Lucas Tarr



Lucas Tarr
Department of Physics
Montana State University
Bozeman, MT 59717-3840

Advisor: Dr. Dana Longcope


Hi! Every institution I've worked at since getting my PhD doesn't provide publically accessible staff directories, let alone work-associated personal websites. This makes it really difficult to figure out how to officially get in touch with me. Hence, I'm left updating my old webpage from graduate-student-days, and there is no personal website I can link you to. But, please do email me!

Here is my current contact info (March, 2020, should be good for a long while)

Dr Lucas A Tarr
Assistant Astronomer
National Solar Observatory
22 Ohia Ku St
Makawao, HI 96768
Room 219

If you try back in a bit, and this page may advance past 1997. Maybe get a little CSS going on, some nice looking headers, colors pleasing to the eye...mood lighting. But I won't lie. Probably not.

Curriculum Vitae

Research Interests

Current and recent projects

I use the Minimum Current Corona (MCC) to model the evolution of photospheric magnetic fields, which are themselves modeled at each time as a Magnetic Charge Topology (MCT). My major contribution has been to allow for regions with variable amounts of flux, the point of which is to study regions with emerging and/or "submerging" flux. I use quotes for the latter, while active-region scale emergence does seem to fit the cartoon of a large, inverted-U-shaped fluxtube crossing photospheric boundary, active-region scale submergence often does not. Instead, each concentrated footpoint appears to separately diffuse and break up into smaller, lower strength chunks by reconnection with the surrounding quiet Sun field.
I have currently applied this framework to a couple regions:


Here's an HMI magnetogram movie of NOAA Active Region 11112, which had a GOES M3.0 flare on October 16th, 2010.

And here's the same region, only now looking at 171 Angstrom data from AIA, rather than a magnetogram from HMI. Just for perspective, the tick marks in those movies are each about the size of Earth. These systems are big!

Test of java script movie of the same thing.

My recent work is a case study focusing on NOAA AR 11158.

List of observed supposed magnetic null points:
See here.


ADS Author query: Link

Talks and Posters

REU 2011 IDL Notes

Background and other things

I grew up on Whidbey Island in Puget Sound, which was an awesome place. I did my undergraduate work at Reed College in Portland Oregon, which was an awesome place. Now I study the sun while living Bozeman Montana, which is an awesome place. I have no complaints. I do a bunch of random other stuff, like play in the school wind orchestra, brew beer, hike, bike, fish, hunt, ski, snowboard, rock climb...blow bubbles...

And finally...

Emperical laws of the internet

Last Updated: May, 2013