Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
A synthesized example showing the usage of different types of speeds (intensity and advection field). The x and y components of the GVF field are rendered in red and green, respectively. The eastern and western US are delineated by the GVF field despite having the same image intensity.
