Nice picture, thanks. I think the word you are looking for is “absorption” or maybe attenuation.
The interaction of radio waves with the atmosphere is highly dependent on angle of incidence, rainfall and time of day. For instance, during daylight hours, AM radio waves are absorbed in the stratosphere, making AM daytime radio a local medium. At night when the stratosphere deionizes, AM radio zips right through the stratosphere, to ionosphere, which looks like a highly polished mirror to AM and signals can travel half way round the globe. (WBZ-AM 1030 Boston has been received in New Zealand, for instance.)
Anyway, believe it or not, it’s more complicated than that simple picture.
Absorbance is indeed what is illustrated. It is the quality of optical density - absorption and attenuation are verbs relating to the process of absorbance.