1. Background source: http://blog.thetechnonaut.com/?p=91 Better modeling through MATLAB: Connecting the auroral oval and the convection reversal boundary Mentors: Dr. Barbara Emery Dr. Delores Knipp Dr. Liying Qian Dr. Wenbin Wang Liam Kilcommons

2. Motive, Means, and Opportunity Granted, the aurora is beautiful, but why bother studying it? Actually, it's pretty important: Auroral particle precipitation associated with Joule heating, biggest energy input (besides solar radiation) into upper atmosphere Ionospheric disturbances and accompanying electric and magnetic fields cause: Power grid damage GPS inaccuracy Air travel re-route Pigeon loss You can't really get to the aurora, so where do you get your data? The aurora is pretty well studied, what else is there to know? In general: ground based remote sensing direct satellite measurements In this case: Defense Meteorology Satellite Program satellites – aurora data OMNI – satellite solar wind and ground based data from various sources Lots! Need better representation of atmosphere response to solar storms Models' representation of aurora needs to be improved (2 nd biggest energy input!)

3. What's this Joule thing? Most familiar incarnation: Wires getting hotter due to current flow (a.k.a ohmic heating) In upper atmosphere: Neutral atoms getting hotter due to collisions with energetic electrons and ions Drives 'neutral winds' Momentum transfer Strong solar storms (lots of precipitation and fast ion convection) cause worldwide changes in neutral winds ion veve vpvp vivi p e Neutrals Auroral precipitation: e- and p+ Ion convection: ions of O, O 2, N 2 etc

4. http://www.atigun.com/photography/aurora-photographs/47-aurora-photographs Duskward, anti-sunward, and other mysterious directional adjectives 18 12 6 0/24 Graphing as if one were looking down on the magnetic north pole Noon Midnight Dawn Dusk 80º 70º N Pole (90º) Angular coordinate = magnetic local time (MLT) Radial coordinate = magnetic latitude (MLAT) Not to scale

5. Ion Convection (or ion drift; the physics are the same) N S The Earth Looks familiar... 12 18 6 E B 0/24 View from the top Dawn-Dusk E-field! 12 18 0/24 6 E x B gives direction of v i Vi? The Ion Drift Velocity 12 18 0/24 6 vivi Convection Reversal Boundary (CRB) DMSP Satellite in a dawn-dusk orbit

6. Our Data Sources: DMSP Satellites IDM – Ion Drift Meter SSJ4 – Electron Flux +X indicates Along-Track Direction Y indicates Cross-Track Direction -Z is Earthward Direction

7. The beginning of this presentation, finally The (scientific) problem: TIE-GCM needs to calculate Joule heating Joule heating calculation requires relative locations (difference in radii) of CRB and auroral oval Positions change constantly and drastically with changes in solar wind TIE-GCM uses a constant (CRB 2 degrees duskward of auroral max flux) 18 12 6 0/24 N.P. My goal: Gather statistics on real life relative CRB and aurora positions Revise a MATLAB data display program to display the CRB and aurora positions for a particular pass of a particular DMSP satellite on a particular day.

8. How I Spent My Summer Vacation The (Programming) Problem: Need a flexible graphical display environment to visualize many kinds of data with different formats Why? 'Big picture' view of sun interacting with high latitude upper atmosphere The Specifics: Incorporate solar data, auroral flux, and ion drift velocities Visualize many different variables, whatever user wants Data NameData SourceDate Range (DMSP F-13) (on site) Frequency of Measurements FormatHeadache Rating Particle FluxDMSP SSJ41987-2005Every secondBinaryHigh Ion Drift VelocityDMSP IDM1987-2002Every 4 seconds ASCII Text Low OMNI Solar Wind Composite Various: ACE, Ground Based, etc. 1978 to Present Every HourASCII Text Low

9. No Need to Reinvent the Wheel, Just Figure Out How It Rolls FeatureOriginal Program: Data Plotter Desired Features for New Program Input Data TypeHeavily PreprocessedRaw Satellite Data Available TimesOnly Selected Events, 2004,2005 Any date for which data for desired plots exists Available DatasetsDMSP PF, IDM, SSJ CHAMP Neutral Density DMSP IDM, SSJ OMNI Solar Data Types of PlotsPolar, Cartesian CalculationsNoneConvection Reversal Boundary, Auroral Max Flux Points The foundation for our visualization tool was Data_Plotter: Matlab GUI ~ 6000 lines of code Originally designed to study neutral density response for specific solar events

10. No Need to Reinvent the Wheel, Just Figure Out How It Rolls The foundation for our visualization tool was Data_Plotter: Matlab GUI ~ 6000 lines of code Originally designed to study neutral density response for specific solar events FeatureOriginal Program: Data Plotter Desired Features for New Program Input Data TypeHeavily PreprocessedRaw Satellite Data Available TimesOnly Selected Events, 2004,2005 Any date for which data for desired plots exists Available DatasetsDMSP PF, IDM, SSJ CHAMP Neutral Density DMSP IDM, SSJ OMNI Solar Data Types of PlotsPolar, Cartesian CalculationsNoneConvection Reversal Boundary, Auroral Max Flux Points Biggest Challenge

11. My Solution: DMSP_Plot.m

12. CRB Max Flux

13. ....and then, last night, around 11 pm there were: (Preliminary) Results! CRB Max Flux CRB Max Flux

14. Progress Report FeatureOriginal Program: Data Plotter Desired Features for New Program Goal Met? Input Data TypeHeavily PreprocessedRaw Satellite DataYes Available TimesOnly Selected Events, 2004,2005 Any date for which data for desired plots exists Yes Available DatasetsDMSP PF, IDM, SSJ CHAMP Neutral Density DMSP IDM, SSJ OMNI Solar Data Yes Types of PlotsPolar, Cartesian Partially; Code still a little buggy CalculationsNoneConvection Reversal Boundary, Auroral Max Flux Points Partially; Partial functionality in seperate code

15. Future Work Perfect CRB and auroral maximum-flux-point finding algorithms Gather statistics on position of aurora center and CRB center and their relative radii as a function of solar wind parameters Compare results to modeled results Use results to devise empirical model for estimating center position and radii of auroral oval with respect to CRB Integrate model into TIEGCM for better Joule heating calculation THANK YOU! QUESTIONS?