Observed Atlantic major hurricane frequency has exhibited pronounced multidecadal variability since the 1940s. However, the cause of this variability is debated. Using observations and a coupled earth system model (GFDL-ESM2G), here we show that the decline of the Atlantic major hurricane frequency during 2005–2015 is associated with a weakening of the Atlantic Meridional Overturning Circulation... Continue Reading →
Carbon uptake and biogeochemical change in the Southern Ocean, south of Tasmania
The carbon content of the water masses of the Southern Ocean south of Tasmania has increased over the period 1995–2011, leading to a general decrease in pH. An enhancement in the upwelling of DIC-rich deep waters is the main plausible cause of the increase in carbon in surface waters south of the Polar Front. North... Continue Reading →
Pacific origin of the abrupt increase in Indian Ocean heat content during the warming hiatus
Global mean surface warming has stalled since the end of the 20th century, but the net radiation imbalance at the top of the atmosphere continues to suggest an increasingly warming planet. This apparent contradiction has been reconciled by an anomalous heat flux into the Pacific Ocean, induced by a shift toward a La Nina-like state... Continue Reading →
US regional tornado outbreaks and their links to spring ENSO phases and North Atlantic SST variability
Recent violent and widespread tornado outbreaks in the US, such as occurred in the spring of 2011, have caused devastating societal impact with significant loss of life and property. At present, our capacity to predict US tornado and other severe weather risk does not extend beyond seven days. In an effort to advance our capability... Continue Reading →
Wind-driven ocean dynamics impact on the contrasting sea-ice trends around West Antarctic
Since late 1978, Antarctic sea-ice extent has overall expanded in all seasons in stark contrast to the retreating Arctic sea-ice extent. However, while the sea-ice extent around East Antarctica has increased monotonically, the sea-ice around West Antarctica exhibits regionally and seasonally inhomogeneous trends. For instance, Antarctic sea-ice extent in the East Pacific has decreased substantially... Continue Reading →
The defining characteristics of ENSO extremes and the strong 2015/16 El Niño
The El Niño Southern Oscillation (ENSO) continues to boast its prominence as Earth's strongest source of year-to-year climate variability with the appearance of a remarkable El Niño event in the boreal winter of 2015. The 2015/16 El Niño was indeed a strong event with dramatic impact on a global scale. However, it exhibited distinct characteristics... Continue Reading →