Melissa, Connie, Melissa, Jieyi, Ambereen, Dorothy King Edward VI High school for Girls

Sunspots: what are they?  Galileo Galilei was the first to make observations of sunspots with his telescope in 1610.

Coronal mass ejections

Butterfly diagrams

 We think that higher solar activity results in a lower intensity of cosmic rays.

Comparing data between 2009 and : This year has a relatively low number of sunspots: it is around the solar minimum. 2014: There is a greater number of sunspots.

Hypothesis Before we began to collate our data, we hypothesised that at the solar maximum there would be more muons detected, due to the increase in solar magnetic field strength. Thus, the sun would 'focus' the cosmic rays toward us.

Solar field strength Polar field (G)

Station Number 502 Based in Amsterdam, In the science park in Amsterdam- Oost Station 502: Universiteit Van Amsterdam

Analysing the data  Download hourly data  Average data for every month - excluding anomalies  Formula ‘ =AVERAGE(…)  Average data for the years - excluding anomalies  Work out standard deviation

Conclusion of data  Ratio of the difference in the averages to the combined standard deviation :  Ratio of the difference in the averages to the combined standard deviation after exception of anomalies :  Enough to call a difference in number of events More events in the solar minimum than the solar maximum

Results – station 502 <= With anomalies Without anomalies =>

Station Number 501 Nikhev Station 501 (Nikhev) Located very close to Station 502 Both in the Science Park

Analysing the data  Again, downloaded hourly data  This time, over full period from 2009 – 2014  Anomalies deleted  Monthly averages calculated  (formula =AVERAGE(…))

 Standard deviation calculated April 2009 was the only month in the six year period for which the detector gave no reliable data Statistically significant result – Ratio of the difference in the averages to the combined standard deviation

Station 501 ( ) The graph shows the average monthly count rate from the solar minimum (2009) to the solar maximum (2014) There is a clear decrease in the count rate from 2009 to 2014 (confirmed by the statistical analysis), appearing to support Parker’s 1963 theory of cosmic-ray modulation by solar wind MINIMUMMAXIMUM

Looking at sunspot data  Sunspot data for years 2009 – 2014 downloaded  Monthly averages calculated  Graph plotted MINIMUMMAXIMUM

Comparing cosmic ray intensity to sunspot data  Graphs illustrate a clear anti- correlation  Support theory that as solar activity increases, cosmic ray intensity decreases SUNSPOT DATA MINIMUMMAXIMUM

Detector 13 (Hervormd Lyceum West – Amsterdam, Netherlands)

2009 = Months missing: most of July, August and September. No data for October, November, December 2014 = Full year of data Detector 13 (Hervormd Lyceum West – Amsterdam, Netherlands)

Graphs (2014)

Graphs (2009)

Statistical Analysis Averages: 2009 = (Maximum) 2014 = (Minimum) Difference = Ratio of the difference in the averages to the combined standard deviation=

Station 8103: Investigating the Solar Cycle  Aim: To determine periods of high and low solar activity. Year Month Day Total North South Average 7 days Jieyi & Melissa

Graphs October 2009 October 2014

Graphs (Cont.) Minimum (2009) This shows that the lowest average value of the week was on October 18 th Despite the values for this week not being the lowest they could have been, we needed to ensure the same week was chosen as in 2014 (maximum). Maximum (2014) This shows the highest average value of the week was on October 21 st This was also the highest value of the whole solar cycle (as shown by the scatter graph on the last slide). October 21 st 2014 October 18th 2009

Data Analysis  The process involved: Finding the total sum of each day Averaging the whole week Calculating the standard deviation of both years Comparing the results:  ΔS ~ =SQRT(B29^2+M29^2)  ΔN ~ =M28-B28  The ratio between the two should be above 3.

Data Analysis (Cont.)

Conclusion & Evaluation  Final value of 14: very much suggests that high sunspot activity is linked with low cosmic ray detections.  In order to obtain more reliable results (reducing variables): Different time of year Different detector Collect weather data

Final Conclusion  Detector 501 = a statistical difference above 3 (more muons detected at solar minimum)  Detector 13 = a statistical difference of 1.9 (more muons detected at solar minimum)  Detector 502 = a statistical difference of 1.4 (more muons detected at solar minimum)

Conclusion continued… - Detector 8103 = a statistical difference of 14 (more muons detected at solar minimum) - If the ratio of the difference in the averages to the combined standard deviation is above 3, this shows a significant statistical difference.