  The presence of intense magnetic fields in and around sunspots is expected to
modify the solar structure and oscillation frequencies. Applying the ring
diagram technique to data from the Michelson Doppler Imager (MDI) on board the
Solar and Heliospheric Observatory (SOHO), we analyze the characteristics of
high-degree f and p modes near active regions and compare them with the
characteristics of the modes in quiet regions. As expected from earlier
results, the f- and p-mode frequencies of high degree modes are found to be
significantly larger in magnetically active regions. In addition, we find that
the power in both f and p modes is lower in active regions, while the widths of
the peaks are larger, indicating smaller lifetimes. We also find that the
oscillation modes are more asymmetric in active regions than those in quiet
regions, indicating that modes in active regions are excited closer to the
surface. While the increase in mode frequency is monotonic in frequency, all
other characteristics show more complex frequency dependences.
