And variations in the thickness and extent of sea ice cloaking the Arctic Ocean are driven by yet another set of complicating factors, ranging from long - term shifts in atmospheric pressure patterns to events as close - focus as the potent Arctic superstorm I reported on earlier this month. (dotearth.blogs.nytimes.com)
The degree to which Arctic air penetrates into middle latitudes is related to the Arctic Oscillation (AO) index, which is defined by surface atmospheric pressure patterns and is plotted in Figure 6. (climatesciencewatch.org)
According to Gerry Bell, Ph.D., NOAA's lead seasonal hurricane forecaster, the major climate factors expected to influence this year's activity are the ongoing multi-decadal signal, which produces wind and atmospheric pressure patterns favorable for hurricane formation, along with ongoing warmer - than - normal sea surface temperatures. (noaanews.noaa.gov)