Preprints
Filtering by Subject: Oceanography
Beyond Single Hazard Framework: Multi-Hazard Worst Case Scenarios from Ensemble Tropical Cyclone Forecasts
Published: 2025-02-22
Subjects: Environmental Engineering, Hydrology, Meteorology, Oceanography, Risk Analysis
Ensemble forecasting is a powerful tool for supporting informed decision-making in managing multi-hazard risks associated with tropical cyclones (TCs). Although TC ensemble forecasts are widely used in operational numerical weather prediction systems, their potential for disaster prediction and management has not been fully exploited. Here we propose a novel, efficient, and practical method to [...]
A bipolar convection seesaw explains Earth system response to Heinrich events
Published: 2025-01-25
Subjects: Biogeochemistry, Climate, Oceanography
Recent rise of water levels of Lake Nakuru, Kenya: Unraveling the Changing Precipitation Regime and its Climatic Drivers
Published: 2025-01-21
Subjects: Atmospheric Sciences, Civil and Environmental Engineering, Engineering, Environmental Engineering, Meteorology, Oceanography, Oceanography and Atmospheric Sciences and Meteorology
The Kenyan Rift Valley has experienced an abrupt and significant rise in its lake levels since 2010, followed by a more rapid rise since 2020. This paper examines the dynamic changes in precipitation patterns and their climatic drivers in the Kenyan Rift Valley region from 1981 to 2021, focusing on Lake Nakuru. Notably, in 2010, a pivotal change point in precipitation aligns with the rising water [...]
OceanTracker 0.5: Fast Adaptable Lagrangian Particle Tracking in Structured and Unstructured Grids
Published: 2025-01-16
Subjects: Numerical Analysis and Scientific Computing, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Particle tracking is frequently used to compute particle movements within hydrodynamic ocean models; however, modelling millions of particles is computationally challenging. OceanTracker is designed to minimise the time required to obtain results from particle tracking. Firstly, by being computationally fast, it enables users to scale to large numbers of particles, thus obtaining better [...]
GelCam: Visualizing Episodic Sinking Particle Flux via a Polyacrylamide Gel-Based Sediment Trap
Published: 2025-01-11
Subjects: Biogeochemistry, Earth Sciences, Oceanography
While particle-intercepting traps remain a dominant method for quantifying the contribution of sinking particles to the biological carbon pump, fluxes are typically integrated over days to months. Observations of time-varying particle flux over shorter durations are very limited. To this end, we prototyped a camera system called “GelCam” which captures a rapid time-lapse image sequence of [...]
Joint effects of submesoscale lateral dispersion and biological reactions on biogeochemical flux
Published: 2024-12-11
Subjects: Applied Mathematics, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Submesoscale dynamics, operating at spatial scales of O(1−10 km) and temporal scales of O(1 day), are particularly important for marine ecosystems as they occur on similar timescales as phytoplankton growth, enabling biophysical feedbacks. While submesoscale dynamics are known to impact biological fluxes by modifying nutrient upwelling, horizontal transport has traditionally been assumed to only [...]
Ocean and Coastal Acidification Monitoring Priorities for the Northeast US and Eastern Canada
Published: 2024-11-06
Subjects: Environmental Monitoring, Geochemistry, Oceanography, Planetary Geochemistry
The Interagency Working Group on Ocean Acidification monitoring Prioritization Plan 2024 calls for Coastal Acidification Networks to identify the ocean and coastal acidification (OCA) monitoring needs most important for their regions. The Northeast Coastal Acidification Network (NECAN) organized a webinar series to study regional needs, which culminated with a workshop in November 2023. This [...]
Towards statistical modeling of chlorophyll-a concentrations in Balikpapan Bay, Indonesia: Implications for algal bloom detection
Published: 2024-10-26
Subjects: Artificial Intelligence and Robotics, Biogeochemistry, Environmental Monitoring, Marine Biology, Oceanography
This study presents a comprehensive statistical analysis of chlorophyll-a dynamics in Balikpapan Bay, Indonesia, combining time series analysis, extreme value modeling, and machine learning techniques to understand phytoplankton variability near Indonesia's planned new capital city. Analysis of daily chlorophyll-a concentrations (2019-2021) revealed a non-Gaussian distribution (skewness = 2.212, [...]
Acoustic Doppler Current Profiler Measurements from Saildrones, with Applications to Submesoscale Studies
Published: 2024-10-25
Subjects: Oceanography
Characterizing submesoscale ocean processes requires high-resolution observations in both space O(1 km) and time O(1 hr). One way to resolve submesoscale features is to deploy multiple mobile platforms, such as Saildrones (SDs), to achieve high-resolution synchronous measurements, but this requires velocity accuracies of O(1 cm/s) to resolve submesoscale velocity gradients. In this study, we [...]
Potential effects of coagulation processes on phytoplankton mortality in the Elbe estuary from a Lagrangian point of view
Published: 2024-10-17
Subjects: Biogeochemistry, Environmental Health and Protection, Environmental Indicators and Impact Assessment, Environmental Monitoring, Oceanography, Water Resource Management
Within the Elbe estuary, a sudden change in depth occurs when the river enters the shipping channel in the Port of Hamburg. This change in depth correlates with a sharp decline in phytoplankton concentrations. This decline affects the estuarine food web and shifts the ecosystem from autotrophic to heterotrophic during the summer months. Previous studies have hypothesized that this collapse is [...]
Questioning Dark Oxygen Production in the Deep-sea Ferromanganese Nodule Field
Published: 2024-10-04
Subjects: Earth Sciences, Geochemistry, Geology, Oceanography
Previous studies have concluded that the natural process where oxygen is consumed as decomposition of organic matter that supplied from shallow waters occurs on the deep-sea floor. Sweetman et al.1 presented the surprising observation that deep-sea ferromanganese nodules generate oxygen, which they labelled as dark oxygen production. The authors claimed that oxygen was generated through the [...]
Carbon storage in Northern Ireland’s aquatic ecosystems: an evidence synthesis to support policy development.
Published: 2024-09-06
Subjects: Biogeochemistry, Marine Biology, Oceanography
Blue carbon is defined as carbon that is naturally sequestered and stored in the world’s aquatic ecosystems. Governments around the world are currently seeking to develop a range of tools to help meet their commitments to reduce greenhouse gas emissions and potentially reverse anthropogenic climate change. As such, there is growing interest from policy makers in natural processes which may be [...]
Two-dimensional Ekman-Inertial Instability: A comparison with Inertial Instability
Published: 2024-08-29
Subjects: Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
In the ocean, submesoscale flows tend to undergo several hydrodynamic instabilities. In particular, Inertial Instability (InI) and Ekman-Inertial Instability (EII) are known to develop in geostrophically balanced barotropic flows whose lateral shear is larger in magnitude and opposite in sign to the Coriolis parameter. Although these instabilities share some elements, their dynamical nature can [...]
The turbulent dynamics of anticyclonic submesoscale headland wakes
Published: 2024-08-10
Subjects: Oceanography
Flow interacting with bathymetry has been posited to be important for dissipation and mixing in the global ocean. Despite this, there are large uncertainties regarding mixing in these environments, particularly as it pertains to the role of submesoscale structures in the dynamics and energetics. In this work we study such flows with a series of Large-Eddy simulations of a submesoscale flow past a [...]
The Overlooked Sub-Grid Air-Sea Flux in Climate Models
Published: 2024-05-18
Subjects: Atmospheric Sciences, Climate, Numerical Analysis and Scientific Computing, Oceanography
Understanding air-sea interaction is crucial for our ability to predict future states of the climate system, and to inform economic and societal decision-making. However, the representation of air-sea interactions in climate models is limited by structural errors associated with model resolution. Coarse-resolution climate models do not resolve small-scale structures in the air-sea state, which, [...]