The Location and Evolution of the South Atlantic Anomaly as Observed - PowerPoint PPT Presentation

The Location and Evolution of the South Atlantic Anomaly as Observed by SOLSTICE Laura O’Connor (University of Michigan) Mentor: Marty Snow (Laboratory for Atmospheric and Space Physics)

Outline • Background information • Description of the region of interest • Motivation for the project • Introduction to the SOLSTICE Instruments • Details of the SOLSTICE Data • Data analysis procedures • Future plans 2011 REU in Solar and Space Physics Outline The SAA SOLSTICE Data Details June 2011 Future Plans

Background • Van Allen Radiation Belt discovered in 1958 • Three modes of motion: rotation around the magnetic field lines, drift, bounce • Mirroring is determined by the strength of the magnetic field Van Allen Radiation Belt Diagram Image Credit: http://www-spof.gsfc.nasa.gov /Education/Iradbelt.html (which is increasingly stronger closer to the Earth’s surface) 2011 REU in Solar and Space Physics Outline The SAA SOLSTICE Data Details June 2011 Future Plans

Background • Region Of Study: South Atlantic Anomaly (SAA) • SAA is a part of the Van Allen radiation belt • Caused by an offset of the Earth’s magnetic field • Sources say the SAA is moving by 0.28 degrees/year Radiation Belts westward and 0.08 Image Credit: Introduction to the Space Environment by Thomas F. Tascione degrees/year northward 2011 REU in Solar and Space Physics Outline The SAA SOLSTICE Data Details June 2011 Future Plans

Motivation • All satellites in low Earth orbit are influenced by the South Atlantic Anomaly • Instruments and other electronics aboard can be susceptible to the regions high radiation 2011 REU in Solar and Space Physics Outline The SAA SOLSTICE Data Details June 2011 Future Plans

Introduction to SOLSTICE • SOLSTICE: SOLar STellar Irradiance Comparison Experiment • There have been two SOLSTICE experiments, one aboard UARS (1991- 2005, 600km) and one aboard SORCE (2003-Present, 645km) • Each SOLSTICE on SORCE is made up of two Instruments: A (primary mode: Middle Ultraviolet) and B (primary mode: Far Ultraviolet) SORCE Spacecraft • SOLSTICE observes the Sun, 18 stars, Image Credit: http://lasp.colorado.edu /sorce/index.htm dark regions of space 2011 REU in Solar and Space Physics Outline The SAA SOLSTICE Data Details June 2011 Future Plans

Introduction to SOLSTICE MUV Detector FUV Detector SOLSTICE Instrument aboard SORCE Image Credit: http://lasp.colorado.edu/sorce/index.htm 2011 REU in Solar and Space Physics Outline The SAA SOLSTICE Data Details June 2011 Future Plans

Data Details • There are two types of data available from SOLSTICE – Inactive Channel Data: SOLSTICE A (FUV Detector) and SOLSTICE B (MUV Detector) from February 4, 2003 to July 1, 2011 – Stellar Dark Region Data: SOLSTICE A (FUV Detector) and SOLSTICE B (MUV Detector) dark region data from February 22, 2003 to July 01, 2011 • Primary data for this study: Inactive channel data for the SOLSTICE A FUV Detector 2011 REU in Solar and Space Physics Outline The SAA SOLSTICE Data Details June 2011 Future Plans

Data Details 2011 REU in Solar and Space Physics Outline The SAA SOLSTICE Data Details June 2011 Future Plans

Data Details 2011 REU in Solar and Space Physics Outline The SAA SOLSTICE Data Details June 2011 Future Plans

Data Analysis Data Collection and Organization Selection of Count Rate Data in 5 Day Intervals Conversion to Geomagnetic Coordinates Average All Data in 5 Day Interval into 1x1 Degree Bins End Result: 360x180 Data Array 2011 REU in Solar and Space Physics Outline The SAA SOLSTICE Data Details June 2011 Future Plans

Data Analysis Select 1 ° Latitude Strip 2011 REU in Solar and Space Physics Outline The SAA SOLSTICE Data Details June 2011 Future Plans

Data Analysis Fit Gaussian To Latitude Strip 2011 REU in Solar and Space Physics Outline The SAA SOLSTICE Data Details June 2011 Future Plans

Data Analysis Fit 2nd Gaussian To Peaks 2011 REU in Solar and Space Physics Outline The SAA SOLSTICE Data Details June 2011 Future Plans

Data Analysis Latitude Extent Center of SAA 2011 REU in Solar and Space Physics Outline The SAA SOLSTICE Data Details June 2011 Future Plans

Results Center of SAA: Longitude 30 Longitude (Degrees) y = -0.3283x + 25.566 28 26 24 22 20 0 1 2 3 4 5 6 7 8 9 Time Since 2003 (Years) Center of SAA: Latitude -12 y = 0.1602x - 18.183 Latitude (Degrees) -14 -16 -18 -20 -22 0 1 2 3 4 5 6 7 8 9 Time Since 2003 (Years) 2011 REU in Solar and Space Physics Outline The SAA SOLSTICE Data Details June 2011 Future Plans

UARS • UARS SOLSTICE (1991- 2005): Stellar Dark Rate Data • Extends time of study through two decades • No Inactive Channel UARS Spacecraft Image Credit: http://umpgal.gsfc.nasa.gov/ 2011 REU in Solar and Space Physics Outline The SAA SOLSTICE Data Details June 2011 Future Plans

UARS 2011 REU in Solar and Space Physics Outline The SAA SOLSTICE Data Details June 2011 Future Plans

UARS 2011 REU in Solar and Space Physics Outline The SAA SOLSTICE Data Details June 2011 Future Plans

Results With UARS Center of SAA: Longitude 35 Longitude (Degrees) 30 25 20 y = -0.2997x + 626.14 15 10 5 0 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 Years Center of SAA: Latitude 0 Latitude (Degrees) -5 y = -0.0705x + 124.46 -10 -15 -20 -25 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 Years 2011 REU in Solar and Space Physics Outline The SAA SOLSTICE Data Details June 2011 Future Plans

Future Directions Magnetic Field Strength at Vassouras 23650 23600 23550 y = -18.389x + 60258 23500 Field Strength (nT) 23450 23400 23350 23300 23250 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 Years 2011 REU in Solar and Space Physics Outline The SAA SOLSTICE Data Details June 2011 Future Plans

Future Directions 2011 REU in Solar and Space Physics Outline The SAA SOLSTICE Data Details June 2011 Future Plans

Future Directions 2011 REU in Solar and Space Physics Outline The SAA SOLSTICE Data Details June 2011 Future Plans

Future Directions Longitude Extent 20 Longitude Extent (Degrees) y = 1.0347x - 2062.8 15 10 5 0 -5 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 Years Latitude Extent 8 Latitude Extent (Degrees) y = 0.1358x - 265.6 7.5 7 6.5 6 5.5 5 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 Years 2011 REU in Solar and Space Physics Outline The SAA SOLSTICE Data Details June 2011 Future Plans

Future Directions 2011 REU in Solar and Space Physics Outline The SAA SOLSTICE Data Details June 2011 Future Plans

Future Directions 2011 REU in Solar and Space Physics Outline The SAA SOLSTICE Data Details June 2011 Future Plans

Future Directions • Possible correlation between SAA and geomagnetic storms • Time Lag – radiation in the belts takes a while to build up 2011 REU in Solar and Space Physics Outline The SAA SOLSTICE Data Details June 2011 Future Plans

Conclusions • The SAA is moving at a rate of 0.3283 degrees/year westward and 0.1602 degrees/year northward • The SAA is increasing in extent by 0.1358 degrees/year in latitude and by 1.0347 degrees/year in longitude, when data from UARS is included in the calculation • There are possible correlations, to be examined more closely, between the South Atlantic Anomaly and geomagnetic activity, solar cycle and the weakening of the Earth’s magnetic field. 2011 REU in Solar and Space Physics Outline The SAA SOLSTICE Data Details June 2011 Future Plans

THANK YOU Any Questions?

References • Image Credit: http://chamorrobible.org/gpw/gpw-200911.htm • Image Credit: http://lasp.colorado.edu/sorce/index.htm • “Introduction to the Space Environment”, Thomas F. Tascione, Orbit Foundation Serie • sTrivedi, N.B., Pathan, B.M., Schuch, Nelson J., Barreto, M., Dutra, L.G. “ Geomagnetcic phenomena in the South Atlantic anomaly region in Brazil”, Adv. in Space Res., 36 (2005) 2021-2024 • Badhwar, Gautam D., “Drift rate of the South Atlantic Anomaly”. Journal of Geophysical Research, vol. 102, no. A2, pp. 2343-2349, 1997 doi:10.1029/96JA03494 2011 REU in Solar and Space Physics References Backup Slides