+255 \]
Take a look at a recent (controversial) Nature letter on atmospheric methane here by Whiteman et al. (you may need to be on campus / use vpn to download it). In addition take a look at this communication about the Whiteman paper.
In tutorial 5 you will have discussed how to estimate the amount of methane released into the atmosphere via the idea proposed in the Nature letter.
In the tutorial we will discuss your figures and what they mean, failure to bring the figures / contribute will result in 20% penalty for this assessment. We will also discuss the concept of the marine cloud brightening scheme of geoengineering. This MATLAB script: albedo_geo.m can be used to look at the effects of geoengineering on the global temperature, discuss how the albedo of a geoengineered planet is calculated.
Try the following:
albedo_geog=linspace(0.356,0.6,50);
co2ppm=385:5:2*385;
for i=1:length(albedo_geog)
for j=1:length(co2ppm)
tsurface(i,j)=albedo_geo(albedo_geog(i),1,co2ppm(j));
end
end
figure
pcolor(co2ppm,albedo_geog,tsurface);shading flat
You aim is to leave the tutorial with an understanding of what this means and why it has been considered as a means to mitigate rising CO2.
For the next tutorial you will prepare a PowerPoint as a group and present it in the final tutorial.
Final tutorial: Prepare a PowerPoint presentation of around 15 minutes to describe your findings. You may work as a group, but share out the work so each person has a chance to present something. Before the final tutorial let me know who contributed and where by email. In deciding your mark for this assessment I will consider: