...
Make a note of the latitude and longitude coordinates. The highest rainfall area was over the Cévennes mountains, approximately 44°25′34″N 03°44′21″E.
Edit prob_tp_compare.mv and set the location:
| Code Block |
|---|
location=[44.0,4.1] # [ lat, lon ] -- use your own values! |
...
| Code Block | ||
|---|---|---|
| ||
param="tp" station=[44.0,4.0] # !use your own values! expID="ens_oper" |
Make sure the steps value is set correctly to +96 hours (00Z 24th Sept):
| Code Block |
|---|
steps=[2012-09-24 00:00,"to",2012-09-24 00:00,"by",6] |
Make sure useClusters='off'.
Do the same for the 2016 operational ensemble reforecast:
...
| Panel | ||
|---|---|---|
| ||
Q. What can you say about the spread? |
...
The paper by Pantillon et al, describes the use of clustering to identify the main scenarios among the ensemble members.This exercise repeats some of the plots from the previous one but this time with clustering enabled.
Using clustering will highlight the ensemble members in each cluster in the plots.
...
- Constructyour own qualitative clusters by choosing members for two clusters
- Generate clusters using principal component analysis (similar to Pantillon et al).
Enter the folder 'Clusters' in the openifs_2018 folder to begin working.
Task 1: Create your own clusters
...
It is usual to create clusters from z500 as it represents the large-scale flow and is not a noisy field. However, for this particular case study, the stamp map of 'tp' (total precipitation) over France is also very indicative of the distinct forecast scenarios.
You can choose any parameter to construct the clusters from.
How to create your own cluster
Right-click 'ens_oper_cluster.example.txt' and select Edit (or make a duplicate)
...
You can create multiple cluster definitions by using the 'Duplicate' menu option to make copies of the file for use in the plotting macros..
The filename is important!
The first part of the name 'ens_oper' refers to the ensemble dataset and must match the name used in the plotting macro.
The 'example' part of the filename can be changed to your choice and should match the 'clustersId'.
As an example a filename of: ens_both_cluster.fred.txt would require 'expId=ens_both', 'clustersId=fred' in the macro.
Plot ensembles with your cluster definition
...
Use the clusters of ensemble members you have created in ens_oper_cluster.example.txt.
...