Why do dry & wet adiabetic lapse rates of cooling differ

-

Dry adiabatic lapse rate is the measure to describe the change of temperature with height.When a parcel of unsaturated air rises through the atmosphere in equilibrium condition it expands & cools at a constant rate @ 1 degree Celsius/100m of ascent.
                                       Saturated adiabatic lapse rate or wet adiabatic lapse rate is the measure used to describe the changing temperature of a saturated body of air through atmosphere due to expansion & the temperature remains between 0.4 degree Celsius to 0.9 degree Celsius per 100m ascent of atmosphere by the air parcel.It is always lower than dry adiabatic lapse rate.
                                           Now! on condensation,saturated adiabetic lapse rate will release more latent heat since it's air parcel contains more water vapor molecules than the air parcel undergoing dry adiabatic lapse rate.We know pressure is inversely proportional to the density.We also know that pressure is inversely proportional to temperature i.e., high temperature produces low pressure & vice versa. Therefore release of latent heat will cause volumetric expansion of both the air parcel undergoing different adiabatic lapse rate's.
Since,temperature ,vapour pressure & density are interdependent variables so change  in one or more inter-molecular force of attraction so the pressure exerted by the individual molecules will be lower since they have  spread due to volumetric expansion over the large area which will be more in case of the air parcel undergoing saturated adiabatic lapse rate ,the density of the aforesaid air pacel will be lower than the air parcel undergoing dry adiabatic lapse rate.
If both density & vapor pressure of the air parcel undergoing  saturated  adiabatic lapse rate is lower than the air mas under going dry adiabatic lapse rate then the temperature of the air mass undergoing saturated adiabatic lapse rate will be more or greater.Therefore,saturated adiabatic lapse rate will decrease @ 1 degree Celsius provided the elevation has to be more than 100m. This is the reason why dry & wet adiabatic lapse rate of cooling differ. 

Comments

Post a Comment

Popular posts from this blog

Distinguish between barotropic & baroclinic conditions of the atmosphere

-
An air mass which is defined as a large body of air whose physical properties especially temperature, moisture & lapse rate are more or less uniform horizontally for hundreds of kilometers.                             barotropic condition of atmosphere is theoretically ideal condition where surfaces of constant pressure are not intersected by isostereic(constant density) surfaces, so that in a vertical cross-section isobars(imaginary lines joining places of equal atmospheric pressure) & isotherms appear parallel i.e,zero baroclinicity.It is a rare phenomenon & is found in case of frontogenesis,separated by baroclinic front zone.          Baroclinic condition of atmosphere is seen in comparatively narrow zones (perhaps 1000Km. in width) of thermal discontinuity also known as fronts in air mass property. They are belts of sharp meteorological gradient recognized as distinct factors in the origin of mid-latitude disturbances. The instability is associated with rising wa
Read more

Airtel DTH: Error B001/Error B003 and Why I left Airtel possibly for Better

-
Image
Why did I decided to Leave?  It has been 2 weeks since I complained about B001 error and Airtel in between replaced 2 set top boxes but problem remained. I have replaced everything as per "diagnosis" of airtel DTH technician but no solution could be reached. Currently, my balance has been deducted from INR200 to INR 10. There are discrepancies with the bills issued against parts replacements conducted during this period. It must be stressed here that I as a customer felt cheated, neglected, harassed by Airtel +Service Partner and I was a 7-8 years+ customer. We never saw that set top box seals were broken in front of our eyes for both the replacements by technicians. My comparison chart for new service provider
Read more

Why do isotherms shift north & south from season to season?

-
An isotherm is an imaginary line drawn on a weather chart or map to join places of equal temperature. Temperature varies from season -as there is high temperature during summer & low temperature during winter with minor changes during transitionary seasons. We know that temperature is proportional to atmospheric pressure & inversely proportional to density.                                                        A.P.=K*D*T                                                           T=A.P*1/D where,A.P.=atmospheric pressure;K=constant;D=density;T=temperature      During the summer season in either of the hemisphere's the sun is vertically overhead of the tropic of cancer/capricorn.The land which has a low specific heat capacity & also being a bad conductor of heat re-radiates the heat to the atmosphere resulting in the spreading of molecules of atmospheric gases due to the heat energy. As molecules spread over a wide region it's pressure on the land becomes l
Read more