LM9 - Fundamentals, Atmospheric stability.pptx

1. KGiSL Institute of Technology
(Approved by AICTE, New Delhi; Affiliated to Anna University, Chennai)
Recognized by UGC, Accredited by NBA (IT)
365, KGiSL Campus, Thudiyalur Road, Saravanampatti, Coimbatore – 641035.
Department of Information Technology
Name of the Faculty : Mr.Mani Deepak Choudhry
Subject Name & Code : OCE551/Air Pollution and Control Engineering
Branch & Department : III IT & Information Technology
Year & Semester : III / V
Academic Year :2022-23

2. SYLLABUS
UNIT 2 - METEROLOGY
Effects of meteorology on Air Pollution - Fundamentals, Atmospheric
stability, Inversion, Wind profiles and stack plume patterns-
Atmospheric Diffusion Theories – Dispersion models, Plume rise.
OCE551/APCE/III IT/V SEM/KG-KiTE

3. OCE551/APCE/III IT/V SEM/KG-KiTE
Course Outcomes
CO 2 Identify, formulate and solve air and noise pollution problems. K2 LEVEL

4. OCE551/APCE/III IT/V SEM/KG-KiTE
Topic
1. Effects of meteorology on Air Pollution
2. Fundamentals, Atmospheric stability
3. Inversion
4. Wind profiles and stack plume patterns
5. Atmospheric Diffusion Theories – Dispersion models
6. Plume rise

5. OCE551/APCE/III IT/V SEM/KG-KiTE
Fundamentals & Atmospheric Stability
• Atmospheric Stability:
• It is the measure of atmospheric tendency to encourage or discourage the
vertical motion which is directly related to different types of weather
conditions and its severity.
• Degree of Atmospheric Stability:
• Temperature difference between air parcel and air surrounding
• The rate at which atmospheric temperature decreases with increase in
altitude is called Lapse Rate.

6. OCE551/APCE/III IT/V SEM/KG-KiTE
Fundamentals & Atmospheric Stability
• Atmospheric Stability:
• The normal rate of decrease of temperature with altitude in the stationary atmosphere at a given time and
location is called Environmental Lapse Rate (ELR). (6.5 °C/Km)
• The rate of change of temperature of an air parcel as it moves upwards through the atmosphere rapidly
called Adiabatic Lapse Rate (ALR).
• If the dry air is expanding and cooling adiabatically it is called Dry Adiabatic Lapse Rate (DALR). (9.8 °C/Km)
• In saturated wet air the rate is calculated to be (6 °C/Km) and it is called as Wet Adiabatic Lapse Rate
(WALR).
• When ELR > DALR it is called Super Adiabatic Lapse Rate (SALR).
• When ELR<ALR, environment is stable so it is called Sub Adiabatic Lapse Rate (DALR).
• When ELR=ALR environment is said to be neutral.

7. OCE551/APCE/III IT/V SEM/KG-KiTE
Fundamentals & Atmospheric Stability
• Lapse – Gradual Change
• Adiabatic – a process occurring without addition of outside heat or loss of its
own internal heat
• Rapid – air parcel moves fast enough that there is no considerable exchange of
heat with surrounding air

8. OCE551/APCE/III IT/V SEM/KG-KiTE