Any system of coordinates in which properties of a fluid are assigned to points in space at each given time, without attempt to identify individual fluid parcels from one time to the next. Since most observations in meteorology are made locally at specified time intervals, an Eulerian system is usually, though by no means always, more convenient. A sequence of synoptic charts is an Eulerian representation of the data. Eulerian coordinates are to be distinguished from Lagrangian coordinates. The particular coordinate system used to identify points in space (Cartesian, cylindrical, spherical, etc. ) is quite independent of whether the representation is Eulerian or Lagrangian. See equations of motion.