Biases in the In Situ Measurement of Particulate Organic Carbon and Its Effect on the Calibration and Validation of Ocean Color Sensors

Particulate organic carbon (POC) plays an oversize role, relative to its standing stock in the global carbon (C) cycle. Accurate measurement of POC is central to understanding the ocean C flux and its sensitivity to climate forcing. POC is a standard NASA ocean color data product, which lacks a consensus, quality-assured measurement protocol for satellite validation. Thus, algorithms based on field measurements lacking verified uncertainties have limited applicability towards climate data records. Different sampling and filtration protocols, and blank corrections, introduce biases in the magnitude of POC measured from the field. A significant filter blank attributable to dissolved organic C (DOC) adsorption that, until recently has been seldom corrected for, likely has introduced biases in POC global datasets

Regulacija vertikalnog fluksa i sastav planktona u jednostavnom ekološkom sistemu: “snapshots” iz malog slanog jezera Rogoznica (Hrvatska)

Vertical flux regulation was investigated in the small, shallow, marine and partly anoxic Lake Rogoznica (eastern coast of the Adriatic Sea) by studying plankton composition, zooplankton fecal pellet (FP) production and vertical carbon flux. The lake is naturally eutrophicated with high nutrient and particulate organic carbon (POC) concentrations and relatively low species diversity. However, the few species found can be highly abundant. Due to a simple ecological structure and low physical forcing, Lake Rogoznica may be regarded as a natural laboratory especially suitable for plankton studies. Only one copepod species, Acartia italica, was found in the lake and had a maximal abundance of 140 animals L-1. The mixotrophic dinoflagellate Ceratium furca and the diatom Chaetoceros curvisetus accounted for ~90% of the phytoplankton biomass. Phytoplankton made up 30% of the POC flux at 5 m and 10% at 10 m depth and was dominated by C. curvisetus and C. furca. Average export of POC was 730 ± 40 mg m-2d-1 at 5 m and 750 ± 90 mg m-2d-1 at 10 m depth, and detritus comprised 68 and 86 % at 5 and 10 m depth, respectively. Despite high copepod abundance and high suspended FP concentration, FP only contributed 4 – 5% of the vertical POC flux. The highest contribution to vertical carbon flux was in terms of detritus, and high retention was likely due to FP grazing or fragmentation by A. italica copepodites above 5 m depth. It is concluded that Lake Rogoznica is a productive system where organic material is rapidly transformed to detritus.Istraživan je vertikalni protok u malom, slanom, plitkom i djelomično anoksičnom jezeru Rogoznica (istočna obala Jadranskog mora) na temelju sastava planktona, produkcije zooplanktonskih fekalnih peleta i vertikalnog protoka ugljika. Jezero je prirodno eutroficirano s visokim koncentracijama hranjivih soli, a posebito čestičnim organskim ugljikom (POC) i relativno niskoj raznolikosti vrsta. Nekoliko pronađenih vrsta su pokazivale visoke brojnosti. Zbog svoje jednostavne ekološke strukture i slabih fizikalnih sila jezero Rogoznica se smatra prirodnim laboratorijem pogodnim za istraživanje planktona. Pronađena je samo jedna vrsta kopepoda, Acartia italica, s maksimalnom brojnošću od 140 jedinki L-1. Miksotrofni dinoflagelat Ceratium furca i diatomeja Chaetoceros curvisetus su bili zastupljeni s ~90% u fitoplanktonskoj biomasi. Fitoplankton predstavlja do 30% u dotoku čestičnog organskog ugljika na dubini od 5 m, te 10% na dubini od 10 m, a prevladavale su vrste C. curvisetus i C. furca. Prosječni dotok čestičnog organskog ugljika iznosio je 730 ± 40 mg m-2 d-1 na dubini od 5 m i 750 ± 90 mg m-2 d-1 na dubini od 10 m, dok je detritus obuhvaćao 68% odnosno 86% dotoka na dubinama od 5 i 10 m. Usprkos visokoj zastupljenosti kopepoda i koncentraciji suspendiranih fekalnih peleta, doprinos fekalnih peleta vertikalnom dotoku čestičnog organskog ugljika je bio samo 4 – 5 %. Najveći doprinos vertikalnom protoku ugljika predstavlja detritus i visoko zadržavanje je vjerojatno posljedica grazing-a fekalnih peleta ili njihove fragmentacije od strane kopepodita A. italica na dubini iznad 5 m. Ustanovljeno je da je jezero Rogoznica produktivni sistem u kojem se organski materijal brzo pretvara u detritus

Virtual Reality and Oceanography: Overview, Applications, and Perspective

With the ongoing, exponential increase in ocean data from autonomous platforms, satellites, models, and in particular, the growing field of quantitative imaging, there arises a need for scalable and cost-efficient visualization tools to interpret these large volumes of data. With the recent proliferation of consumer grade head-mounted displays, the emerging field of virtual reality (VR) has demonstrated its benefit in numerous disciplines, ranging from medicine to archeology. However, these benefits have not received as much attention in the ocean sciences. Here, we summarize some of the ways that virtual reality has been applied to this field. We highlight a few examples in which we (the authors) demonstrate the utility of VR as a tool for ocean scientists. For oceanic datasets that are well-suited for three-dimensional visualization, virtual reality has the potential to enhance the practice of ocean science

Alignment of Optical Backscatter Measurements From the EXPORTS Northeast Pacific Field Deployment

Backscattering of light is commonly measured by ocean observing systems, including ships and autonomous platforms, and is used as a proxy for the concentration of water column constituents such as phytoplankton and particulate carbon. Multiple on-going projects involve large numbers of independent measurements of backscatter, as well as other biologically relevant parameters, to understand how biology is changing in time and space throughout the global ocean. Rarely are there sufficient measurements to test how well these instruments are inter-calibrated in real-world deployment conditions. This paper develops a procedure to align multiple independently calibrated backscatter instruments to each other using nearby profiling casts and applies this method to nine instruments deployed during a recent field campaign in the North Pacific during August–September of 2018. This process revealed several incorrect calibrations; post-alignment, all nine instruments aligned extremely well with each other. We also tested an alignment to a deep-water reference and found that this method is generally sufficient but has significant limitations; this procedure lacks the ability to correct instruments measuring only shallow profiles and can only account for additive offsets, not multiplicative changes. These findings highlight the utility of process studies involving several independent measurements of similar parameters in the same area

Pojava rijetkih mikroflagelata Prorocentrum arcuatum Issel i Hermesinum adriaticum Zacharias u Rogozničkom jezeru (istočna Jadranska obala)

The marine Lake Rogoznica is a small, karstic habitat with potential anthropogenic influence, situated in the eastern-central Adriatic coast. In this naturally eutrophic, hypoxic and periodically anoxic lake, an investigation of the microplankton community was performed during the 1995- 1998 period when the ecology of the lake was greatly influenced by strong stratification and the appearance of anoxic conditions in the entire water column. The microplankton community (maximum abundance 1.06 x 107 cells L-1) was composed of 40 taxa, mainly diatoms (62.5%) and dinoflagellates (29%). The research provided evidence of exceptionally dense populations and the seasonally-recurrent appearance of two rare microflagellates: Prorocentrum arcuatum Issel (dinoflagellate) and Hermesinum adriaticum Zacharias (heterotrophic microflagellate). The development of H. adriaticum and P. arcuatum mostly increased during the summer under conditions of nitrate deficiency, while the co-dominant diatom Chaetoceros curvisetus Cleve appeared during the spring when higher nitrate concentrations were present. Canonical Correspondence Analysis (CCA) indicated the importance of temperature, oxygen, silicate and nitrate on the incidence of these dominant species. The investigation of these microflagellates has allowed for the gaining of insight into their ecophysiological characteristics as well as the monitoring of their distribution in the Mediterranean, which has possibly expanded due to climate changes.Rogozničko jezero, smješteno u obalnom dijelu srednjeg Jadrana, je prirodni eutroficirani morski sustav s potencijalnim antropogenim utjecajem. U tom ekstremom okolišu, sa značajkama meromiktičkog i anoksičnog sustava, provedeno je istraživanje mikroplanktona u razdoblju od 1995. do 1998. godine. U mikroplanktonskoj zajednici (maksimalna abundancija 1.06 x 107 stanica L-1) određeno je 40 taksona, većinom dijatomeja (62.5%) i dinoflagelata (29%). Zabilježene su iznimno visoke abundancije i sezonsko opetovano pojavljivanje dva rijetka mikroflagelata: Prorocentrum arcuatum Issel (dinoflagelat) i Hermesinum adriaticum Zacharias (hetrotrofan mikroflagelat). Maksimalan razvoj P. arcuatum i H. adriaticum zabilježen je ljeti u uvjetima nedostatka dušika. Kodominanatna vrsta u zajednici bila je dijatomeja Chaetoceoros curvisetus Cleve koja je imala maksimalan razvoj u proljeće u uvjetima bogatim dušikom. Statistička analiza ukazala je na važnost temperature, kisika, silikata i nitrata na razvoj navedenih vrsta. Ovim istraživanjem dobivene su nove spoznaje o ekofiziološkim svojstvima rijetkih vrsta, kao i spoznaje o njihovom prisustvu i razvoju u Mediteranu, koje bi moglo biti pod utjecajem klimatskih promjena

Standards and practices for reporting plankton and other particle observations from images

This technical manual guides the user through the process of creating a data table for the submission of taxonomic and morphological information for plankton and other particles from images to a repository. Guidance is provided to produce documentation that should accompany the submission of plankton and other particle data to a repository, describes data collection and processing techniques, and outlines the creation of a data file. Field names include scientificName that represents the lowest level taxonomic classification (e.g., genus if not certain of species, family if not certain of genus) and scientificNameID, the unique identifier from a reference database such as the World Register of Marine Species or AlgaeBase. The data table described here includes the field names associatedMedia, scientificName/ scientificNameID for both automated and manual identification, biovolume, area_cross_section, length_representation and width_representation. Additional steps that instruct the user on how to format their data for a submission to the Ocean Biodiversity Information System (OBIS) are also included. Examples of documentation and data files are provided for the user to follow. The documentation requirements and data table format are approved by both NASA’s SeaWiFS Bio-optical Archive and Storage System (SeaBASS) and the National Science Foundation’s Biological and Chemical Oceanography Data Management Office (BCO-DMO).This report was an outcome of a working group supported by the Ocean Carbon and Biogeochemistry (OCB) project office, which is funded by the US National Science Foundation (OCE1558412) and the National Aeronautics and Space Administration (NNX17AB17G). AN, SB, and CP conceived and drafted the document. IC, IST, JF and HS contributed to the main body of the document as well as the example files. All members of the working group contributed to the content of the document, including the conceptualization of the data table and metadata format. We would also like thank the external reviewers Cecile Rousseaux (NASA GSFC), Susanne Menden-Deuer (URI) Frank Muller-Karger (USF), and Abigail Benson (USGS) for their valuable feedback

EXPORTS North Atlantic eddy tracking

The EXPORTS North Atlantic field campaign (EXPORTS-NA) of May 2021 used a diverse array of ship-based and autonomous platforms to measure and quantify processes leading to carbon export in the open ocean. The success of this field program relied heavily on the ability to make measurements following a Lagrangian trajectory within a coherent, retentive eddy (Sections 1, 2). Identifying an eddy that would remain coherent and retentive over the course of a monthlong deployment was a significant challenge that the EXPORTS team faced. This report details the processes and procedures used by the primarily shore-based eddy tracking team to locate, track, and sample with autonomous assets such an eddy before and during EXPORTS-NA.This field deployment was funded by the NASA Ocean Biology and Biogeochemistry program and the National Science Foundation Biological and Chemical Oceanography programs. Initial gliders deployments were performed by the RRS Discovery and the authors thank the Porcupine Abyssal Plain – Sustained Observatory of the Natural Environment Research Council (NERC, UK), which is principally funded through the Climate Linked Atlantic Sector Science (CLASS) project supported by NERC National Capability funding (NE/R015953/1) and by IFADO (Innovation in the Framework of the Atlantic Deep Ocean) EAPA_165/2016. Technical assistance with glider deployment was provided by Marine Autonomous Robotic Systems (NOC). The authors thank Inia Soto Ramos for assistance in publishing this manuscript through the NASA Technical Memorandum series. This is PMEL contribution number 5372

Know Before You Go: A Community-Derived Approach to Planning for and Preventing Sexual Harassment at Oceanographic Field Sites

Sexual harassment is a pervasive problem on oceanographic research vessels and while conducting fieldwork in general. A variety of factors contribute to inadequate protection against sexual harassment, such as poor training in prevention, support, and response; remoteness of field sites; academic hierarchies that reinforce uneven power dynamics that extend to fieldwork; and multi-institutional teams with distinct policies or reporting structures that can lead to confusion in reporting and responding to incidents in the field. In compromising individuals’ physical and mental health, sexual harassment can negatively affect research expeditions. For example, harassed individuals may decide to refrain from working on complicated team-based tasks, which can be a safety issue. A broader concern is that sexual harassment deters talented people from pursing or maintaining employment in ocean science. Harassment must be treated with the same gravity as research misconduct and safety policy infringements. When planning a research expedition, science team leaders are responsible for the safety of their team and other colleagues aboard and would benefit from resources aimed at helping team leadership create a plan to ensure safety and inclusivity. To address this resource gap, 18 participants in the Workshop to Promote Field Safety in Ocean Sciences, convened by the Consortium for Ocean Leadership and held May 17–18, 2022, in Washington, DC, developed a checklist for use by scientific leaders and others to assist in planning for participant safety and to prevent harassment the field. The checklist specifies the timing of, and who is responsible for, specific actions that should be taken to improve safety while conducting fieldwork, whether on a research vessel or on land. It also provides additional resources and suggestions for leaders on how to amend the checklist to address their specific fieldwork situations

Saildrone: adaptively sampling the marine environment

Author Posting. © American Meteorological Society, 2020. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Bulletin of the American Meteorological Society 101(6), (2020): E744-E762, doi:10.1175/BAMS-D-19-0015.1.From 11 April to 11 June 2018 a new type of ocean observing platform, the Saildrone surface vehicle, collected data on a round-trip, 60-day cruise from San Francisco Bay, down the U.S. and Mexican coast to Guadalupe Island. The cruise track was selected to optimize the science team’s validation and science objectives. The validation objectives include establishing the accuracy of these new measurements. The scientific objectives include validation of satellite-derived fluxes, sea surface temperatures, and wind vectors and studies of upwelling dynamics, river plumes, air–sea interactions including frontal regions, and diurnal warming regions. On this deployment, the Saildrone carried 16 atmospheric and oceanographic sensors. Future planned cruises (with open data policies) are focused on improving our understanding of air–sea fluxes in the Arctic Ocean and around North Brazil Current rings.The Saildrone data collection mission was sponsored by the Saildrone Award, an annual data collection mission awarded by Saildrone Inc., and the Schmidt Family Foundation. The research was funded by the NASA Physical Oceanography Program Grant 80NSSC18K0837 and 80NSSC18K1441. The work by T. M. Chin, J. Vazquez-Cuerzo, and V. Tsontos was carried out at the Jet Propulsion Laboratory (JPL), California Institute of Technology, under a contract with the National Aeronautics and Space Administration (NASA). Piero L.F. Mazzini was supported by California Sea Grant Award NA18OAR4170073. We thank CeNCOOS for providing the HF radar data in the Gulf of the Farallones. Jose Gomez-Valdes was supported by CONACYT Grant 257125, and by CICESE. Work by Joel Scott and Ivona Cetinic was supported through NASA PACE. The work by Lisan Yu was supported by NOAA Ocean Observing and Monitoring Division under Grant NA14OAR4320158