Halimun (Upslope fog)

Fog is a natural phenomenon which we had known and lived since childhood. The phenomenon has been commonplace. In fact, if the fog visible in the middle of the night was cold and clear starry sky, then at our place, it would be a sign that tomorrow noon, the weather will be warm climates, and the sun will be shining. In geophysics, fog is called radiation fog, and never odder.

Merriam-Webster's Dictionary gives the meaning of fog are: vapor condensed to fine particles of water suspended in the lower atmosphere that differs from cloud only in being near the ground. source

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Meteo Go specifies the terminology of the fog: as of points of water which is the result of condensation or sublimation of water vapor floating in the atmosphere near the ground surface. source

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And an explanation of fog, most simple, is as written in Encyclopedia of the National Geographic Societty: Fog is a cloud that touches the ground. Fog can be thin or thick, meaning people have difficulty seeing through it. source

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Though already very knew the fog, and so accustomed with it, but when in an early-morning, mid-way into Banda Aceh, Sumatra, and we are over the road which is above the mountain range, we look down; toward a populated valley, that is where we saw 'clouds of' fog.

We were not able to pass just like that, and let the charming scenery in that early morning, be missed. Immediately, we got out of the car, and went to the edge of cliff to enjoy the panorama. At that time, spontaneously, my lips are saying: this is the kingdom of Halimun. The clouds, or exactly, the fog, its like creeping above the village on the slopes of the mountain, makes our eyes did not blink.

Fog as it was in our place better known as Halimun; the fog of the mountain slope. The fog may, sometimes, is imagined like a white dragon. But in fact it is a the fog known in climatology and geophysics as 'Upslope fog'.

This fog occurs when moist air rises slowly along the slopes of the mountains that will experience an adiabatic cooling. At a certain height the cold air will condense to form the fog. If the moist air rising too quickly would happen convective turbulence, which causes condensation on a higher layer, so that will be formed stratus clouds. source

In cool weather, watching from above, a village that was still asleep enveloped by the fog, it is a bit strange but fun.

Here are some pictures that I can take to the rather interesting spectacle. Hope you like it.