Driven by the Beaufort High and associated wind-stress curl, the anticyclonic ocean gyre over the Canada Basin, as known as the Beaufort Gyre, is a dominant feature of the Arctic Ocean circulation. The Beaufort Gyre is the largest freshwater reservoir in the Arctic Ocean (Proshutinsky et al., 2009) and also is a region of the largest summer sea... Continue Reading →
Recent warming of the Indian Ocean suppresses the Indian summer monsoon circulation
A recent article published in Science Advances analyzed an atmospheric reanalysis dataset (MERRA2) covering the 1980–2016 period to show that a significant warming occurred in the Indian Ocean over the study period, and thus reduced the temperature difference between the Indian subcontinent and Indian Ocean in boreal summer. The reduced land-ocean temperature difference in turn produced anomalous... Continue Reading →
Increasing water temperature tied to rapid sea level rise along the U.S. East Coast during 2010-2015
In a new article accepted for publication in the Geophysical Research Letters, Ricardo Domingues (CIMAS University of Miami & NOAA/AOML) and his coauthors explored the observed rapid sea level rise along the U.S. East Coasts during 2010-2015, which is linked to extensive flooding and “sunny day” flooding (or nuisance flooding) events in large urban areas including... Continue Reading →
Natural variability in the Southern Ocean as a driver of the observed Antarctic sea-ice expansion trends
A team of scientists from Princeton University, NOAA-GFDL, and UCAR performed global climate model simulations, using a newly developed coupled ocean–atmosphere model SPEAR (Seamless System for Prediction and Earth System Research). When this model was driven with changes in past radiative forcing, the model simulation did not reproduce the observed increasing trends in sea-ice concentration around... Continue Reading →
Ocean acidification may induce toxic algal bloom and disrupt the pelagic food web
A field experiment led by a team of scientists from GEOMAR Helmholtz Centre for Ocean Research Kiel and others (Riebesell et al., 2018) showed that the toxic microalga Vicicitus globosus, known for its wide geographical distribution and confirmed role in fish kills, has an advantage under ocean acidification, increasing its abundance in natural plankton communities at CO2 levels higher... Continue Reading →
Antarctic meltwater slows down global warming by more than a decade
A new study published in Nature used climate models to explore the effects of meltwater from the Antarctic ice sheets and ice shelves on global surface temperature under a warming climate. The study found that the increasing meltwater decreases the surface salinity of the Southern Ocean and thus increases the near-surface stratification, which in turn... Continue Reading →
Deep convection that feeds the AMOC may occur in Arctic Sea under a warming climate
The Atlantic Meridional Overturning Circulation (AMOC) is a key ocean circulation system that carries heat, salt, carbon and other biogeochemical elements along its paths, redistributing them between hemispheres and across ocean basins, and thus is a crucial component of the global heat, salt and carbon balances. At present, the subduction of dense water (i.e., deep convection) that... Continue Reading →
Antarctic Ice Sheet retreat in the Amundsen Sea driven by central tropical Pacific SST variability
A new study appeared in Nature Geoscience (Jenkins et al., 2018) analyzed ocean temperature, salinity, dissolved-oxygen and current measurements from 2000 to 2016 near the Dotson Ice Shelf in the Amundsen Sea to determine temporal changes in net basal melting. The study showed that a decadal cycle dominates the ocean record, which is highly correlates with... Continue Reading →
Deglacial atmospheric CO2 increase caused by enhanced abyssal circulations in the Pacific Ocean
Paleo records indicate that during the last deglaciation period (19,000–9,000 years ago) atmospheric CO2 level increased by about 80 ppm. A new study published in Nature Geoscience analysed neodymium (Nd) isotope data in North Pacific sediment cores to find an increase in 14C age of North Pacific subsurface waters sourced from Antarctica indicating an enhanced abyssal overturning... Continue Reading →
Increasing role of the North Atlantic in anthropogenic ocean heat uptake
Anthropogenic aerosols preferentially cool the Northern Hemisphere, and the effect on surface heat flux into the North Atlantic opposes the greenhouse gas (GHG) effect. However, aerosols are projected to decline in the near future, reinforcing the greenhouse effect on the North Atlantic heat uptake. As a result, the surface uptake of anthropogenic heat by the... Continue Reading →