System and Method for Isolating Inertial and Non Inertial Velocities in the Ocean

摘要

System and method for partitioning a time series of velocity fields into inertial and non-inertial components to account for the variation of the inertial period over the range of latitudes within the field and to maintain the fidelity of non-inertial variability over both shorter and longer time scales. The system and method can facilitate flow interpretations and drift predictions by separating the less-reliable inertial components from the more-reliable non-inertial background.

主权项

1. A method for isolating an inertial oscillation component of a velocity field in a geographic area of a body of water, comprising:
(a) receiving data of a velocity field in a geographic area in a body of water, the velocity field comprising a plurality of water velocities at a corresponding plurality of associated locations in the water, each velocity having an inertial component and a non-inertial component, the inertial component of each velocity corresponding to an inertial oscillation of the body of water at the location associated with the velocity, and each associated location being identified by its latitude and longitude; (b) for each location in the velocity field, determining a corresponding inertial period, the inertial period being a temporal period of the inertial oscillation of the body of water at the latitude of that location; (c) receiving a specification of a specified time period over which the velocity data is to be analyzed, the specified time period comprising a series of specified time steps; (d) receiving data of the velocity field for each time step, the data at each time step comprising data of the velocities in the velocity field at that time step; (e) for each time step, calculating a weighted average of velocities within an inertial period of a specified location in the velocity field, the weighted average comprising the isolated non-inertial component of the velocities at the specified location at that time step,
wherein the weighted average at each time step is calculating by multiplying each of the velocities within the inertial period by at most a factor equal to a period of the time step,
each of the velocities at a beginning and/or an end of the inertial period being multiplied by a value corresponding to a prorated percentage of the time step, determined by an extent in the time step to which the inertial period encompassing those velocities extends beyond the beginning of the time step, and each of the remaining velocities within the inertial period being multiplied by a value corresponding to the entire time step;summing the multiplied velocities, and dividing the summed velocities by the inertial period; (f) for each velocity in the velocity field associated with the specified location, subtracting the weighted average of velocities found in step (e) from the velocity to obtain the isolated inertial component of the velocity at the specified location; and (g) repeating steps (b)-(f) for each location in the velocity field to obtain the isolated inertial component of the velocities in the velocity field.