Francis has hypothesized that the warming Arctic is altering global circulation patterns, which could make the warm west — cold east pattern more common. (sciencemag.org)
According to the note, he challenged Weinberg's assertion that global circulation patterns move CO2 out of the deep oceans to the surface where it escapes into the atmosphere, a process known as «upwelling.» (insideclimatenews.org)
There are plenty of diagrams that show how global circulation patterns work (in fact, I have included one more below). (earthobservatory.nasa.gov)