We considered three methods that are traditionally utilized to identify, by using of satellite data, synoptic eddies. A comparison is carried out on the example of a water area located in the NW Pacific. 1) Sea level anomalies, 2) relative vorticity, and 3) Okubo-Weiss parameters are mapped based on satellite altimetry data. It has been revealed that the distribution of these three differs significantly in number, size, and allocation of isolated irregularities that are usually identifed as mesoscale eddies. Heterogeneities that are identified using the relative vorticity have smaller spatial scales compared with ones allocated in the sea level anomalies. Only distribution of sea level anomalies or relative vorticity can give a false picture of the vortices. Heterogeneities allocated in these fields are not synonymous with vortices since Okubo-Weiss parameter has positive values for them. We demonstrated that researchers often make erroneous interpretation of the altimetry data, finding eddies where they do not really exist. Formation of various heterogeneities in the sea level anomalies as well as in the relative vorticity could be influenced by other forces, especially by westward propagating planetary waves (low-frequency Rossby waves) and by their interaction with sea currents.