Para as questões de 16 a 25, leia o texto seguinte e complete as lacunas com a palavra ou expressão correta.

Atmospheric Physics is the study of physical processes in the atmosphere; understanding the climate and the weather, and the physical reasons ____16______ it is as it is and how it might change in the future. My own particular research background is in radiative transfer and ____17______ I mean the transport of electromagnetic radiation through the atmosphere; _____18_____ the Sun’s radiation coming in, getting absorbed and scattered in the air, and the transfer of heat radiation emitted by the Earth’s surface. From a _____19_____ physics perspective there’s an awful lot of things about the atmosphere that we don’t understand, and of course, it’s very classical physics in the ____20______ that it’s looking at fluid dynamics and thermodynamics applied to the natural environment. What motivates us really is to try and explain what we see in the environment, what _____21_____ it and what might change it in the future, both in _____22_____ of local weather but also climate, by _____23_____ I mean larger areas and larger timescales. My background has led me to an interest in how solar radiation _____24_____ in the atmosphere, so ____25______ at how changes in the Sun might affect the climate for the past year.