NDVI in February 1989
To be able to understand arguments used in discussions on global change, it is important to study the theory of global climatic systems, and to relate these theories to verifiable conditions in the real world.
Textbooks on environmental science, geography, biology, physics and chemistry can be very useful in providing theories.
Earth observation from satellites gives us the opportunity to investigate the real world and thus supplement these theories. We can make measurements of real world conditions and draw conclusions based on our theoretical understanding.
In the following exercises we will study the interrelationship between:
Sea surface temperature in the Atlantic
Vegetation coverage in Africa
Global wind systems
We will look at seasonal variations and how they are correlated.
The study will be based on Earth observation data obtained from Meteosat and NOAA satellites. The digital image data will be processed in easy to use image processing software.
The digital material
When working with weather and climate, especially global atmospheric circulation, images showing sea surface temperatures around Africa and images of the seasonal extension of vegetation can be included for illustration purposes in the same way as traditional, printed maps. Such material may be analysed in small groups or together in the classroom.
As the material is in digital form, it is extremely detailed and varied compared to printed maps and pictures, which typically present only a selection of what can be conveyed using digital information.
Digital image processing enables the data to be presented in many different ways, emphasising selected geographical information or other aspects. A temperature image may, for example, be processed into a thematic map with coloured temperature intervals.
The richness of detail contained in such geographical data provides exciting new opportunities for user-specified studies of particular phenomena.
The user can therefore make decisions on the basis of the study process' visual analysis and its outputs - for instance maps and other quantitative measurements. A fuller analysis may be based on this, but it will also include other relevant sources.
The student is given an opportunity to work with modern, high-tech mapping methods, which are increasingly important as environmental conditions continue to be mapped by Earth observation techniques.
Teacher and student roles
The aim is that, as much as possible, the student's work be independent and exploratory. The material invites the students to explore with the images, guided by detailed product goals set by the teacher, which should include description, analysis, and explanation.
The product goals will be important guidelines. Through the teacher demanding measurements and descriptions of specific conditions, the students will discover phenomena that demand analysis and explanation. In the process, the students may find surprising results that they (and maybe the teacher as well) will be unable to explain without further investigation.
The Internet, therefore, offers an oppportunity to communicate with experts in different fields and thus for students and teachers to obtain answers from experts to complicated geographical questions, which may be outside the teacher's scope of knowledge.
In order for students to be able to achieve the set goals of independent description, analysis and explanation, it is assumed that they have a basic knowledge of geographical terminology and methods learnt in the traditional classroom.
However, the students' sense of wonder and discovery will still provide strong motivation for independent in-depth study, under the watchful eye of their teacher.