| | 10 | - Numerical stability : |
| | 11 | - a semi-implicit would be possible with Q^{t+1}_{stream,i} and we agreed after some thinking that it can be made to conserve. |
| | 12 | - A local full implicit would also be possible. That would be local to the atmospheric grid. |
| | 13 | |
| | 14 | - Numerical tests |
| | 15 | - \tau=\lambda . g_stream is the key parameter. |
| | 16 | - \lambda and g_stream are probably not independent and thus it is only on the adjusted model that the maximal time step can be selected. |
| | 17 | - Current tests seem to indicate that the order of magnitude would be hours. |
| | 18 | - At high flow the Amazon flow at 6km/h. If an HUT has a dominant river segment of length 12km it would be traversed in two hours. |
| | 19 | |
| | 20 | - Topoindex or \lambda |
| | 21 | - This will be the key parameter. It describes the geometry of the HTU and needs to be aggregated from the high resolution data available. One also sees by the calculation above that the result of this integration will be key for the numerical stability. |
| | 22 | - Looking at the distribution of the topoindex over the domain simulated a reasonable maximum time step can be selected. |
| | 23 | |
| | 24 | - Floodplains |
| | 25 | - The fraction of flooded area in low flow conditions needs to be verified. |
| | 26 | - The explanations lacked the hypothesis on the transect perpendicular to the dominant river of the HTU. |
| | 27 | - The results of Ronny Lauerwald need to taken into account. |
| | 28 | |
| | 29 | - Conclusion |
| | 30 | - In the coming weeks Jan will advance on the topoindex aggregation and discuss the results with Agnès. |
| | 31 | - Once there is a satisfactory solution it will be presented to the group. |
| | 32 | - Then we will move to adjust the parameters (i.e. the three time constants (g)) to produce a usable model. |
| | 33 | - Then we can move to improve the numerical scheme. |
| | 34 | - If possible, there will be another meeting before Anthony travels back to Buenos Aires, else it will be later. |
| | 35 | |
| | 36 | |
| | 37 | |
