Racemization of amino acids in sediments from Saanich Inlet, British Columbia
Amino acid racemization as enantiomers in core sediment samples
Brown, F. S.↗
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Use of ERTS-1 pictures in coastal oceanography in British Columbia
The ERTS-1 color composite picture of the Vancouver-Victoria region illustrates the value of ERTS data for coastal oceanography. The water of the Fraser River plume which is so clearly visible in the center of the scene has been of interest to oceanographers on the west coast of Canada for a long time as an easily visible tracer of surface water circulation in the strait of Georgia. Maps of the plume at different states of the tide and with different river flow and weather were compiled from oblique aerial photographs in 1950 and used in the siting of sewage and other outfalls in the Vancouver area. More recently high level aerial photomosaics have been used to map the plume area, but the plume can spread over distances of 30 to 40 miles and many photographs, with the uneven illumination inherent in wide angle coverage, are needed for the mosaic. The ERTS satellite gives the first complete view of the plume area. Electronic enhancement of the images shows that the satellite's narrow angle coverage allows very weak surface turbidity features to be made visible to give information on surface currents over a wide area.
Gower, J. F. R.↗
Satellite interferometry for regional assessment of landslide hazard to pipelines in northeastern British Columbia, Canada
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Sergey Samsonov↗
Measuring Atmospheric CO 2 Enhancements From the 2017 British Columbia Wildfires Using a Lidar
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Jianping Mao↗
Aerosol Formation and Ejection via Pyrocumulonimbus Clouds in the British Columbia Fires of Late Summer 2017
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Earth Sciences↗
Population Genomic Analyses Reveal Connectivity via Human-Mediated Transport across Populus Plantations in North America and an Undescribed Subpopulation of Sphaerulina musiva
Domestication of plant species has affected the evolutionary dynamics of plant pathogens in agriculture and forestry. A model system for studying the consequences of plant domestication on the evolution of an emergent plant disease is the fungal pathogen Sphaerulina musiva. This ascomycete causes leaf spot and stem canker disease of Populus spp. and their hybrids. A population genomics approach was used to determine the degree of population structure and evidence for selection on the North American population of S. musiva. In total, 122 samples of the fungus were genotyped identifying 120,016 single-nucleotide polymorphisms after quality filtering. In North America, S. musiva has low to moderate degrees of differentiation among locations. Three main genetic clusters were detected: southeastern United States, midwestern United States and Canada, and a new British Columbia cluster (BC2). Population genomics suggest that BC2 is a novel genetic cluster from central British Columbia, clearly differentiated from previously reported S. musiva from coastal British Columbia, and the product of a single migration event. Phenotypic measurements from greenhouse experiments indicate lower aggressiveness of BC2 on Populus trichocarpa. In summary, S. musiva has geographic structure across broad regions indicative of gene flow among clusters. The interconnectedness of the North American S. musiva populations across large geographic distances further supports the hypothesis of anthropogenic-facilitated transport of the pathogen.
Biochemistry & Molecular Biology↗
Genetic Identification of Lamprey Genera and Anadromous Ecotypes in Watersheds of the Northeastern Pacific Ocean
ABSTRACT Nonparasitic, nonmigratory Western Brook Lamprey (WBL; Lampetra ayresii ), and parasitic, anadromous Western River Lamprey (WRL; L. ayresii ) are sympatric lampreys that likely represent different life history variations of a single species. Novel genetic tools are critical for differentiating WBL and WRL, whose larvae preclude morphological identification (ID) and will enable comprehensive assessment of imperiled native lampreys of the Northeastern Pacific (including WBL, WRL, and Pacific Lamprey, Entosphenus tridentatus ). We developed 47 candidate single nucleotide polymorphism (SNP) markers using whole genome resequencing of WBL ( N = 24) and WRL ( N = 15) from Ksi Ts'oohl Ts'ap Creek (Nass River, British Columbia, Canada) which are likely ecotypes distinguished by few divergent SNPs across multiple chromosomes. We used five novel candidate SNPs to perform genetic ID of WBL and WRL ecotypes in collections of mixed native lampreys from lower Columbia River tributaries ( N = 1474), Ksi Ts'oohl Ts'ap Creek ( N = 352), and ocean phase WRL from the Georgia Basin (Salish Sea, British Columbia, Canada; N = 91). Two previously published SNPs were used to ID genera, Entosphenus versus Lampetra . Morphological ID utilized photographs collected from a subset of genotyped lampreys, and high concordance was demonstrated between ID methods for genera (99%) and Lampetra ecotypes (> 98%). We characterized spatial and temporal composition of lamprey genera and ecotypes surveyed across NE Pacific tributaries under the expectation these compositions would be similar across nearby sites and across years at the same site. Proportions of lamprey genera were highly variable within regions and across years; however, Lampetra ecotypic proportions were spatially and temporally stable. WRL were rare in lower Columbia tributaries (~1% average rate among Lampetra ) and common further north (> 40% of Lampetra ). Genetic ID methods are powerful monitoring tools that create the novel ability to ascertain genera and ecotypes regardless of life stage, while increasing the efficiency of surveys by eliminating time‐intensive morphological data collection.
Silver, G. S. [Columbia River Inter‐Tribal Fish Co↗
The Pacific Northwest Heat Wave of 25–30 June 2021: Synoptic/Mesoscale Conditions and Climate Perspective
Abstract An unprecedented heat wave occurred over the Pacific Northwest and southwest Canada on 25–30 June 2021, resulting in all-time temperature records that greatly exceeded previous record maximum temperatures. The impacts were substantial, including several hundred deaths, thousands of hospitalizations, a major wildfire in Lytton, British Columbia, Canada, and severe damage to regional vegetation. Several factors came together to produce this extreme event: a record-breaking midtropospheric ridge over British Columbia in the optimal location, record-breaking midtropospheric temperatures, strong subsidence in the lower atmosphere, low-level easterly flow that produced downslope warming on regional terrain and the removal of cooler marine air, an approaching low-level trough that enhanced downslope flow, the occurrence at a time of maximum insolation, and drier-than-normal soil moisture. It is shown that all-time-record temperatures have not become more frequent and that annual high temperatures only increased at the rate of baseline global warming. Although anthropogenic warming may have contributed as much as 1°C to the event, there is little evidence of further amplification from increasing greenhouse gases. Weather forecasts were excellent for this event, with highly accurate predictions of the extreme temperatures. Significance Statement This paper describes the atmospheric evolution that produced an extreme heat wave over the Pacific Northwest during June 2021 and puts this event into historical perspective.
Meteorology & Atmospheric Sciences↗
Genotype–environment associations across spatial scales reveal the importance of putative adaptive genetic variation in divergence
Abstract Identifying areas of high evolutionary potential is a judicious strategy for developing conservation priorities in the face of environmental change. For wide‐ranging species occupying heterogeneous environments, the evolutionary forces that shape distinct populations can vary spatially. Here, we investigate patterns of genomic variation and genotype–environment associations in the hermit thrush ( Catharus guttatus ), a North American songbird, at broad (across the breeding range) and narrow spatial scales (at a hybrid zone). We begin by building a genoscape or map of genetic variation across the breeding range and find five distinct genetic clusters within the species, with the greatest variation occurring in the western portion of the range. Genotype–environment association analyses indicate higher allelic turnover in the west than in the east, with measures of temperature surfacing as key predictors of putative adaptive genomic variation rangewide. Since broad patterns detected across a species' range represent the aggregate of many locally adapted populations, we investigate whether our broadscale analysis is consistent with a finer scale analysis. We find that top rangewide temperature‐associated loci vary in their clinal patterns (e.g., steep clines vs. fixed allele frequencies) across a hybrid zone in British Columbia, suggesting that the environmental predictors and the associated candidate loci identified in the rangewide analysis are of variable importance in this particular region. However, two candidate loci exhibit strong concordance with the temperature gradient in British Columbia, suggesting a potential role for temperature‐related barriers to gene flow and/or temperature‐driven ecological selection in maintaining putative local adaptation. This study demonstrates how patterns identified at the broad (macrogeographic) scale can be validated by investigating genotype–environment correlations at the local (microgeographic) scale. Furthermore, our results highlight the importance of considering the spatial distribution of putative adaptive variation when assessing population‐level sensitivity to climate change and other stressors.
59 BASIC BIOLOGICAL SCIENCES↗
New K-feldspar Pb isotope results for Mesozoic arc crust in the Pacific Northwest, U.S.A. and Canada: comparison with the Mojave-Salinia province of southern California and Implications for Baja-BC
Measurements of lead isotopic compositions in detrital K-feldspar have been increasingly used as a tool to assess sediment provenance. We compiled a database of previously published Pb isotope data from 700 bedrock K-feldspar samples and 1,423 age-corrected bedrock whole rock samples from western North American igneous and metamorphic bodies. Additionally, we report 66 new K-feldspar Pb isotope data for plutons throughout the Pacific Northwest region of the United States and British Columbia. Results show that the Pb isotope values of plutonic K-feldspar depend on the isotopically juvenile or evolved nature of underlying crust. Samples obtained from the mid Cretaceous – mid Eocene Coast Plutonic Complex, North Cascades, and Intermontane superterrane that occur west of the initial 87 Sr/ 86 Sr (Sri) = 0.706 isopleth exhibit a highly restricted 207 Pb/ 206 Pb and 208 Pb/ 206 Pb values centred upon 0.83 and 2.03, respectively. Conversely, rocks overlying older continental crust further east such as the Middle Jurassic – Late Cretaceous Omineca crystalline belt, Idaho batholith, and Boulder Batholith exhibit far greater variation of Pb isotope values that parallel the 100 Ma isochron calculated from a two-stage Pb evolution model. We demonstrate that Pb isotopic results from the Idaho and Boulder Batholith region can be used to define distinctive subregions for Pb isotopic provenance analysis, and compare these signatures to the Mojave-Salinian batholith of southern California and western Arizona, as these two areas have previously been proposed as source regions for extraregional sediment that was deposited within the Nanaimo Basin during the Campanian – Maastrichtian. Future Pb isotopic analysis of detrital K-feldspar from the Nanaimo Basin of southwestern British Columbia may effectively distinguish between potential extraregional sources separated by thousands of kilometres.
Coast Plutonic Complex↗
Regional and Temporal Variability of Atmospheric River Seasonality: Influences of Detection Algorithms and Moisture Transport Dynamics
Abstract Understanding the regional and temporal variability of atmospheric river (AR) seasonality is crucial for preparedness and mitigation of extreme events. While ARs were thought to peak in winter, recent research shows they exhibit region‐specific seasonality and are heavily influenced by the chosen detection algorithm. This study examines the link between the year‐to‐year consistency of peak‐AR activity to the presence of a dominant seasonal pattern, considering both location and algorithm choice. Regions are categorized by their temporal characteristics: consistent patterns (e.g., East Asia), patterns with occasional outliers (e.g., British Columbia coast), and regions lacking a clear dominant peak season (e.g., South Atlantic, parts of Australia). Hence, not all regions display a consistent seasonal cycle of AR activity. This study quantifies the extent to which a region experiences a dominant peak season of AR activity (or lacks one) and offers insights to enhance decision‐making in water management, natural hazard preparedness, and forecasting. Furthermore, given our finding that detection algorithms influence the peak season of AR activity, we also examine two diagnostic variables representative of moisture transport to corroborate our results. Integrated vapor transport, which captures meridional and zonal moisture transport, and Moist Wave Activity, representing moisture intrusions from lower to higher latitudes, are examined. Our analysis indicates that inconsistencies in the seasonal cycle of AR activity are not solely due to discrepancies in detection algorithms but also arise from changes in moisture transport. Plain Language Summary Atmospheric rivers (ARs) are critical weather phenomena that can cause extreme events like heavy rainfall and flooding. Understanding when and where ARs are most likely to occur throughout the year is essential for preparing and responding to these events. Traditionally, ARs were thought to peak in winter, but recent studies show this varies by region. Our study helps address the challenge decision‐makers face in anticipating and preparing for AR events by providing insights into the consistency of peak seasonal patterns across different areas. Some regions, like East Asia, and the British Columbia coast, show a consistent peak season, while others, like the South Atlantic and parts of Australia, have significant year‐to‐year variations, making it hard to identify a dominant season. To better understand these changes over time, the study also examines how moisture moves in the atmosphere, using Integrated Vapor Transport (which looks at moisture movement in various directions) and Moist Wave Activity (which tracks moisture shifts from lower to higher latitudes). The findings suggest that inconsistencies in AR patterns are due not only to detection methods but also due to changes in moisture transport. Key Points The peak season of atmospheric river activity can change depending on the year in some areas Interannual variations in the peak season can make identifying a dominant season challenging for some regions Frequent shifts in peak season across years reflect inconsistencies tied to detection algorithms and to underlying dynamics
Kamnani, Diya↗
AmeriFlux FLUXNET-1F CA-DSM Delta Salt Marsh
This is the AmeriFlux Management Project (AMP) created FLUXNET-1F version of the carbon flux data for the site CA-DSM Delta Salt Marsh. This is the FLUXNET version of the carbon flux data for the site CA-DSM Delta Salt Marsh produced by applying the standard ONEFlux (1F) software. Site Description - This site is a tidal salt marsh on the eastern side of the Boundary Bay Wildlife Management Area (WMA) in Delta, British Columbia, Canada. This area is located on the southern front of the Fraser River. The total area of the Boundary Bay WMA is 11,470 ha, and the eastern part surrounding the flux tower accounts for 39 ha. This area is surrounded by farms and dikes. The Provincial Government purchased this area in 1974 limiting public access and designated it as WMA in 1995. This area has a mixed semidiurnal tidal cycle. The dominant species is Saltgrass (Distichlis spicata) with a canopy height of ~40 cm. The tower is in a high marsh system and was installed to analyze energy, H2O, CO2, and CH4 fluxes on September 3, 2021.
Knox, Sara [The University of British Columbia]↗
Modern freshwater microbialite analogues for ancient dendritic reef structures
Microbialites are organosedimentary structures that can be constructed by a variety of metabolically distinct taxa. Consequently, microbialite structures abound in the fossil record, although the exact nature of the biogeochemical processes that produced them is often unknown. One such class of ancient calcareous structures, Epiphyton and Girvanella, appear in great abundance during the Early Cambrian. Together with Archeocyathids, stromatolites and thrombolites, they formed major Cambrian reef belts. To a large extent, Middle to Late Cambrian reefs are similar to Precambrian reefs, with the exception that the latter, including terminal Proterozoic reefs, do not contain Epiphyton or Girvanella. Here we report the discovery in Pavilion Lake, British Columbia, Canada, of a distinctive assemblage of freshwater calcite microbialites, some of which display microstructures similar to the fabrics displayed by Epiphyton and Girvanella. The morphologies of the modern microbialites vary with depth, and dendritic microstructures of the deep water (> 30 m) mounds indicate that they may be modern analogues for the ancient calcareous structures. These microbialites thus provide an opportunity to study the biogeochemical interactions that produce fabrics similar to those of some enigmatic Early Cambrian reef structures.
Non-NASA Center↗
AmeriFlux CA-RBM Richmond Brackish Marsh
This is the AmeriFlux version of the carbon flux data for the site CA-RBM Richmond Brackish Marsh. Site Description - This site is a tidal brackish marsh on the southern side of the Sturgeon Bank Wildlife Management Area (WMA) in Richmond, British Columbia, Canada. This area is situated within the estuary of the Fraser River. The total area of Sturgeon Bank WMA is 5,152 ha, of which the tidal marsh area is 205 ha. The southern of the WMA is characterized as a brackish marsh, which transitions to a salt marsh as you go north. Human development has influenced this area for almost 200 years. Human activities in this area began in the early 1800s, which included dredging, dyke and entrainment structures, agriculture, and other uses. The areas were designated as WMA in 1998. This area experiences a semidiurnal tidal cycle. The flux tower is located near the southern edge of the marsh, where the dominant species is cattail (Typha latifolia), with a canopy height of 160 cm. The tower is in a high marsh system and was installed to analyze energy, H2O, CO2, and CH4 fluxes on June 1, 2022.
Knox, Sara [The University of British Columbia]↗
AmeriFlux FLUXNET-1F CA-RBM Richmond Brackish Marsh
This is the AmeriFlux Management Project (AMP) created FLUXNET-1F version of the carbon flux data for the site CA-RBM Richmond Brackish Marsh. This is the FLUXNET version of the carbon flux data for the site CA-RBM Richmond Brackish Marsh produced by applying the standard ONEFlux (1F) software. Site Description - This site is a tidal brackish marsh on the southern side of the Sturgeon Bank Wildlife Management Area (WMA) in Richmond, British Columbia, Canada. This area is situated within the estuary of the Fraser River. The total area of Sturgeon Bank WMA is 5,152 ha, of which the tidal marsh area is 205 ha. The southern of the WMA is characterized as a brackish marsh, which transitions to a salt marsh as you go north. Human development has influenced this area for almost 200 years. Human activities in this area began in the early 1800s, which included dredging, dyke and entrainment structures, agriculture, and other uses. The areas were designated as WMA in 1998. This area experiences a semidiurnal tidal cycle. The flux tower is located near the southern edge of the marsh, where the dominant species is cattail (Typha latifolia), with a canopy height of 160 cm. The tower is in a high marsh system and was installed to analyze energy, H2O, CO2, and CH4 fluxes on June 1, 2022.
Knox, Sara [The University of British Columbia]↗
Beyond-classical computation in quantum simulation
Quantum computers hold the promise of solving certain problems that lie beyond the reach of conventional computers. However, establishing this capability, especially for impactful and meaningful problems, remains a central challenge. Here, we show that superconducting quantum annealing processors can rapidly generate samples in close agreement with solutions of the Schrödinger equation. We demonstrate area-law scaling of entanglement in the model quench dynamics of two-, three-, and infinite-dimensional spin glasses, supporting the observed stretched-exponential scaling of effort for matrix-product-state approaches. We show that several leading approximate methods based on tensor networks and neural networks cannot achieve the same accuracy as the quantum annealer within a reasonable time frame. Thus, quantum annealers can answer questions of practical importance that may remain out of reach for classical computation.
King, Andrew D. [D-Wave Quantum Inc., Burnaby, BC ↗
Metatranscriptomics reveals a shift in microbial community composition and function during summer months in a coastal marine environment
Abstract Temperate coastal marine waters are often thermally stratified from spring through fall but can be dynamic and disrupted by tidal currents and wind‐driven upwelling. These mixing events introduce deeper, cooler water with a higher partial pressure of CO 2 (pCO2) and its associated microbial communities to the surface. Anecdotally, these events impact shellfish hatcheries and farms, warranting improved understanding of changes in composition and activity of marine microbial communities in relation to environmental processes. To characterize both compositional and functional changes associated with abiotic factors, here, we generate a reference metatranscriptome from the Strait of Georgia over representative seasons and analyze metatranscriptomic profiles of the microorganisms present within intake water containing different pCO 2 levels at a shellfish hatchery in British Columbia from June through October. Abiotic factors studied include pH, temperature, alkalinity, aragonite, calcite, and pCO 2 . Community composition changes were observed to occur at broad taxonomic levels and most notably to vary with temperature and pCO 2 . Functional gene expression profiles indicated a strong difference between early (June–July) and late summer (August–October) associated with viral activity. The taxonomic data suggest this could be due to the termination of cyanobacteria and phytoplankton blooms by viral lysis in the late season. Functional analysis indicated fewer differentially expressed transcripts associated with abiotic variables (e.g., pCO 2 ) than with the temporal effect. Microbial composition and activity in these waters vary with both short‐term effects observed alongside abiotic variation and long‐term effects observed across seasons. The analysis of both taxonomy and functional gene expression simultaneously in the same samples by environmental RNA (eRNA metatranscriptomics) provided a more comprehensive view for monitoring water bodies than either would in isolation.
Sutherland, Ben J. G.↗
Results and Limits of Time-Division Multiplexing for the BICEP Array High-Frequency Receivers
Time-division multiplexing is the readout architecture of choice for many ground and space experiments, as it is a very mature technology with proven outstanding low-frequency noise stability, which represents a central challenge in multiplexing. Once fully populated, each of the two BICEP Array high-frequency receivers, observing at 150 GHz and 220/270 GHz, will have 7776 TES detectors tiled on the focal plane. The constraints set by these two receivers required a redesign of the warm readout electronics. The new version of the standard multichannel electronics, developed and built at the University of British Columbia, is presented here for the first time. BICEP Array operates time-division multiplexing readout technology to the limits of its capabilities in terms of multiplexing rate, noise and cross talk, and applies them in rigorously demanding scientific application requiring extreme noise performance and systematic error control. Finally, future experiments like CMB-S4 plan to use TES bolometers with time-division/SQUID-based readout for an even larger number of detectors.
47 OTHER INSTRUMENTATION↗