ИСТИНА

We used data of the auroral particle precipitations measured by the DMSP satellite mission to obtain the plasma pressure profiles for different MLT sectors before, during, and after isolated geomagnetic substorms with minimum value of AL index ranging between -300 and -1200 nT. Tsyganenko 2001, 2004 and IGRF geomagnetic field models were used to map the obtained pressure profiles into the equatorial plane. For some events we reached to compare these profiles with the plasma pressure measured in situ by THEMIS mission satellites. It was found that the pressure profiles become steeper before the onset and during the expansion phase of substorm, and the value of pressure also increases. The analysis of the corresponding solar wind data showed that these increases are correlated with the increases in the solar wind dynamic pressure.