Paper Push: 2026-07-09
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每日论文推送：BGC-Argo、海色/海洋光学、海洋热浪与碳泵Daily Paper Push: BGC-Argo, ocean colour/ocean optics, marine heatwaves and carbon pump
本期由 GitHub Actions 自动检索生成：Nature/Science 系列优先，其次是用户指定重点期刊，再补充重点关注团队的新论文，最后纳入其他相关期刊；历史去重后保留 13 篇，不超过每日 50 篇上限。 This issue was generated automatically by GitHub Actions: Nature and Science series first, then the user-defined priority journals, then new papers from the focused team, followed by other relevant journals as topical supplements. After deduplication, 13 papers remain, below the daily limit of 50.
Download Word summary
无 mechanism sketch 图。今天的意大利语卡片： No mechanism sketch figure today. Daily Italian card:
每日一句意大利语Daily Italian
Sta come torre ferma, che non crolla.
Dante, Commedia, Purgatorio V, 14; Italian original from Kalliope
这句写人应像坚固的塔一样站稳，不因风声而动摇。它是《炼狱篇》中很适合做每日提醒的句子。
Stand like a firm tower that does not collapse. It is a compact image of steadiness under pressure.
趋势总结Trend Summary
本期重点关注 BGC-Argo、海色遥感/海洋光学、海洋热浪、浮游植物垂向结构和碳泵过程。筛选逻辑不再只限于重点期刊；当高影响力期刊当天新增较少时，会额外检索重点关注团队作者的新论文，并用海洋、海色/光学和碳循环关键词过滤，再从其他相关期刊补充候选论文。
This issue focuses on BGC-Argo, ocean-colour remote sensing, ocean optics, marine heatwaves, vertical phytoplankton structure and carbon-pump processes. The selection is no longer limited to priority journals; when few high-impact papers are newly available, the workflow also checks focused-team authors and filters those papers with ocean, ocean-colour/optics, and carbon-cycle keywords before adding other relevant journals as supplements.
重点期刊：按影响力和相关性排序Key journals: ordered by impact and relevance
1. Phytoplankton Bloom in an Arctic Fjord During Late‐Summer in Response to Atlantic Water Inflow and Atmospheric Forcings
作者Authors: Teesha Mathew; Subeesh Meethale Puthukkottu; Divya T. David; Vidya Pottekkatt Jayapalan; Ahammed Shereef; Nuncio Murukesh; Sourav Chatterjee
发表月份Publication month: 2026-07 2026-07
Journal of Geophysical Research: Oceans · DOI: 10.1029/2025jc023453
关键词Tags: phytoplankton; vertical structure phytoplankton; vertical structure
摘要：Kongsfjorden 是斯瓦尔巴群岛西部的北极峡湾，受到大西洋温暖咸水 (AW) 平流的强烈影响，近几十年来初级生产力发生了显着变化。 CTD 观测结果显示，2014 年夏季平均叶绿素浓度异常高，远高于典型的夏季最大值。初夏生产力的提高与南水流入量的增加有关，这为峡湾提供了温暖、营养丰富的水域。相比之下，夏末出现了短暂但强烈的生产力峰值，覆盖了整个水体。本研究使用物理生物地球化学模型研究了驱动这种异常生产力的机制。 初夏的生产力主要由与 AW 平流相关的直接养分供应来维持，而夏末的水华主要由对流混合引起的垂直养分输送驱动。夏末，大气冷却增强了海气温度梯度，特别是当相对温暖的南海占据表层时。这种梯度的增加会导致大量的海洋热量损失，这一点可以通过增强的感热通量来证明。由此产生的浮力损失破坏了上层海洋的稳定性，引发对流混合，将营养丰富的地下水带入真光带。这种垂直补给缓解了夏末时期普遍存在的养分限制，从而维持了观察到的晚季开花。 我们的研究结果强调了一种独特的机制，可以在传统的夏季开花期之后维持高生产力，并强调大气强迫在增强的 AW 影响下调节峡湾生产力的关键作用。在北极不断扩大和海冰覆盖面积下降的背景下，此类事件可能会变得更加频繁，可能会延长生产季节并改变北极海洋生态系统的动态。
Abstract: Kongsfjorden, an Arctic fjord on west Svalbard, is strongly influenced by the advection of warm, saline Atlantic Water (AW) and has undergone pronounced changes in primary productivity in recent decades. Summer‐averaged chlorophyll concentration from CTD observations revealed exceptionally high values in 2014, far above the typical summer maxima. Enhanced productivity during early summer was associated with increased AW inflow, which supplied warm, nutrient‐rich waters to the fjord. In contrast, a short‐lived but intense productivity peak occurred in late summer, spanning the entire water column. This study investigates the mechanisms driving this anomalous productivity using a physical‐biogeochemical model. The productivity during early summer is primarily sustained by direct nutrient supply associated with AW advection, whereas the late‐summer bloom is largely driven by vertical nutrient transport induced by convective mixing. During late summer, atmospheric cooling enhances the air‐sea temperature gradient, particularly when relatively warm AW occupies the surface layer. This increased gradient promotes substantial ocean heat loss, as evidenced by enhanced sensible heat flux. The resulting buoyancy loss destabilizes the upper ocean, triggering convective mixing that entrains nutrient‐rich subsurface waters into the euphotic zone. This vertical replenishment alleviates the nutrient limitation typically prevailing during the late‐summer period, thereby sustaining the observed late‐season bloom. Our results highlight a distinct mechanism that can sustain high productivity beyond the conventional summer bloom period and emphasize the critical role of atmospheric forcing in modulating fjord productivity under enhanced AW influence. In the context of ongoing Arctic amplification and declining sea ice cover, such events may become more frequent, potentially extending the productive season and changing the dynamics of Arctic marine ecosystems.
2. Ocean alkalinity enhancement reduces silica ballasting during export due to amplified dissolution
作者Authors: Philipp Suessle; Kai Georg Schulz; Joana Barcelos e Ramos; Nico Manuel Sievers; Julieta Schneider; Juliane Katharina Tammen; Leila Kittu; Laura Marín-Samper; et al.
发表月份Publication month: 2026-07 2026-07
Biogeosciences · DOI: 10.5194/bg-23-4691-2026
关键词Tags: carbon pump; phytoplankton carbon pump; phytoplankton
摘要：海洋碱度增强（OAE）是一种二氧化碳去除（CDR）技术，旨在以与人类相关的时间尺度将二氧化碳（CO2）储存在海洋中。然而，根据 OAE 强度，海水碳酸盐化学形态的变化可能会改变群落驱动的生物量积累、颗粒化学计量以及颗粒输出过程中的转化。利用富营养化北海（德国赫尔戈兰）的中生态系统，我们在两种稀释情景（局部与均匀 OAE 添加）下建立了 39 d 的 6 个碱度水平。使用 NaOH 和 CaCl2 将总碱度 (TA) 增加至 ΔTAmax= 1250 µmol kg−1（250 µmol TA kg−1 增量），以模拟钙基矿物溶解过程中的阳离子释放，导致强烈的碳酸盐化学扰动（例如，pHmax > 9. 25）。 为了比较等效水华阶段的群落介导的碳输出，在中生态系统特定的水华和输出事件中而不是在固定采样日评估测量结果，从而解释了 OAE 引起的春季水华时间的变化。在水华期间，在不平衡的 OAE 下，平均浮游植物生物量（作为水体中叶绿素 a 和颗粒有机碳的浓度，POWC）保持不变。相比之下，二氧化硅压载比随着 pHT 的增加而下降：悬浮的生物二氧化硅与颗粒有机碳的比率（BSiWC : POCWC，其中 WC = 水柱）下降高达 50%，而出口的 BSiSed : POCSed（其中 Sed = 沉积物）下降 60%，表明下沉过程中加剧。与悬浮的 BSi 相比，下沉的下降幅度更大：POC 与出口过程中 pH 值增强的 BSi 溶解一致。 下沉颗粒的孔隙率随 pHT 的增加而增加，并与 BSiSed : POCSed 共同变化，表明颗粒质量特征可以调节运输过程中的溶解。有机物再矿化指标显示对碱度添加没有任何反应，并且颗粒下沉速度不随悬浮或下沉二氧化硅压载比而变化。在稀释情况下，不平衡的 OAE 可能会减少二氧化硅压载，潜在地减少碳再矿化，缩短封存时间尺度，并削弱二氧化碳的净去除，而溶解二氧化硅再生对硅藻生产力的影响仍未解决。量化 pH 驱动的 BSi 溶解如何与水华和出口动态相互作用对于评估 OAE 功效和生态安全至关重要。
Abstract: Ocean alkalinity enhancement (OAE) is a carbon dioxide removal (CDR) technology proposed to store carbon dioxide (CO2) in the ocean on human-relevant time scales. However, depending on OAE intensity, resulting shifts in seawater carbonate chemistry speciation could alter community-driven biomass build-up, particulate stoichiometry, and transformation during particle export. Using mesocosms in the eutrophic North Sea (Helgoland, Germany), we established six alkalinity levels under two dilution scenarios (localized vs. uniform OAE additions) for 39 d. Total alkalinity (TA) was increased to ΔTAmax= 1250 µmol kg−1 (250 µmol TA kg−1 increments) using NaOH with CaCl2 to simulate cation release during calcium-based mineral dissolution, causing strong carbonate chemistry perturbations (e.g., pHmax > 9.25). To compare community-mediated carbon export across equivalent bloom phases, measurements were assessed within mesocosm-specific bloom and export events rather than on fixed sampling days, thereby accounting for OAE-induced shifts in spring bloom timing. During blooms, average phytoplankton biomass (as the concentrations of chlorophyll a and particulate organic carbon in the water column, POCWC) remained unchanged under unequilibrated OAE. In contrast, silica ballasting ratios declined with increasing pHT: suspended biogenic silica to particulate organic carbon ratios (BSiWC : POCWC, where WC = water column) decreased by up to 50 %, while exported BSiSed : POCSed (where Sed = sediment) decreased by 60 %, indicating intensification during sinking. The stronger decline in sinking compared to suspended BSi : POC is consistent with pH-enhanced BSi dissolution during export. Porosity of sinking particles increased with pHT and co-varied with BSiSed : POCSed, suggesting particle-quality traits can modulate dissolution during transit. Organic matter remineralization metrics showed no response to alkalinity addition, and particle sinking velocities did not scale with suspended or sinking silica ballasting ratios. Across dilution scenarios, unequilibrated OAE may reduce silica ballasting, potentially shoaling carbon remineralization, shortening sequestration timescales, and weakening net CO2 removal, while effects of dissolved silica regeneration on diatom productivity remain unresolved. Quantifying how pH-driven BSi dissolution interacts with bloom and export dynamics will be critical for evaluating OAE efficacy and ecological safety.
3. Heterogeneous future Arctic Ocean primary productivity changes projected in CMIP6
作者Authors: Léna Champiot-Bayard; Lester Kwiatkowski; Martin Vancoppenolle
发表月份Publication month: 2026-07 2026-07
Biogeosciences · DOI: 10.5194/bg-23-4735-2026
关键词Tags: phytoplankton phytoplankton
摘要：由于气候变化，北冰洋正在经历深刻的环境变化，预计本世纪净初级生产量（NPP）将增加。本研究分析了整个 21 世纪泛北极和次区域范围内的 NPP 趋势及其驱动因素，比较了耦合模型比对项目第 6 阶段 (CMIP6) 和第 5 阶段 (CMIP5) 的预测，以评估模型各代之间的差异。使用多模型方法，我们评估了不同浮游植物功能类型（PFT）、硅藻和纳米浮游植物的预测，并研究了物理和生物地球化学限制（包括光、营养和温度限制）的作用。我们的研究结果表明，北冰洋 NPP 的增加主要是由于海冰覆盖面积减少造成的，导致季节性冰区扩张导致无冰季节更长。 然而，NPP 的变化表现出明显的空间异质性，北极流入陆架区域大幅增加，而巴芬湾和北欧海的减少则有所缓和。这些差异是由于北冰洋物理和生物地球化学核电厂限制之间的平衡不同造成的。在相当的辐射强迫下，CMIP6 的多模型平均北冰洋 NPP 增幅是 CMIP5 的四倍，到本世纪末的不确定性高出三倍。这种差异归因于 CMIP6 中较高的基线营养水平，以及比 CMIP5 中更明显的海冰损失和更大的变暖。更好地模拟未来北冰洋核电厂的关键方面仍然是当前营养水平的代表、通过海冰的光传输以及减少气候敏感性的模型不确定性。
Abstract: The Arctic Ocean is experiencing profound environmental changes due to climate change, with Net Primary Production (NPP) broadly projected to increase this century. This study analyzes NPP trends and their drivers across pan-Arctic and sub-regional scales throughout the 21st century, comparing Coupled Model Intercomparison Project Phase 6 (CMIP6) and Phase 5 (CMIP5) projections to assess how model generations differ. Using a multi-model approach, we assess projections for different Phytoplankton Functional Types (PFTs), diatoms and nanophytoplankton, and examine the role of physical and biogeochemical constraints including light, nutrient, and temperature limitations. Our results reveal that Arctic Ocean NPP increases are primarily driven by reduced sea ice cover, leading to longer ice-free seasons in the expanding seasonal ice zone. However, NPP changes exhibit pronounced spatial heterogeneity, with strong increases in Arctic inflow shelf regions, tempered by decreases in Baffin Bay and Nordic Seas. These differences are due to the varying balance between physical and biogeochemical NPP constraints across the Arctic Ocean. The multi-model mean Arctic Ocean NPP increase is four times larger in CMIP6 than in CMIP5, under comparable radiative forcing, with a three times higher uncertainty at the end of the century. This difference is attributed to higher baseline nutrient levels in CMIP6, combined with more pronounced sea ice loss and greater warming than in CMIP5. Key aspects to better simulate future Arctic Ocean NPP remain the representation of present-day nutrient levels, light transmission through sea ice and reduced model uncertainty in climate sensitivity.
4. Use of Remote Sensing and In Situ Monitoring to Evaluate Turbidity in an Open-Pit Mining Lake
作者Authors: Luisa da Cunha Vieira; Danilo Marques de Magalhães; Hugo de Oliveira Fagundes
发表月份Publication month: 2026-07 2026-07
Remote Sensing · DOI: 10.5194/isprs-annals-xi-3-2026-663-2026
关键词Tags: ocean colour ocean colour
摘要：退役露天矿坑湖的形成引起了人们对长期水质的担忧。浊度是悬浮颗粒物的关键指标，影响水体透明度和水生生态过程。本研究利用卫星图像和现场数据来估算巴西新利马阿瓜斯克拉拉斯矿 (MAC) 坑湖的表面浊度，以生成连续的时间序列，并评估其是否符合巴西现行环境立法规定的阈值。 Landsat 5 和 8 图像用于得出光谱浊度指数。基于卫星和现场数据之间的时间重叠，开发了线性回归模型（R² = 0. 77）并应用于扩展浊度时间序列。结果表明，浊度值仍低于 1 类淡水的法定限值。 在初始充填阶段观察到较高的浊度水平，这与暴露的斜坡有关，并且在雨季期间由于沉积物径流而出现间歇性增加。随着时间的推移，植被的逐步恢复和人为干扰的最小化有助于水质条件的稳定。事实证明，现场测量和遥感的结合是监测采矿后环境水质的有效方法，支持环境责任评估和关闭管理。
Abstract: The formation of pit lakes in decommissioned open-pit mines has raised concerns regarding long-term water quality. Turbidity, a key indicator of suspended particulate matter, influences water clarity and aquatic ecological processes. This study estimates surface turbidity in the Águas Claras Mine (MAC) pit lake in Nova Lima, Brazil, using satellite imagery and in situ data to generate a continuous time series and assess compliance with thresholds established by current Brazilian environmental legislation. Landsat 5 and 8 imagery were used to derive a spectral turbidity index. Based on the temporal overlap between satellite and field data, a linear regression model (R² = 0.77) was developed and applied to extend the turbidity time series. The results indicate that turbidity values remained below the legal limits for Class 1 freshwater. Higher turbidity levels were observed during the initial filling phase, associated with exposed slopes, as well as episodic increases during the rainy season due to sediment runoff. Over time, progressive revegetation and minimal anthropogenic disturbance contributed to the stabilization of water quality conditions. The integration of in situ measurements and remote sensing proved to be an effective approach for monitoring water quality in post-mining environments, supporting both environmental liability assessment and closure management.
5. Shoreline extraction and coastal change detection from satellite SAR using thresholding-based methods
作者Authors: Corienne Erasmus; Shelley Haupt; Bolelang Sibolla
发表月份Publication month: 2026-07 2026-07
Remote Sensing · DOI: 10.5194/isprs-annals-xi-3-2026-871-2026
关键词Tags: ocean colour; backscattering ocean colour; backscattering
摘要：海岸侵蚀是沉积物随着时间的推移逐渐流失，对南非的海岸线构成重大威胁。监测和发现海岸侵蚀对于有效管理海岸环境至关重要，可以通过划定海岸边界来量化。合成孔径雷达 (SAR) 等遥感技术为提取大片海岸区域的海岸线位置提供了独特的机会。在这项研究中，C 波段 SAR 数据被用来推导南非东开普省三个不同感兴趣区域十年期间的后向散射系数。使用阈值和边缘检测技术来描绘海岸线位置。 计算了海岸侵蚀和增生趋势，结果表明三个不同研究区的线性回归率（LRR）表现出不同的海岸侵蚀季节性趋势。海岸线 LLR 范围在 -0 之间。 01和-3。累西腓角地区为 28 m/年，0. 17 和 -4.纳尔逊·曼德拉湾海滨每年 78 m。总体模式是冬季侵蚀，夏季增生。相反，对于 Kings Beach 地区，存在一致的吸积趋势，LRR 值范围在 0. 94 至 1. 68 m/年之间。本研究的结果表明，SAR 遥感和基于阈值的方法可能是检测和监测海岸侵蚀季节性模式的合适技术。
Abstract: Coastal erosion, which is the gradual loss of sediment over time, poses a significant threat to South Africa’s coastline. The monitoring and detection of coastal erosion is essential for the effective management of coastal environments and can be quantified by the delineation of coastal boundaries. Remote sensing techniques such as Synthetic Aperture Radar (SAR) offer an unique opportunity to extract shoreline positions over large areas of the coast. In this study, C-band SAR data was used to derive backscatter coefficients for three different areas of interest in the Eastern Cape province in South Africa over a ten year period. Thresholding and edge detection techniques were used to delineate shoreline positions. The coastal erosion and accretion trends were calculated and the results indicated that the Linear Regression Rate (LRR) for the three different study areas showed various coastal erosion seasonality trends. The shoreline LLR ranged between −0.01 and −3.28 m/year for the Cape Recife area and 0.17 and −4.78 m/year for the Nelson Mandela Bay beach front. The overall pattern was erosion during the winter months and accretion during the summer months. In contrast, for the Kings Beach area, there was a consistent accretion trend where the LRR values ranged between 0.94 and 1.68 m/year. The findings of this study suggest that SAR remote sensing and thresholding-based methods could be a suitable technique for detecting and monitoring coastal erosion seasonality patterns.
6. A spatial and spectral Analysis of the Sentinel-2 nighttime Image
作者Authors: Merlijn I. Dingemanse; Daniele Cerra; Ferran Gascon; Tobias Storch
发表月份Publication month: 2026-07 2026-07
Remote Sensing · DOI: 10.5194/isprs-annals-xi-3-2026-359-2026
关键词Tags: ocean colour; bio-optics ocean colour; bio-optics
摘要：夜间光学遥感为了解自然活动，特别是人类活动提供了宝贵的见解。这项研究评估了 Sentinel-2 任务的夜间成像能力，使用唯一可用的夜间采集（不限于海洋观测）进行暗信号校准，2015 年覆盖了阿拉伯联合酋长国和迪拜。我们使用波斯湾上空的颗粒检查了探测极限，提取了不同感兴趣区域的辐射光谱，并分析了照明类型和温度。结果表明保守的夜间检测极限约为。可见/近红外波段为0. 37 W/m2/μm/sr，短波红外波段为0. 08 W/m2/μm/sr。 Sentinel-2 的高空间分辨率和多光谱波段虽然是为白天观测而设计的，但能够检测和分类明亮的可见光/近光和短波红外发射器。与 2025 年获取的高光谱 EnMAP 图像进行比较，验证了分类并揭示了十年来城市照明的变化。尽管存在局限性，但这项研究强调了 S2 在夜间遥感方面的潜力，并支持对未来卫星任务夜间能力的考虑。
Abstract: Nighttime optical remote sensing provides valuable insights into natural and, in particular, human activities. This study evaluates the nighttime imaging capabilities of the Sentinel-2 mission using the only available nighttime acquisition not limited to ocean observations for dark signal calibration, covering the United Arab Emirates with Dubai in 2015. We checked the detection limit using granules over the Persian Gulf, extracted radiance spectra for different regions of interest, and analysed lighting types and temperatures. Results suggest a conservative nighttime detection limit of approx. 0.37 W/m2/μm/sr for visible/near infrared bands, and 0.08 W/m2/μm/sr for short-wave infrared bands. Sentinel-2’s high spatial resolution and multispectral bands, although designed for daytime observations, were capable of detecting and classifying bright visible/near and short-wave infrared emitters. Comparisons with hyperspectral EnMAP imagery acquired in 2025 validated the classifications and revealed changes in urban lighting over a decade. While limitations apply, this study highlights S2’s potential for nighttime remote sensing and supports considerations of nighttime capabilities for future satellite missions.
7. Flood mapping using multi-temporal Sentinel-1 SAR images: A case study from Lower Tubarão River Sub-basin, Santa Catarina State, Brazil
作者Authors: Liliana Sayuri Osako
发表月份Publication month: 2026-07 2026-07
Remote Sensing · DOI: 10.5194/isprs-annals-xi-3-2026-441-2026
关键词Tags: ocean colour; backscattering ocean colour; backscattering
摘要：洪水是由强降雨引发的自然灾害，对洪泛区等低洼地区的破坏性尤其严重。在洪水易发地区，有效的灾害管理依赖于预防、监测和应急响应策略。在这种背景下，遥感，特别是合成孔径雷达（SAR），由于其能够在恶劣天气条件和持续云层覆盖下获取数据，已成为洪水测绘和监测不可或缺的一部分。处理为 RGB 合成图像的多时相 SAR 图像可实现洪水模式的快速可视化，而基于地理对象的图像分析 (GEOBIA) 方法则通过集成反向散射阈值和地形高程数据改进了洪水区域的分类。 本研究调查了巴西南部图巴朗河下游子流域 (LTRSb) 在 2019 年 5 月 24 日至 25 日期间累积降雨量达 260 毫米的极端降水事件后洪水的时空动态。使用在事件前后获取的 Sentinel-1B SAR 图像来绘制洪水区域地图，总体分类精度为 88%。结果表明，事件发生三天后，洪水覆盖了 LTRSb 的 140 平方公里（29%），主要影响农业区（86. 3 平方公里）和牧场区（47. 6 平方公里）。 15天后，淹没范围降至62平方公里，两个月后降至15平方公里，农业用地始终占淹没面积的97%。城市化地区（约 1 平方公里）也受到影响，表明基础设施和公共卫生面临重大风险。 这些发现凸显了基于SAR的洪水监测对于水文流域风险评估和灾害管理的重要性。
Abstract: Floods are natural hazards triggered by intense rainfall and are particularly destructive in low-lying areas such as floodplains. In flood-prone regions, effective disaster management relies on prevention, monitoring, and emergency response strategies. In this context, remote sensing, especially Synthetic Aperture Radar (SAR), has become indispensable for flood mapping and monitoring due to its ability to acquire data under adverse weather conditions and persistent cloud cover. Multi-temporal SAR imagery processed into RGB composites allows rapid visualization of inundation patterns, while the Geographic Object-Based Image Analysis (GEOBIA) approach improves the classification of flooded areas through the integration of backscatter thresholds and terrain elevation data. This study investigates the spatial and temporal dynamics of flooding in the Lower Tubarão River Sub-basin (LTRSb), southern Brazil, following an extreme precipitation event that produced 260 mm of accumulated rainfall between May 24 and 25, 2019. The Sentinel-1B SAR images, acquired pre- and post-event, were used to map flooded areas with an overall classification accuracy of 88%. The results indicate that three days after the event, flooding covered 140 km² (29%) of the LTRSb, predominantly affecting agricultural (86.3 km²) and pasture areas (47.6 km²). The flooded extent decreased to 62 km² after 15 days and to 15 km² after two months, with agricultural land consistently accounting for 97% of the flooded area. Urbanized areas (≈1 km²) were also impacted, indicating significant risks to infrastructure and public health. These findings highlight the importance of SAR-based flood monitoring for risk assessment and disaster management in hydrographic basins.
8. Leveraging Polarized Ku- and C-band Radar Backscatter Time Series for Sea Ice Thickness Prediction using Random Forest
作者Authors: Mehran Dadjoo; Dustin Isleifson
发表月份Publication month: 2026-07 2026-07
Remote Sensing · DOI: 10.5194/isprs-annals-xi-3-2026-403-2026
关键词Tags: ocean colour; backscattering ocean colour; backscattering
摘要：近几十年来，由于气候变化，北极海冰厚度一直在下降，这使得准确的预测对于环境监测和气候建模变得越来越重要。微波遥感与机器学习相结合已成为估计海冰厚度的一种有前景的方法。本研究利用从地基 Ku 和 C 波段散射仪以三种偏振（VV、HH 和 HV）收集的时间序列反向散射数据，研究了实验室生长海冰厚度（27-47 厘米）的预测。随机森林模型应用于时间序列，结合了标准化雷达截面 (NRCS) 值和各种时间变量（超前时间和滞后时间）的统计特征（平均值和标准差）。该模型实现了较高的预测精度，最低误差记录为 RMSE = 0. 03 cm。 使用排列重要性方法进行的特征重要性分析表明，共极化 C 波段特征（C-VV 和 C-HH）是预测海冰厚度最具决定性的参数。这些发现强调了将微波遥感与随机森林模型相结合的潜力，以增强海冰厚度预测，并为北极地区的未来研究和实时监测提供宝贵的见解。
Abstract: Arctic sea ice thickness has been declining over recent decades due to climate change, making accurate prediction increasingly critical for environmental monitoring and climate modeling. Microwave remote sensing combined with machine learning has emerged as a promising approach for estimating sea ice thickness. This study investigates the prediction of lab-grown sea ice thickness (27–47 cm), using time-series backscatter data collected from surface-based Ku- and C-band scatterometers in three polarizations (VV, HH, and HV). A Random Forest model was applied to the time series, incorporating Normalized Radar Cross-Section (NRCS) values and statistical features (mean and standard deviation) across various temporal variables (lead and lag times). The model achieved high prediction accuracy, with the lowest error recorded at RMSE = 0.03 cm. Feature importance analysis using the Permutation Importance method revealed that co-polarized C-band features (C-VV and C-HH) were the most determining parameters in predicting sea ice thickness. These findings underscore the potential of integrating microwave remote sensing with Random Forest models to enhance sea ice thickness prediction and provide valuable insights for future research and real-time monitoring in Arctic regions.
9. Cross-Platform Comparison of Marine Boundary Layer Cloud and Drizzle Properties over the Southern Ocean Using Airborne, Shipborne, and Satellite Observations
作者Authors: Anik Das; Xiquan Dong; Baike Xi
发表月份Publication month: 2026-07 2026-07
Remote Sensing · DOI: 10.3390/rs18132262
关键词Tags: vertical structure vertical structure
摘要：海洋边界层（MBL）云强烈影响南大洋（SO）的辐射和降水，但它们的垂直结构和微物理特性在观测平台上仍然受到很少的限制。本研究使用 SO 云、辐射、气溶胶传输实验研究 (SOCRATES) 的飞机观测、SO 上空气溶胶、辐射和云测量 (MARCUS) 的船基观测以及 CloudSat 的卫星观测，比较了 3 公里以下单层、以液体为主的 MBL 云的宏观物理和微观物理特性。 根据 SOCRATES 期间测量的原位液滴尺寸分布 (DSD) 开发的经验反射率-微观物理检索框架应用于 MARCUS M-WACR 和 CloudSat CPR 反射率观测，以检索云和毛毛雨粒子的数量浓度 (N)、有效半径 (re) 和液态水含量 (LWC) 的垂直剖面。在仪器灵敏度、采样差异和检索不确定性所施加的限制内，云边界高度和检索的微物理特性在三个平台上表现出广泛的一致性。然而，CloudSat CPR 观测由于垂直分辨率较粗糙和反射率灵敏度较低而表现出较大偏差，包括对约 500 m 以下低云的有限检测。 观察到的垂直结构与凝结生长、夹带和碰撞聚结过程一致。总体而言，结果表明三个平台的云和毛毛雨特性具有广泛的一致性，同时强调了仪器灵敏度、垂直分辨率和采样差异对云边界检测和微物理反演的影响。
Abstract: Marine boundary layer (MBL) clouds strongly influence radiation and precipitation over the Southern Ocean (SO), yet their vertical structures and microphysical properties remain poorly constrained across observational platforms. This study compares macrophysical and microphysical properties of single-layer, liquid-dominant MBL clouds below 3 km using aircraft observations from the SO Clouds, Radiation, Aerosol Transport Experimental Study (SOCRATES), ship-based observations from Measurements of Aerosols, Radiation, and Clouds over the SO (MARCUS), and satellite observations from CloudSat. An empirical reflectivity–microphysics retrieval framework developed from in situ droplet size distributions (DSDs) measured during SOCRATES was applied to MARCUS M-WACR and CloudSat CPR reflectivity observations to retrieve vertical profiles of number concentration (N), effective radius (re), and liquid water content (LWC) for cloud and drizzle particles. Cloud boundary heights and retrieved microphysical properties show broad agreement across the three platforms within the limitations imposed by instrumental sensitivity, sampling differences, and retrieval uncertainties. However, CloudSat CPR observations exhibit larger deviations because of their coarser vertical resolution and lower reflectivity sensitivity, including limited detection of low clouds below ~500 m. The observed vertical structures are consistent with condensational growth, entrainment, and collision–coalescence processes. Overall, the results demonstrate broad consistency in cloud and drizzle properties across the three platforms, while highlighting the impacts of instrumental sensitivity, vertical resolution, and sampling differences on cloud boundary detection and microphysical retrievals.
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10. Bacterial extracellular vesicles exhibit distinct functional potential across biogeographic provinces of the South Pacific Ocean
作者Authors: Eduard Fadeev; Neza Orel; Tinkara Tinta; Leila Afjehi-Sadat; Haoran Liu; Thomas J Browning; Zhongwei Yuan; Eric P Achterberg; et al.
发表月份Publication month: 2026-07 2026-07
The ISME Journal · DOI: 10.1093/ismejo/wrag171
关键词Tags: phytoplankton phytoplankton
摘要：细菌细胞外囊泡（BEV）是由不同类型的细菌释放的纳米级膜结构，能够在细胞之间运输和传递生物化合物。在实验室模型系统中对 BEV 的实验研究表明，这些纳米颗粒可能在海洋细菌群落的生态生理学中发挥多种作用，但它们在环境中的功能潜力仍不清楚。在这里，我们描述了南太平洋 5,000 多海里表层水域 BEV 种群的蛋白质组组成，将 BEV 货物与产生它们的细菌群落联系起来。在一系列生物地球化学条件下均观察到海洋 BEV 的存在，其总体丰度与细菌细胞相当（最多 108 个 BEV L-1）。 然而，海洋 BEV 的蛋白质负载在不同海洋区域之间存在显着差异。在浮游植物大量繁殖的条件下，BEV种群富含碳水化合物转运蛋白，并且在营养有限的水域中含有与铁吸收相关的蛋白质。这些数据表明，BEV 可以使细胞在海洋环境中执行关键的细胞外功能。我们的观察结果强调了海洋 BEV 的普遍存在以及其在整个海洋尺度上的生态潜力的生物地理模式。
Abstract: Bacterial extracellular vesicles (BEVs) are nanoscale membranous structures released by diverse types of bacteria, and are capable of transporting and delivering biological compounds between cells. Experimental investigation of BEVs in laboratory model systems indicates that these nanoparticles may play a number of roles in the ecophysiology of marine bacterial communities, but their functional potential in the environment remains unclear. Here we describe the proteomic composition of BEV populations over more than 5,000 nautical miles of surface waters in the South Pacific, linking BEV cargoes to the bacterial communities producing them. The presence of marine BEVs was consistently observed across a range of biogeochemical conditions, with an overall abundance comparable to that of bacterial cells (up to 108 BEVs L-1). The protein cargo of marine BEVs, however, differed significantly among ocean regions. The BEV populations were enriched in carbohydrate transporters under phytoplankton bloom conditions, and contained iron uptake-related proteins in nutrient-limited waters. These data suggest that BEVs could enable cells to perform key extracellular functions in the marine environment. Our observations highlight the ubiquity of marine BEVs and biogeographic patterns in their ecological potential across oceanic scales.
其他相关期刊：按主题相关性补充Other relevant journals: topical supplements
11. Microbial degradation of jellyfish detritus promotes phytoplankton growth in coastal marine ecosystems
作者Authors: Tinkara Tinta; Eduard Fadeev; Mauro Celussi; Cecilia Balestra; Katja Klun; Patricija Mozetič; Gerhard J Herndl
发表月份Publication month: 2026-07 2026-07
ISME Communications · DOI: 10.1093/ismeco/ycag185
关键词Tags: phytoplankton; microbial carbon phytoplankton; microbial carbon
摘要：胶状浮游动物（以下称为刺胞动物水母动物和栉水母或“水母”）广泛存在于海洋生态系统中，可以形成大量水华，在腐烂时释放出大量不稳定的富含蛋白质的有机物（果冻-OM）。这种材料会促进细菌的强烈活动，但其生态后果仍知之甚少。我们进行了两阶段微观实验，模拟入侵栉水母 Mnemiopsis leidyi 的水华腐烂，以研究果冻-OM 的微生物加工及其对初级生产的影响。在第一阶段，在三天的时间里，我们观察到果冻-OM刺激机会性细菌群落的快速生长。 该群落以假交替单胞菌科为主，它们是多种水母的关键降解者，其氨基酸、脂质和碳水化合物的代谢增强，细胞外酶活性升高，包括亮氨酸氨肽酶、脂肪酶、几丁质酶和碱性磷酸酶。这些过程导致了明显的铵积累。在第二阶段，将新鲜微生物群落暴露于果冻-OM降解残留物中，导致初级生产力和浮游植物生物量在五天内显着增加。这主要是硅藻，并且可能是由积累的铵推动的。与此同时，细菌群落转向通常与浮游植物大量繁殖相关的类群。 总之，这些结果在现场观测的进一步支持下，揭示了水母腐烂和浮游植物生长之间可能存在的耦合，表明水母繁殖是短暂但强大的营养源，能够引发生态系统的转变。由于水母预计将在未来的海洋条件下繁衍生息，我们的研究结果强调需要重新评估它们在生物地球化学循环中的作用，特别是作为浮游植物动力学被忽视的驱动因素。
Abstract: Gelatinous zooplankton (hereinafter cnidarian Medusozoa and ctenophores or “jellyfish”) are widespread in marine ecosystems and can form massive blooms, releasing large amounts of labile, protein-rich organic matter (jelly-OM) upon decay. This material fuels intense bacterial activity, yet its ecological consequences remain poorly understood. We conducted a two-stage microcosm experiment simulating a bloom decay of the invasive ctenophore Mnemiopsis leidyi to examine microbial processing of jelly-OM and its effect on primary production. In the first stage, over the course of three days, we observed jelly-OM stimulating rapid growth of opportunistic bacterial community. The community was dominated by Pseudoalteromonadaceae – key degraders of diverse jellyfish, which exhibited enhanced metabolism of amino acids, lipids, and carbohydrates and elevated extracellular enzymatic activities, including leucine aminopeptidase, lipase, chitinase, and alkaline phosphatase. These processes led to marked ammonium accumulation. In the second stage, exposure of a fresh microbial assemblage to residues from jelly-OM degradation resulted in a significant increase of primary production and phytoplankton biomass over a period of five days. This was dominated by diatoms and was likely fueled by accumulated ammonium. Concurrently, the bacterial community shifted toward taxa typically associated with phytoplankton blooms. Together, these results, further supported by in situ observations, reveal a likely coupling between jellyfish decay and phytoplankton growth, suggesting that jellyfish blooms act as transient but powerful nutrient sources capable of triggering ecosystem shifts. As jellyfish are projected to thrive under future ocean conditions, our findings underscore the need to re-evaluate their role in biogeochemical cycles—particularly as overlooked drivers of phytoplankton dynamics.
12. EVALUACIÓN ESPACIO TEMPORAL DEL CRECIMIENTO DEL ABONO VERDE MEDIANTE TELEDETECCIÓN MULTIESPECTRAL CON UAV, SIG Y ANÁLISIS FISICOQUÍMICO DEL SUELO
作者Authors: Hernán Eriberto Chamorro Sevilla; Rodrigo Ernesto Salazar López; Nanci Margarita Inca Chunata; Keylly Marcela Chávez Inca
发表月份Publication month: 2026-07 2026-07
Revista Científica Multidisciplinaria InvestiGo · DOI: 10.56519/k6y27q77
关键词Tags: phytoplankton; ocean colour phytoplankton; ocean colour
摘要：本研究利用多光谱无人机遥感、GIS 和土壤理化分析评估了安第斯高海拔条件下绿肥混合物（Vicia sativa L. 和 Avena sativa L.）的时空动态。使用DJI Mavic 3多光谱无人机在海拔2850米的高度进行了现场实验。数据收集于2026年3月和2026年5月。对植被指数（NDVI、SAVI和NDRE）与土壤理化性质（包括pH、有机碳、磷、钾和土壤质地）之间进行相关分析。实验室分析表明，土壤呈弱碱性，具有沙壤土质地，但有机碳和速效磷浓度较低。多光谱图像显示，在两个监测日期之间，冠层活力和生物量显着增加。 SAVI 有效地减少了早期生长阶段的土壤背景影响，而 NDVI 显示出与生物量发展相关的更大的时间变化。相比之下，NDRE 保持相对稳定，表明作物的叶绿素分布和生理状况更加均匀。多光谱无人机图像、GIS 和土壤理化分析的集成被证明是评估安第斯高原条件下绿肥作物时空发育的有效方法。这种综合方法能够识别与土壤理化特性相关的作物发育的空间变异性，为支持特定地点的作物管理和可持续农业实践提供有价值的信息。
Abstract: This study evaluated the spatiotemporal dynamics of a green manure mixture (Vicia sativa L. and Avena sativa L.) under high-Andean conditions using multispectral UAV remote sensing, GIS, and soil physicochemical analysis. Field experiments were conducted at an altitude of 2,850 m above sea level using DJI Mavic 3 Multispectral UAV. Data were collected in March and May 2026. Correlation analysis was performed between vegetation indices (NDVI, SAVI, and NDRE) and soil physicochemical properties, including pH, organic carbon, phosphorus, potassium, and soil texture. Laboratory analyses showed that the soil was slightly alkaline, with a sandy loam texture but low concentrations of organic carbon and available phosphorus. Multispectral imagery revealed a considerable increase in canopy vigor and biomass between the two monitoring dates. SAVI effectively minimized soil background effects during the early growth stage, whereas NDVI showed greater temporal variability associated with biomass development. In contrast, NDRE remained relatively stable, indicating a more uniform chlorophyll distribution and physiological condition of the crop. The integration of multispectral UAV imagery, GIS, and soil physicochemical analysis proved to be an effective approach for assessing the spatiotemporal development of green manure crops under high-Andean conditions. This integrated methodology enabled the identification of spatial variability in crop development associated with soil physicochemical properties, providing valuable information to support site-specific crop management and sustainable agricultural practices.
13. Spatio-Temporal Analysis of Land Use Land Cover Dynamics, Synergy of Land Surface Temperature and Snow Cover Fluctuations in Gilgit River Basin, North Pakistan
作者Authors: Atta Ur Rahman; Osama Amjad; Hussain Zia; Muhammad Dawood
发表月份Publication month: 2026-04 2026-04
International Journal of Innovations in Science and Technology · DOI: 10.33411/ijist/1842
关键词Tags: ocean colour ocean colour
摘要：本研究利用遥感和 GIS 技术探讨了 1995 年至 2024 年期间巴基斯坦北部吉尔吉特河流域 (GRB) 的土地利用土地覆盖 (LULC)、地表温度 (LST) 和积雪的时空动态。通过 Google Earth Engine (GEE) 应用多时相 Landsat 卫星图像（Landsat 5、7、8 和 9）来分析 LULC 变化、LST 与积雪变化的关系。监督分类 i. e.随机森林算法揭示了显着的 LULC 变换。定居点扩张表明，城市扩张和人口增长迅速增加（+6,736. 92 公顷）。建成区面积的变化集中在农田面积上。这是因为植被覆盖和农业用地转变为建筑用地。 在植被覆盖范围内，该区域观察到森林覆盖面积退化和农业用地丧失（-43,676. 09 公顷）。同样，在积雪覆盖的情况下，观察到了重大变化（-169,211. 68 公顷）。所得值表明冰川退缩，积雪有限。这主要归因于香港和香港地区的气候变化和气温上升。因此，直接影响河流流量和水安全。此外，贫瘠土地的增长（+203,535. 44 公顷），几乎所有土地利用类别都发生了积极变化。结果，出现了荒漠化、土地退化以及积雪和植被丧失。此外，+86 等水体也出现了小幅上升。 74 公顷，微小变化是由于冰川融化导致地表水暂时增加。结果，形成了小湖泊。 e. 冰川湖和冰川河湖也得到了发展。分析显示，LST 表现出强烈的变暖趋势（+0. 17°C/年，*p*
Abstract: This study explores the spatio-temporal dynamics of Land Use Land Cover (LULC), Land Surface Temperature (LST) and snow cover in the Gilgit River Basin (GRB), North Pakistan during the period 1995-2024 using remote sensing and GIS technologies. Multi-temporal Landsat satellite imagery (Landsat 5, 7, 8 and 9) was applied through Google Earth Engine (GEE) to analyze LULC changes, relationship of LST and snow cover variability. Supervised classification i.e. random forest algorithm revealed significant LULC transformations. Settlement expansion shows, rapid increases were recorded in urban sprawl and population growth (+6,736.92 ha). These changes in built-up area are concentrated in areas under farmland. This is because of the conversion of vegetation cover and agricultural land into built-up areas. In the context of vegetation cover, the region observed the degradation in area under forest cover and loss of agricultural land (-43,676.09 ha). Similarly, in case of snow cover, critical changes were observed (-169,211.68 ha). The resultant values illustrate glaciers retreat along with limited snow accumulation. This is largely attributed to climatic change and rising temperature in the HKH region. As a result, it has a direct impact on river discharge and water security. Furthermore, growth in barren land (+203,535.44 ha), where positive changes in almost all the land use classes. Consequently, desertification, land degradation and loss of snow and vegetation cover occurred. Additionally, slight rise has been seen in water bodies such as +86.74 ha and the minor changes are due to glacial melting which temporarily increases the surface water. As a result, small lakes i.e. glacial and glacio-fluvial lakes were also developed. The analysis revealed that LST exhibited a strong warming trend (+0.17°C/year, *p*
