Mark Miesch

Capturing a Sleeping Sun

Chart of early observations highlights two Maunder minima
Thursday, November 5, 2015

Three hundred years ago, the Sun began to wake up. For 70 years—from about 1645 to 1715—the Sun had been eerily quiet, with very few sunspots erupting on its surface.

Solar Cycle Variability Induced by Title Angle Scatter in a Babcockl-Leighton Solar Dynamo Model

Variability in sunspot number (SSN) in STABLE dynamo simulations of the solar cycle using the observed random scatter in sunspot pair tilt angle of 15 degrees. (a) 19 magnetic cycles are highlighted with red and blue representing the northern and southern hemispheres respectively. Red shaded areas indicate periods when the SSN in the north exceeds that in the south and blue shaded areas indicate the opposite. (b) Long-term SSN variability in the same simulation, exhibiting extended periods of low and high a
Saturday, April 15, 2017

We present results from a three-dimensional Babcock–Leighton dynamo model that is sustained by the explicit emergence and dispersal of bipolar magnetic regions (BMRs). On average, each BMR has a systematic tilt given by Joy’s law.

Driving Solar Giant Cells Through the Self-Organization of Near-Surface Plumes

Global 3D simulations of solar giant-cell convection.
Friday, March 24, 2017

Global 3D simulations of solar giant-cell convection have provided significant insight into the processes which yield the Sun’s observed differential rotation and cyclic dynamo action.

Meridional Circulation Dynamics in a Cyclic Convective Dynamo

Meridional flow variations induced by magnetic cycles.
Friday, March 24, 2017

Surface observations indicate that the speed of the solar meridional circulation in the photosphere varies in anti-phase with the solar cycle.

A Theoretical Study of the Build-up of the Sun's Polar Magnetic Field by Using a 3D Kinematic Dynamo Model

Time evolution of two bipolar magnetic regions (BMRs)
Monday, January 9, 2017

We develop a three-dimensional kinematic self-sustaining model of the solar dynamo in which the poloidal field generation is from tilted bipolar sunspot pairs placed on the solar surface above regions of strong toroidal field by using the SpotMaker algorithm and then the transport of this poloida

Babcock-Leighton Solar Dynamo: The Role of Downward Pumping and the Equatorward Propagation of Activity

Snapshots of poloidal field
Monday, October 10, 2016

The key elements of the Babcock-Leighton dynamos are the generation of poloidal field through decay and dispersal of tilted bipolar active regions and the generation of toroidal field through the observed differential rotation.

Convection in Oblate Solar-Type Stars

3D simulation image
Wednesday, July 13, 2016

We present the first global 3D simulations of thermal convection in the oblate envelopes of rapidly-rotating solar-type stars.

Welcome Bidya Binay Karak!

Portrait of Bidya Binay Karak

Bidya is no stranger to solar dynamo modeling. He earned his PhD in 2013 under the direction of Arnab Choudhuri at the Indian Institute of Science (IISc) in Bangalore.

A new Solar Superstorms documentary

NCSA Press Release–Several scientists from HAO at NCAR, including Yuhong Fan, Mark Miesch, Nick Nelson, and Matthias Rem


Star simulation image
Monday, February 6, 2012

Mark Miesch and colleagues Ben Brown (Univeristy of Wisconsin-Madison), Nick Nelson and Juri Toomre (University of Colorado-Boulder), and Allan Sacha Brun (National Center for Scientific Research, France) our making progress studying and connecting the solar dynamo and magnetic flux emergence.

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