Oceanography and Atmospheric Sciences and Meteorology Commons^™

A Blueprint To Greener Shorelines: Advancing The Effectiveness, Sustainability, And Widespread Adoption Of Coastal Nature-Based Solutions Through Transdisciplinary Research, Taylor M. Sloey, Sierra Hildebrandt, Rebecca L. Morris, Matthew V. Bilskie, Aaron Bland, David Bushek, Gabriella Dipetto, Daniel Elefant, Vincent Encomio, Ramin Familkhalili, Christine Hladik, Danielle Kreeger, Avery B. Paxton, Cindy M. Palinkas, Latina Steele, Andrew Scheld, Daisuke Taira, Jason D. Toft, Armando J. Ubeda, Christine Whitcraft, Donna Marie Bilkovic

Biological Sciences Faculty Publications

Coastal nature-based solutions (NbS) have emerged as powerful tools to enhance sustainable development and ecological restoration goals. As a rapidly growing field spanning across social, political, ecological, economic, and engineering disciplines, it is critical that researchers working in coastal NbS regularly attempt to identify emerging focal areas for scientific inquiry. Following the 27th Biennial meeting of the Coastal and Estuarine Research Federation, we provide a transdisciplinary perspective (including biologists, engineers, oceanographers, geoscientists, economists, and facilitators of workforce training programs) of pertinent research questions that, if answered, will advance the effectiveness, sustainability, and widespread adoption of coastal NbS. These suggestions for …

Thermal Tolerance Limits Of Mesophotic Corals In American Samoa, Daniel Barshis, Veronica Z. Radice, Katherine E. Parker, Nicholas Evensen

Biological Sciences Faculty Publications

We analyzed the thermal tolerances of multiple coral species from an upper mesophotic (38–40m) and a shallow reef (5–10m) with our portable Coral Bleaching Automated Stress System (CBASS). Depth generalist Montipora grisea (deep and shallow) and depth specialists Pachyseris speciosa and Leptoseris sp. (deep only) were assayed from Leone, located on the western coast of Tutuila in American Samoa. Fragments from 10 genotypes of each species were exposed to a 17-hour thermal stress assay reaching four maximum temperatures ranging from 30–38°C under in situ light conditions (150 μmol photons m⁻² s⁻¹ under a Lee Filters “deep …

An Economic And Production Analysis Of Seaweed Farms In California And The Pacific Northwest, Brian Donovan

Cal Poly Humboldt theses and projects

Since the early 2010s, the seaweed aquaculture industry has steadily expanded in the United States, with states like Alaska, Maine, Hawaii, and Connecticut leading the way in the development of this emerging sector. However, information gaps remain concerning certain aspects of the domestic seaweed aquaculture industry. The purpose of this study was to examine the status of the seaweed aquaculture industry along the West Coast of the United States; specifically in the states of California, Oregon, and Washington. Seaweed farmers in these states were invited to voluntarily complete surveys asking important production, economic, and commercial questions regarding their operations. Data …

Modeling The Impact Of Climate Change On Plant Hardiness Zones Across The Contiguous United States Using Empirical Bayesian Kriging Regression Prediction, Daniel Donkor

Graduate Theses/Dissertations

Mapping plant hardiness zones is crucial to understanding and predicting the spatial distribution of plants in response to climatic conditions. The United States Department of Agriculture (USDA) developed the plant hardiness zones based on the average of annual extreme minimum temperatures using the Parameter elevation Regression on Independent Slope Model (PRISM). While the USDA’s 2012 and 2023 Plant Hardiness Zone maps remain standard references, they offer limited geostatistical transparency that causes more complications in replicating. This study applies Empirical Bayesian Kriging Regression Prediction (EBKRP) method to generate Plant Hardiness Zone maps, analyze spatial and temporal shifts in the plant hardiness …

Evaluation Of Practical Methods To Determine If A Karst Creek Is Gaining Or Losing: Case Study Of Leith Creek, Elizabeth Jones

Graduate Theses/Dissertations

Karst landscapes are abundant in Missouri, with features such as caves, springs, and sinkholes that form through the dissolution of limestone. Leith Creek is a small stream in Polk County, Missouri fed by two springs and the shallow unconfined Springfield Plateau aquifer, a highly karstified aquifer which is made up of limestone and minor interbedded shale-mudstone units. To determine if Leith Creek is gaining or losing, stream flow, water chemistry and temperature sensors were monitored. Stream flow results required multiple visits to take measurements while temperature sensors required two visits, one to install the dataloggers and another to remove the …

Integrated Valuation Of The Ecological, Social And Economic Benefits Provided By A Multifunctional Nature-Based Solution, Laura Costadone, Shan Zhang

ODU Articles

Nature-based Solutions (NbS) offer multifunctional approaches to address climate change and environmental challenges, providing a sustainable alternative to traditional gray infrastructure. Despite their promise, widespread adoption remains limited, in part due to an incomplete understanding of their full costs and benefits relative to conventional infrastructure. Traditional benefit–cost analyses often overlook non-monetized benefits and the interconnected ecosystem services provided by NbS. This study introduces a methodological approach to quantify both the physical and monetary value of ecosystem services and co-benefits delivered by an NbS project. We applied an integrated valuation framework to a case study in Virginia Beach, VA, USA, where …

The Lotus At Dawn: Rethinking Climate Resilience In An Archipelago, Marie Franchesca M. Borras

English Faculty Publications

Super Typhoon Rai, locally called Odette, hit the Philippines on December 16, 2021, devastating General Luna, a municipality in Surigao del Norte. Due to this natural disaster, this study—originally written as a pre-pandemic autoethnographic account via flâneuserie—endeavors to understand how the mobility of city dwellers contributes to the anthropogenic climate by exploring the ethics of care. Additionally, it seeks to posit inquiries on what it means to be climate-resilient in an archipelagic country such as the Philippines. Beyond economic methodologies, it is pivotal to examine issues of care that deal with our relationship with nature by understanding how, for example, …

Foreign Object Detection System Development Using Edge Devices Integrated With Quadcopter Autonomous Tracking, Chi-Chia Huang, Ching-Hung Lee

Journal of Marine Science and Technology–Taiwan

This study proposes an all-weather autonomous foreign-object detection system capable of operating in low-light environments. We used a highly mobile quadcopter equipped with an edge-computing device as the inspection platform. On the software side, we integrated a low-light image enhancement model, a path-tracking algorithm, and a foreign object detection model to achieve rapid object detection. A lightweight, low-light image-enhancement model reduces the need for additional lighting equipment, thereby enabling reliable detection under low-light conditions. The path-tracking algorithm integrates a lightweight semantic segmentation model with traditional image-processing techniques to establish flight paths efficiently and reliably. The foreign-object detection component employs state-of-the-art …

Optimization Of Underactuated Ship Sliding Mode Controller Based On The Ddpg Algorithm, Lin Ma, Mingzhe Qi, Shicai Chen, Hongwei Bian, Jian Zhang

Journal of Marine Science and Technology–Taiwan

Due to the development of ship intelligence, the demand for precise controllers is increasing day by day. In traditional design, the trial-and-error method often leads to the use of inaccurate controller parameters, causing oscillations when environmental disturbances are present. To address these issues, this study introduces deep learning to optimize the controller parameters, particularly those used for sliding mode controllers in underactuated ships. We adopt the Deep Deterministic Policy Gradient (DDPG) algorithm based on the Actor Critic framework. By freely setting the reward function to match the control objective, the trained model can output more accurate controller parameters, with the …

Experiments On Aluminum Alloy Additive Layer Waam Lamination Using The Arc Current Reduction Technique, Jukkapun Greebmalai, Eakkachai Warinsiriruk, Chao-Hsiang Hsiao, Yin-Tien Wang

Journal of Marine Science and Technology–Taiwan

Recent advancements in additive manufacturing have been propelled by innovations in processes, materials, and fabrication techniques. This study specifically focuses on the optimizing Wire and Arc Additive Manufacturing (WAAM) within the Gas Metal Arc Welding (GMAW) process. The goal is to build laminated layers using aluminum alloy from the five-thousand series. In this research, a novel technique is introduced that employs a reduced arc-current during the additive layer progress for aluminum alloys, along with a double pulse current in the GMAW process to enhance weldability. The material used for addition is ER5356 aluminum wire, which is applied to an Al-5083 …

An Optimization Model For Supporting Bunkering Decisions In Bulk Shipping, Chung-Cheng Lu, Hui-Chieh Li, Hung-Yu Chen

Journal of Marine Science and Technology–Taiwan

This study addresses a bunkering optimization problem for bulk shipping carriers that explores route deviation to find optimal bunkering locations and amounts. A mixed integer linear programming (MILP) model is developed to determine optimal bunkering decisions that minimize total operating costs, including total daily operating costs, bunkering costs, port charges and surcharges, while observing time window constraints at loading/unloading ports. The proposed model is evaluated using instances generated from real data provided by H company with its operational headquarters in Taipei, Taiwan, which operates a fleet of handysize ships in East and South Asia. The results indicate that optimization models …

Assessment Of Coastal Navigation Safety: A Case Study Of Boka Bay With Stakeholder Perspectives, Ivan Mraković, Rino Bošnjak

Journal of Marine Science and Technology–Taiwan

The navigational safety of Boka Bay, i.e., a critical maritime area along the Adriatic coast, is of great importance owing to its ecological sensitivity, diverse marine traffic, and significant economic activity. This study provides a comprehensive assessment by analyzing the perspectives of various stakeholders, including seafarers, local pilots, skippers, regulatory authorities, and others engaged in maritime activities within the bay. Using a structured questionnaire survey, both quantitative and qualitative data were collected in formats such as descriptive responses, Yes/No choices, and Likert scale ratings, ensuring a well-rounded understanding of navigational practices and challenges. The data were analyzed using descriptive statistics, …

A Hybrid Model To Assess Commercial Port Resilience In Taiwan, Po-Hsing Tseng, James J.H. Liou

Journal of Marine Science and Technology–Taiwan

Since 2021, international commercial ports have faced unprecedented challenges (e.g., COVID-19 pandemic, Suez Canal congestion), impacting daily life, work, human well-being, properties, the environment, and socio-economic activities. The adaptation capability resilience of international commercial ports to respond to external changes has become crucial. This study develops an expert knowledge-based hybrid multi-criteria decision-making model integrating Best-Worst Method (BWM), Rough Dombi Aggregator, and Combined Compromise Solution (CoCoSo) to evaluate port resilience capabilities, using Taiwan's international commercial ports as a case study. We propose four evaluation dimensions encompassing 13 indicators: detection capability, resistance capability, resource integration capability, and recovery capability. The BWM determined …

An Evaluation Of The Possibility And Effectiveness Of Renewable Energy In Container Terminal At Jinhae New Port, Min-Seop Sim, Yul-Seong Kim, Chang-Hee Lee

Journal of Marine Science and Technology–Taiwan

The international goals of combating climate change and reducing greenhouse gas emissions are driving container terminal operators to adopt renewable energy solutions. This study evaluated the feasibility and effectiveness of introducing renewable energy and eco-fuels for energy independence at the Jinhae New Port Container Terminal, South Korea. Using portfolio analysis, eight renewable energy technologies (solar power, solar thermal energy, wind energy, hydropower, marine energy, geothermal energy, bioenergy, and waste-to-energy) and seven eco-friendly fuels (electricity, liquefied natural gas, liquefied petroleum gas, hydrogen fuel cells, ammonia fuel cells, bioenergy, and hybrid systems) were assessed. Survey data from stakeholders identified solar, wind, and …

High-Resolution Modeling Of Extreme Heat Events With Socioeconomic Consideration: A Real-Case Wrf-Les Approach, Maryam Golbazi, Frank Liu, Yin-Hsuen Chen, Timothy W. Juliano, Heather Richter

ODU Articles

The overarching goals of this work is to explore best practices for micro-scale modeling of a real case, identify relevant phenomena by using high-resolution modeling, and to explore their implications for public health, and climate resilience strategies in Hampton Roads, VA, USA. This project employs the Weather Research and Forecasting (WRF) model to conduct a comprehensive study of Hampton Roads, utilizing a coupled mesoscale to microscale modeling capable of resolving boundary layer turbulence. This study has three primary objectives: (1) to establish the optimal mesoscale to Large-Eddy Simulation (LES) configurations for complex geographical regions such as the Hampton Roads (HR) …

Atmospheric Chemistry Experiment (Ace) Winds, Matthew Wyatt, Peter F. Bernath, Chris Boone, Léo Lavy, Ryan Johnson

Chemistry & Biochemistry Faculty Publications

The Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) uses limb geometry to measure transmittance spectra of Earth's atmosphere by solar occultation. Line-of-sight wind speeds can be derived via Doppler shifts of molecular lines in infrared spectra. The wind look direction angles relative to geodetic North are derived from geometry. We validate the new ACE version 5.3 (v.5.3) line-of-sight winds with MIGHTI and meteor radar vector wind observations and find a ±15 m/s sunrise/sunset shift above 80 km. We also compare line-of-sight winds from ACE-FTS v.5.2 and v.5.3 with vector winds from the MERRA-2, HWM14, and WACCM-X models. A ±15 m/s …

Sustainable Management Of Erosive Shores: An Interdisciplinary Approach Integrating Engineering And Social Sciences At A Tide-Dominant Beach Area, Jun Ik Sohn, Hyun Dong Kim, Kiran Adhithya Ramakrishnan

Civil & Environmental Engineering Faculty Publications

This study investigates the causes and consequences of shoreline erosion at Kkotji Beach, a prominent tourist destination on the west coast of South Korea, where the degradation of the coastal environment has increasingly threatened the local tourism industry and economy, by employing a mixed-methods approach that combines field observations with MIKE 21 hydrodynamic simulations and by integrating perspectives from coastal engineering and the social sciences to develop practical, site-specific strategies for mitigating erosion, enhancing public awareness, and promoting sustainable coastal planning and development that support long-term environmental resilience and economic stability. The results show that dominant ebb currents drive southward …

Low Salinities Impair Heat Tolerance And Alter Reproductive Traits With No Implications For Survival In A Marine Annelid From Coastal Habitats, Gabrielle Newton, Gloria Massamba-N'Siala

Biological Sciences Faculty Publications

Climate change is expected to intensify salinity and temperature fluctuations in estuarine and coastal habitats. However, the impact of salinity variation on ectotherms’ thermal tolerance remains underexplored, limiting our understanding of the interplay between these stressors. This study investigated salinity-dependent changes in life history traits (survival, growth rate, fecundity, and egg size) over a 33-day exposure to a salinity gradient (12, 17, 22, 27, 32, 35, 40, 45, 50) in the marine annelid Ophryotrocha labronica. Individuals that survived the salinity treatments were assessed for their upper and lower thermal tolerance limits. Female individuals, the target of the study, exhibited …

Cellular Responses Of Astrangia Poculata (Ellis And Solander, 1786) And Its Symbiont To Experimental Heat Stress, Tyler E. Harman, Daniel Barshis, Briana Hauff Salas, Kevin B. Strychar

Biological Sciences Faculty Publications

Climate change has had devastating effects on tropical coral reefs; however, much less is known regarding how heat stress affects temperate coral. This research focuses on Astrangia poculata (Ellis and Solander, 1786) collected from Narragansett Bay, RI, during the summer and winter seasons and understanding the effect of experimental thermal extremes (i.e., 26 °C) on seasonally different populations. Photosynthetic efficiency (Fv/Fm), symbiont density (via an inverse relationship with pixel intensity), and oxidative stress via reactive oxygen species (ROS) concentrations were measured on symbiotic and aposymbiotic A. poculata. Higher Fv/Fm rates were observed in summer- vs. winter-collected corals (p ≤ …

Alternative Splicing In A Coral During Heat Stress Acclimation And Recovery, Nitin Baliga, Kathryn Stanklewicz, Jacob Valenzuela, Serdar Turkarsian, Wei-Ju Wu, Kelly Gomez-Campo, Nicolas Locatelli, Trinity Conn, Veronica Radice, Katherine Parker, Rachel Alderdice, Line Bay, Christian Voolstra, Daniel Barshis, Iliana Baums

Biological Sciences Faculty Publications

Climate change has caused drastic declines in corals. As sessile organisms, corals acclimate to environmental shifts through genome-wide changes in gene expression, epigenetic modifications, and alterations in microbiome composition. However, alternative splicing (AS), a conserved mechanism of stress response in many organisms, has been under-explored in corals. Using short-term acute thermal stress assays, we investigated patterns of AS in the scleractinian coral Acropora cervicornis during response to low (33°C), medium (35°C), and high (37°C) heat stress and subsequent overnight recovery. Our findings demonstrate reproducible dynamic shifts in AS of at least 40 percent of all genes during response to heat …

Analyzing Microbial Communities In Porites Astreoides, Sanaa Caldwell, Katie Parker, Daniel Barshis

Biological Sciences Faculty Publications

Coral reefs are vital marine ecosystems that support many different species and ecosystem services through protecting coastlines from storms and erosion, providing raw materials for medication, and facilitating diversity amongst marine species. Anthropogenic climate change is causing ocean temperatures to exceed the range of coral thermal tolerance resulting in more coral bleaching events globally. However, some corals have the capacity to withstand high temperatures through different thermal tolerance strategies. A balanced microbial community plays a critical role in coral health and recent studies have indicated that a balanced microbiome is associated with temperature-stress tolerant corals. Yet, there is a severe …

Summer Temperature Maxima Already Challenge Thermal Capacities Of Coral In The Southern Persian/Arabian Gulf, Rachel Alderdice, Gabriela Perna, Hannah Manns, Anna Fiesinger, Luigi Colin, Kathryn Stankiewicz, Kelly Gomez-Campo, Samantha Goyen, Line Bayse, Nitin Baliga, Jake Valenzuela, Iliana B. Baums, Daniel J. Barshis, John A. Burt, Christian R. Voolstra

Biological Sciences Faculty Publications

The future of coral reefs remains uncertain as intensifying ocean warming continues to drive coral decline and demise worldwide. Corals occurring in extreme environments such as the Persian/Arabian Gulf (PAG), the world’s warmest sea, represent a promising resource to study the genetic architecture of thermal tolerance. However, their thermal capacities remain unresolved. We applied short-term heat stress assays using the Coral Bleaching Automated Stress System (CBASS) to determine signatures of thermal tolerance from three common species (Porites harrisoni, Platygyra daedalea, and Cyphastrea microphthalma) across three sites (two in the extreme southern PAG and a more benign …

Selective Nutrient Incorporation May Underestimate Heterotrophy Of A Mixotrophic Reef-Building Coral, Connor R. Love, Marleen Stuhr, Michael D. Fox, Veronica Z. Radice, Maoz Fine, Kelton W. Mcmahon, David L. Valentine

Biological Sciences Faculty Publications

Mixotrophic reef-building corals acquire nutrition via photosynthate translocation from endosymbiotic microalgae and by heterotrophic prey/particle capture. Heterotrophy promotes resistance to, and recovery from, environmental stress, but quantifying coral heterotrophy remains difficult due to complex resource exchanges within the coral holobiont. We interrogated the response of multiple biomarkers to coral heterotrophy using fatty acid profiling and stable isotope analysis of Stylophora pistillata grown along a controlled feeding gradient from pure autotrophy to pure heterotrophy. We found that fatty acids and nitrogen were effectively incorporated into both coral host and symbiont tissues, while carbon, which is the primary target for conventional heterotrophy …

Swimming In Sh*T: Quantifying Lagoon Flushing Impacts On Fecal Indicator Bacteria In Surf Zones Of Three Beaches On The East End Of Long Island, Ny, Brody C. Eggert

Pomona Senior Theses

This thesis investigates how lagoon flushing influences fecal indicator bacteria (FIB) concentrations—specifically enterococcus bacteria—in the surf zones of East Hampton and Southampton, New York. Focusing on the coastal lagoons of Georgica Pond, Sagg Pond, and Mecox Bay, the study analyzes how episodic inlet openings and environmental conditions affect enterococcus levels at adjacent recreational beaches. Using over 700 observations from the Surfrider Foundation’s Blue Water Task Force (BWTF) database, I construct a series of statistical models ranging from ordinary least squares to mixed effects frameworks; this thesis shows my process in developing this model. My analysis reveals that open inlets between …

Predictive Maintenance In Naval Vessel Propulsion Systems For Enhanced Marine Operations Using A Bigmm-Hmm Framework With Divergence-Based Clustering, Farshid Javadnejad, Hyoshin John Park, Samuel Kovacic, Andres Sousa-Poza

Engineering Management & Systems Engineering Faculty Publications

This study introduces a BiGMM-HMM Integration Framework designed to improve predictive maintenance strategies for naval vessel propulsion systems, addressing the need for efficient and reliable operation in marine engineering applications. The framework effectively manages multimodal sensor data by leveraging a unique combination of Gaussian Mixture Models (GMMs) and Hidden Markov Models (HMMs) in a bidirectional architecture. It analyses the dynamic interactions between sensors and subsystems. Two preprocessing methods are evaluated: Method 1 focuses on subsystem interactions, employing divergence-based root cause analysis to identify key sensor variables by clustering of sensors and subsystems. In contrast, Method 2 processes the entire dataset …

Suntan (And Other Solar Tigonometric Functions), John Adam

Mathematics & Statistics Faculty Publications

Question 1: If I₀ is the solar irradiance (power per unit area, W/m²) reaching my head, express the intensity on the side of my face (I_s) in terms of θ. Assume for now that the irradiance is independent of path length through the atmosphere and that my face is normal to the direction θ = 90°.

Using the 1962 U.S. Standard Atmosphere,² Hottel (1976)³ expressed the solar irradiance using the formula

I = I₀(a₀ + a₁e^{−k sec θ}), where A is the elevation in kilometers and

a₀ = 0.4237 − 0.00821(6 − A)²; a₁ = 0.5055 …

A Question Of Transparency, John Adam

Mathematics & Statistics Faculty Publications

Question 1: Why is it easier to see through rain than fog?

Start thinking about this by imagining a fixed volume (V) of water being dispersed into, say, N identical droplets of diameter d. Surface area and volume considerations should lead to the answer in terms of V and d.

Question 2: (a) How "long" (in meters) might such a rain shower or fog bank be?

Hint: Suppose you are looking along a linear stack of S cubes with 1-m sides (through the rain or fog). Each cube contains N drops. If p is the visibility (i.e., the fraction of …

A Multispecies, Multisite Assessment Of Coral Thermal Tolerances In American Samoa, Using Acute Heat Stress Assays, Ponchanok Weeriyanun, Nicolas R. Evensen, Katherine E. Parker, Veronica Z. Radice, Daniel J. Barshis

Biological Sciences Faculty Publications

Reef-building corals are being impacted by increasing seawater temperatures, with marine heatwaves leading to mass bleaching events and extensive mortality. However, corals can display variation in thermal tolerance, both within and among species. In this study, we sampled four coral species (Acropora hyacinthus, Montipora grisea, Pocillopora verrucosa, and Porites lobata) from two sites on Tutuila, American Samoa, with contrasting environmental regimes but similar Maximum Monthly Means (MMM). Coral fragments were subjected to short-term acute heat stress experiments using the Coral Bleaching Automated Stress System (CBASS). PAM Fluorometry was used to measure the symbiont’s effective quantum yield (Fv/Fm) following heat stress …

Moderate Heating Renders 7.8-Million-Year-Old Sedimentary Organic Matter Bioavailable, Shuchai Gan, Verena B. Heuer, Frauke Schmidt, Lars Wormer, Faming Wang, Rishi R. Adhikari, Patrick Hatcher, Ann Pearson, Kai-Uwe Hinrichs

Chemistry & Biochemistry Faculty Publications

Marine sediments are a large reservoir of recalcitrant organic matter and host microbes at subsurface depths exceeding 2.4 kilometers and temperatures up to 120°C, yet the mechanisms supplying bioavailable substrates remain unclear. Here, we investigated 7.8-million-year-old sediment from IODP Site C0012 off the Nankai Trough, Japan, through incubations at 20°, 35°, 55°, and 85°C to simulate burial temperatures. Using 3D fluorescence spectroscopy and ultrahigh-resolution mass spectrometry, we tracked changes in dissolved organic matter (DOM). At 35°C, humic-like DOM was released alongside metal ions, exhibiting low bioavailability. At 55°C, abiotic decomposition of humic compounds generated smaller, more bioavailable DOM, promoting fermentation. …

Co₂ Isotopologues From The Ace Satellite, D. English, P. Bernath, C. Boone

Chemistry & Biochemistry Faculty Publications

Carbon dioxide isotopologues have been studied thoroughly in the troposphere. In the stratosphere, the minor oxygen CO₂ isotopologues have anomalous abundances due to their exchange reactions with isotopically fractionated ozone, differentiating them from tropospheric CO₂. Previously a model predicted that this anomalous isotopic abundance continues into the mesosphere but lacked verification from experimental observations. Here we use the Atmospheric Chemistry Experiment Fourier Transform Spectrometer which records infrared transmittance spectra of the Earth's limb from low Earth orbit using solar occultation. These infrared spectra provide measurements of global CO₂ isotopologue volume mixing ratios (VMRs) from the upper troposphere to the lower …