Daily log [June] [July]
1 July, 2008
Defined new inital fields for all next runs. Here are some of the standard curves that will be used from now on.

Initial field configuration

Radial profiles for the two used alpha effects. The dashed line indicates the Mean Field (Parker) alpha effect and the solid line
indicates the surface Babcock-Leighton alpha effect. On the radial profile (right), the amplitudes are a free parameter.

The used magnetic diffusivity profiles: dashed line corresponds
to the toroidal diffusivity and the solid line corresponds to the
poloidal diffusivity.
9 of July, 2008
We increase the lower boundary of the radial alphaBL profile. Besides the typical low limit, RbBL = 0.95R, we tested 2 new lower limits ( RbBL = 0.97R, RbBL = 0.98R) for the radial profile of alphaBL given by:
We also tested the difference of using the standard Surya resolution (129x129) and doubling the resolution. Results here!
10 of July
Today I re-ran the diffusion process for a field near solar max. New relevant depths are now available to facilitate the analysis and choice of the proper lower cutoff of the alphaBL.
Also several runs where made to find the supercritical value of alphaMF0. First we switched off the buoyancy algorithm and afterwards we switched on the buoyancy but with a threshold of 8.0 instead of 0.8.
11 to 15 of July
The hunt continues. We are still looking for the supercritical dynamo solutions for the Parker Mean Field alpha effect.
16 of July
Run's database formated be subject to facilitate acess to the data:
- Just Babcock-Leighton alpha effect working
- Just Parker Mean Field alpha effect working
- Both alpha effect in simultaneous with several parameters chaging (almin, alMF0, alBL0, etc...)
17 and 18 of July
We tried to increase the magnetic diffusivity et1=0.1 instead of the standard et1=0.04 in the hope that this would solve some problems. The results are unstable and we were not able to achieve stabel dynamo solutions. See RUN126 to RUN129.
One problem with the runs made to detect the supercritical alphaMF was detected. In these runs the units of magnetic field are defined by the upper quenching of the alphaMF effect (since there is no alphaBL). We were using 0.1 to this upper quenching but that is only valid in the presence of the alphaBL where the units are defined by the alphaBL upper limit. Thus, the value of the upper cutoff of the alphaMF was updated to 1.0 in RUN130, to RUN134. Since the value of 1.0 corresponds now to 104G, the buoyancy algorithm is now correctly defined as 8.0, which corresponds to 8 x 104G. This seems to indicate that the first runs with the alphaMF upper cutoff at 0.1 and buoyancy at 0.8 are valid but there is another problem with those. The amplitude of the initial condition is set to 1.0, so if the field is getting quenched at 0.1, the initial condition will take to much time to go away. In the new runs (130 ~ 134) though, the amplitude of the initial conditions is 1.0 but so is the quenching term. Still getting one side oscillations...
21 to 24 of July
I detected an error with previous runs RUN100 to RUN103 (trying to find a dynamo solution just using alphaMF). The upper cutoff of the alphaMF quenching term was 10 (in code units) which corresponded to 10^5 G. This was corrected to 1 (in code units, or 10^4G). The runs were repeated and the results are now available in VOL2, with the new denomination (112b, 112c, 112d, 112e). Other RUNS with the same error were found but not repeated since the are in a range of alphaMF0 that is already in saturation. There "bad runs" are marked in gray and the images are fade.
I also started to implement the stochastic fluctuations in both the alpha effects. The results are available at VOL3. Some experiments with the buoyancy threshold have also been done. A modification was made to the base code, and now all variables that define limits or values of the saturation fields, etc, are presented in the beginning of the program. This makes it easier to check the code units.
The chosen reference run is RUN144 and the stochastic fluctuations are being applied to it.
25 to 26 of July
I have continued to run models with stochastic fluctuations but the obtained results are difficult to interpret for now. There is some saturation of the B_phi that I still don't know why it happens...
27 to 29 of July
Some results of the stochastic fluctuations simulations are coming out. There seem to be happening something strange with the parity though. Check VOL3, runs 165 to 174.
30 and 31 of July
Working on the final presentation.
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