Magnetic clouds are large-scale transient structures in the solar wind with
low plasma β, low-amplitude magnetic field fluctuations, and twisted
field lines with both ends often connected to the Sun. Their inertial-range
turbulent properties have not been examined in detail. In this Letter, we
analyze the normalized cross helicity, σc​, and residual energy,
σr​, of plasma fluctuations in the November 2018 magnetic cloud observed
at 0.25 au by the Parker Solar Probe. A low value of ∣σc​∣ was present
in the cloud core, indicating that wave power parallel and anti-parallel to the
mean field was approximately balanced, while the cloud's outer layers displayed
larger amplitude Alfv\'enic fluctuations with high ∣σc​∣ values and
σr​∼0. These properties are discussed in terms of the cloud's solar
connectivity and local interaction with the solar wind. We suggest that low
∣σc​∣ is likely a common feature of magnetic clouds given their
typically closed field structure. Anti-sunward fluctuations propagating
immediately upstream of the cloud had strongly negative σr​ values.Comment: 9 pages, 4 figures; accepted for publication in the Astrophysical
Journal Letters 2020 August 1