The evolution of the mixed layer temperature anomalies in the Mozambique Channel is analysed using a mixed layer heat budget covering sub-seasonal to interannual time scales. Sub-seasonal variations in mixed layer temperature are largely dominated by surface heat fluxes, except along the southern coast of Mozambique and Madagascar, where both the advection and the residual terms become significant. The northern Channel is dominated by the mean flow while the southern Channel is modulated by both the mean and eddy terms. Minimum heat gain through advection is observed in the channel during January–February when the Northeast Madagascar current opposes the northwesterly monsoonal winds. During the 1997/98 El Niño/positive Indian Ocean dipole, extreme warming and coral bleaching events were noted in the northern Channel. Such warming was linked with the relaxation of local winds, positive heat gain from the atmosphere and the shedding of large anticyclonic eddies northwest of Madagascar, associated with the arrival of downwelling Rossby waves. By contrast, upwelling Rossby waves and large cyclonic eddies in the Channel occurred during the 1998–2001 protracted La Niña, but only the northern part of the Channel experienced significant negative anomalies in mixed layer temperature. While no coral bleaching hotspots were noted in the northern Channel in summer 1999/2000 due to negative anomalies in advection, marine heatwaves occurred in the southern Channel during that summer. Finally, the protracted 1998–2001 La Niña was the last time that substantial upwelling Rossby wave activity occurred in the tropical South Indian Ocean; recent La Niña events showed muted or weak upwelling Rossby wave activity, including the recent 2020–2022 protracted event. Post-2001 also occurs at the same time as a stronger warming trend in the southwest Indian Ocean region.

使用涵盖次季节到年际时间尺度的混合层热收支分析了莫桑比克海峡混合层温度异常的演变。混合层温度的次季节变化主要由地表热通量主导，但莫桑比克和马达加斯加南部海岸除外，那里的平流项和剩余项都变得很重要。北部水道以平均流量为主，而南部水道则受到平均和涡流项的调节。 1 月至 2 月期间，当马达加斯加东北部洋流与西北季风对峙时，海峡中通过平流获得的热量最小。 1997/98 年厄尔尼诺现象/正印度洋偶极子期间，北部海峡出现了极端变暖和珊瑚白化事件。这种变暖与当地风的减弱、大气中的正增热以及马达加斯加西北部大型反气旋涡流的脱落有关，而马达加斯加西北部的大型反气旋涡旋又与下降的罗斯比波的到来有关。相比之下，1998-2001年持续的拉尼娜期间，海峡内出现了上升的罗斯贝波和大型气旋涡，但只有海峡北部的混合层温度出现了显着的负异常。虽然由于平流负异常，1999/2000年夏季北部海峡没有出现珊瑚白化热点，但该年夏季南部海峡出现了海洋热浪。最后，1998-2001年持续的拉尼娜现象是热带南印度洋最后一次出现大量上升的罗斯比波活动；最近的拉尼娜事件显示罗斯比波上涌活动减弱或微弱，包括最近的 2020-2022 年持续事件。 2001年后，西南印度洋地区也出现了更强烈的变暖趋势。