Satellite Image Gallery

Welcome to Hong Kong Observatory's Satellite Image Gallery!

Here, you can find images of significant weather events and interesting phenomena captured by satellites (GMS, NOAA, FY-1 and EOS satellites) over the Asia-Pacific region. The topics include calamities such as typhoons and severe floods, as well as other interesting phenomena such as fog banks and hill fires. Members of the public may recall the 4 direct hits by tropical cyclones in 1999 and the record rainfall of 3,343.0 mm as recently as 1997, with damage amounting to hundreds of million dollars or more. In addition to the purpose of public education, this gallery aims at heightening public awareness towards disaster preparedness.

The images are specially enhanced by the Hong Kong Observatory for your viewing. The enhancement is done by assigning different colours (red, blue or green) to images taken by different frequency channels on the satellite. These images are then suitably combined to bring out features of interest. The resulting composite image is called a 'false colour image'. Please see Notes for the advanced reader.

Tropical Cyclone	Event Date	Description
Tropical Storm Kompasu	16 July 2004	Kompasu was the only tropical cyclone in 2004 necessitating the issuance of No. 8 Gale or Storm Signal in Hong Kong.
Typhoons in Northern and Southern Hemispheres	28 December 2002 and 16 April 2003	Typhoons in Northern and Southern Hemispheres have opposite sense of rotation.
Flight of typhoon trio	31 August 2002	Three typhoons hitting the western North Pacific simultaneously.
Typhoon Haiyan over the East China Sea	16 October 2001	Haiyan at the peak of its strength and tracking northeastward.

Heavy rain / Flood	Event Date	Description
Flooding over Eastern China at the wake of Tropical Storm Mindulle	30 June 2004 and 4 July 2004	Tropical Storm Mindulle skirted along the coast of Eastern China in early July 2004, bringing torrential rain to that region.
A very localized rainstorm	18 October 2002	Autumnal weather in Hong Kong is usually dry with plenty of sunshine. 18 October 2002, however, was an exception.
Flooding near Dongting Hu, Hunan Province	27 August 2002	Central China affected by disastrous floods in August 2002.
Disastrous floods across Southeast Asia	26 September 2000	One of the most disastrous floods in recent decades hitting four countries in Southeast Asia.

Dust storms / Fire / Volcanic ash	Event Date	Description
Hill fire in Guangdong	16 January 2005	Hill fire broke out in inland Guangdong on 16 January 2005.
Haze over Pearl River Delta in Autumn	30 October 2004 and 1 November 2004	An easterly airstream prevailed over Hong Kong on 30 October 2004, holding off the haze to the northwest.
Eruption of Ruang Volcano, Indonesia	25 September 2002	Eruption of Ruang Volcano sent volcanic ash to a height of 15 km.
Wildfires in New South Wales, Australia	4 December 2002	New South Wales, Australia experienced one of the most violent wildfires for many years.
Dust storms over northeastern China	8 April 2002	Dust storms extensively affecting the northeastern part of China.
Dust storms reaching the East China Sea	21 March 2002	Dust storms from northern China reaching the East China Sea.
Hill fire	27 November 2001	Hill fires affecting southern China under a very dry airstream.
Eruption of Miyakejima Volcano	10 August 2000	Volcanic ash from Miyakejima Volcano in August 2000 soaring to great heights in the atmosphere.

Fog	Event Date	Description
Fog over the Pearl River Delta	6 March 2006	Fog shrouded Hong Kong, lowering visibility to 200 m.
Fog along coastal region of Guangdong	15 February 2006	Sea fog lingering along the coast of Guangdong.
Fog over southeastern coast of China	12-13 January 2006	Widespread fog covering southeastern coast of China and the adjacent waters.
Fog over the coastal areas of Guangdong	17 January 2002	Widespread fog affecting Hong Kong and the adjacent waters.

Miscellaneous	Event Date	Description
Fair weather cumulus along coast of Guangdong	28 October 2004	This is a high-resolution image captured by an Earth Observing System (EOS) satellite on 28 October 2004.
Cold Front	7 March 2003	A sharp edge of cloud marking the location of a southward-moving cold front.
Vortex streets	15 January 2003	Vortex street appearing downwind of Cheju Island under wintry prevailing winds.
Fengyun-1D satellite image	15 August 2002	The first Fengyun-1D satellite image received by the Hong Kong Observatory.
Sun Glint	18 June 2002	Reflection of sunlight over a relatively calm sea.
Fohn Effect	8 January 2002	Under the influence of easterly winds, Fohn effect appeared over Luzon, the Philippines.
Condensation Trails	22 October 2001	Condensation trails (contrails) produced by aircraft.
Urban development around the Pearl River Estuary	15 October 2001	Extensive urban development witnessed around the Pearl River Estuary areas.

Notes:

GMS-5, which stands for Geostationary Meteorological Satellite 5, is operated by the Japan Meteorological Agency. It is located above the Equator at longitude 140^oE, and some 35,800 km away. As it follows the Earth's rotation closely, it is stationary relative to the Earth's surface (hence the name 'geostationary'). This enables it to view, and obtain images of, the same part of the Earth all the time.

NOAA and FY-1 satellites are polar-orbiting meteorological satellites which are operated by the US National Oceanic and Atmospheric Administration and the China Meteorological Administration respectively. They revolve around the Earth along paths roughly passing over the poles. As they move, they obtain images of different parts of the Earth. One to two images are normally received in Hong Kong from each satellite every day. Orbiting at several hundred kilometres aloft, these satellites are closer to the Earth than geostationary ones and thus produce images of higher resolution.

Terra and Aqua are polar-orbiting satellites of the Earth Observing System (EOS) operated by the U.S. National Aeronautics and Space Administration (NASA). They revolve around the Earth along paths passing over the polar region. As they move, they take pictures of different parts of the Earth. Two images are normally received in Hong Kong from each satellite every day.

Notes for the advanced reader