  By the study of the dynamical processes related to entropy, this work aims to
create a mathematical tool to identify magnetic clouds (MCs) in the
interplanetary space using only interplanetary magnetic field (IMF) data. Used
as basis for an analysis methodology, the spatio-temporal entropy (STE)
measures the image (recurrence plots) "structuredness" in both space and time
domains. Initially we worked with the Huttunen et al. 2005's dataset and
studied the 41 MCs presenting a shock wave identified before the cloud. The STE
values for each Bx, By, Bz IMF time series, with dimension and time delay equal
to one, were respectively calculated. We found higher STE values in the sheaths
and zero STE values in some of the three components in most of the MCs (30
among 41 events). In a physically consistent manner, data windows of 2500
magnetic records were selected as the calculation interval for the time series.
As not all MCs have zero STE simultaneously, we created a standardization index
(an entropy index, called as EI) to allow joining the result of the three
components. With the use of EI three not known MCs were indeed identified and
then the MVA method allowed calculating their boundaries. Thus the EI is
proposed as an auxiliary tool to identify MC candidates based only on IMF
analysis. In a promissor condition, this methodology implemented gives basis
for an automatic MC identification procedure and surely useful for space
weather purposes.
