Abstract:
Long-period modulations are shown in aerosol
optical depth measured by the Microtops II Sun photometer over a high-altitude site the central Himalayan region
(Nainital, 29.4◦ N, 79.5◦ E, 1958 m a.m.s.l.) for the first time.
Fourier analysis of aerosol optical depth showed dominant
25–45 day oscillations observed in MODerate-resolution
Imaging Spectro radiometer data. Further, a Hovmiller
diagram showed westward (northward) propagation at a different longitude (latitude), confirming that the modulations
are associated with Rossby waves. It is also shown that
the Rossby wave amplitude causes an additional warming
of 4.16 ± 0.98 W m−² over the observational site. Hence,
the present study illustrates the importance of wave-induced
aerosol dynamics and the corresponding radiative effects.
