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We study properties of waves of frequencies above the photospheric acousticcut-off of $\approx$5.3 mHz, around four active regions, through spatial mapsof their power estimated using data from Helioseismic and Magnetic Imager (HMI)and Atmospheric Imaging Assembly (AIA) onboard Solar Dynamics Observatory(SDO). The wavelength channels 1600 {\AA} and 1700 {\AA} from AIA are now knownto capture clear oscillation signals due to helioseismic p modes as well aswaves propagating up through to the chromosphere. Here we study in detail, incomparison with HMI Doppler data, properties of the power maps, especially theso called 'acoustic halos' seen around active regions, as a function of wavefrequencies, inclination and strength of magnetic field (derived from thevector field observations by HMI) and observation height. We infer possiblesignatures of (magneto-)acoustic wave refraction from the observation heightdependent changes, and hence due to changing magnetic strength and geometry, inthe dependences of power maps on the photospheric magnetic quantities. Wediscuss the implications for theories of p mode absorption and mode conversionsby the magnetic field.

Properties of high-frequency wave power halos around active regions: an analysis of multi-height data from HMI and AIA onboard SDO