Figure 1
Data assimilation scheme. (a) At each cycle k of the KF, an analysis (red squares) is calculated from the comparison of the background (blue dots) with the observation (green stars). (b) At each cycle k of the EnKF, an ensemble of analyses (red squares) is calculated from the comparison of each background (blue dots) with the observation (green stars).
Table 1
Set up of the twin experiments for the model parameters (MP), the boundary conditions (BC) and the initial condition (IC).
| MP | BC | IC | ||||
|---|---|---|---|---|---|---|
| ρ | ν | u_west | y | x | magnitude | |
| Reference | 1.0 | 1.0 | 20.0 | 10 | 10 | 1.0 |
| Control 1 | 5.0 | 0.5 | 10.0 | 10 | 10 | 1.0 |
| Assim 1 | и[0.5, 8.5] | и[0.2, 1.2] | и[0.0, 20.0] | 10 | 10 | 1.0 |
| Control 2 | 1.0 | 1.0 | 20.0 | 12 | 8 | 2.0 |
| Assim 2 | 1.0 | 1.0 | 20.0 | и[10, 14] | и[6, 10] | и[1.0, 3.0] |
Figure 2
Final tracer field (t = 0.1 s) of the reference experiment. The green cross symbols show the locations of the observations.
Figure 3
Test case 1: root mean square of the final tracer field error (t = 0.1 s) with respect to the reference experiment. The green cross symbols show the locations of the observations.
Figure 4
Test case 1: histogram of the parameter values before (blue) and after (red) DA analysis.
Figure 5
Test case 2: root mean square of the final tracer field error (t = 0.1 s) with respect to the reference experiment. The green cross symbols show the locations of the observations.
Figure 6
Test case 2: histogram of the source position and magnitude before (blue) and after (red) DA analysis.
Figure 7
Smurf architecture. The different colors refer to the different classes: Experiment (blue), Model (purple), Assim (red), Instrument (green) and Perturbation (orange). Lines ending with an arrow indicate the next step in the chain, whereas lines ending with a dot indicate a call to another class method. Dashed lines are specific to ensemble systems such as the EnKF.