Nearshore sea ice shield Antarctic ice shelves from the damaging impact of ocean waves

The Larsen ice shelves extend along the east coast of the Antarctic Peninsula over the northwest part of the Weddell Sea. From north to south, these segments are called the Larsen A, B, C, and D, bordered by Filchner–Ronne Ice Shelf south of the Weddell Sea. In 1995, the Larsen A ice shelf completely disintegrated,... Continue Reading →

North Atlantic zonal winds will shift northward and become more extreme in the future

The warming response of the upper atmosphere is much stronger in the tropics due to higher water vapor content and frequent deep tropical convection that maintains the atmosphere column well-mixed. As a result, the zonal jet strength, which is largely proportional to the meridional gradient of atmosphere temperature via "thermal wind relationship" is projected to... Continue Reading →

Why climate models are unable to reproduce the observed Antarctic sea-ice expansion

Antarctic sea-ice has expanded over the period of continuous satellite monitoring, which seemingly contradicts ongoing global warming resulting from increasing concentrations of greenhouse gases. A variety of hypotheses have been proposed to explain the observed Antarctic sea-ice expansion and corresponding model–observation discrepancy, but the issue remains unresolved. In a new study published in Nature Climate... Continue Reading →

Sea-ice retreat may invigorate the weakening Atlantic Meridional Overturning Circulation

Due to rapidly rising air temperature over the Arctic and subarctic regions, the ocean-to-air turbulent (i.e., sensible and latent) heat flux over the Greenland, Iceland, and Norwegian Seas (GINS) has diminished (i.e., less cooling of the surface ocean) steadily during the satellite period (i.e., since the 1970s). This may lead to a reduction of deep... Continue Reading →

Arctic Ocean is experiencing dramatic weight loss due to increasing freshwater storage

The freshwater cycle in the Earth System is a delicate balance between the net loss (i.e., evaporation > precipitation) in the warm tropical-subtropical oceans, the net gain (i.e., precipitation > evaporation) in the cold polar oceans, and the net poleward transport by the atmosphere. These processes maintain the tropical-subtropical oceans salty and the polar oceans... Continue Reading →

Why does the Arctic temperature rise faster in the cold season?

The Arctic warming response to increasing greenhouse gas is substantially greater than the rest of the globe. It has been suggested that this phenomenon, commonly referred to as Arctic amplification, and its peak in boreal fall and winter result primarily from the so-called lapse-rate feedback, which is associated with the vertical structure of tropospheric warming,... Continue Reading →

Increasing influence of warm and salty Atlantic water on the cold season Arctic sea ice melting

The Arctic Ocean in the upper 100 - 200 m is typically characterized by a cold and fresh surface mixed layer and a layer of rapidly increasing salinity with depth, as known as halocline, separating the surface mixed layer from the warm and salty Atlantic water at depth. Due to large vertical density gradient and... Continue Reading →

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 →

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