Sentences with phrase «cyclone activity varies»

Part of the difficulty in identifying the human component, if any is, as the IPCC Summary itself notes, that tropical cyclone activity varies naturally over the decades.

Not exact matches

NOAA has issued its annual forecast for the hurricane season, along with its now - standard explanation that there is a natural cycle of multidecadal (40 - 60 year) length in the North Atlantic circulation (often referred to as the «Atlantic Multidecadal Oscillation» — see Figure), that is varying the frequency of Atlantic tropical cyclones, and that the present high level of activity is due to a concurrent positive peak in this oscillation.

When we examine the relationship between SST and intensity, we find that although SSTs contribute significantly to tropical cyclone activity, their influence varies markedly over time.