Tidal currents flood and ebb with the tide, but their motion does not average to zero everywhere over a tidal cycle. 

A recent study published in National Science Review has revealed that the Indian Ocean Dipole (IOD), traditionally regarded as a single climate mode, consists of two distinct types with different physical mechanisms and climate impacts. The findings advance the understanding of Indian Ocean variability and provide new insights into how IOD events influence regional climate.

Improving the subseasonal-to-seasonal (S2S) forecast skill for East Asian winter cold surges remains a grand challenge in operational meteorology. Using ECMWF hindcast data, a research team systematically identified the "high-skill windows" of week-3 cold surge forecasts. They found that a "warm-west/cold-east" sea surface temperature dipole over the mid-latitude North Pacific emerges as a consistent precursor of these windows under both El Niño and La Niña conditions, but that the dipole alone is not enough: high skill emerges only when the SST anomalies in all the key regions, including the Barents-Kara Seas, the Indian Ocean and the tropical Pacific, meet their thresholds at the same time. This makes it possible to pre-screen a subseasonal forecast's reliability before it is issued. The work was published in SCIENCE CHINA Earth Sciences.

 NOAA Fisheries scientists are tracking West Coast conditions as part of our Integrated Ecosystem Assessment. Here are some of the changes in ocean conditions and marine life that typically signal the arrival of El Niño’s influence along the West Coast.

A series of studies sheds new light on the early stages of the evolution of the planet closest to the Sun. Using experimental petrology, the researchers are reconstructing in the laboratory the formation of Mercury’s core, the crystallisation of its magma ocean and the formation of its mantle.

Climate change continues to threaten the world’s coral reefs, which support at least a quarter of all marine life. Though probiotics have been shown to rehabilitate corals in aquarium experiments, demonstrating the efficacy of such microbial therapy in the ocean is difficult. In a study publishing in the Cell Press journal Cell Reports on September 3, researchers establish that both live probiotic and inactivated postbiotic treatments improve coral health—while the animals are under thermal stress during a natural marine heatwave.

Michigan State University researchers are uncovering the secrets of how some plants adapt to toxic salt, with help from coastal wildflowers that thrive in salt-laden ocean spray that kills other plants. The research could lead to ways to make crops more resilient to salt exposure from other sources, such as winter road salt or worsening storm surges.

Global study of more than 23,000 marine mollusk species projects major shifts in body size by 2100 — including surprising growth in some animals and ocean regions