“It’s a cloudy day.”
“A heavy marine layer is blanketing the coast of Southern California.”
Those are words that are typically not welcomed to outdoor adventurists. But we view clouds positively, both in the cold of winter and the warmth of summer.
Perhaps this perspective is due to our location in Southern California, but here are the reasons why:
When the water starts to get cold in the winter and we head down to the beach for an early morning swim, we welcome the clouds. And when the water is warm and the air is even warmer, we also welcome the clouds.
During the winter, we view the clouds like the Earth’s blankets covering the surface of the ocean, helping us to keep warm. Does this make sense?
Scientists tell us that clouds are able to keep areas of the planet warmer at night by trapping outgoing infrared radiation. During the day, the UV rays and visible light are absorbed by the earth. At night, this radiation is released as it escapes back to space, which is why temperatures fall at night. Without clouds, heat from the sun enters and leaves the atmosphere without anything getting in the way. However, with cloud cover, the outgoing radiation is trapped and the temperature at the planet’s surface does not decrease relatively as much.
Which is why we view clouds as natural blankets of water and dust holding in the heat of the earth. And like our bedroom blankets, the thicker the better on cold days. The thinner clouds higher up in the atmosphere do not hold as much water and let more heat energy escape back out to space. So low heavy cloud cover is more welcomed on a cold day.
Conversely, when the weather is warm and the water is a bit too warm for comfort, the cloud cover seem to have a dramatic effect on the comfort level in the water. Clouds can cause the surface temperature to be less than expected by decreasing the amount of solar energy reaching the surface depending on the cloud thickness, how widespread the clouds are and how long they block solar radiation. With greater cloud cover during the day, the surface temperature will generally be cooler than expected.
Especially along the beach cities of California, there is often a marine layer in the morning hours. The timing when the marine layer lifts determines how much solar warming can take place. The longer it stays, the cooler it remains.
So the clouds can help increase the perceived warmth during winter and the perceived coolness in summer – a welcomed respite during the seasons for opposite reasons.
It’s our simple perspective of the atmosphere in Southern California where weather descriptions like June gloom are part of the local vernacular.
Copyright © 2012 by Open Water Source