Visualization showing the changes in snow cover and sea ice with the seasons, for the years 2019-2021.
Global snow cover and sea ice waxes and wanes with the seasons, as the axial tilt of the Earth with respect to the Sun oscillates throughout the year. As can be seen in this visualization, the cycles of ice and snow are about six months out of phase between the Northern and Southern Hemispheres, since the north is tilted towards the Sun when the nouth is tilted away, and vice versa.
Interactive Multisensor Snow and Ice Mapping System (IMS)/IMS Daily Northern Hemisphere Snow and Ice Analysis - 24 km Resolution also referred to as: IMS Daily Northern Hemisphere Snow and Ice Analysis
GCMD keywords can be found on the Internet with the following citation:
Olsen, L.M., G. Major, K. Shein, J. Scialdone, S. Ritz, T. Stevens, M. Morahan, A. Aleman, R. Vogel, S. Leicester, H. Weir, M. Meaux, S. Grebas, C.Solomon, M. Holland, T. Northcutt, R. A. Restrepo, R. Bilodeau, 2013. NASA/Global Change Master Directory (GCMD) Earth Science Keywords. Version 220.127.116.11.0