Wavelet analysis of Solar plasma flow wave phenomena for they identification

Abstract:

Research to the identification of plasma streams in the Solar wind from the spectral wavelet skeleton images in a magneto-hydrodynamic rangeis devoted. The basis of the approach developed laid parametric classification differentiated bandwidths spectral features of Solar plasma flows in the form of magnetic clouds without sheath and with them (MC, MC + Sheath), corotating interaction regions (CIR), shock waves (Shocks) and high-speed streams from coronal holes (HSS). To demonstrate the method 30 events registration of these types of plasma flows on the ACE and Wind spacecraft during the period from 1998 to 2007 was considered, according directory NASA (http://cdaw.gsfc.nasa.gov) and NOAA (http://ngdc.noaa.gov). Within each event received wavelet spectra for: minute data density N, velocity V, temperature T , pressure P, and interplanetary magnetic field module | B | and components Bx, By, Bz. In consideration included fluctuations in the period range 2-30 min ( 8.3-0.6 mHz) and 31-60 min (0.6-0.3 mHz) . To find a set of parameters most relevant to each type of flow applied neural network classification method . The result was that in the period range 2-30 min neural network performs reliable (in over 50 % of cases) identification of the type of flows CIR (83%) and Shocks (66%) using a set of parameters N, V, and P. In the range of periods 31-60 min neural network performs reliable identification of types of streams using the following sets of parameters: V, P , | B |, Bz for MC (100% identification); N, V, P , Bzfor MS + Sheath (83%) and V, T, P for HSS (in 66% of cases). Thus demonstrated that the original classification algorithm parametric data, in the flow of the Solar wind recorded in Earth orbit patrol spacecraft and submitted wavelet skeleton images useful for "on-line " monitoring of near space. This approach will help to detect the early stages in the Solar wind flow geoeffective structure to predict global geomagnetic disturbances.