Interannual Variabilities of the Southern Bay of Bengal Cold Pool Associated with the El Niño–Southern Oscillation

Abstract

The southern Bay of Bengal (BOB) cold pool (SCP) plays an important role in the regional climate fluctuation of the BOB. However, the interannual variability in the SCP is still unknown. Multisource satellite remote sensing data and assimilation have been applied to explore the interannual variability in the SCP and its relationship with El Niño–Southern Oscillation (ENSO) events for the period 1982–2020. The anomalous SST of the SCP in the summer following the peak phase (i.e., winter) of the ENSO was closely related to the ENSO events. El Niño (La Niña)-induced the warm (cold) anomaly of the SCP starting from May and persisted throughout August with a peak value appearing in June during the El Niño (La Niña) decaying years. In the El Niño decaying years, the southwest monsoon current (SMC) was weakened, forced locally by the weakening southwesterly wind and remotely by the easterly wind anomaly at the equator associated with El Niño. The El Niño-related weakening SMC and the associated less cold advection led to the warm anomaly of the SCP. In addition, El Niño-related atmospheric heating also made a comparable contribution to the evolution of the SCP’s SST. In the early stage (15 May to 10 June), its contribution to the warming of the SCP was much larger than that of the SMC, whereas from mid-June to August, it reversed to have a cooling effect and partially offset the advection heating induced by the SMC on the SCP. In the La Niña decaying years, similar oceanic and atmospheric processes operated but in an opposite way.

Study on the Source of Debris Flow in the Northern Scenic Spot of Changbai Mountain Based on Multi-Source Data

“…Previous studies have mostly applied offset-tracking technology to the fields of earthquakes, glaciers and landslides, but few people have applied this technology to the surface deformation monitoring of debris flows [32][33][34][35][36]. Chen used SBAS-InSAR technology to monitor the deformation of the debris flow source area of Xulong Ditch and obtain the annual deformation of the area [20].…”

Seasonal and Spatial Variability of Chlorophyll-a in Response to ENSO and Ocean Current in the Maritime Boundary of Bangladesh

“…However, the seasonal and spatial variability of Chl-a is yet to be explored particularly across the maritime boundary of Bangladesh in the northern BoB at different depths and distances from the coast. On the other hand, the BoB experiences significant climatic events such as the Indian Ocean Dipole (IOD), the El Niño-Southern Oscillation (ENSO), and the Madden-Julian Oscillation (MJO), [29][30][31] prompting investigations into their potential impacts on the BoB. Studies have examined the relationship between El Niño and IOD [32], the variability of sea surface temperature during ENSO and IOD events [33], and conducted time-series analysis of chlorophyll-a (Chl-a) with respect to IOD events [34].…”