Evolution of a coronal hole wind stream and its coronal source region during CR 2039-2050

During solar minimum conditions the heliospheric structure of thesolar wind can be similar for several consecutive Carringtonrotations. This leads to co-rotating interaction regions in the solarwind and also implies that the magnetic field configuration of thesolar corona in the respective source regions changes onlyslowly. However, neither the solar wind nor the corresponding coronalstructures remain exactly the same but evolve from one Carringtonrotation to the next. Thus, such a configuration is well suited tostudy the evolution of these structure.During Carrington rotation 2040-2049 a recurring transition betweencoronal hole wind with hot Fe charge states and coronal hole wind withcool Fe charge states has been observed. This implies that theheliospheric structure is comparatively stable during this time periodand thus, these Carrington rotations serve as an interesting test caseto study the evolution of both the respective coronal hole wind streamand its source region.Observations from Solar Wind Ion Composition Spectrometer (SWICS), theSolar Wind Proton and Alpha Monitor (SWPAM) and the magnetometer (MAG)on the Advanced Composition Explorer (ACE) are used to characterizethe properties of the coronal hole wind stream. A combination ofballistic back-mapping with a potential field source surface (PFSS)model allows to trace the solar wind package from the spacecraft backto the source surface and down to the photosphere and investigate thecoronal source region of these streams. The PFSS model requires themagnetic field configuration at the photosphere which is taken fromthe Michelson Doppler imager (MDI) magnetograms on board of the Solarand Heliospheric Observatory (SOHO). With these tools we analyze theproperties of a recurring coronal hole wind stream over the course of12 Carrington rotations with respect to the similarities anddifferences in solar wind proton speed, proton density, protontemperature, charge state composition, in-situ magnetic field strengthobserved at ACE and correlate these with changes in the coronalmagnetic field of the source region as provided by the PFSS model.