Elucidating the relationships between surface-level ozone and meteorology

Surface-level ozone (O3) is associated with respiratory morbidity and mortality, affects vegetation and ecosystems, and impacts the global climate. The cause of day-to-day variations in O3 remains an open question and is key in interpreting past air quality as well as the ways that future climatic changes will affect air pollution. To this end, we investigate the drivers of O3 variability on daily timescales across the Northern Hemisphere with a special emphasis on the United States. Using observations and chemical transport model simulations, we show that positive relationships between O3 and meteorological variables such as temperature and humidity persist only across continental regions in the mid-latitudes (~ 35-60˚N); elsewhere, these relationships are weak or significantly negative. The covariance of O3 with meteorology is driven by an association with transport, not a direct dependence on chemistry or emissions. We find that neither stagnation or cyclones can explain day-to-day variations in O3 or extreme events. Ultimately, we tie spatial and temporal variations in the O3-meteorology relationships to the jet stream. The jet stream regulates the surface-level mean meridional flow, which affects fluxes of O3, heat, and moisture. These results provide significant gains in understanding the dominant role of transport on O3 variability and reconcile spatial variations in the relationships among O3, temperature, humidity, and the jet stream

Satellite data for environmental justice:a scoping review of the literature in the United States

In support of the environmental justice (EJ) movement, researchers, activists, and policymakers often use environmental data to document evidence of the unequal distribution of environmental burdens and benefits along lines of race, class, and other socioeconomic characteristics. Numerous limitations, such as spatial or temporal discontinuities, exist with commonly used data measurement techniques, which include ground monitoring and federal screening tools. Satellite data is well poised to address these gaps in EJ measurement and monitoring; however, little is known about how satellite data has advanced findings in EJ or can help to promote EJ through interventions. Thus, this scoping review aims to (1) explore trends in study design, topics, geographic scope, and satellite datasets used to research EJ, (2) synthesize findings from studies that use satellite data to characterize disparities and inequities across socio-demographic groups for various environmental categories, and (3) capture how satellite data are relevant to policy and real-world impact. Following PRISMA extension guidelines for scoping reviews, we retrieved 81 articles that applied satellite data for EJ research in the United States from 2000 to 2022. The majority of the studies leveraged the technical advantages of satellite data to identify socio-demographic disparities in exposure to environmental risk factors, such as air pollution, and access to environmental benefits, such as green space, at wider coverage and with greater precision than previously possible. These disparities in exposure and access are associated with health outcomes such as increased cardiovascular and respiratory diseases, mental illness, and mortality. Research using satellite data to illuminate EJ concerns can contribute to efforts to mitigate environmental inequalities and reduce health disparities. Satellite data for EJ research can therefore support targeted interventions or influence planning and policy changes, but significant work remains to facilitate the application of satellite data for policy and community impact.</p

Elucidating the relationships between surface-level ozone and meteorology

Surface-level ozone (O3) is associated with respiratory morbidity and mortality, affects vegetation and ecosystems, and impacts the global climate. The cause of day-to-day variations in O3 remains an open question and is key in interpreting past air quality as well as the ways that future climatic changes will affect air pollution. To this end, we investigate the drivers of O3 variability on daily timescales across the Northern Hemisphere with a special emphasis on the United States. Using observations and chemical transport model simulations, we show that positive relationships between O3 and meteorological variables such as temperature and humidity persist only across continental regions in the mid-latitudes (~ 35-60˚N); elsewhere, these relationships are weak or significantly negative. The covariance of O3 with meteorology is driven by an association with transport, not a direct dependence on chemistry or emissions. We find that neither stagnation or cyclones can explain day-to-day variations in O3 or extreme events. Ultimately, we tie spatial and temporal variations in the O3-meteorology relationships to the jet stream. The jet stream regulates the surface-level mean meridional flow, which affects fluxes of O3, heat, and moisture. These results provide significant gains in understanding the dominant role of transport on O3 variability and reconcile spatial variations in the relationships among O3, temperature, humidity, and the jet stream

Disproportionate Clean Air Act violations occur in communities of color throughout the United States

The United States (U.S.) Clean Air Act seeks to prevent and abate ambient air pollution, while also providing a framework to identify and address violations. Little research has examined where or how frequently violations of the Clean Air Act occur and how marginalized communities may bear a disproportionate share of these violations, despite the fact that marginalized communities experience persistent, disproportionate pollution levels and associated health impacts. Here, we leverage data on Clean Air Act enforcement and compliance together with demographic data to show that the most serious violations of the Act—high priority violations (HPVs)—predominantly occur in communities of color throughout the U.S. Specifically, we find that the number of facilities with an HPV within communities with the largest proportion of people of color is nearly two times greater than in communities with the smallest proportion. Only 6% of facilities with an HPV address their violations within the timeframe mandated by the U.S. Environmental Protection Agency, and a larger share of facilities with an HPV in disadvantaged communities do not address their violations within this timeframe compared to facilities with an HPV in non-disadvantaged communities. Enforcing agencies should improve how violations are communicated and addressed. To this end, we suggest several ways to empower individuals and communities with easy-to-access data related to Clean Air Act violations and that enforcement practices and reporting be standardized across enforcing agencies

Climate change effects on wildland fire risk in the Northeastern and Great Lakes states predicted by a downscaled multi-model ensemble

This study is among the first to investigate wildland fire risk in the Northeastern and the Great Lakes states under a changing climate. We use a multi-model ensemble (MME) of regional climate models from the Coordinated Regional Downscaling Experiment (CORDEX) together with the Canadian Forest Fire Weather Index System (CFFWIS) to understand changes in wildland fire risk through differences between historical simulations and future projections. Our results are relatively homogeneous across the focus region and indicate modest increases in the magnitude of fire weather indices (FWIs) during northern hemisphere summer. The most pronounced changes occur in the date of the initialization of CFFWIS and peak of the wildland fire season, which in the future are trending earlier in the year, and in the significant increases in the length of high-risk episodes, defined by the number of consecutive days with FWIs above the current 95th percentile. Further analyses show that these changes are most closely linked to expected changes in the focus region’s temperature and precipitation. These findings relate to the current understanding of particulate matter vis-à-vis wildfires and have implications for human health and local and regional changes in radiative forcings. When considering current fire management strategies which could be challenged by increasing wildland fire risk, fire management agencies could adapt new strategies to improve awareness, prevention, and resilience to mitigate potential impacts to critical infrastructure and population

Air pollution impacts from warehousing in the United States uncovered with satellite data

Abstract Regulators, environmental advocates, and community groups in the United States (U.S.) are concerned about air pollution associated with the proliferating e-commerce and warehousing industries. Nationwide datasets of warehouse locations, traffic, and satellite observations of the traffic-related pollutant nitrogen dioxide (NO2) provide a unique capability to evaluate the air quality and environmental equity impacts of these geographically-dispersed emission sources. Here, we show that the nearly 150,000 warehouses in the U.S. worsen local traffic-related air pollution with an average near-warehouse NO2 enhancement of nearly 20% and are disproportionately located in marginalized and minoritized communities. Near-warehouse truck traffic and NO2 significantly increase as warehouse density and the number of warehouse loading docks and parking spaces increase. Increased satellite-observed NO2 near warehouses underscores the need for indirect source rules, incentives for replacing old trucks, and corporate commitments towards electrification. Future ground-based monitoring campaigns may help track impacts of individual or small clusters of facilities

Dataset for "Public Health Benefits from Improved Identification of Severe Air Pollution Events with Geostationary Satellite Data"

&lt;p&gt;Dataset for "Public Health Benefits from Improved Identification of Severe Air Pollution Events with Geostationary Satellite Data" to be published in GeoHealth doi: 10.1029/2023GH000890&lt;/p&gt

Evolving Drivers of Brazilian SARS‐CoV‐2 Transmission: A Spatiotemporally Disaggregated Time Series Analysis of Meteorology, Policy, and Human Mobility

Abstract Brazil has been severely affected by the COVID‐19 pandemic. Temperature and humidity have been purported as drivers of SARS‐CoV‐2 transmission, but no consensus has been reached in the literature regarding the relative roles of meteorology, governmental policy, and mobility on transmission in Brazil. We compiled data on meteorology, governmental policy, and mobility in Brazil's 26 states and one federal district from June 2020 to August 2021. Associations between these variables and the time‐varying reproductive number (Rt) of SARS‐CoV‐2 were examined using generalized additive models fit to data from the entire 15‐month period and several shorter, 3‐month periods. Accumulated local effects and variable importance metrics were calculated to analyze the relationship between input variables and Rt. We found that transmission is strongly influenced by unmeasured sources of between‐state heterogeneity and the near‐recent trajectory of the pandemic. Increased temperature generally was associated with decreased transmission and increased specific humidity with increased transmission. However, the impacts of meteorology, policy, and mobility on Rt varied in direction, magnitude, and significance across our study period. This time variance could explain inconsistencies in the published literature to date. While meteorology weakly modulates SARS‐CoV‐2 transmission, daily or seasonal weather variations alone will not stave off future surges in COVID‐19 cases in Brazil. Investigating how the roles of environmental factors and disease control interventions may vary with time should be a deliberate consideration of future research on the drivers of SARS‐CoV‐2 transmission