What is driving the diurnal variation in tropospheric NO2 columns over a cluster of high emission thermal power plants in India?

Sachin D. Ghude, Rama Krishna Karumuri, Chinmay Jena, Rachana Kulkarni, G. G. Pfister, Veeresh S. Sajjan, Prakash Pithani, Sreyashi Debnath, Rajesh Kumar, B. Upendra, Santosh H. Kulkarni, D. M. Lal, R. J. Vander A, Anoop S. Mahajan