As the surface ocean warms and polar ice sheets melt due to increasing anthropogenic greenhouse gases in the atmosphere, near-surface stratification is increasing almost everywhere, including the major deep water formation regions in the high-latitude North Atlantic and around Antarctica. As a result, the global Meridional Overturning Circulation (MOC), also known as the global ocean... Continue Reading →
Papers that I enjoyed reading in February 2023
Zhang, R., Sun, S., Chen, Z., Yang, H., & Wu, L. (2023). Rapid 21st century weakening of the Agulhas current in a warming climate. Geophys. Res. Lett., 50, e2022GL102070. https://doi.org/10.1029/2022GL102070: The Agulhas current is projected to slow down and become shallower during the rest of the 21st century, partly in response to the slowdown of... Continue Reading →
Antarctic Bottom Water (AABW) export pathways across the Southern Ocean
The Antarctic Bottom Water (AABW) is the densest water mass of the global ocean that covers about 30 ~ 40% of the global ocean volume with temperatures ranging from -0.8 to 2°C and salinities from 34.6 to 34.7 psu. It forms around Antarctica and spreads into the Southern Ocean and then into the Atlantic, Indian,... Continue Reading →
How I review a scientific paper
As a career scientist, I review scientific papers regularly, at least once every month. For instance, I reviewed a total of 18 papers in 2021, and many of them 2 ~ 3 times for revisions. I think I can speak for almost everyone that nobody really enjoys reviewing papers. We do it because it is... Continue Reading →
Java-Sumatra Niño/Niña: two long-lost siblings of El Niño
There are many siblings, cousins, and distant relatives of El Niño spanning the Pacific, Atlantic, and Indian Oceans who share a feature in common: ocean surface temperature anomalies along eastern boundaries linked to changes in the upwelling of cooler water from below. So far, climate scientists have identified a total of 14 members of this... Continue Reading →
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 →
An overlooked role of the subtropical gyre circulation in regulating the AMOC
It is a common practice in Physical Oceanography to separate the Atlantic Ocean circulations into the meridional overturning and wind-driven gyre components with an assumption that the two components are largely independent of each other. An article published in Nature Communications suggests that the two components are not at all independent. The study shows that... 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 →