Systematic investigations of optical dayglow emissions at OI 557.7, OI 630.0, and OI 777.4 nm have been carried out simultaneously over a large field of view (~140°). These emission intensities are obtained during January–March ...

As an observational evidence, it is reported that long period oscillations near 21- and 30-days generated in the lower atmosphere (troposphere and lower stratosphere) in the Indian tropical regions have possible influences ...