United States East Research Articles

Projecting Future Energy Production from Operating Wind Farms in North America. Part I: Dynamical Downscaling

Abstract New simulations at 12-km grid spacing with the Weather and Research Forecasting (WRF) Model nested in the MPI Earth System Model (ESM) are used to quantify possible changes in wind power generation potential as a result of global warming. Annual capacity factors (CF; measures of electrical power production) computed by applying a power curve to hourly wind speeds at wind turbine hub height from this simulation are also used to illustrate the pitfalls in seeking to infer changes in wind power generation directly from low-spatial-resolution and time-averaged ESM output. WRF-derived CF are evaluated using observed daily CF from operating wind farms. The spatial correlation coefficient between modeled and observed mean CF is 0.65, and the root-mean-square error is 5.4 percentage points. Output from the MPI-WRF Model chain also captures some of the seasonal variability and the probability distribution of daily CF at operating wind farms. Projections of mean annual CF (CFA) indicate no change to 2050 in the southern Great Plains and Northeast. Interannual variability of CFA increases in the Midwest, and CFA declines by up to 2 percentage points in the northern Great Plains. The probability of wind droughts (extended periods with anomalously low production) and wind bonus periods (high production) remains unchanged over most of the eastern United States. The probability of wind bonus periods exhibits some evidence of higher values over the Midwest in the 2040s, whereas the converse is true over the northern Great Plains. Significance Statement Wind energy is playing an increasingly important role in low-carbon-emission electricity generation. It is a “weather dependent” renewable energy source, and thus changes in the global atmosphere may cause changes in regional wind power production (PP) potential. We use PP data from operating wind farms to demonstrate that regional simulations exhibit skill in capturing actual power production. Projections to the middle of this century indicate that over most of North America east of the Rocky Mountains annual expected PP is largely unchanged, as is the probability of extended periods of anomalously high or low production. Any small declines in annual PP are of much smaller magnitude than changes due to technological innovation over the last two decades.

Dynamic downscaling of wind speed over the North Atlantic Ocean using CMIP6 projections: Implications for offshore wind power density

Offshore wind energy is an important agent to fight climate change. However, it is simultaneously very sensitive to climate change. This study analyzes the future changes in wind speed of 10 m above sea surface (V10) in the North Atlantic Ocean and how these variations may affect offshore wind energy resources for three potential subregions (the United States (US) East Coast, western Iberian Peninsula, and the Caribbean Sea). Dynamic downscaling of three different future scenarios of the CESM2 global climate model (CMIP6 project) was performed using the WRF-ARW atmospheric model. V10 is expected to decrease in the winter and spring seasons but increase in summer and autumn, mainly in tropical regions up to 30 °N. Annually, it shows the maximum increase in the tropical region. For the Iberian Peninsula subregion, significant increases in summer are expected for wind power density (WPD) along the 21st century, but there is uncertainty for the other seasons. A WPD decrease in winter and increases in summer and autumn are expected along the 21st century for the US subregion. No significant changes were observed at annual scale. Finally, for the Caribbean Sea, a decrease is projected in the Yucatan Basin and considerable increases are foreseen for the Colombia and Venezuela basins.

Experiences of social work students in the early stages of the COVID-19 pandemic: a mixed-methods study

ABSTRACT The COVID-19 pandemic has triggered a growing body of research on the impacts of pandemics on students globally. This holds true for the social work discipline: pandemic-related research on the overall social work education and practice has been on the ascendancy. That said, there is still the need for research studies that specifically focus on the impacts of pandemics and crises on social work students. This exploratory, IRB-approved mixed-methods study collected quantitative and qualitative data from 66 undergraduate and graduate social work students at a large public state university on the United States east coast. Participants responded to survey questions about their experiences and stress responses and areas of support during the early part of the ongoing pandemic. Utilizing the researchers’ own public university in the U.S. east coast as a case study, this article highlights examples and explores the level of institutional, faculty, and staff support from both the undergraduate and graduate levels. This paper contributes to the social work field by examining student stress responses through quantitative and qualitative data from students’ self-reported responses. It also highlights certain protective factors—including support systems and coping mechanisms—for students during the early stages of the pandemic.

Modulation of North American Heat Waves by the Tropical Atlantic Warm Pool

AbstractHeat waves are among the deadliest natural hazards affecting the United States (US). Therefore, understanding the physical mechanisms modulating their occurrence is essential for improving their predictions and future projections. Using observational data and model simulations, this study finds that the interannual variability of the tropical Atlantic warm pool (AWP, measured as the area enclosed by the 28.5°C sea surface temperature isotherm) modulates heat wave occurrence over the US Great Plains during boreal summer. For example, a larger than normal AWP enhances atmospheric convection over the Caribbean Sea, driving an upper tropospheric anticyclonic anomaly over the Gulf of Mexico and Great Plains, which strengthens subsidence, reduces cloud cover, and increases surface warming. This circulation anomaly thus weakens the Great Plains low‐level jet and associated moisture transport into the Great Plains, leading to drought conditions and increased heat wave occurrence for most of the US east of the Rockies.

A Hybrid Dynamical Approach for Seasonal Prediction of Sea‐Level Anomalies: A Pilot Study for Charleston, South Carolina

AbstractUsing Earth system models for seasonal sea‐level prediction remains challenging due to model biases and initialization shocks. Here we present a hybrid dynamical approach for seasonal sea‐level prediction to alleviate some of these issues. The approach is based on convolving atmospheric forcings with sea‐level sensitivities to these forcings. The sensitivities are pre‐computed by the adjoint model of the Estimating Circulation and Climate of the Ocean (ECCO) system. The forcings are a concatenation of ECCO forcings before prediction initialization and a 10‐member predicted atmospheric forcing ensemble from the Community Climate System Model version 4 (CCSM4) after initialization, with offline forcing bias corrections applied using the observationally‐constrained ECCO seasonal forcing climatology. As a pilot study, we conducted 12‐month hindcasts from 1995 to 2016 in Charleston (United States East Coast). Our approach avoids drifts in CCSM4 sea‐level predictions and beats seasonal climatology and damped persistence as predictors up to a 6‐month lead time. The prediction skill comes from two factors: (a) ECCO forcings prior to prediction initialization influence sea level after initialization through delayed oceanic adjustments (e.g., coastally‐trapped waves, open‐ocean Rossby waves, and advection of steric anomalies) leading to skillful predictions beyond 2 months after initialization, and (b) the 10‐member CCSM4 ensemble forcing predictions have relatively good skill at 1–2 months lead times. Our method is computationally efficient for operational sea‐level prediction at specific locations and can attribute sea‐level prediction skill and uncertainty to specific forcings or forcing from particular regions, thereby providing useful information to seasonal prediction centers for improving their prediction systems.

Genomic Degeneration and Reduction in the Fish Pathogen Mycobacterium shottsii.

ABSTRACTMycobacterium shottsii is a dysgonic, nonpigmented mycobacterium originally isolated from diseased striped bass (Morone saxatilis) in the Chesapeake Bay, USA. Genomic analysis reveals that M. shottsii is a Mycobacterium ulcerans/Mycobacterium marinum clade (MuMC) member, but unlike the superficially similar M. pseudoshottsii, also isolated from striped bass, it is not an M. ulcerans ecovar, instead belonging to a transitional group of strains basal to proposed “Aronson” and “M” lineages. Although phylogenetically distinct from the human pathogen M. ulcerans, the M. shottsii genome shows parallel but nonhomologous genomic degeneration, including massive accumulation of pseudogenes accompanied by proliferation of unique insertion sequences (ISMysh01, ISMysh03), large-scale deletions, and genomic reorganization relative to typical M. marinum strains. Coupled with its observed ecological characteristics and loss of chromogenicity, the genomic structure of M. shottsii is suggestive of evolution toward a state of obligate pathogenicity, as observed for other Mycobacterium spp., including M. ulcerans, M. tuberculosis, and M. leprae.IMPORTANCE Morone saxatilis (striped bass) is an ecologically and economically important finfish species on the United States east coast. Mycobacterium shottsii and Mycobacterium pseudoshottsii were originally described in the early 2000s as novel species from outbreaks of visceral and dermal mycobacteriosis in this species. Biochemical and genetic characterization place these species within the Mycobacterium ulcerans/M. marinum clade (MuMC), and M. pseudoshottsii has been proposed as an ecovar of M. ulcerans. Here, we describe the complete genome of M. shottsii, demonstrating that it is clearly not an M. ulcerans ecovar; however, it has undergone parallel genomic modification suggestive of a transition to obligate pathogenicity. As in M. ulcerans, the M. shottsii genome demonstrates widespread pseudogene formation driven by proliferation of insertion sequences, as well as genomic reorganization. This work clarifies the phylogenetic position of M. shottsii relative to other MuMC members and provides insight into processes shaping its genomic structure.

Shallow Faulting and Folding in the Epicentral Area of the 1886 Charleston, South Carolina, Earthquake

ABSTRACT The moment magnitude (Mw) ∼7 earthquake that struck Charleston, South Carolina, on 31 August 1886 is the largest historical earthquake in the United States east of the Appalachian Mountains. The fault(s) that ruptured during this earthquake has never been conclusively identified, and conflicting fault models have been proposed. Here we interpret reprocessed seismic reflection profiles, reprocessed legacy aeromagnetic data, and newly collected ground penetrating radar (GPR) profiles to delineate faults deforming the Cretaceous and younger Atlantic Coastal Plain (ACP) strata in the epicentral area of the 1886 earthquake. The data show evidence for faults folding or vertically displacing ACP strata, including apparent displacements of near-surface strata (upper ∼20 m). Aeromagnetic data show several northeast (NE)-trending lineaments, two of which correlate with faults and folds with vertical displacements as great as 55 m on the seismic reflection and radar profiles. ACP strata show only minor thickness changes across these structures, indicating that much of the displacement postdates the shallowest well-imaged ACP strata of Eocene age. Faults imaged on the seismic reflection profiles appear on GPR profiles to displace the erosional surface at the top of the upper Eocene to Oligocene Cooper Group, including where railroad tracks were bent during the 1886 earthquake. Some faults coincide with changes in river trends, bifurcations of river channels, and unusual river meanders that could be related to recent fault motion. In contrast to our interpreted NE fault trends, earthquake locations and some focal mechanisms in the modern seismic zone have been interpreted as defining a nearly north-striking, west-dipping zone of aftershocks from the 1886 earthquake. The relationship between the modern seismicity and the faults we image is therefore enigmatic. However, multiple faults in the area clearly have been active since the Eocene and deform strata in the upper 20 m, providing potential targets for field-based geologic investigations.

Impacts of Large‐Scale Urbanization and Irrigation on Summer Precipitation in the Mid‐Atlantic Region of the United States

AbstractThis study investigates how urbanization and irrigation in the United States east of the Rocky Mountains affect summer precipitation in the Mid‐Atlantic region (MAR) using convection‐permitting regional model simulations with/without urbanization or irrigation. A feature tracking algorithm is used to identify precipitation from mesoscale convective systems (MCSs), isolated deep convection (IDC), and non‐convective systems (NC). Overall, urbanization suppresses all three types of precipitation in the MAR by reducing water vapor content and convective available potential energy, while irrigation enhances IDC and NC precipitation but suppresses MCS precipitation. Examination of the MCS and IDC initiation locations indicates that irrigation suppresses MAR precipitation produced by MCSs initiated in the Great Plains and Midwest (GP) but enhances MAR precipitation from MCSs initiated locally within the region. Irrigation induces a mid‐level cyclonic circulation anomaly centering in the Southeast, hindering the eastward propagation and development of MCSs from the GP.

Mid- to Late-Quaternary Geomorphic and Paleoseismic Event History, Cheraw Fault, Southeastern Colorado

ABSTRACT Despite its subdued expression and isolated location within the Great Plains of southeastern Colorado, the 80 km long Cheraw fault may be one of the most active faults in North America east of the Rocky Mountains. We present geomorphic analyses, geochronology, and paleoseismic trenching data to (1) document the rupture history of the ∼45 km long southwestern section of the Cheraw fault over the past ∼19 ka, and (2) evaluate slip rate changes for the entire fault over the past ∼200 ka. Results from new trenches excavated at the Old Ranch site show evidence of four surface rupture events since ∼19 ka, each with an average vertical displacement of 0.75 ± 0.15 m. An additional event is likely only slightly older than ∼19 ka. Evidence for relatively small displacements at and near the Old Ranch site indicates that most of these earthquakes were magnitude (M) 7 or less and likely did not rupture the full length of the Cheraw fault. Since ∼19 ka, the average slip rate is ∼0.16 ± 0.3 mm/yr near the Old Ranch site with an average interevent time of 3–5 ka. New geochronologic data for mid- to late-Quaternary geomorphic surfaces cut by the Cheraw fault imply rapid incision by local Arkansas River tributaries from ∼145 to ∼100 ka. Maximum vertical offsets of 7–9 m for these surfaces indicate that from ∼19 to >200 ka the average slip rate was no greater than ∼0.03 mm/yr. The accelerated slip rate since ∼19 ka indicates a possible response to rapid erosional unloading and/or a limited late Cenozoic, <40 ka, paleoseismic history for the Cheraw fault.

Recent geomorphological changes in the Paraiba do Sul delta, South America East Coast

The Paraiba do Sul River delta, a South America east coast system, presents deposits recording complex sedimentary dynamics in the deltaic plain during the Little Ice Age (LIA). The use of optically stimulated luminescence (OSL) dating, sediment grain-size characterization, and morpho-chronological analysis showed that from ∼450 to 100years (LIA period), both in lower to upper deltaic plain, remodeling occurred in conjunction with the coastline regression. The freshwater and sediment influx increases due to the moisture enhancements during the LIA resulted in the intensification of the fluvial dynamic, channel downcutting on the marine terrace, and sedimentary environments remodeling. Further, the base-level changes occasioned by the coastline regression strengthen the geomorphological dynamics associated with the recent changes in the Paraiba do Sul delta. Currently, the coastal erosion problem found in the area seems to reflect the coupling between climate dynamic (rainfall rates decrease) and multiple-scale anthropic intervention. Results show a high sensitivity of humid tropical deltaic systems to short-time climate events, further contribute to broadening discussions on the complexity of this delta system’s morphosedimentary evolution during the Late Holocene.

The damselfly genus Megaloprepus (Odonata: Pseudostigmatidae): Revalidation and delimitation of species-level taxa including the description of one new species.

As the longest-winged odonate species of the extant world, Megaloprepus caerulatus (Drury, 1782) has received attention by many entomologists. While the behavior and ecology of this species has been subject of intense studies, biogeography and species status throughout its distributional range in old-growth Neotropical forests are less well known. For tropical forests, this information is a sine qua non when estimating the impact of degradation and climate change. Recent population genetic analyses, quantitative morphometric, and traditional taxonomic studies rediscovered a complex composed of cryptic species within the genus Megaloprepus Rambur, 1842up until now still regarded as a monotypic genus. Here we introduce one new species Megaloprepus diaboli sp. nov. from the southern Pacific coast of Costa Rica and from the central Caribbean coast of Honduras and Guatemala. The holotype is from the Corcovado National Park, Costa Rica (N82855.62 W833513.92), and was deposited at the National Museum of Costa Rica. Aside from M. caerulatus, two formerly described and later refused species within the genus were reevaluated and consequently raised to species status: Megaloprepus latipennis Selys, 1860 is found in the northeastern regions of Mesoamerica and Megaloprepus brevistigma Selys, 1860 in South America east of the Andes. Morphological descriptions of selected specimens (holotype of M. diaboli, lectotype of M. latipennis, and the mature males of M. brevistigma and M. caerulatus) are provided. Diagnostic features of the four species are illustrated, discussed, and summarized in a key to adult males.

Evidence for Increasing Frequency of Extreme Coastal Sea Levels

Projections of extreme sea levels (ESLs) are critical for managing coastal risks, but are made complicated by deep uncertainties. One key uncertainty is the choice of model structure used to estimate coastal hazards. Differences in model structural choices contribute to uncertainty in estimated coastal hazard, so it is important to characterize how model structural choice affects estimates of ESL. Here, we present a collection of 36 ESL data sets, from tide gauge stations along the United States East and Gulf Coasts. The data are processed using both annual block maxima and peaks-over-thresholds approaches for modeling distributions of extremes. We use these data sets to fit a suite of potentially non-stationary generalized extreme value distributions and generalized Pareto distributions by covarying the ESL statistics with multiple climate variables. For all of the sites and statistical model structures for tide surge considered here, we find that accounting for changes in the frequency of coastal extreme sea levels provides a better fit to data than using a stationary extreme value model. Further, when maximizing the a posteriori probability of the model parameters, given the available tide gauge data, generalized extreme value distribution structures with non-stationary scale parameter are preferred over non-stationary location parameter. These results have implications for how deep uncertainties in coastal flood hazards are characterized, particularly in how studies incorporate potential non-stationarity in storm surge statistics.

AMI: Global Masterbatch market set to prosper

According to AMI (Applied Market Information Ltd), the masterbatch market continues to be dynamic, maintaining growth throughout the pandemic in all major global regions, and outperforming the growth of both GDP and the underlying polymer demand. It is now worth more than US$ 30 billion and expected to have an average annual growth of more than 5%. The fastest double-digit growth will be in developing global regions, whereas more moderate growth will be experienced in the well-established markets of Europe, North America and North East Asia.

The Shift of the Center of Gravity of the Church from the West to the Majority World

Almost everywhere throughout the Majority World (MW), that is Africa, Asia, Latin America, and Middle East and North Africa (MENA), Christianity used to be called the ‘white-man's religion’. But that is the case no more—the church has exploded all over the MW. In this paper I would like to look at this shift in Christianity worldwide, and what implications it has for the global church, and especially for us in Asia. My purpose here is not to highlight the weaknesses of the Western church and to glorify the growth of the churches in the MW. Rather my hope is that this will help us have a clearer understanding of the challenges before us so that we can labor more fruitfully for the advance of the gospel in the Asian context. In the process I will also raise questions which hopefully will help point the way forward.

Alternative approaches to measuring concentration in liner shipping

Shipping has always had a special relationship with competition law and economics. Even if special competition law regimes for the shipping industry continue to exist, most countries nowadays accept the notion that shipping markets should be more competitive. Competition authorities monitor this in a more or less regular fashion, with various market concentration indexes. The liner shipping industry is peculiar in its widespread cooperation schemes between carriers, in the form of vessel sharing agreements, also known as consortia. Carriers engage in cooperation with all of their major competitors in a system of consortia that is highly interlinked. This brings considerable risks of abuse of market power. Yet, the system of inter-linked consortia has never been systematically mapped, nor do competition authorities appear to monitor them. This article addresses this gap, by proposing alternative indicators, in addition to the traditional industry concentration indexes such as the Herfindahl–Hirschman Index (HHI), that take the reality of consortia into account. Here, five possible alternative indicators are considered: the market share of consortia and independent operators; the share of consortia exceeding market share thresholds; the industry market concentration of consortia; a modified HHI that takes consortia into account; and interlinkages between consortia. We analyse the current state of concentration of liner shipping on the basis of these indicators using a new and unique database that contains deployed ship capacity of container carriers on all of their liner services. Based on this dataset we provide an overview of differences in industry concentration across world regions and developments over time. Traditional indicators show an increase in industry concentration. For example, over the trade corridors to and from Northern Europe, the HHI scores in 2006 ranged from 604 to 2463, and from 1164 to 4882 in 2021. The alternative criteria show additional industry concentration. We show that in 2021, 704 out of more than 1500 agreements among carrier consortia had a combined market share of at least 30%, and 102 of them had a combined market share of at least 50%. We also observe that in 2021, the carriers active in alliances operated 85% of the consortia capacity. Although carriers that are in the same alliance operate most of these consortia, it is also noteworthy that carriers that are not in the same alliance operate a considerable part (24%) of the consortia. Our calculations of modified Herfindahl–Hirschman Index (MHHI)indexes that take consortia into account show that industry concentration is higher when consortia are taken into account: for example on the trade corridor Northern Europe-North America East Coast, the MHHI has reached the threshold of 2500 points, despite an HHI score of around 1500. In the conclusion of the article, we put forward ways in which these alternative indicators could be used by competition authorities.

A Novel Framework for Parametric Analysis of Coastal Transition Zone Modeling

AbstractVulnerability of coastal regions to extreme events motivates an operational coupled inland‐coastal modeling strategy focusing on the coastal transition zone (CTZ), an area between the coast and upland river. To tackle this challenge, we propose a top‐down framework for investigating the contribution of different processes to the hydrodynamics of CTZs with various geometrical shapes, different physical properties, and under several forcing conditions. We further propose a novel method, called tidal vanishing point (TVP), for delineating the extent of CTZs through the upland. We demonstrate the applicability of our framework over the United States East and Gulf coasts. We categorize CTZs in the region into three classes, namely, without estuary (direct river–coast connection), triangular‐, and trapezoidal‐shaped estuary. The results show that although semidiurnal tidal constituents are dominant in most cases, diurnal tidal constituents become more prevalent in the river segment as the discharge increases. Also, decreasing the bed roughness value promotes more significant changes in the results than increasing it by the same value. Additionally, the estuary promotes tidal energy attenuation and consequently decreases the reach of tidal signals through the upland. The proposed framework is generic and extensible to any coastal region.

The content of toxic metals in the hair of students from different regions of the world

The results of a study on the content of toxic metals in the hair of first-year students of the Peoples Friendship University of Russia who arrived for training from various climatogeographic regions of the world are presented. The research involved first-year students from Africa, Latin America, the Near and Middle East, and Southeast Asia. A group of first-year students from the Moscow region acted as a control during the research. Studies have shown that there are significant differences in the content of toxic metals (Al, As, Hg, Pb, Cd, Sn) in the hair of foreign first-year students, depending on the region of residence. Students from Africa and Latin America were characterized by the highest content of toxic metals in their hair.

Common Environmental Pollutants Negatively Affect Development and Regeneration in the Sea Anemone Nematostella vectensis Holobiont

The anthozoan sea anemoneNematostella vectensisbelongs to the phylum of cnidarians which also includes jellyfish and corals. Nematostella are native to United States East Coast marsh lands, where they constantly adapt to changes in salinity, temperature, oxygen concentration and pH. Its natural ability to continually acclimate to changing environments coupled with its genetic tractability renderNematostellaa powerful model organism in which to study the effects of common pollutants on the natural development of these animals. Potassium nitrate, commonly used in fertilizers, and Phthalates, a component of plastics are frequent environmental stressors found in coastal and marsh waters. Here we present data showing how early exposure to these pollutants lead to dramatic defects in development of the embryos and eventual mortality possibly due to defects in feeding ability. Additionally, we examined the microbiome of the animals and identified shifts in the microbial community that correlated with the type of water that was used to grow the animals, and with their exposure to pollutants.

Soil Moisture Influence on the Incidence of Summer Mesoscale Convective Systems in the U.S. Great Plains

Abstract Mesoscale convective systems (MCS) are known to develop under ideal conditions of temperature and humidity profiles and large-scale dynamic forcing. Recent work, however, has shown that summer MCS events can occur under weak synoptic forcing or even unfavorable large-scale environments. When baroclinic forcing is weak, convection may be triggered by anomalous conditions at the land surface. This work evaluates land surface conditions for summer MCS events forming in the U.S. Great Plains using an MCS database covering the contiguous United States east of the Rocky Mountains, in boreal summers 2004–16. After isolating MCS cases where synoptic-scale influences are not the main driver of development (i.e., only non-squall-line storms), antecedent soil moisture conditions are evaluated over two domain sizes (1.25° and 5° squares) centered on the mean position of the storm initiation. A negative correlation between soil moisture and MCS initiation is identified for the smaller domain, indicating that MCS events tend to be initiated over patches of anomalously dry soils of ∼100-km scale, but not significantly so. For the larger domain, soil moisture heterogeneity, with anomalously dry soils (anomalously wet soils) located southwest (northeast) of the initiation point, is associated with MCS initiation. This finding is similar to previous results in the Sahel and Europe that suggest that induced meso-β circulations from surface heterogeneity can drive convection initiation.

Biomass Burning Over the United States East Coast and Western North Atlantic Ocean: Implications for Clouds and Air Quality.

Biomass burning (BB) aerosol events were characterized over the U.S. East Coast and Bermuda over the western North Atlantic Ocean (WNAO) between 2005 and 2018 using a combination of ground-based observations, satellite data, and model outputs. Days with BB influence in an atmospheric column (BB days) were identified using criteria biased toward larger fire events based on anomalously high AERONET aerosol optical depth (AOD) and MERRA-2 black carbon (BC) column density. BB days are present year-round with more in June-August (JJA) over the northern part of the East Coast, in contrast to more frequent events in March-May (MAM) over the southeast U.S. and Bermuda. BB source regions in MAM are southern Mexico and by the Yucatan, Central America, and the southeast U.S. JJA source regions are western parts of North America. Less than half of the BB days coincide with anomalously high PM2.5 levels in the surface layer, according to data from 14 IMPROVE sites over the East Coast. Profiles of aerosol extinction suggest that BB particles can be found in the boundary layer and into the upper troposphere with the potential to interact with clouds. Higher cloud drop number concentration and lower drop effective radius are observed during BB days. In addition, lower liquid water path is found during these days, especially when BB particles are present in the boundary layer. While patterns are suggestive of cloud-BB aerosol interactions over the East Coast and the WNAO, additional studies are needed for confirmation.