Third team meeting: Bern, 10-14 July, 2023
On-site participants:
Bhowmik, Cameron, Charbonneau, Karak, Lemerle, Norton, Petrovay, Sreedevi, Upton, Yeates
Online attendees:
Team members: Theo Chatzistergos, Jie Jiang, Dibyendu Nandi, Kalevi Mursula
Young researchers:
Beijing: Zhang Zebin, Luo Yukun, Wang Ruihui
Budapest: Mohammed Talafha, Guilherme Nogueira, Laura Magyar
Kolkata: Shaonwita Pal, Chitradeep Saha, Priyansh Jaswal, Suprabha Mukhopadhyay
Montreal: Christian Tibeault
Stanford/Bangalore: Bibhuti Jha
Varanasi: Akash Biswas, Pawan Kumar, Vindya Vashishth
Monday
09:00-12:30 informal discussions
14:00 opening, brief self-intro of participants;
summary of work done by the team since 2019
break
15:30 Topic 1: Modelling the AR source
Robert Cameron:
Joy’s law and the alpha effect,
Anu Sreedevi:
Origins and evolution of BMR
Tuesday
9:30 Topic 2: The AR source: observations
Ruihui Wang:
Catalogue of individual ARs as source term in SFT models
Pawan Kumar:
Effect of irregular properties of BMR on the polar field and solar cycle
variability
break
Anthony Yeates:
Active regions in historical data
14:00
Akash Biswas:
Exploring the reliability of polar field rise rate as a precursor for
an early prediction of solar cycle
Topic 3: Meridional flow
Prantika Bhowmik:
Memory of Solar Cycles in Fluctuating Meridional Circulation
Mohammed Talafha:
Effect of active region inflows on polar field buildup
Wednesday
9:30 Topic 4: The underlying dynamo
Kalevi Mursula:
Hale cycle in solar hemispheric radio flux and sunspots:
Evidence for a northward shifted relic field
Priyansh Jaswal:
Discovery of a causal relation: the decay rate of the Sun’s
dipole moment is related to the rate of rise of the following
sunspot cycle
break
Jie Jiang:
Constraining the outer boundary condition for Babcock-Leighton
dynamo models
14:00 The underlying dynamo -continued.
Vindya Vashishth:
Grand minima and maxima in chaotic regimes of solar dynamo:
Comparison with observations
Chitradeep Saha:
Origin of supermodulation in the Sun’s activity cycle
break
Paul Charbonneau:
Behavior of Babcock-Leighton-type dynamos in the moderately
to strongly supercritical regime, including interaction with
low-amplitude stochastic noise.
19:00 Banquet
Restaurant Rosengarten
https://www.rosengarten.be/en
Thursday
9:30 Cycle prediction
Lisa Upton:
Comparison of precursor based predictions of cycle 25
Kristof Petrovay:
The Cycle 25 tension
Shaonwita Pal:
Prediction of Solar Cycle 25 using algebraic quantification of sunspots
14:00
Alex Lemerle:
Systematic errors in cycle prediction
Further topics:
Bidya Karak:
Hemispheric asymmetry / coupling / nonlinearity
Aimee Norton:
On flux emergence rate in active regions
Lisa Upton:
Joy’s law in historical simulations
Friday
09:00-12:00 team plenary discussion & official closing of project
On day 2 we decided to extend the team’s activities to experimental studies of the advection of passive scalars in a flow. Site testing indicated a section of the Aare river north of Bern’s old town as an optimal location. Some team members volunteered for test particles. Here are the brave ones:
The bravest of the brave combined this with an aerodynamic pilot project:
[click to play movie]