1. Solar weather consists of the Sun’s effects upon its planetary system and the solar activities it causes. Solar activities, such as flares and CMEs, form through sunspots. Sunspots are areas characterized by intense magnetic and electromagnetic activity between convergent magnetic fields of opposing poles. Sunspots have been used to predict future solar activities, such as solar flares and CMEs, due to their cyclic correspondence with the 11-year solar cycle. Solar flares usually occur near sunspots where the strong magnetic field forms a pathway between the corona (Sun’s outer layer) and the core. Sunspot numbers and solar flare numbers are directly proportional and vary annually in accordance with each other. Solar flares and CMEs are eruptions occurring on the Sun’s surface that release up to 6×10 25 J. Solar flares emit ultraviolet radiation, x-rays, visible light, and CMEs. CMEs include charged particles such as protons and electrons that are released. Fluctuations in solar radiation affect the Earth’s atmosphere and magnetosphere which in turn cause auroras. Auroras are natural light events produced when the Earth’s magnetosphere deflects the Sun’s charged emissions. Solar flares are classified using a scale based on their power. X-class flares, considered the strongest types of flares, have a range of power that extends from 10 -4 to 10 -3 W/m 2. M-class flares, which are the second strongest flare type, range from 10 -5 to 10 -4 W/m 2. C- class flares range from 10 -6 to 10 -5. B-class flares range from 10 -7 to 10 -6. A-class flares, which are the weakest, have a range of 10 -8 to 10 -7 W/m 2. Often following a solar flare is a CME. The purpose of this study was to correlate solar flare and CME intensity. Sponsors: National Aeronautics and Space Administration (NASA) Goddard Space Flight Center (GSFC) Goddard Institute for Space Studies (GISS) New York City Research Initiative (NYCRI) CUNY Queensborough Community College Contributors: Kevin Chen (HSS) Ariane Marchese (HSS) Matthew O’Connell (HSS) Adam Carbone (UG) Michael Hirschberger (UG) Mr. Daniel Mezzafonte (HST) Dr. Paul Marchese (PI) Time specific solar images from the Solar and Heliospheric Observatory (SOHO), Solar Terrestrial Relations Observatory Ahead (STEREO A), and Solar Terrestrial Relations Observatory Behind (STEREO B) satellites were studied. SOHO, STEREO A, and STEREO B provided varying visual perspectives of the Sun. The triangulation method was used to determine if a CME was Earth directed. Data for x-ray flux from solar flares, background x-ray flux and CME velocity were obtained from Geostationary Operational Environmental Satellite (GOES-13) and SOHO. Total daily x-ray flux (watts/meter 2 ) was calculated for 2000-2012. Daily CME energy was calculated by squaring its velocity (km 2 /s 2 ) for 2000-2012. X-ray flux was statistically correlated to CME energy and graphed. http://iswa.ccmc.gsfc.nasa.gov/IswaSystemWebApp/ http://www.solarmonitor.org/ ftp://ftp.ngdc.noaa.gov/STP/space-weather/solar-data/solar-features/solar-flares/x-rays/goes/ http://www.swpc.noaa.gov/ftpdir/warehouse/2012/2012_DPD.txt http://swc.gsfc.nasa.gov/main/score The Relationship Between Solar Flares and Coronal Mass Ejections Figure 3: The x-ray flux of the years 2000-2012 correlates with the number of flare occurrences shown in figure 2. The highest flux levels occurred in 2001, a solar maximum. After 2001, a decline can be observed as the data approach 2008, the solar minimum. After 2008, there is a rise in flux as the graph approaches 2013, which is another solar maximum. Please note that this graph uses the logarithmic scale. Figure 4: X-ray flux and CME energy for the period of 2000-2012. Both datasets show a slight decrease between October 2006 and late 2008 and an increase between late 2008 and April 2012. Correlation coefficient is 0.16. The results of this preliminary study weakly support the hypothesis for 2000-2012. Although the correlation coefficient calculated over the entire time series was 0.16, coefficients were greater in some cases when calculated by year, especially around the years of solar maxima. This is due to the increase in magnitude and fluctuation of x-ray flux and CME energy. Future work will include further examining the correlation between these two data sets by studying specific periods in which high-intensity flare events occurred. In addition, a lag period between the two data sets will be investigated by taking into account satellite locations and CME velocities. Finally, a more comprehensive data set will be obtained for CME energy, since there were many days in which CME measurements were not available. Abstract Solar flares and their associated coronal mass ejections (CMEs) are an integral part of solar weather that can have profound effects on Earth’s atmosphere. The charged particles emitted by strong CMEs as well as strong x-ray fluxes produced by solar flares can cause damage to satellites, disrupt radio and GPS signals, and strain power grids. It is critical to understand how solar flare intensity influences the magnitude and occurrence of CMEs so as to minimize and prevent the negative effects that could result from them. This study seeks to further this flare-to-CME relationship. To do this, x-ray flux, a defining element of solar flare intensity, was correlated graphically and numerically with CME energy for the years 2000-2012. X-ray flux data used in this correlation consisted of both background and solar flare flux, which were both summed together for each day of each year. CME energy was obtained by squaring the 2nd-order speed at 20 Rs (solar radii) and summing these squared values for each day of each year. Our results show that for the entire time series of 2000-2012, a 0.16 correlation exists between the two data sets. For individual years, the correlation coefficient increased for years around maxima (0.48 for 2003, 0.40 for 2001, 0.31 for 2012). These preliminary results suggest a moderate correlation between the intensities of the two data sets when examined around solar maxima. Introduction Materials and Methods References Results Conclusion and Future Work Figure 2: The annual frequency of solar flares through the years 1975-2012 displays a cyclic trend that correlates with the 11-year solar cycle. Please note that this graph uses the logarithmic scale. Figure 1: STEREO (Solar Terrestrial Relation Observatory) is made up of two satellites ( STEREO A and STEREO B) that orbit the Sun. Figure 5: X-ray flux and CME energy for 2001, the solar maximum. Similar trends in the two data sets can be seen starting in March. Correlation coefficient is 0.40. Figure 6: X-ray flux and the CME energy for 2003. Similar trends in the data sets occur. Correlation coefficient is 0.48, which was the highest observed in our study. Figure 7: X-ray flux and the CME energy for 2012, a solar maximum. Similar trends in the data sets occur. Correlation coefficient is 0.31.