Inhomogeneous Kinetic Alfvén Waves in the Near-Sun Solar Wind

Abstract Intervals of intense electromagnetic, broadband plasma waves are reported in the near-Sun solar wind. These identified as kinetic Alfvén (KAWs), based on comparison between data and theory for their observed electric- to magnetic-field ratio, magnetic compressibility, a function frequency. In contrast KAW observations at 1 au, KAWs wind found be spatially inhomogeneous, preferentially occurring where ambient field experiences strong deviations from Parker spiral direction, including during switchbacks clusters switchbacks. To extent that turbulent fluctuations small scales characterized KAWs, here create an expectation KAW-driven particle heating should also inhomogeneous wind, being strongest regions KAWs. Finally, discrepancy observation is frequencies two decades above frequency effects begin manifest, possible origins this considered.