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 →
Future El Niño events will develop faster and persist longer
Previous studies based on the climate models participating in the Coupled Model Intercomparison Project (CMIP) have suggested an increase in the frequency of extreme El Niño events in the 21st Century in response to increasing greenhouse gases. Several studies have attributed these shifts in El Niño frequency and amplitude to the projected changes in the... Continue Reading →
New aircraft-based observations confirm the role of the Southern Ocean as a significant carbon sink
Ship-based CO2 flux estimates of the contemporary air-sea flux of CO2 showed that the Southern Ocean (south of 35oS) plays an important role as a significant carbon sink, with a net uptake at the rate of −0.8 ~ −1.0 Pg C/year (Takahashi et al., 2009; Landschützer et al., 2014) largely consistent with climate model-based estimates... Continue Reading →
Increasing river alkalinity slows ocean acidification in river-dominated ocean margins
Although ocean acidification (OA) is mainly driven by the ocean uptake of anthropogenic carbon dioxide from the atmosphere, multiple factors including changes in ocean temperature, biological processes, and river discharge influence its temporal progression. In a new paper accepted in the Geophysical Research Letters, a team of researchers from the Northern Gulf Institute of the... 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 →
Zooplanktons eat microplastics? Yes, they do and it may reshape the global ocean-biogeochemistry
Plastics are now widely distributed in the global ocean, serving as a new and serious contaminant for marine ecosystems. For instance, ingestion of small plastic detritus ( 0.1 μm ~ 5 mm), “microplastics” by fish, mussels and seabirds has been widely reported. A recent study (Cole et al., 2013) used fluorescence bioimaging techniques to show... 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 →
