Recently, associate researcher Wang Yuntao of the State Key Laboratory of Satellite Marine Environmental Dynamics and others published a paper on the Journal of Geophysical Research detailing the temporal and spatial pattern of the temperature front in the East Pacific and the dynamic mechanism of the formation and migration of the dominant front, and found that the wind field drove seasonal changes of the nearshore front, El Niño and Southern Oscillation (ENSO) modulated the inter-annual changes of the equatorial open ocean front, and enhanced the understanding of ocean dynamic processes in the global ocean.

By analyzing the change characteristics of the monthly frontal frequency, it is found that the East Pacific has eight active frontal areas, which are mainly distributed in the coastal and equatorial open ocean waters. Among them, the main feature of the nearshore front is seasonal change: the mid-latitude area is affected by the wind field in the equator direction along the coast, and the nearshore upwelling brings cold water to the sea surface, which drives the generation of the front and the front reaches its peak in the local summer. Under the continuous action of wind field, vortex, and Rossby wave, the front migrates to the far shore and finally moves to the far shore, which affects the dynamic environment of the open ocean; the equatorial area is affected by the topography of the piedmont, and the wind field is enhanced when it passes through the mountains. The vertical mixing caused leads to the decrease of the nearshore water temperature and the formation of a front with the warm water on the far shore, which plays an important role in the local ocean dynamic process and the mesoscale air-sea coupling.

The equatorial open ocean area forms an equatorial upwelling under the action of the wind field, which drives the generation of fronts. Under the combined action of Rossby wave and equatorial instability wave, the front has the characteristic of passing westward. By analyzing the relationship between the inter-annual variability of the front and ENSO, it is found that the equatorial region forms wind field concentration in the El Niño year, which weakens the upwelling, so the frontal activity is significantly reduced. Since the frontal activity has certain advancement compared with the ENSO index, the frontal characteristics of the equatorial region can be used to predict the occurrence of events such as El Niño.

The study uses the front detection algorithm to describe the temporal and spatial pattern of the ocean front in the East Pacific, deepens the understanding of ocean-scale dynamic processes, and has universal reference significance for the global frontal active areas, and provides support for further assessment of the primary productivity, carbon cycle, fishery resources and other scientific issues.