Observations made by Hong Kong Observatory during partial solar eclipse today

22 July 2009

A partial solar eclipse was visible in Hong Kong from 8.15am to 10.46am today (July 22), with the maximum eclipse occurring at 9.26am. The weather was mainly fine during the eclipse. Although the sun was occasionally blocked by clouds, the eclipse was still visible for a long period from many places in Hong Kong. Figure 1 shows the image of the solar eclipse photographed by the Observatory's telescope.

Affected by the solar eclipse and variations in the cloud amount, the Kings Park meteorological station recorded decreases in the ultra-violet index (Fig. 2), solar radiation (Fig. 3) and temperature (Fig. 4). Temperatures over the territory (Fig. 5) generally fell slightly, and were lower than those at the same time yesterday, with the maximum fall close to 3 degrees Celsius.

Fig. 1 Image of the solar eclipse photographed by the Observatory's telescope at 9.27am.

Fig. 2 The ultra-violet index fell by about 2 during the solar eclipse.

Fig. 3 The global solar radiation recorded at the King's Park meteorological station dropped by some 400W/m2 during the eclipse.

Fig. 4 The temperature at the King's Park meteorological station dropped by about 1 degree Celsius during the eclipse.

Fig. 5 Temperatures at 9.30am in the territory were generally lower than those at the same time yesterday, with the maximum fall close to 3 degree Celsius.