Accelerated warming of the Antarctic interior caused by moist air intrusion from the Weddell Sea

In a new study published in Nature Climate Change, Clem and colleagues reported that the South Pole has experienced a record-high warming of 1.81 ± 1.02°C during the last 30 years, three times larger than the global average. They used observational records to show that the recent warming of the South Pole, which started around 2000 following... Continue Reading →

Compensating change in the Indo-Pacific MOC in response to the Atlantic MOC slowdown

The climate model simulations forced with increasing anthropogenic greenhouse gases consistently project a robust decline of the Atlantic Meridional Overturning Circulation (MOC) and a strengthening of the Southern Hemisphere westerly winds, which may in turn result in an increase in the Southern Ocean MOC. In a research article recently accepted in the Journal of Physical... Continue Reading →

While the warming of northern hemisphere oceans almost stalled, the southern hemisphere oceans are heating up

Observations from Argo floats and satellite shows that the rate of global ocean warming during 2005-2015 is largely consistent with the climate simulations under the increasing greenhouse gas concentration. However, during that period, the southern hemisphere oceans have absorbed up to 98% of the net global ocean heat gain, while the warming of northern hemisphere... Continue Reading →

Future sea-ice loss slows down the subtropical Pacific shallow overturning cell and enhances the tropical warming

Under the high emission scenario for the future (RCP 8.5), a nearly ice-free Arctic Ocean (i.e., sea-ice extent less than 10-6 km2 for at least five consecutive years) in northern summer is likely before 2050. A decrease in Antarctic sea-ice extent is also expected during the 21st century, but at a slower rate with large uncertainty.... Continue Reading →

Increasing poleward intrusion of the Circumpolar Deep Water and its impact on the changing ocean-biogeochemistry of the Southern Ocean

A study published in Nature Geoscience (Bronselaer et al., 2020) analyzed new observations from autonomous floats with ocean-biogeochemical sensors (Bio-Argo) along with historical shipboard ocean measurements to document changes in Southern Ocean physical and ocean-biogeochemical variables (i.e., temperature, salinity, pH, concentrations of nitrate, dissolved inorganic carbon and oxygen) during the last two decades. Due to... Continue Reading →

Pantropical response to global warming and the emergence of a La Nina-like mean state trend

During the past century, the tropical Pacific Ocean has warmed significantly less than the other tropical oceans  in response to increasing greenhouse gases (GHGs). This La Nina-like warming trend in the observations is in stark contrast to the El Nino-like warming trend projected by the Coupled Model Intercomparison Project (CMIP) models for both the 20th... Continue Reading →

North Atlantic Tropical Cyclones have become increasingly likely to “stall” near the coast

Hurricane Dorian was a powerful storm that reached a maximum sustained wind of 185 mph (Cat 5 ≥ 157 mph) during its landfall over Abaco Islands on September 1, 2019. Hurricane Dorian made landfall on Grand Bahama with about the same intensity and stalled just north of the island for 24 hours, causing massive damages... Continue Reading →

New multivariate metrics help better monitor and predict global coral breaching events

Key factors that affect regional coral bleaching have been well studied and documented. These include extreme warm temperatures, the duration of extreme cold temperatures, and temperature bimodality (i.e., the exposure of corals to two distinct temperature regimes). However, some of these factors are more important than others in different regions because there are complex and interactive responses to... Continue Reading →

Recent warming of the tropical Indian Ocean may sustain the AMOC from slowing down

A recent study published in Nature Climate Change used a series of coupled ocean-atmosphere model simulations to demonstrate that the tropical Indian Ocean (TIO) warming reduces rainfall over the tropical Atlantic by strengthening the Walker circulation (i.e., increased ascending motion over TIO and increased subsidence over tropical Atlantic). This increases salinity of the upper tropical Atlantic Ocean.... Continue Reading →

Recent recovery of the Antarctic Bottom Water and its contribution to the Global Meridional Overturning Circulation

The lower limb of the Global Meridional Overturning Circulation (GMOC) is supplied by  the sinking of the heavy water mass that forms around the Antarctica, known as the Antarctic Bottom Water (AABW).  Repeat hydrographic data along the Atlantic, Pacific and Indian Ocean sections observed during the mid 1990s, 2000s and 2010s indicate that the volume... Continue Reading →

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