1:45 PM - 3:15 PM
[O07-P21] The relationship between sunspot number and typhoons
Keywords:typhoon, sun, sunspot
Introduction
I wanted to connect meteorological phenomena and astronomy. Then I focused on the sun. The sun has been giving a huge amount of energy to the earth. And it should have effect on meteorological phenomena. On the other hand, typhoon is disaster that cause great damage to Japan every year. If it can be predicted, the damage can be reduced. For that reason, this study’s goal is to show that solar activity has effect on the number and power of typhoons.
Method
Sunspot number was used to see the solar activity. Sunspot number is index that shows how active the sun with sunspots that appear on it. Assuming that the relative number of sunspots is R, the observation method, observation device, and the coefficient for correcting individual differences between observers is k, the number of sunspot groups is g, and the total number of sunspots is s, it is defined this.
R=k10g+s (1)
The definition of typhoon is tropical cyclone with maximum wind speed of over 34 knots in western pacific. On this report it means that in the global. ACE (Accumulated Cyclone Energy) is index shows lifespan and power of tropical cyclone. In order to see the transition over a long period of time, the relative number of black spots, the number of typhoons, and the ACE from 1951 to 2020 are summarized with using the data published on the Internet.
Conclusion
Figure 1 shows the relationship between the sunspot number and the number of typhoons in the western pacific from 1951 to 2020, and Figure 2 shows the two-year time lag correlation since 1990. From these figures, it can be seen that the number of typhoons has changed two years later than sunspot number since 1990. The correlation coefficient was 0.47 at this time. Figure 3 shows the relationship between the sunspot number and the number of typhoons in the globe from 1951 to 2020, but the two-year time lag correlation seen in the western pacific was not found. Also relationship between sunspot number and ACE was not found. From these, It cannot be concluded that solar activity directly affects the typhoon, but at least it seems to be related. The two-year time lag correlation seen since 1990 was very weak, but clearly stronger than the others. However, it is limited in western pacific. Possible causes are factors that affect typhoons other than solar activity. For example, the El Nino phenomenon is known to be related to ACE. By examining the differences between the western pacific since 1990 that has two-year time lag correlation and other regions and times, we can investigate the effects of the sun in detail. The problem for the future is to consider other factors as well. Therefore, we will first investigate the meteorological difference between the time when there is a time lag correlation and the time when there is not it.
Acknowledgments
I would like to thank Ms. Sato for giving us appropriate advice from the beginning to the end and for her polite guidance.
References
National Astronomical Observatory of Japan https://www.nao.ac.jp/
Japan Meteorological Agency https://www.jma.go.jp/jma/index.html
Sunspot Index and Long-term Solar Observations www.sidc.be/silso/
International Best Track Archive for Climate Stewardship https://www.ncdc.noaa.gov/ibtracs/
National Hurricane Center
https://www.ncdc.noaa.gov/ibtracs/
Hiroko Miyahara 2009-12 Solar activity, cosmic rays, and climate change
I wanted to connect meteorological phenomena and astronomy. Then I focused on the sun. The sun has been giving a huge amount of energy to the earth. And it should have effect on meteorological phenomena. On the other hand, typhoon is disaster that cause great damage to Japan every year. If it can be predicted, the damage can be reduced. For that reason, this study’s goal is to show that solar activity has effect on the number and power of typhoons.
Method
Sunspot number was used to see the solar activity. Sunspot number is index that shows how active the sun with sunspots that appear on it. Assuming that the relative number of sunspots is R, the observation method, observation device, and the coefficient for correcting individual differences between observers is k, the number of sunspot groups is g, and the total number of sunspots is s, it is defined this.
R=k10g+s (1)
The definition of typhoon is tropical cyclone with maximum wind speed of over 34 knots in western pacific. On this report it means that in the global. ACE (Accumulated Cyclone Energy) is index shows lifespan and power of tropical cyclone. In order to see the transition over a long period of time, the relative number of black spots, the number of typhoons, and the ACE from 1951 to 2020 are summarized with using the data published on the Internet.
Conclusion
Figure 1 shows the relationship between the sunspot number and the number of typhoons in the western pacific from 1951 to 2020, and Figure 2 shows the two-year time lag correlation since 1990. From these figures, it can be seen that the number of typhoons has changed two years later than sunspot number since 1990. The correlation coefficient was 0.47 at this time. Figure 3 shows the relationship between the sunspot number and the number of typhoons in the globe from 1951 to 2020, but the two-year time lag correlation seen in the western pacific was not found. Also relationship between sunspot number and ACE was not found. From these, It cannot be concluded that solar activity directly affects the typhoon, but at least it seems to be related. The two-year time lag correlation seen since 1990 was very weak, but clearly stronger than the others. However, it is limited in western pacific. Possible causes are factors that affect typhoons other than solar activity. For example, the El Nino phenomenon is known to be related to ACE. By examining the differences between the western pacific since 1990 that has two-year time lag correlation and other regions and times, we can investigate the effects of the sun in detail. The problem for the future is to consider other factors as well. Therefore, we will first investigate the meteorological difference between the time when there is a time lag correlation and the time when there is not it.
Acknowledgments
I would like to thank Ms. Sato for giving us appropriate advice from the beginning to the end and for her polite guidance.
References
National Astronomical Observatory of Japan https://www.nao.ac.jp/
Japan Meteorological Agency https://www.jma.go.jp/jma/index.html
Sunspot Index and Long-term Solar Observations www.sidc.be/silso/
International Best Track Archive for Climate Stewardship https://www.ncdc.noaa.gov/ibtracs/
National Hurricane Center
https://www.ncdc.noaa.gov/ibtracs/
Hiroko Miyahara 2009-12 Solar activity, cosmic rays, and climate change