In the hot season I dream of a cool season with its slab of cool bright air moving from China down over the kingdom. True enough, there are days like that, but it seems to me that the cool season is more a series of cycles with the condition I've described deteriorating into something else, such as the cool, dull, hazy day yesterday, January 8.
I am no atmospheric scientist, but it appears to me that what is going on is as shown in the sketch. The cloudless winter sky with a radiant temperature often below 10° C is a sink for outward radiation of heat, and the ground surface is pulled down a degree or two below the air temperature.
With the lower air becoming cooler, we have an inversion layer that traps everything, the aroma of freshly shampooed hair from the girl standing next to me on the skytrain platform to delicious garlic cooking smells, to automobile exhaust. Further, the early morning air temperature is very close to the dewpoint, so I speculate that some of the haze is condensed moisture from the air. You can see that the wind starts to shift from northerly to the east and then toward the south, perhaps accounting for the rising dewpoint as moist air begins to move him from the gulf of Siam. This process has gone on for several days, increasingly dullish times for us on the ground, and we wait eagerly for a new arrival of cool fresh air from the north. Interior slabs and walls in my condo, having bottomed out at a chilly 26°, start rising back to 28° or so, and it's time to turn on the fan.
Let's hope for another blast of Chinese air!
No comments:
Post a Comment