Jump to content
The Weather Forums

Swayseeker

Members
  • Content Count

    5
  • Joined

  • Last visited

Community Reputation

1 Neutral

About Swayseeker

  • Rank
    Forum Newbie
  1. Air with a lower density will rise, but if the pressure exerted by the less dense air is the same as the pressure of the surrounding air, which it usually is, air cannot rush in to the space occupied by the less dense air. For instance if you warm up the air in a house to hundreds of degrees above outside temperature, the air is far less dense inside, but the molecules are moving faster and the pressure inside the house is the same as that outside if you keep windows open. Air does not move into the house (except for some mixing, etc).
  2. Vegetation has a high emissivity (close to that of a blackbody) so it can lose heat fast. But if there is material with high heat content (rocks, big trunks of trees, etc) it takes longer to cool down. Hillsides lose the energy by radiating and the air immediately above the ground then becomes cool and moves down the slope. With clouds and high relative humidity the sky temperatures is higher and you get more downwelling radiation (there is a formula, or rather there are formulas for the downwelling radiation) which keeps everything warmer. A leaf, with its high emissivity and low heat content
  3. I would like a bit of a review of my ideas and would appreciate it if anyone points out a serious fault with them - see ideas below: Transporting moist air by means of natural convection in a pipe: Run a huge black pipe, that will get hot in the sun, from the sea to a few hundred metres above the area needing rain. Moist air from the sea will rise in the pipe by means of natural convection and cause convectional rain. This idea could bring rain to many areas. It would be similar to a solar updraft tower, which can deliver huge volumes of air per second to the atmosphere. Heat the seawater by c
  4. Air can hold more water vapour when it is hotter. When the relative humidity is as high as 100% the vapour will start condensing out if the air cools. Here is an example of how relative humidity changes: Suppose you have a given mass (parcel) of air that is heated. It expands and pushes the surrounding air out, but if you measure pressure of the surrounding air before and after you will find it remains the same (if you are quick enough to measure pressure before it rises significantly) and so does the pressure of the heated, though less dense air. The heated air is at the same pressure as the
  5. Say I heat air that has a relative humidity of 60% near the ground. Let the initial temperature be 10 deg C and suppose I heat it to 25 deg C. Then the relative humidity is about 23.2%. If I use an environmental lapse rate of 6.5 deg C per km and an adiabatic lapse rate of 9.8 deg C then this air could rise (25-10)/(9.8-6.5)=4.5 km before it is at the same temperature as the surrounding air (it will then not rise or fall). The dew point for an RH of 23.2 and temperature of 25 deg C is 2.4. Espy's equation now tells me that the parcel only has to rise 125(25-2.4) = 2825 m before clouds form. It
×
×
  • Create New...