Transient obscuration event captured in NGC~3227 II. Warm absorbers and
  obscuration events in archival XMM-Newton and NuSTAR observations
  The relation between warm absorber (WA) outflows of AGN and nuclear
obscuration activities caused by optically-thick clouds (obscurers) crossing
the line of sight is unclear. NGC 3227 is a suitable target to study the
properties of both WAs and obscurers, because it matches the following
selection criteria: WAs in both ultraviolet (UV) and X-rays, suitably variable,
bright in UV and X-rays, good archival spectra for comparing with the obscured
spectra. To investigate WAs and obscurers of NGC~3227, we used a broadband
spectral-energy-distribution model built in our Paper I and the photoionization
code of SPEX software to fit archival XMM-Newton and NuSTAR observations in
2006 and 2016. Using unobscured observations, we find four WAs with different
ionization states (log$\xi$ [erg cm/s]~-1.0, 2.0, 2.5, 3.0). The
highest-ionization WA has a higher hydrogen column density (~$10^{22}$/cm$^2$)
than the other three WAs (~$10^{21}$/cm$^2$). Their outflow velocities range
from 100 to 1300 km/s, and show a positive correlation with the ionization
parameter. These WAs are estimated to be between the outer broad-line-region
(BLR) and the narrow line region. Besides, we find an X-ray obscuration event
in 2006, which was missed by previous studies. It can be explained by a single
obscurer. We also study the previously published obscuration event in 2016,
which needs two obscurers in the fit. A high-ionization obscurer
(log$\xi$~2.80; covering factor $C_f$~30%) only appears in 2016, which has a
high column density (~$10^{23}$/cm$^2$). A low-ionization obscurer
(log$\xi$~1.0-1.9; $C_f$~20%-50%) exists in both 2006 and 2016, which has a
lower column density (~$10^{22}$/cm$^2$). These obscurers are estimated to be
in the BLR by their crossing time of transverse motions. The obscurers and WAs
of NGC 3227 have different distances and number densities, which indicate that
they might have different origins.
