1. Task 4 – Proposals and Questions
Combine digital maps and local measurements
ARCGIS as easy tool to apply for classification
Digital topographic maps are necessary
In situ survey of all sitings has to be mandatory
Without in situ survey the sealing is not possible to determine in a correct way
Interpretation of the definition of classes is not clearly
Regarding 3 circles: „and“ or „or“ relations
Representativeness: within a circle of 500 m, what about coastal sitings or peaks of mountains?

2. How to execute the CIMO-classification in DWD (Germany)
Laserlocater
Digital terrain model
Georeferenced maps /aerial photographs
Geographical information system
Obstacles
Shadowing effects
Lakes, sealing areas…
Natural horizon shadowing

3. Heat-sources in Surface

4. Point-Cloud from digital-terrain-system with 10m accuracy

6. Air Temperature an Humidity - Class 1
“A source of heat (or expanse of water) is considered to have an impact if it occupies more than 10% of the surface within a circular radius of 100 m surrounding the screen, makes up 5% of an annulus of m, or covers 1% of a 10 m radius area.“ (WMO-No. 8)
For discussion
It’s parameter class 1, if heat sources and expanse of water occupy
less than 10 % in a circular radius of 100 m (= 3142 m²) and
less than 5 % in an annulus of m (= 126 m²) and
less than 1 % of a 10 m radius area (= 3,1 m²).

7. Air Temperature an Humidity - Class 2
“A source of heat (or expanse of water) is considered to have an impact if it occupies more than 10% of the surface within a radius of 30 m surrounding the screen, makes up 5% of an annulus of 5-10 m, or covers 1% of a 5 m radius area.“ (WMO-No. 8)
For discussion
It’s parameter class 2, if heat sources and expanse of water occupy
less than 10 % in a circular radius of 30 m (= 283 m²) and
less than 5 % in an annulus of 5-10 m (= 12 m²) and
less than 1 % of a 5 m radius area (= 0,8 m²).

8. Air Temperature an Humidity - Class 3
“A source of heat (or expanse of water) is considered to have an impact if it occupies more than 10% of the surface within a radius of 10 m surrounding the screen or makes up 5% of a 5 m radius area.“ (WMO-No. 8)
For discussion
It’s parameter class 3, if heat sources and expanse of water occupy
less than 10 % in a circular radius of 10 m (= 31 m²) and
less than 5 % of a 5 m radius area (= 4 m²).

9. Representative of the relief
“A method to judge if the relief is representative of the surrounding area is the following:
Does a move of the station by 500 m change the class obtained?“ (WMO No. 8)
How do you solve it practically?
Tell it in steps.
Examples: Sites on the peak of a mountain or on the beach or coast.