ATMO 170A1 1st Edition Lecture 11Outline of Last Lecture I. Controls of Global TemperatureII. LatitudeIII. Land/WaterIV. Ocean CurrentsV. Elevation a. Wind Chill IndexVI. Measuring Air TemperatureOutline of Current Lecture II. Atmospheric Humiditya. Specific Humidityb. Saturation Specific Humidityc. Relative HumidityCurrent LectureAtmospheric Humidity- Three phases of water are related to molecular motion; an increase or decrease in motion creates a phase change.◦ Ice is the coolest/slowest phase.◦ Water vapor is the warmest/fastest phase.- Specific Humidity◦ The ratio between the mass of water vapor in the parcel with the total mass of the air in the parcel (q).▪ Large q → a lot of water vaporThese 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.▪ Small q → a little water vapor▪ q = kg of water vapor ÷ kg of air OR q = g of water ÷ kg of air ▪ If there is 1 kg of water and 2 g of water vapor, q = 2 g/kg▪ Only changes if you add (evaporation/transpiration) or remove water vapor- Saturation Specific Humidity◦ The maximum amount of water vapor that could be in the air (upper limit of how much water vapor can be in the air before it saturates)◦ When the rate of evaporation equals the rate of condensation, the system is said to be in equilibrium and the air is said to be saturated.◦ In the environment, saturated air is air that contains as much water vapor as possible.◦ Same number of molecules evaporate as condense → Air is saturated ◦ This is a very strong function of temperature, but does not tell you anything about how much water is ACTUALLY in the air. It tells you how much water COULD be in theair.◦ It depends very strongly on the temperature of the air.◦ If you know the temperature, you know the saturation specific humidity.- Relative Humidity◦ How close the air is to being saturated◦ RH = how much water vapor is in the air ÷ the maximum possible amount◦ RH = a ÷ qs x 100%◦ This does not tell you how much water vapor is in the air. ◦ Dew – Frost – Clouds: Air is