velocity {satin}

Ocean currents velocities

Description

Calculate ocean current speed and direction from eastward and northward components (Copernicus data).

Usage

velocity(u, v, depth = 1) 

Arguments

u

a satin object with eastward ocean current velocities (in m/s).

v

a satin object with northward ocean current velocities (in m/s).

depth

an integer referring to a depth level.

Details

This function calculates the resulting velocity vectors in the same way as the "quiver" function. In addition, these values are returned togheter with their direction in degrees.

Value

A list with 2 elements, “speed” and “rhumb”, both of class "satin". The former contains the resulting velocity vectors as drawn by "quiver", while the second their direction in degrees.

Author(s)

Héctor Villalobos

Examples

if(interactive()){
# import copernicus data with potential temperatures and ocean current velocities
oc <- read.cmems("global-reanalysis-phy-001-030-daily_1560792767602_GC_2013-14.nc")

vel <- velocity(u = oc$uo, v = oc$vo)

# Plots overlaying velocity vectors 
plot(vel$speed)
quiver(u = oc$uo, v = oc$vo, main = "", length=0.02, scale = 0.7, add2map = TRUE)	   

plot(vel$rhumb, col.sep = 90, scheme = c('#d7301f', '#fc8d59','#fdcc8a', '#fef0d9'))
quiver(u = oc$uo, v = oc$vo, main = "", add2map = TRUE)
}