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Project

The main topic of this REU research project is solar dynamo modeling. We are going to investigate the response of a solar dynamo subjected to stochastic fluctuations in the alpha effect. We will include two alpha effects, one operating in the bulk of the convection zone (Mean Field Alpha) and another one operating near the surface (Babcock-Leighton Alpha).

 

Daily log         [1-15 June]    [16-30 June]

3 June, 2008
Getting to know the campus, bureaucracy, computer setup and IDL tutorial (skipped!)

4 to 6 of June, 2008
Attending some IDL classes and the SVECSE 2008 conference. This summer work has been discussed and it will be all about dynamo simulations.

7 and 8 June, 2008
Hiking to the "M" mountain in the morning. Very beautiful sight seeing. Star reading papers on low order dynamos and the Surya code. Ilidio is going away and my "alone" journey at MSU starts.

9 June, 2008
Dário meet SURYA Dynamo Code, SURYA meet Dário! Start reading about computational implementation of partial differential equations, and start dwelling on SURYA's routines.

10 and 11 June, 2008
Playing whit the code and developing plotting programs in MATLAB to display the interesting stuff.

12 and 13 June, 2008
Meeting with Dybiendu and Andrés to talk about the work for the two next months. Start fiddling with the literature.

14 and 15 June, 2008
Hiking to CottonWood mountain. Again very beautiful sight seeing and I more snow than one would expect. Soacking shoes, some sun burns on the arms and a lot of good images recorded in my mind.

16 and 17 June, 2008
More literature... Trying to find out how to implement the needed things in the code. Calibration runs on the way...
RUN0 - Model ran with default parameters for tmax=100.

alphas alphas

Figures:
LEFT: dashed line is the Mean Field alpha effect and solid line is the Babcock-Leighton alpha effect as a function of radius.
RIGHT: both alphas as a function of radius and angle (theta)

18 June, 2008
Addition of two alpha effects to the code. See Runs_Log.txt for more details..

19 June, 2008
Correction of the alpha effects in the code, both radial and quenching term were revised.
Results in file RUN3

The used profile of the two alphas plotted from within the code (click to enlarge):
alphas

The result of changing some of the alphas thresholds. The number of grid points was also doubled. See Runs_Log.txt for more details.
RUN4, RUN5, RUN6

20 June, 2008
Exploring the space parameter for alMF0 and alBF0 in order to find a stable dynamo solution with our model.
Several runs done: RUN7 to RUN20. See Runs_Log.txt and Runs_Graphs for more details. No stable solution found. The debuging shows that the model has no problem with the doubled grid resolution implemented. The problem seems to reside in the quenching term of the alpha effects.

21 June, 2008
Hike to Bear Trap Canyon.

22 June, 2008
Continuing to explore the space parameter for alMF0 and alBF0. Stable dynamo action achieved in RUN22 for alMF0 and alBL0 of the order of 5. The period of the cycle is still to low and the latitudes where the eruptions first occur are of the order of 60º.

23 June, 2008
For low values of the two alpha effects we get a stable dynamo action. The period is still to small though. Check RUN24, RUN25 and RUN26.

28 June, 2008
The Runs_Graphs web page has been divided into (vol. 1) and (vol. 2) to facilitate the access to the more recent data. Several runs were made to find out the critical value of the initial amplitude of the alphaBL effect, i.e., αBL0 .

 

Daily Log   [July]

 

Other info

Solar Physics Group (SEI) from Instituto Superior Técnico (Lisbon, Portugal) (only in portuguese for now)

Personal Calendar (countdown)

Dário Passos, 2008