ATMO 336 1st Edition Lecture 12 Outline of Last Lecture II. Vapor pressureIII. Evaporation and condensation in a closed systema. Rate of evaporationb. Rate of condensationc. Saturation vapor pressureIV. Evaporation and condensation in the atmosphereV. ParcelsVI. Relative humiditya. Relative humidity formulab. Mixing ratio formulac. Saturation mixing ratio formulaVII. Dew pointVIII. Difference between air temp. and dew point temperature indicate whether relative humidity is low or highOutline of Current Lecture IX. Summary of how water behaves based on relative humidityX. Energy transfera. Radiationb. Conduction c. Convectioni. Dry convection (natural dry convection and forced dry convection)ii. Moist convectionCurrent Lecture- Summary of how water behaves based on relative humidityo If RH= 100% (Td=T), there will be no net evaporation or condensation since the rate of evaporation is equal to the rate of condensationo If RH<100% (Td<T) any liquid water present will evaporate with time, since the rate of evaporation is greater than the rate of condensationo If RH>100% (Td>T) water vapor will condense to liquid water until RH falls back to 100%, since the rate of condensation is greater than the rate of evaporation. When this occurs, it is only a temporary situation until sufficient water vapor condenses out of the air- Energy transfero For object to be warm, energy addedo For object to be cold, energy removedThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.o Energy balance for object If energy = to energy out, temp of object remains constant If energy > energy out, temp of object increases If energy < energy out,, temp of object decreaseso Energy is transferred between objects that are at diff. temps. Direction of energy always from hot  coldo Three mechanisms for energy transfer: Radiation Conduction Convection- Radiationo Is the transmission of energy through space or through a material medium in the form ofelectromagnetic waves.o All objects in universe emit radiation energy. Hotter the object, the greater the amount of radiation energy it emits- Conductiono Transfer of energy by direct collisions of molecules (touching)o Heat conductivity= rate at which energy is transferred within a materialo Water and metals are good heat conductors, while air is a poor heat conductor (or a good heat insulator) The higher the heat conductivity, the faster heat flows through material by conductiono Rate of conductive heat transfer depends The temp difference between two objects that are touching or the temperature difference from one end to the other within a single object. The larger the temp.difference, the faster the heat transfer Conductivity of the material, for example, the conductive heat transfer in water is much faster than in airo Water has a large heat capacity, which means water must absorb a lot of heat (energy) to raise its temp.- Convectiono Is the transfer of heat by actual movement of mass within a fluid.o Very important means of energy transport in the atmosphere, especially moist conventiono Only happens in liquids and gaseso 2 types of convection dry convection: - natural dry convections, simply warm air rising and cold air sinking. Parcels of air continue to rise as long as the parcel air temp remains warmer than temp of ther surrounding parcel. This is initiated by the uneven heating of the ground surface on sunny days.o Thermals=currents of rising heated air- Forced dry convection= when winds stir up the air, forces air to mix which transfers heat or energy from warmer to colder regions Moist convection- Accounts for energy removed due to evaporation of water (usually from near the ground surface), then delivered when the water condenses (usually high in the atmosphere where clouds form)o Water vapor contains more internal energy than water. When water evaporates, you can say that the energy is stored in the water vapor. Overall, energy is removed from the region where water evaporated and released where water condenses, thus transferring energy from one location to another- Rate of heat loss via evaporation depends on the net ration of evaporation, which depends on relative humidity. Also depends on the windo The faster the windspeed, the faster the rate of net evaporationo Vapor pressure deficit= net rate of evaporation determined off of this. It is the saturation vapor pressure (based on the liquid water temperature) minus the vapor pressure in the