22 research outputs found
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Persistent spatial structuring of coastal ocean acidification in the California Current System
The near-term progression of ocean acidification (OA) is projected to bring about sharp changes in the chemistry of coastal upwelling ecosystems. The distribution of OA exposure across these early-impact systems, however, is highly uncertain and limits our understanding of whether and how spatial management actions can be deployed to ameliorate future impacts. Through a novel coastal OA observing network, we have uncovered a remarkably persistent spatial mosaic in the penetration of acidified waters into ecologically-important nearshore habitats across 1,000âkm of the California Current Large Marine Ecosystem. In the most severe exposure hotspots, suboptimal conditions for calcifying organisms encompassed up to 56% of the summer season, and were accompanied by some of the lowest and most variable pH environments known for the surface ocean. Persistent refuge areas were also found, highlighting new opportunities for local adaptation to address the global challenge of OA in productive coastal systems
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Observations of internal wave packets propagating alongâshelf in northern Monterey Bay
Internal waves of depression were observed propagating
alongâshelf and into northern Monterey Bay, California
(CA) on the inner shelf. These waves had amplitudes
approximately equal to the thermocline depth (âŒ4 m), and
were unstable to shear and mix the thermocline. Isopycnal
gradient spectra showed that the wave packets lead to an elevated
mean dissipation rate of Δ = 2.63 Ă 10â5 m3 sâ2 for up
to 2 hours after wave passage. The proximity to the surface
created strong surface convergences that can actively transport
buoyant material, such as plankton, back into the bay.
The wave packets were observed regularly over the upwelling
season across multiple years suggesting they may have
large effects on the documented spatial variation of phytoplankton
and larvae on the inner shelf. The timing of the
waves suggests they are not formed by tides interacting with
bathymetry, but are generated by buoyant plume propagation
2023 Astrophotonics Roadmap: pathways to realizing multi-functional integrated astrophotonic instruments
This is the final version. Available on open access from IOP Publishing via the DOI in this recordData availability statement:
The data that support the findings of this study are available upon reasonable request from the authors.Photonic technologies offer numerous functionalities that can be used to realize astrophotonic instruments. The most spectacular example to date is the ESO Gravity instrument at the Very Large Telescope in Chile that combines the light-gathering power of four 8 m telescopes through a complex photonic interferometer. Fully integrated astrophotonic devices stand to offer critical advantages for instrument development, including extreme miniaturization when operating at the diffraction-limit, as well as integration, superior thermal and mechanical stabilization owing to the small footprint, and high replicability offering significant cost savings. Numerous astrophotonic technologies have been developed to address shortcomings of conventional instruments to date, including for example the development of photonic lanterns to convert from multimode inputs to single mode outputs, complex aperiodic fiber Bragg gratings to filter OH emission from the atmosphere, complex beam combiners to enable long baseline interferometry with for example, ESO Gravity, and laser frequency combs for high precision spectral calibration of spectrometers. Despite these successes, the facility implementation of photonic solutions in astronomical instrumentation is currently limited because of (1) low throughputs from coupling to fibers, coupling fibers to chips, propagation and bend losses, device losses, etc, (2) difficulties with scaling to large channel count devices needed for large bandwidths and high resolutions, and (3) efficient integration of photonics with detectors, to name a few. In this roadmap, we identify 24 key areas that need further development. We outline the challenges and advances needed across those areas covering design tools, simulation capabilities, fabrication processes, the need for entirely new components, integration and hybridization and the characterization of devices. To realize these advances the astrophotonics community will have to work cooperatively with industrial partners who have more advanced manufacturing capabilities. With the advances described herein, multi-functional integrated instruments will be realized leading to novel observing capabilities for both ground and space based platforms, enabling new scientific studies and discoveries.National Science Foundation (NSF)NAS
Relationships between attitudes and performance in young childrenâs mathematics
Most studies of childrenâs attitudes to mathematics have dealt with children in second grade or later, and have suggested that attitudes deteriorate, and anxiety increases with age. The present study investigated attitudes to mathematics in 67 English and 49 Chinese children at the end of their first year of school. The participants were given Thomas and Dowkerâs (2000) Mathematics Attitude Questionnaire, which uses pictorial rating scales to assess primary school childrenâs mathematics anxiety, liking for mathematics, unhappiness at poor performance in mathematics, and self-rating in mathematics. They were also given the British Abilities Scales Basic Number Skills test. Attitudes were generally positive, though not more so than previously found for older primary school children. The Chinese children performed better in the arithmetic test and also rated themselves higher than the English children, but did not differ in other attitudes. Self-rating in mathematics and lack of unhappiness at poor performance were associated with better performance in the English group. There were no significant relations between attitudes and performance in the Chinese group. Implications of the findings are discussed
Relationships between attitudes and performance in young childrenâs mathematics
Most studies of childrenâs attitudes to mathematics have dealt with children in second grade or later, and have suggested that attitudes deteriorate, and anxiety increases with age. The present study investigated attitudes to mathematics in 67 English and 49 Chinese children at the end of their first year of school. The participants were given Thomas and Dowkerâs (2000) Mathematics Attitude Questionnaire, which uses pictorial rating scales to assess primary school childrenâs mathematics anxiety, liking for mathematics, unhappiness at poor performance in mathematics, and self-rating in mathematics. They were also given the British Abilities Scales Basic Number Skills test. Attitudes were generally positive, though not more so than previously found for older primary school children. The Chinese children performed better in the arithmetic test and also rated themselves higher than the English children, but did not differ in other attitudes. Self-rating in mathematics and lack of unhappiness at poor performance were associated with better performance in the English group. There were no significant relations between attitudes and performance in the Chinese group. Implications of the findings are discussed
Carbonate system parameters of an algal-dominated reef along West Maui
Constraining coral reef metabolism and carbon chemistry dynamics are
fundamental for understanding and predicting reef vulnerability to rising
coastal CO2 concentrations and decreasing seawater pH. However, few
studies exist along reefs occupying densely inhabited shorelines with known
input from land-based sources of pollution. The shallow coral reefs off
Kahekili, West Maui, are exposed to nutrient-enriched, low-pH submarine
groundwater discharge (SGD) and are particularly vulnerable to the
compounding stressors from land-based sources of pollution and lower
seawater pH. To constrain the carbonate chemistry system, nutrients and
carbonate chemistry were measured along the Kahekili reef flat every 4âŻh
over a 6-day sampling period in March 2016. Abiotic process â primarily SGD
fluxes â controlled the carbonate chemistry adjacent to the primary SGD vent
site, with nutrient-laden freshwater decreasing pH levels and favoring
undersaturated aragonite saturation (Ωarag) conditions. In
contrast, diurnal variability in the carbonate chemistry at other sites
along the reef flat was driven by reef community metabolism. Superimposed on
the diurnal signal was a transition during the second sampling period to a
surplus of total alkalinity (TA) and dissolved inorganic carbon (DIC)
compared to ocean endmember TA and DIC measurements. A shift from positive
net community production and positive net community calcification to
negative net community production and negative net community calcification
was identified. This transition occurred during a period of increased
SGD-driven nutrient loading, lower wave height, and reduced current speeds.
This detailed study of carbon chemistry dynamics highlights the need to
incorporate local effects of nearshore oceanographic processes into
predictions of coral reef vulnerability and resilience
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Persistent spatial structuring of coastal ocean acidification in the California Current System.
The near-term progression of ocean acidification (OA) is projected to bring about sharp changes in the chemistry of coastal upwelling ecosystems. The distribution of OA exposure across these early-impact systems, however, is highly uncertain and limits our understanding of whether and how spatial management actions can be deployed to ameliorate future impacts. Through a novel coastal OA observing network, we have uncovered a remarkably persistent spatial mosaic in the penetration of acidified waters into ecologically-important nearshore habitats across 1,000âkm of the California Current Large Marine Ecosystem. In the most severe exposure hotspots, suboptimal conditions for calcifying organisms encompassed up to 56% of the summer season, and were accompanied by some of the lowest and most variable pH environments known for the surface ocean. Persistent refuge areas were also found, highlighting new opportunities for local adaptation to address the global challenge of OA in productive coastal systems
Persistent Spatial Structuring of Coastal Ocean Acidification in the California Current System
The near-term progression of ocean acidification (OA) is projected to bring about sharp changes in the chemistry of coastal upwelling ecosystems. The distribution of OA exposure across these early-impact systems, however, is highly uncertain and limits our understanding of whether and how spatial management actions can be deployed to ameliorate future impacts. Through a novel coastal OA observing network, we have uncovered a remarkably persistent spatial mosaic in the penetration of acidified waters into ecologically-important nearshore habitats across 1,000âkm of the California Current Large Marine Ecosystem. In the most severe exposure hotspots, suboptimal conditions for calcifying organisms encompassed up to 56% of the summer season, and were accompanied by some of the lowest and most variable pH environments known for the surface ocean. Persistent refuge areas were also found, highlighting new opportunities for local adaptation to address the global challenge of OA in productive coastal systems