NUMERICAL MODELS FOR POLLUTANT DISPERSION IN THE ATMOSPHERE
Centre for Atmospheric and Fluids Sciences Indian Institrte of T`echnology,New Delhi
Submitted to the Indian Institute of Technology, Delhi for the award of the degree of
DOCTOR OF PHILOSOPHY
... to my parents
This is to certify that the thesis entitled
;NUMERICAL MODELS FOR POLLUTANT DISPERSION IN THE ATMOSPHERE"
being submitted by SWATI BASU for the award of the degree of DOCTOR OF PHILOSOPHYi is a record of the original bonafide research work carried out by her. She has worked under our
joint guidance and supervision and has fulfilled the require merits for the submission of this thesis. The results presented in this thesis have not been submitted in part or full to any other University or Institute for award of any degree/diploma.
(N• RAGHAVA N
Senior Planetarium Educator Jawaharlal Nehru Memorial Fund Teen
( o. P. S1 A )
Senior Scientific Officer,I Centre for Atmospheric and
Indian Institute of Technology', New Delhi.
I am deeply indebted to Dr. (Mrs.) N. Raghavan under whose supervision I have worked for the last three and a half years* for her painstaking guidance, immense help and constant encouragement throughout this work.
I am also grateful to Dr. O.P. Sharma for his help from time to time.
I am grateful to Professor M.P. Singh who in his
capacity as Head of the Department extended all the necessary facilities and help and encouzgement throughout the duration of this work.
My sincere thanks are due to India Meteoro.Iogical Department for provision of various data which was required
from time to time and also to Department of Science and Technology for sponsoring the project
a.tthe Centre for Atmospheric and Fluids Sciences', I• I• T.', New Delhi.
I thank Miss Neelam Dhody for her accurate and meticulous typing of the thesis.'
Finally. 7 would like to thank my husband and in—laws without whose cooperation and encouragement it would not have been possible to complete the work.'
ST ATI BASU
CHAPTER T: REVIEW
1.1 Introduction 1
1.2 The Need for PBL Model 2
1.3 Summary of Selected PBL Models 3
KM-theory and Turbulent Energy
(TE) Equation 5
1•S Dispersal of Pollutants 10
1.6 The Coupled Model lz
CHAPTER .1I= ASSUMPTIONS AND FORMULATION
2.1 Introduction 30
2.2 PBL Model Assumptions- 33 2.3 Formulation of Mixing Lengths 35 2.4 Simplification of the Advection 38
2.5 Model Equations and Formulation 41 2.6 Numerical Schemes and Procedure 44
2.7 Input Parameters 48
CHAPTER Il-I: THE NEUTRAL BOUNDARY LAYER
3.1 Introduction 50
3.2 Model Formulation 5*1
3.3 Numerical Experiments 54 3.4 Comparison With Observations 58 3.5 Height_ o.f Maximum Diffusivity 59 3.6 Discussion of Results 60
3.7 Conclusions 65
CHAPTER Ij: THE NOCTURNAL BOUNDARY L7YEi .
4.1 Introduction 68
4•:2 Model Formulation 69 4.3 Numerical Experiments 73 4.4 Discussion of Results 78
4.5 Conclusion 82
CHAPTER 'V: CONVECTIVE BOUNDARY LAYER
5.1 Introduction 86
5.2 Model Formulation 89
5.3 Numerical Experiments 92 5.4 Discussion of Results 94
5.5 Conclusion 95
CHAPTER '`'I: THE ADVECTION DIFFUSION MODEL
6.1 Introduction 96
6.2 Assumptions and Formulations 100 6.3; Numerical Experiments 104 6.4 Discussion of ...Results 108
6.5- Conclusions 110
CHAPTER VII: THE COUPLED MODEL
7.1 Introduction 115' 7•'2 Model Formulation 117 7.3' Numerical Experiments 119 7.4 Discussion of Results 127
7.51 Conclusion 131
CHAPTER VIII. SUGGESTION ' FOR FUTURE ti'dORK.
8.1 Achievements 135
8.2 Future Work Suggested; 136
8.3 Conclusions 136
LIST OF PUBLICATIONS AND PRESENTATIONS 146