A1D4.3
A1D4.3
From Soteria
Lead Beneficiary: MTA-KFKI-RMKI
Beneficiaries involved: DTU, UOulu, KULeuven
Due Date: month 24
Goal
Report on results of Task 4.2 Solar wind – magnetosphere coupling and the terrestrial impact
Progress so far
At KFKI RMKI 5 intervals were investigated in 2003 and 2005 when the magnetopause and the bow shock were unusually close to the Earth due to large interplanetary disturbances (solar wind dynamic pressure > 10 nPa and southward magnetic field Bz < -5 nT). The standoff distance of the nose of both discontinuities was calculated (cf. Shue et al., JGR, 1997; Farris and Russell, JGR, 1994) and their displacements were determined from Cluster observations. Interplanetary parameters were taken from the OMNI dataset using ACE, WIND, and Geotail measurements. Disturbances in the magnetic field and in the fluxes of energetic particles were also analysed at geostationary orbit based on GOES measurements. OMNI and GOES data were taken from http://cdaweb.gsfc.nasa.gov Two of the selected intervals are included in the Event Catalogue put together by WP4 (see A1D4.1). KFKI-RMKI provided the magnetopause standoff distances for all 8 time intervals presented in the catalogue.
At KU Leuven selected conditions for realistic modeling of reconnection regions both in the dayside and in the tail were investigated by implicit particle-in-cell code Parsek in collaboration with the teams of NASA MMS mission. The focus has been primarily in elucidating the role of electron holes and their induced turbulence on the reconnection. Access to the SPENVIS online system is acquired and its use is studied, in order to utilize it for investigating the effect of radiation on satellites.
UOulu has studied the effect of instrument radiation damage on energetic particle fluxes measured by the MEPED instrument onboard all (some ten) low-altitude NOAA/POES satellites. Radiation damage increases the effective energy threshold of the instrument and leads to erroneously low fluxes already 2 years after satellite launch. Detailed intercalibration between the NOAA satellites was made to obtain the first long-term series of corrected energetic particle fluxes for 30 years (1979-2009). This work is currently under review in Journal of Atmospheric and Solar-Terrestrial Physics.
UOulu has developed a semi-empirical model that allows to estimate the separate contributions of the ring current, the magnetopause current and the tail current on the Dcx/Dst index. The model is based on solar wind observations and the energetic particle fluxes measured by the NOAA MEPED instruments. We have applied this model to estimate the contribution of the three current systems during the selected WP4 events. Preliminary analysis shows that the tail current contribution to the Dcx/Dst index is very large during the main phase of some but not all storms. We will still improve the model and use the calibrated MEPED data to study the current systems and dynamics over up to three solar cycles. A paper describing this work is under preparation.
DTU is working on identifying the individual contributions of ring current, magneto-pause currents, field-aligned currents and ionospheric currents on magnetic perturbations at mid- an low latitudes, both at ground and as measured by LEO-satellites (Oersted and CHAMP). Particular effort has been put into quantifying the effect of high-latitude field-aligned currents at mid- and low latitudes, and the first results of this was presented at the EGU 2009 general assembly. In addition computer codes to estimate the different contributions as given in MHD model output, such as BatsRus, has been made in close collaboration with the CCMC at NASA.
List of the people working on this deliverable: MTA-KFKI-RMKI: Mariella Tatrallyay, Zoltan Nemeth; DTU: Susanne Vennerstrom; UOulu: Kalevi Mursula, Timo Asikainen; KU Leuven: Marina Skender
