| Date | November 2017 | Marks available | 5 | Reference code | 17N.2.SL.TZ0.6 |
| Level | SL | Paper | 2 | Time zone | no time zone |
| Command term | Discuss | Question number | 6 | Adapted from | N/A |
Question
Weather forecasters use computer models which are able to simulate future weather patterns. These forecasts were originally limited to the near future. However, modern systems can now produce long range forecasts.
The simulation of the weather forecasting models produces specific data which can be output in a variety of ways.
Suggest two reasons why these simulations have improved both in their accuracy and their range.
Suggest why forecasts become less accurate the more long range they become.
Discuss whether historical data can be accurately used to forecast future weather.
Define the term visualization.
With the help of examples, discuss how the development in the way such data is visualized has made the results of these simulations more accessible to the general public.
Markscheme
Award up to [4 max].
Modern computer systems have become increasingly more powerful;
Which allows more complicated systems to be simulated;
In a short/acceptable period;
The understanding of (the science of) weather has steadily improved/more historic weather patterns can be accessed;
Allowing more accurate modelling to take place;
More data can now be retrieved;
Through satellites, ground stations etc.;
Only the major/known variables can be input into the model;
Approximations have to be made to represent complex processes;
These or other minor/unknown variables will not have a significant effect in the short term;
But will have (unknown) effects in the long-term/small errors have a cumulative effect over the long-term/butterfly effect;
Award [1] for each valid point discussed, and a further [1] up to [5 max] for a good expansion of this point.
Investigate past weather patterns in order to see if past forecasts were correct or not and make adjustments to your model appropriately;
Look at specific events in the past (e.g. appearance of El Nino) to see how they affected future weather patterns in different areas, and then apply this to new occurrences of these events;
However, historical data does not take into account new factors, such as how carbon emissions are contributing to global warming;
The representation of (abstract) data;
In a way that is understandable by humans;
Standard simulations produce numerical values (which are not easily understood by the general public);
Modern simulations include
Graphics that are related to the data output;
e.g. rain drops/a smiling sun;
CGI/animation can produce motion;
e.g. showing a belt of rain crossing the country;
Which are more easily understood by the general public;
