全球海洋暖化已增加海洋熱浪（Marine Heatwaves）的發生頻率與強度。亞齊（Aceh）近海位於熱帶東印度洋東部，在背景暖化與印度—太平洋氣候變異的影響下，正變得越來越容易受到海洋熱浪衝擊。本研究檢視 1985 至 2025 年期間控制亞齊海域海洋熱浪的海氣交互作用，並評估 16 個局部珊瑚礁棲地的累積熱壓力。本研究整合 41 年多感測器資料集，包括海表溫度（Sea Surface Temperature）與度加熱週（Degree Heating Weeks）、大氣與淡水通量、海流與鹽度資料、光學參數以及氣候指數。結果顯示，整個海盆的海表溫度呈現每十年 0.15–0.30°C 的升溫趨勢。2010 年後出現明顯的體制轉變，標誌著更頻繁熱異常現象的開始。在空間分布上，西部海岸線與離岸屏障島成為主要熱壓力熱點，尤其在季風轉換季節最為顯著。本研究辨識出七個極端海洋熱浪年份：2010、2015、2016、2019、2020、2024 與 2025 年。其中，2024 年事件達到前所未有的 432 個海洋熱浪加權日，顯著超過三倍標準差上限的 319 日。度加熱週在 2010、2016 與 2024 年頻繁超過高度致死性的 8°C-weeks 閾值。2016 年，高度脆弱的近岸棲地累積熱壓力接近 15°C-weeks，顯示其面臨嚴重的大規模白化風險。物理驅動機制分析指出，北部棲地（區域A）受到持續性海表溫度鋒面保護，在季風高峰期間，其溫度梯度大於 0.008°C/km，鋒面發生機率達 80–100%。相較之下，西部沿岸區域的鋒面發生機率極低，僅約 1–5%。強降水（>10–14 mm/day）遠高於微弱的蒸發冷卻作用，且潛熱通量僅約 -40 至 -80 W/m²，形成強烈負值的淨淡水通量。這會產生浮力較強的低鹽表層水，增強上層海洋層化，抑制水動力交換，並將強烈的淨海表熱通量（>100 W/m²）滯留於淺層近岸陸棚上方。這些條件可解釋西部與離岸珊瑚棲地，即區域B 與 C，尤其是第二、第三與第四組，所觀測到的持續且嚴重海洋熱浪。熱帶氣旋 Senyar 的個案研究進一步顯示，強烈的風驅海流（>0.6 m/s）可引發快速的冷卻，使近岸海表溫度降至 28.5°C。然而，該風暴同時也造成嚴重的次壓力因子，包括濁度升高（Kd490值 > 0.2 m⁻¹）、沉積物再懸浮（有色溶解物 > 0.1 m⁻¹），以及風暴後強烈的浮游植物增生現象（葉綠素濃度 > 3.5 mg/m³）。整體而言，本研究指出，災難性海洋熱浪正逐漸與大尺度氣候模態脫鉤，反而主要受到持續升高的熱基準線，以及局部近岸水體滯留與層化交互作用所驅動。;Global ocean warming has increased the frequency and intensity of marine heatwaves (MHWs). Located in the eastern tropical Indian Ocean， the waters off Aceh are becoming increasingly vulnerable to MHWs under background warming and Indo-Pacific climate variability. This study examines the ocean–atmosphere interactions controlling MHWs in Aceh waters from 1985 to 2025 and evaluates cumulative thermal stress across 16 localized coral reef habitats. The analysis integrates a 41-year multi-sensor dataset， including sea surface temperature (SST) and Degree Heating Weeks (DHW) from NOAA， atmospheric and freshwater fluxes from ECMWF ERA5， ocean currents and salinity from Copernicus， optical parameters from NASA， and climate indices from NOAA CPC. Results show a basin-wide SST warming trend of 0.15–0.30°C per decade， progressively reducing the region’s thermal safety margin. A clear post-2010 regime shift marks the onset of more frequent thermal anomalies. Spatially， the western coastline and offshore barrier islands emerge as major hotspots of thermal stress， especially during the inter-monsoon seasons. Seven extreme MHW years were identified: 2010， 2015， 2016， 2019， 2020， 2024， and 2025. Notably， the 2024 event reached an unprecedented 432 MHW-weighted days， significantly exceeding the three-sigma upper limit (319 days). DHW frequently surpassed the highly lethal 8°C-weeks threshold in 2010， 2016， and 2024. In 2016， highly vulnerable nearshore habitats experienced cumulative thermal stress approaching 15°C-weeks， indicating a severe risk of mass bleaching. Analysis of physical drivers indicates that northern habitats (Region A) are protected by persistent SST fronts， with gradients>0.008°C/km and frontal probabilities of 80–100% during peak monsoon periods. In contrast， western coastal zones show extremely low frontal probabilities (1–5%). Strong precipitation (>10–14 mm/day) greatly exceeds weak evaporative cooling， with latent heat flux limited to -40 to -80 W/m²， producing a strongly negative net freshwater flux. This creates a buoyant， low-salinity surface layer that enhances upper-ocean stratification， suppresses hydrodynamic exchange， and traps strong net surface heat flux (>100 W/m²) over the shallow coastal shelf. These conditions explain the persistent and severe MHWs observed in the western and offshore coral habitats (Regions B and C， especially Groups II， III， and IV). A case study of Tropical Cyclone Senyar further shows that extreme wind-driven currents (>0.6 m/s) can induce rapid mechanical cooling， lowering coastal SST to 28.5°C. However， the storm also generated severe secondary stressors， including elevated turbidity (Kd490 > 0.2 m⁻¹)， sediment resuspension (CDM > 0.1 m⁻¹)， and a strong post-storm phytoplankton bloom (chlorophyll-a > 3.5 mg/m³). Overall， this study indicates that catastrophic MHWs are becoming increasingly decoupled from large-scale climate modes and are instead driven by a persistently elevated thermal baseline interacting with localized coastal stagnation and stratification.
