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Acoustic and magnetoacoustic waves are considered to be possible agents ofchromospheric heating. We present a comparison of deposited acoustic energyflux with total integrated radiative losses in the middle chromosphere of thequiet Sun and a weak plage. The comparison is based on a consistent set ofhigh-resolution observations acquired by the IBIS instrument in the Ca II 854.2nm line. The deposited acoustic-flux energy is derived from Doppler velocitiesobserved in the line core and a set of 1737 non-LTE 1D hydrostaticsemi-empirical models, which also provide the radiative losses. The models areobtained by scaling the temperature and column mass of five initial models VALB-F to get the best fit of synthetic to observed profiles. We find that thedeposited acoustic-flux energy in the quiet-Sun chromosphere balances 30-50 %of the energy released by radiation. In the plage, it contributes by 50-60 % inlocations with vertical magnetic field and 70-90 % in regions where themagnetic field is inclined more than 50 degrees to the solar surface normal.

Chromospheric Heating by Acoustic Waves Compared to Radiative Cooling: II -- Revised Grid of Models