Anonymous
Anonymous asked in Science & MathematicsWeather · 8 years ago

why is surface temperature important in determining atmospheric stability?

Unstable atmospheres often produce cumulonimbus clouds with rain and thunderstorms in the summer in the Midwest US. During a long, hot summer afternoon, the ground heats much faster than the atmosphere. Explain why the surface temperature is very important in determining atmospheric stability. Thank you for your help!

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  • 8 years ago
    Best Answer

    Well, essentially, everything starts with the surface heating. The atmosphere itself does not really warm itself up - the main constituents of the atmosphere, nitrogen and oxygen, are relatively transparent to solar radiation. (Aside: Ozone and other greenhouse gases are not so, but they make up less than 2% of the atmosphere). However, the ground is very translucent, or nontransmissive, with solar radiation. When it begins to heat up, the air, through conduction at the surface and convection as the air mixes, begins to heat up and turn.

    Refocusing on the question, let's look at a simple concept called the lapse rate. As you go up in the atmosphere, in general, the air cools due to there being less of it - by the ideal gas law, as pressure goes down at a constant volume, so does temperature. In general, the lapse rate tends to be about a degree Celsius per 200 meters of ascent. So, after a kilometer climb, you would feel about 5C cooler.

    Keeping this in mind, remember that cooler air is more dense than warmer air. As air is a fluid, the denser warm air wants to rise, with the cooler air descending. For the most part, when the air is stable, the process is evened out. However, most "exciting" weather, or thunderstorms and rain, come when cooler air overlays warmer air, taking into account the lapse rate I mentioned above.

    Now, if you think about it, surface heating will tend to warm the air even more through conduction, and thus, it will create more vigorous overturning, or convection. Looking through a parcel of air that is going up, sort of like a bubble going from the bottom of a pot of boiling water, if the parcel is warmer than its surroundings, it will continue to rise. Since the lapse rate is fairly well-established, if you can make the parcel warmer or the airmass at the bottom warmer, it will continue to rise through the atmosphere until its energy (or density) makes it slow down.

    (Sorry if this is a long answer, but it's important to follow all of the steps in it.)

    Source(s): meteorologist/climatologist
  • 3 years ago

    Todo gave you an wonderful answer. i will in basic terms problematic on the assumption of the greenhouse result. for the period of sunlight hours, the solar heats the floor of the earth (some million/2 of the image voltaic power reaches it). At night, that warmth radiates lower back into area as infrared waves. The stability of it incredibly is named, the solar's internet radiation. it incredibly is often constructive (greater earnings than loss) on the equator and continually detrimental on the poles. the place I stay, in Norway, it incredibly is constructive approximately six months of the summer season. It potential that, case in point a severe tension potential heat climate throughout the summer season however the same severe tension in January potential severe chilly. The greenhouse result's on the subject of the quantity of warmth power coming in, and that escaping. the ingredient is, the better the frequency of electromagnetic radiation, the greater power it contains. yet how plenty is going out and in relies upon on the character of the ambience. case in point, ozone (O3) filters a good number of the extremely-violet frequencies. Carbon dioxide and water vapor filters a good number of the infra-pink frequencies. So, from the warmth gained throughout the day, much less get away at night while carbon dioxide will boost. yet observe that the large greenhouse element isn't CO2 yet effortless, water vapor! besides, I examine that the standard temperature at sea point has boost by utilising approximately one degree Celsius interior the previous 35 years interior the northern hemisphere. some million/2 a level interior the southern and no sizeable substitute between the tropics. That seems to greater healthful the distribution of the earth's inhabitants the the burning of fossil gasoline, does not it?

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