Name Last First Module 05 Activity 01 GEOG 104 Principles of Physical Geography Atmospheric Humidity Part 1 The illustration above shows a typical vertical cross section in the atmosphere with the red curve indicating temperature at different heights in the atmosphere In the following we will only consider adiabatic processes that is a type of thermodynamic process that occurs without transferring heat or mass between the thermodynamic system and its environment Answer the following prompts to explain why the wet adiabatic lapse rate is smaller than the dry adiabatic lapse rate How is lapse rate defined The rate at which temperature changes with altitude in the Earth s Atmosphere What happens as an air parcel moves up in the atmosphere Pressure decreases there is a temperature change depending on whether the parcel is dry or moist expansion and cooling cloud formation precipitation and environmental lapse rate which is the actual temperature change What happens to the relative humidity and why It increases because as the parcels ascend in the atmosphere and cool they can reach their dew point temperature and become saturated What happens at the level of condensation Air parcels reach their dew point become saturated form clouds through condensation release latent heat and may contribute to precipitation formation as they continue to rise and cool What happens when the air continues to rise The parcel continues to go through several processes It is fundamental to weather patterns as they influence cloud formation precipitation and the overall behavior of atmosphere And why is the wet adiabatic lapse rate smaller than the dry adiabatic one The wet adiabatic lapse rate is smaller than the dry adiabatic one because of the latent heat release associated with the phase change of water vapor into liquid water during condensation Part 2 The map below shows the relative humidity in the contiguous United States on Monday June 30 2014 What areas have high humidity and what areas have low humidity The eastern half of the US has high humidity whereas the western half has low humidity How are these regions different States in the western half of the US such as Nevada and Arizona have drier more arid climates as well as deserts States in the easter half such as Louisiana and Florida have wetlands making their climates more tropical What factors control humidity Temperature increasing affects humidity because the warmer the air the more water can be absorbed The amount of rainfall can also affect the humidity though because if there is no water to be absorbed it can still be hot with a low humidity Try to explain this map The areas that have more available water such as Florida have higher humidity States like Arizona which consists of mostly desert have a lower humidity because there just isn t much water to be absorbed