1:45 PM - 3:15 PM
[O11-P118] Relationship between the solar seeing fluctuations and the upper atmosphere movement
Keywords:Seeing, Solar Image, Upper Atmosphere, Wind Direction, Solar Altitude
1. Background and Objective
This research aims to investigate whether solar seeing fluctuations reflect the movement of upper atmospheric winds. The study observes the phenomenon where solar seeing fluctuates in different directions due to atmospheric layers, and seeks to clarify the relationship between wind direction in the upper atmosphere and solar seeing.
2. Methods
2.1 Experiment 1 (Measurement of Solar Image Fluctuations)
On May 29, 2024, between 16:40 and 16:41, a one-minute video of the Sun was captured using a telescope with an AstroSolar filter on the school rooftop. The video was converted into 900 still images, with each image showing 8 directions from the center of the Sun (Figure 1). To determine the true orientation, the white light solar image and sunspot positions were compared with the National Astronomical Observatory of Japan’s data and the image was rotated to align with the celestial North Pole. Using spherical trigonometry (cosine rule), the solar altitude (24°), azimuth (280°), declination (δ=6.33°), and the latitude of the observation site (φ=35°) were used to calculate the angle γ = 54°. The image was then rotated 54° to correct for orientation (Figure 2). The distance from the center of the Sun to the circumference was measured in pixels for each direction.
2.2 Experiment 2 (Solar Seeing Observation at Solar Noon)
On November 9, 2024, between 13:40 and 13:41, a one-minute video of the Sun was captured at solar noon using the same method as Experiment 1. The data was then processed (Figure 3).
2.3 Experiment 3 (Relationship between Solar Altitude and Seeing Fluctuations)
From 9:30 to 14:30 on March 30, 2025, a video of the Sun was captured every hour and converted into 500 still images. The same image processing method as in Experiment 1 was applied (Figure 4).
2.4 Measurement Accuracy
ImageJ software was used to analyze brightness changes in the solar image and extract the contour lines clearly. Smoothing interpolation was applied to areas with gradual brightness changes, and the positions of the contours were measured with an accuracy of 0.2 pixels.
3. Results
Figures 5 to 12 show the wind direction at high altitudes for the day, based on data from the Japan Meteorological Agency.
3.1 Experiment 1
Figure 5 shows that the radial values in directions ①-② and ⑦-⑧ were more disturbed than those in other directions.
3.2 Experiment 2
Figure 6 indicates that the radial values in directions ③-④ were more disturbed than those in other directions.
3.3 Experiment 3
In Figure 7, the radial values in directions ①-② and ⑦-⑧ are disturbed. Figures 8 to 11 show that the values in direction ⑤-⑥ are disturbed. At 14:30 (Figure 12), there is a tendency for poorer seeing in directions closer to the horizon. Further analysis will continue, and details will be reported in the future.
4. Discussion
When the Sun is at a low altitude, seeing becomes more active as it approaches the horizon. This indicates a relationship between solar fluctuations and atmospheric variability. The direction of fluctuations observed at higher solar altitudes corresponds with the direction of the upper atmospheric wind, suggesting that these fluctuations reflect the upper atmospheric wind flow. Additionally, at 9:30 (Figure 7), the solar image fluctuated towards the horizon, while at 10:30 (Figure 8), the fluctuations changed to align with the wind flow of the upper atmosphere. This suggests that the atmospheric layer responsible for the fluctuations may have shifted from near the Earth's surface to higher altitudes.
5. Conclusion
At low solar altitudes, the solar image fluctuates towards the horizon, while at higher altitudes, it fluctuates in the direction of the upper atmospheric wind. This suggests that different atmospheric layers may influence seeing based on the Sun's altitude. Future work will focus on identifying which atmospheric layers at ground level affect solar seeing.
6. References National Astronomical Observatory of Japan Website: https://eco.mtk.nao.ac.jp/cgi-bin/koyomi/cande/horizontal.cgi
Conversion from Horizontal Coordinates to Equatorial Coordinates: http://park12.wakwak.com/~maki/hc2ec.htm
Spherical Triangle Angles: https://hooktail.sub.jp/vectoranalysis/SphereTriangle/
Japan Meteorological Agency Website: https://www.jma.go.jp/jma/index.html
This research aims to investigate whether solar seeing fluctuations reflect the movement of upper atmospheric winds. The study observes the phenomenon where solar seeing fluctuates in different directions due to atmospheric layers, and seeks to clarify the relationship between wind direction in the upper atmosphere and solar seeing.
2. Methods
2.1 Experiment 1 (Measurement of Solar Image Fluctuations)
On May 29, 2024, between 16:40 and 16:41, a one-minute video of the Sun was captured using a telescope with an AstroSolar filter on the school rooftop. The video was converted into 900 still images, with each image showing 8 directions from the center of the Sun (Figure 1). To determine the true orientation, the white light solar image and sunspot positions were compared with the National Astronomical Observatory of Japan’s data and the image was rotated to align with the celestial North Pole. Using spherical trigonometry (cosine rule), the solar altitude (24°), azimuth (280°), declination (δ=6.33°), and the latitude of the observation site (φ=35°) were used to calculate the angle γ = 54°. The image was then rotated 54° to correct for orientation (Figure 2). The distance from the center of the Sun to the circumference was measured in pixels for each direction.
2.2 Experiment 2 (Solar Seeing Observation at Solar Noon)
On November 9, 2024, between 13:40 and 13:41, a one-minute video of the Sun was captured at solar noon using the same method as Experiment 1. The data was then processed (Figure 3).
2.3 Experiment 3 (Relationship between Solar Altitude and Seeing Fluctuations)
From 9:30 to 14:30 on March 30, 2025, a video of the Sun was captured every hour and converted into 500 still images. The same image processing method as in Experiment 1 was applied (Figure 4).
2.4 Measurement Accuracy
ImageJ software was used to analyze brightness changes in the solar image and extract the contour lines clearly. Smoothing interpolation was applied to areas with gradual brightness changes, and the positions of the contours were measured with an accuracy of 0.2 pixels.
3. Results
Figures 5 to 12 show the wind direction at high altitudes for the day, based on data from the Japan Meteorological Agency.
3.1 Experiment 1
Figure 5 shows that the radial values in directions ①-② and ⑦-⑧ were more disturbed than those in other directions.
3.2 Experiment 2
Figure 6 indicates that the radial values in directions ③-④ were more disturbed than those in other directions.
3.3 Experiment 3
In Figure 7, the radial values in directions ①-② and ⑦-⑧ are disturbed. Figures 8 to 11 show that the values in direction ⑤-⑥ are disturbed. At 14:30 (Figure 12), there is a tendency for poorer seeing in directions closer to the horizon. Further analysis will continue, and details will be reported in the future.
4. Discussion
When the Sun is at a low altitude, seeing becomes more active as it approaches the horizon. This indicates a relationship between solar fluctuations and atmospheric variability. The direction of fluctuations observed at higher solar altitudes corresponds with the direction of the upper atmospheric wind, suggesting that these fluctuations reflect the upper atmospheric wind flow. Additionally, at 9:30 (Figure 7), the solar image fluctuated towards the horizon, while at 10:30 (Figure 8), the fluctuations changed to align with the wind flow of the upper atmosphere. This suggests that the atmospheric layer responsible for the fluctuations may have shifted from near the Earth's surface to higher altitudes.
5. Conclusion
At low solar altitudes, the solar image fluctuates towards the horizon, while at higher altitudes, it fluctuates in the direction of the upper atmospheric wind. This suggests that different atmospheric layers may influence seeing based on the Sun's altitude. Future work will focus on identifying which atmospheric layers at ground level affect solar seeing.
6. References National Astronomical Observatory of Japan Website: https://eco.mtk.nao.ac.jp/cgi-bin/koyomi/cande/horizontal.cgi
Conversion from Horizontal Coordinates to Equatorial Coordinates: http://park12.wakwak.com/~maki/hc2ec.htm
Spherical Triangle Angles: https://hooktail.sub.jp/vectoranalysis/SphereTriangle/
Japan Meteorological Agency Website: https://www.jma.go.jp/jma/index.html