Tropical ocean warming provides optimal growth condition for iron-limited cyanobacterium

Although the cyanobacterium (Trichodesmium) fixes as much as half of the nitrogen (N2) that supports tropical open-ocean ecosystem, its growth is limited by iron (Fe) availability. A study published in Nature Climate Change performed laboratory experiments to show that the optimum growth temperature of Fe-limited Trichodesmium is about 32°C, which is much higher than for Fe-replete cells (about... Continue Reading →

Co-variability of salinity, nutrients and coastal currents in the northern Gulf of Mexico and its impact on plankton biomass

The northern Gulf of Mexico (GoM) is a region strongly influenced by river discharges of freshwater and nutrients, which promote a highly productive coastal ecosystem that host commercially valuable marine species. A new study appeared in Scientific Report utilized a regional ocean-biogeochemical model and observations to show that El Niño - Southern Oscillation (ENSO) is a main... Continue Reading →

Global meridional overturning circulation revisited

Ocean tracers such as heat, salt and carbon are perpetually carried by the global meridional overturning circulation (GMOC) and redistributed between hemispheres and across ocean basins from their source regions. The GMOC is therefore a crucial component of the global heat, salt and carbon balances. In a new article accepted in Geophysical Research Letter, a... 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 →

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