Fig. 2
![Fig. 2](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2Fs40645-018-0184-7/MediaObjects/40645_2018_184_Fig2_HTML.gif)
Cross-correlation between day-to-day variability of GAIA temperature data and GPS-scintillation index S4. The observation period is March and April 2003. The red square in each panel indicates the area of data analysis of Fig. 1 (results by Ogawa et al. (2009)). The temperature data are taken at different altitudes and times as follows. a 5 km altitude and 0930 UT (1630LT at Kototabang), b 5 km altitude and 1530 UT (2230 LT at Kototabang), c 40 km altitude and 0930 UT, d 40 km altitude and 1530 UT, e 100 km altitude and 0930 UT, and f 100 km altitude and 1530 UT. “C” and “D” indicate areas of high correlation coefficients