The Spatio-temporal Variation Pattern of Thermospheric Mass Density
Revealed by Co-clustering
Abstract
The spatio-temporal distribution characteristics of thermospheric mass
density have been given more attention with an increasing demand for
spacecraft launches and low Earth orbital prediction. More and more
patterns of spatial structure and temporal variation are being
discovered. Notwithstanding these developments, the study of
spatio-temporal coupling in characteristics analysis remains quite
limited. In this study, we use a co-clustering method to explore and
analyze the spatio-temporal coupling structural characteristics of
thermospheric mass density. The processed GOCE satellite dataset is
divided into 5 temporal clusters and 20 spatial clusters by the
co-clustering method. In terms of spatial structure, the density has an
obvious zonal distribution structure and hemispheric asymmetry.
Moreover, due to the influence of the Earth’s magnetic field, there is
an average angle about 2.00° between the band structure and the
latitudinal circle. In terms of temporal structure, the temporal
patterns of density can be grouped into five period types, namely the
quiet period, the moderate activity period, the event period, the
oscillation period and the recovery period. And significant positive
correlation can be found between the F10.7 indices and the temporal
density variation. This study explores the spatial structure and
temporal pattern of thermospheric mass density and its driving forces
from the perspective of spatio-temporal coupling based on a statistical
method, which can provide a new idea of spatio-temporal coupling method
for spatio-temporal evolution of thermospheric mass density.