INTRO TO WEATHER
INTRO TO WEATHER MET 1010
Popular in Course
Popular in Meteorology
This 4 page Class Notes was uploaded by Maureen Ledner on Friday September 18, 2015. The Class Notes belongs to MET 1010 at University of Florida taught by Staff in Fall. Since its upload, it has received 20 views. For similar materials see /class/206629/met-1010-university-of-florida in Meteorology at University of Florida.
Reviews for INTRO TO WEATHER
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 09/18/15
Chapter 5 Water vapor pressure in millibars is water vapor partial pressure water vapor pressure E water vapor molecules X pressure inside parcel total of molecules 1 argon atom Parcel 3 water vapor molecules molecules can t pass 200 nitrogen molecules through wall but 54 oxygen molecules walls can expand and contract Pressure inside parcel 1015 millibars Water vapor pressure g 1015 millibars 118 millibars Adding water vapor molecules or increasing pressure or removing nonwater molecules increases water vapor pressure Saturation implies that if more water is added to a parcel water vapor will condense to form water liquid when the parcel comes to equilibrium at that temperature Lid Measure pressure of Q water vapor PWV above water at each temperature T allow to come to equilibrium Water vapor in air Measure temperature T see gure 512 PWV is a strong function of T Temperature What happens if PWV approaches Ptmal What causes boiling Boiling occurs when the saturation vapor pressure equals the total pressure above the liquid As T increases eventually PWV will equal Pmtal open container What if container is closed Ptotalwill increase as PWV gt Pmtal So temperature required to boil will increase This is the principle of the pressure cooker water boils at a higher temperature and thus cooks food faster Ptotal Small bubble of water vapor forms If PWV Pmtal the bubble can W survive If Pmtal gt PW the bubble will collapse Note For an open container Ptotal will always equal atmosphere pressure in that location Relative Humidity RH RH E actual water vapor pressure j X 100 percent saturation water vapor pressure Note Humans are more sensitive to how close air is to saturation than they are to actual water vapor content in air Dew point The temperature to which air would have to be cooled with no change in pressure or water content for saturation to occur Example Keeping your house comfortable in Florida in summer Suppose Dew point is 75 F overnight low is 72 F So RH will be 100 by morning Windows were open and fans running overnight so inside house will be about 72 F and 100 RH by morning Now close all windows and doors At 2pm outside temperature reaches 95 F and 90 RH heat index over 130 ouch However house is well insulated so temperature inside rises to 80 F due to heat conduction through walls and roof and radiative heating What is RH inside the house now assume no water enters house From table 1 p 117 Actual water vapor pressure 27mb Saturation water vapor pressure at 80 F 35mb So RH 77 heat index N 82 3 very warm but not deadly A sling psychrometer measures the wetbulb temperature which is the lowest temperature that can be attained by evaporative cooling A large wetbulb depression indicates a low RH I a Humans sweat to keep their bodies cool s 5 As water evaporates from wet surface energy is required latent heat This energy is supplied by the wet surface and this loss of energy heat cools the surface Evaporation becomes more and more difficult as air gets closer to saturation At saturation condensation evaporation Condensation gives off heat and warms surface
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'