Data assimilation setting
The experiment setting is similar to Twin Experiment 4, but where EnKF-GS is run over three different periods: run 1: Cold Start - 01/05/2015, run 2: 01/05/2015-01/10/2015, and run 3: 01/10/2015 - 01/01/2016. Moreover, run 2 and run 3 started with the last Kalman gain from the last analyses in the previous runs. In this way, unlike in Twin Experiment 4, the smoothing of the Kalman gain really took place. Here the parameter time regularisation per day is set to 0.95. It means that when analysis time interval is 7 days, the Kalman gain of a previous analysis gets a weighing/smoothing factor of 0.698.
Results
At assimilation station
Time series
A significant overshoot occurs after the first analysis in the period of when CHG and CHC are non zero.
RMSE over 51 analyses
At all stations