Sea surface cooling along tropical cyclone (TC) tracks has been well observed, but a complete understanding of the full three‐dimensional structure of upper ocean TC‐induced cooling is still needed. In this study, observed ocean temperature profiles derived from Argo floats and TC statistics from 1996 to 2012 are used to determine the three‐dimensional structure of TC‐induced cooling over the northwest Pacific. The average TC‐induced sea surface temperature change derived from Argo reaches −1.4°C, which agrees well with satellite‐derived estimates. The Argo profiles further reveal that this cooling can extend to a depth of ~30 m and can persist for about 20 days. The time scale of cooling recovery is somewhat longer in subsurface layers between a depth of ~10–15 m. Over the ocean domain where the mixed layer is shallower (deeper), the cooling is stronger (weaker), shallower (deeper), and more (less) persistent. The effect of initial MLD on the cooling derived from Argo observations may be only half of the idealized piecewise continuous model of tropical cyclone. These findings have implications for the total upper ocean heat content change induced by northwest Pacific TCs.

Mesoscale eddies are ubiquitous and energetic features in the ocean. Although eddies are known to form dipoles from time to time, it is unclear how often they do so. Using satellite altimetry data, here we show that mesoscale dipoles are surprisingly widespread in the global ocean. About 30–40% of the mesoscale eddies identified in altimeter data are paired up as dipoles, and the percentage is even higher in energetic regions such as the Gulf Stream and the Southern Ocean. Composite analysis involving Argo float data further reveals that these mesoscale dipoles have a relatively uniform three‐dimensional structure. We find that the presence of mesoscale dipoles can strongly enhance wind Ekman pumping velocity and lead to deep‐reaching vertical motions inside the dipoles via eddy deformation and frontogenesis. Such strong vertical exchanges promoted by mesoscale dipoles may play an important role in regulating the Earth's biogeochemical processes.

The interannual variability of the eastward current in the western South China Sea (SCS) during the summer of 1993–2012 is examined with satellite altimeter data and Regional Ocean Modeling System (ROMS) model output. It is found that the meridional location of the eastward current displays apparent interannual variability. The core of the eastward current shifts between 10.7°N and 17.6°N with a standard deviation of 1.6°. Results from Sverdrup theory and ROMS experiments demonstrate a close dynamic linkage between the north‐south migration of the eastward current and the SCS summer monsoon anomaly on the interannual time scale. When the summer monsoon has southwesterly (northeasterly) anomaly, the eastward current moves southward (northward). With the southward (northward) shift of the eastward current, the summer cold filament in the SCS moves southward (northward) as well.

Satellite observations of sea surface temperature (SST) show that SST in 2004, 2006, and 2016 broke the previous record in the Yellow and East China Seas (YECS). The underlying cause of the record‐breaking SSTs in the YECS is still under debate. Our analysis results demonstrate that enhanced solar radiation and weakened wind, due to a high‐pressure system over the YECS splitting from the western Pacific subtropical high, were mainly responsible for the record‐breaking SSTs in these 3 years. The enhanced solar radiation and weakened wind both depressed oceanic turbulent mixing, and more heat was concentrated in a shallower mixed layer, inducing an anomalous SST rise and resulting in the record‐breaking SSTs.