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We compare the properties of kG magnetic structures in the solar network and in active region plage at high spatial resolution. Our analysis used six SP scans of the solar disc centre aboard Hinode SOT and inverted the obtained spectra of the photospheric 6302 \AA line pair using the 2D SPINOR code. Photospheric magnetic field concentrations in network and plage areas are on average 1.5 kG strong with inclinations of 10-20 degrees, and have <400 m/s internal and 2-3 km/s external downflows. At the disc centre, the continuum intensity of magnetic field concentrations in the network are on average 10% brighter than the mean quiet Sun, whilst their plage counterparts are 3% darker. A more detailed analysis revealed that all sizes of individual kG patches in the network have 150 G higher field strengths on average, 5% higher continuum contrasts, and 800 m/s faster surrounding downflows than similarly sized patches in the plage. The speed of the surrounding downflows also correlates with the patch area, and patches containing pores can produce supersonic flows exceeding 11 km/s in individual pixels. Furthermore, the magnetic canopies of kG patches are on average 9 degrees more horizontal in the plage compared to the network. Most of the differences between the network and plage are due to their different patch size distributions, but the intrinsic differences between similarly sized patches is likely results from the modification of the convection photospheric convection with increasing amounts of magnetic flux., Comment: Accepted by A&A

We present data of 10 penumbral microjets (PMJs) observed in H\alpha, Ca II 8542 \AA, and Fe I 6302 \AA line pair with the Swedish 1 m Solar Telescope (SST) with CRISP and Ca II K with SST/CHROMIS in active region NOAA 12599 on the 12th October 2016 at \mu=0.68. All four Stokes parameters of the Ca II 8542 \AA and Fe I 6302 \AA lines were observed and a series of test pixels was inverted using the Stockholm inversion code. Our analysis revealed for the first time that PMJs are visible in H\alpha, where they appear as dark features with average line-of-sight (LOS) upflows of 1.1\pm0.6 km/s, matching the LOS velocities from the inversions. Based on the H\alpha observations we extend the previous average length and lifetime of PMJs to 2815\pm530 km and 163\pm25 s, respectively. The plane-of-sky (POS) velocities of our PMJs of up to 17 km/s tend to give increased velocities with distance travelled. Furthermore, two of our PMJs with significant Stokes V signal indicate that the PMJs possess an increased LOS magnetic field of up to 100 G compared to the local pre-/post- PMJ magnetic field, which propagates as quickly as the PMJs' POS velocities. Finally, we present evidence that PMJs display an on average 1 minute gradual precursory brightening that only manifests itself in the cores of the Ca II lines. We conclude that PMJs are not ordinary jets but likely are manifestations of heat fronts that propagate at the local Alfven velocity.

The formation of an Ha filament in active region (AR) 10953 is described. Observations from the Solar Optical Telescope (SOT) aboard the Hinode satellite starting on 27th April 2007 until 1st May 2007 were analysed. 20 scans of the 6302A Fe I line pair recorded by SOT/SP were inverted using the SPINOR code. The inversions were analysed together with SOT/BFI G-band and Ca II H and SOT/NFI Ha observations. Following the disappearance of an initial Ha filament aligned along the polarity inversion line (PIL) of the AR, a new Ha filament formed in its place some 20 hours later, which remained stable for at least 1.5 days. The creation of the new Ha filament was driven by the ascent of horizontal magnetic fields from the photosphere into the chromosphere at three separate locations along the PIL. The magnetic fields at two of these locations were situated directly underneath the initial Ha filament and formed orphan penumbrae already aligned along the Ha filament channel. The 700 G orphan penumbrae were stable and trapped in the photosphere until the disappearance of the overlying initial Ha filament, after which they started to ascend into the chromosphere at 10pm5 m/s. Each ascent was associated with a simultaneous magnetic flux reduction of up to 50% in the photosphere. The ascended orphan penumbrae formed dark 'seed' structures in Ha in parallel with the PIL, which elongated and merged to form an Ha filament. The filament channel featured horizontal magnetic fields of on average 260 G at log(tau)=-2 suspended above the nearly field-free lower photosphere. The fields took on an 'inverse' configuration at log(tau)=-2 suggesting a flux rope for the new Ha filament. The orphan penumbral fields ascend into the chromosphere 9-24 hours before the Ha filament is fully formed. The destruction of the initial Ha filament was likely caused by the flux emergence at the third location along the PIL., Comment: 14 pages, 10 Figures, accepted in A&A

The properties of magnetic fields forming an extended plage region in AR 10953 were investigated. Stokes spectra of the Fe I line pair at 6302 \AA recorded by the spectropolarimeter aboard the Hinode satellite were inverted using the SPINOR code. The code performed a 2D spatially coupled inversion on the Stokes spectra, allowing the retrieval of gradients in optical depth within the atmosphere of each pixel, whilst accounting for the effects of the instrument's PSF. Consequently, no magnetic filling factor was needed. The inversion results reveal that plage is composed of magnetic flux concentrations (MFCs) with typical field strengths of 1520 G at log(\tau)=-0.9 and inclinations of 10-15 degrees. The MFCs expand by forming magnetic canopies composed of weaker and more inclined magnetic fields. The expansion and average temperature stratification of isolated MFCs can be approximated well with an empirical plage thin flux-tube model. The highest temperatures of MFCs are located at their edges in all log(\tau) layers. Whilst the plasma inside MFCs is nearly at rest, each is surrounded by a ring of downflows of on average 2.4 km/s at log(\tau)=0 and peak velocities of up to 10 km/s, which are supersonic. The downflow ring of an MFC weakens and shifts outwards with height, tracing the MFC's expansion. Such downflow rings often harbour magnetic patches of opposite polarity to that of the main MFC with typical field strengths below 300 G at log(\tau)=0. These opposite polarity patches are situated beneath the canopy of their main MFC. We found evidence of a strong broadening of the Stokes profiles in MFCs and particularly in the downflow rings surrounding MFCs (expressed by a microturbulence in the inversion). This indicates the presence of strong unresolved velocities. Larger magnetic structures such as sunspots cause the field of nearby MFCs to be more inclined., Comment: 19 pages, 25 figures, accepted by A&A

The Hinode mission has revealed copious amounts of horizontal flux covering the quiet Sun. Local dynamo action has been proposed to explain the presence of this flux. We sought to test whether the quiet Sun flux detected by Hinode is due to a local or the global dynamo by studying long-term variations in the polarisation signals detectable at the disc centre of the quiet Sun between November 2006 and May 2012, with particular emphasis on weak signals in the internetwork. The investigation focusses on line-integrated circular polarisation V_tot and linear polarisation LP_tot profiles obtained from the Fe I 6302.5 \AA absorption line in Hinode SOT/SP. Both circular and linear polarisation signals show no overall variation in the fraction of selected pixels from 2006 until 2012. There is also no variation in the magnetic flux in this interval of time. The probability density functions (PDF) of the line-of-sight magnetic flux can be fitted with a power law from 1.17 x 10^17 Mx to 8.53 x 10^18 Mx with index \alpha=-1.82 \pm 0.02 in 2007. The variation of \alpha 's across all years does not exceed a significance of 1\sigma. Linearly polarised features are also fitted with a power law, with index \alpha=-2.60 \pm 0.06 in 2007. Indices derived from linear polarisation PDFs of other years also show no significant variation. Our results show that the ubiquitous horizontal polarisation on the edges of bright granules seen by Hinode are invariant during the minimum of cycle 23. This supports the notion that the weak circular and linear polarisation is primarily caused by an independent local dynamo.