DSpace 集合:

Lateral Coastal Blue Carbon Export Fuels a Deep-Ocean Carbon Sink in an Oligotrophic Warm Pool

2026-01-01T00:00:00Z

標題: Lateral Coastal Blue Carbon Export Fuels a Deep-Ocean Carbon Sink in an Oligotrophic Warm Pool 作者: Hsieh, Hsueh-Han; Shih, Yung-Yen; Chow, Chun-Hoe; Chung, Tzu-Chieh; Wu, Syun-Han; Abedneko, Vicente G.; Liao, Chin-Hsin; Lee, Tse-Min; Zhang, Jingjing; Chen, Jianfang; Guo, Laodong; Bacosa, Hernando P.; Hung, Chin-Chang 摘要: Coastal blue carbon (CBC) ecosystems export organic matter offshore, but their contribution to deep-ocean carbon sequestration remains insufficiently quantified. We measured depth-resolved particulate organic carbon (POC) fluxes, delta 13C signatures, and environmental DNA (eDNA) from sediment traps deployed at 150, 500, and 1,000 m in the western North Pacific warm pool. POC fluxes at 1,000 m were two- to four-fold higher than predicted by classical attenuation models, indicating efficient deep-water transfer driven by both vertical export and lateral inputs. eDNA from sinking particles revealed macroalgae, mangrove, and seagrass taxa throughout the mesopelagic and bathypelagic layers, demonstrating long-distance transport of CBC material. delta 13C values showed predominantly marine-derived POC, but with measurable CBC contributions persisting at depth. These observations identify a previously underappreciated pathway linking coastal vegetation to deep-ocean carbon storage in oligotrophic gyre systems. They also highlight the need for ground-truth biological carbon pump (BCP) measurements, particularly for oceanic island countries with small land areas yet large exclusive economic zones (EEZs), where accurate carbon accounting depends on in situ validation of model-based estimates.

Pattern Referencing for Hourly Temperature Forecasting: A Diurnal-Aware, Imputation-Free Model with an Expanding Reference Set

2026-01-01T00:00:00Z

標題: Pattern Referencing for Hourly Temperature Forecasting: A Diurnal-Aware, Imputation-Free Model with an Expanding Reference Set 作者: Wu, Nan-jing 摘要: Hourly near-surface air temperature over the Chiayi-Tainan coastal plain in southwestern Taiwan exhibits strong spatial variability and rapid transitions driven by sea-land breezes, radiative cooling, and diurnal forcing. This study revisits and extends an earlier pattern-referencing weighted k-nearest neighbor (WKNN) forecaster for hourly one-step-ahead prediction. The extensions include (i) using observed temperatures on the original physical scale (no mandatory normalization or standardization), (ii) incorporating diurnal-cycle predictors (sine and cosine of hour), and (iii) adopting an expanding reference set as new observations accumulate. Missing inputs are handled natively by computing similarity using only available components at each forecast time. The model is evaluated at 14 stations with year-long hourly forecasting in 2025 and is compared with persistence, an autoregressive integrated moving average (ARIMA) (3, 1, 3) benchmark, and an earlier baseline configuration using a fixed reference set, normalized inputs, and no diurnal predictors. Across stations, the proposed design reduces overall errors and improves tracking during rapid transitions. Case studies for a cold episode in January and the annual maximum-temperature episode in June show closer tracking of observed temperature evolution during rapidly changing conditions. An outage-prone period in August further demonstrates an operational advantage: Even under widespread missing observations across the station network, forecasts can still be issued whenever at least a subset of predictors is available. Overall, diurnal-aware pattern-referencing with direct inputs and an expanding reference set provides an accurate and deployable option for coastal station networks subject to intermittent missing observations. SIGNIFICANCE STATEMENT: Coastal weather in southwestern Taiwan can change quickly over short distances and hours, yet station networks often have gaps. We present a simple forecasting approach that predicts next-hour air temperature by finding past situations that most resemble the current one, while using only the measurements that are actually available at that moment. The method keeps temperatures in their original units, adds time-of-day information, and continuously updates its reference set as new observations arrive. Tested at 14 stations over 2025, it reduces errors overall and improves tracking during rapid cold and heat transitions. This improves real-time temperature guidance when data streams are unreliable.

Dynamic bio-regionalization of a highly variable oceanic system: Insights from the Southern South China Sea

2026-01-01T00:00:00Z

標題: Dynamic bio-regionalization of a highly variable oceanic system: Insights from the Southern South China Sea 作者: Rosli, Mohd Ikmal Shafiq; Cheah, Wee; Chow, Chun Hoe; Tseng, Wan-Ling; Abu Samah, Azizan 摘要: Classifying ecologically distinct biological regions with similar phytoplankton dynamics is crucial for marine resource management. The southern South China Sea (SSCS) is one of the world's most ecologically important and productive regions. It is a highly dynamic system, characterized by the extensive shallow Sunda Shelf (<200 m) in the south and a deep basin (> 1000 m) in the north. While the entire basin is influenced by reversing monsoonal winds, coastal regions are shaped by both monsoonal winds and riverine inputs. Clustering such a variable system remains challenging, and no study has systematically classified its bio-regions. Using empirical orthogonal function analysis and fuzzy-c means clustering on 24 years of satellite-derived chlorophyll-a (chl-a) data, we identified three distinct regions: (1) the eastern boundary of the SSCS, (2) the central SSCS and off the coast of Vietnam, and (3) the western region from the Karimata Straits to the Mekong River mouth. The eastern region exhibits unimodal seasonality, while the central and western regions display bimodal seasonality. These regions are temporally dynamic, shifting in size and location on interannual timescales. During the 1998 El Ni & ntilde;o, chl-a variability in the deep basin changed drastically under intense warming. In contrast, during the 2015 El Ni & ntilde;o, despite strong warming, chl-a variability remained statistically similar to climatology. While monsoonal modulation by the El Ni & ntilde;o Southern Oscillation influences these patterns, our results show that interannual variability is complex and diverse, warranting further validation for improved modelling and fisheries management.

Cold Pool Formation Over the Taiwan Bank Driven by Shoaling Internal Tides

2026-01-01T00:00:00Z

標題: Cold Pool Formation Over the Taiwan Bank Driven by Shoaling Internal Tides 作者: Chang, Ming-Huei; Yeh, Yu-Yu; Cheng, Yu-Hsin; Yang, Yiing Jang; Ko, Dong Shan; Wang, Shih-Hong 摘要: Cold, saline, and chlorophyll-rich surface waters are frequently observed over the Taiwan Bank in the southern Taiwan Strait, forming a distinct feature referred to as the Green-Cold Pool (GCP). Despite its ecological importance, the physical mechanisms sustaining this cold pool remain unclear. Using an integrated analysis of in situ hydrographic and microstructure observations, geostationary satellite measurements of sea surface temperature (SST) and chlorophyll-a, and high-resolution numerical simulations, we demonstrate that the GCP is primarily driven by shoaling and breaking semidiurnal internal tides. Internal tides generated in the Luzon Strait propagate northwestward and shoal over the continental slope south of the Taiwan Bank. As the internal tide trough encounters the steep slope, it steepens and evolves into internal tidal bores. These bores propagate upslope, inducing cold-water run-up from downslope regions and pushing previously uplifted cold water farther onto the bank. Strong turbulent diffusivity of O(10-3-10-1) m2 s-1 develops near the bore head and within the bottom boundary layer, promoting intense vertical mixing and irreversible upward transport of O(10-3) m s-1. This combined effect forms a bottom-mixed layer (BML) that supplies cold, saline, and nutrient-rich water onto the bank. Depending on the intensity and vertical extent of turbulence, the BML may remain capped by a thin warm surface layer or outcrop at the surface, producing the observed cold SST signal. Barotropic tidal currents modulate the semidiurnal migration of the cold pool but are insufficient to sustain its persistence.