Marine Air Research Articles

Characterization of atmospheric arsenic wet deposition transport pathways and potential sources areas in the Pearl River Delta region

This study tracked the characteristics of atmospheric wet deposition of the toxic element arsenic (As) at both urban (Guangzhou (GZ)) and forested (Dinghushan Natural Reserve (DHS)) sites within the Pearl River Delta (PRD) region between 2016 and 2019, examining its correlation with rainfall patterns. Additionally, by employing backward trajectory analysis and the potential source contribution function (PSCF) in conjunction with pertinent emission inventories, we pinpointed the main pathways of atmospheric arsenic transport and evaluated the emission contributions from priority source areas. The study revealed that the atmospheric arsenic wet deposition fluxes at the GZ and DHS sites exhibited a trend of increase followed by a decrease over the four-year period. Wet season deposition fluxes were more than triple those of the dry season, with urban site showing a difference of over four times. Notably, wet season As deposition at both sites was predominantly affected by heavy rainfall from marine air masses, constituting 31% of the total deposition. The predominant trajectory directions contributing to arsenic deposition at GZ and DHS were northeast (55%) and south (53%), respectively. The primary source areas for both sites were largely outside the PRD region, with the GZ site having 80% to 95% of its source area in the non-PRD region, compared to 69% to 88% at the DHS site. Furthermore, non-PRD areas contributed approximately 65% to arsenic emissions for both sites, with the industrial sector being the dominant emission source, exceeding 97% of the total emissions.

Characterization of Airborne Microbial Communities in Northern Thailand: Impacts of Smoke Haze Versus Non-Haze Conditions.

Data on airborne microorganisms, particularly in Southeast Asia, are more limited compared to chemical data. This study is the first to examine the community and diversity of microorganisms on PM2.5 in an urban area of Northern Thailand during both smoke haze and non-smoke haze periods of 2020. This study evaluated the composition of airborne bacteria and fungi and analyzed their association with the chemical composition of PM2.5 and meteorological variables. Significantly higher concentrations of PM2.5 and more chemical compounds were observed during the smoke haze period compared to the non-smoke haze period. Increased PM2.5 concentrations significantly altered both bacterial and fungal communities. The diversity and richness of airborne bacteria increased, whereas those of fungi decreased. The level of PM2.5 concentration (the carrier), the chemical composition of PM2.5 (the resources for survival), and the local meteorological conditions (relative humidity (RH)) were associated with the differences in bacterial and fungal populations. In addition, air originating from the west of the receptor site, influenced by both terrestrial and marine air mass routes, contributed to higher bacterial diversity and richness during the smoke haze period. In contrast, fungal diversity and richness were greater when the air came from the southwest, following a marine route. However, the primary health concern is pathogens, which were present in both periods (such as Clostridium, Aspergillus, and Cladosporium) and were especially abundant during smoke haze periods. This study highlights those airborne microorganisms, along with the particles and their chemical composition, are important components that can impact health, including that of humans, animals, and the environment.

Bridging gas and aerosol properties between the northeastern US and Bermuda: analysis of eight transit flights

Abstract. The western North Atlantic Ocean is strongly influenced by continental outflow, making it an ideal region to study the atmospheric transition from a polluted coastline to the marine environment. Utilizing eight transit flights between the NASA Langley Research Center (LaRC) in Hampton, Virginia, and the remote island of Bermuda from NASA's Aerosol Cloud meTeorology Interactions oVer the western ATlantic Experiment (ACTIVATE), we examine the evolution of trace gas and aerosol properties off the US East Coast. The first pair of flights flew along the wind trajectory of continental outflow, while the other flights captured a mix of marine and continental air mass sources. For measurements within the boundary layer (BL), there was an offshore decline in particle N<100 nm, N>100 nm, CH4, CO, and CO2 concentrations, all leveling off around ∼900 km offshore from the LaRC. These trends are strongest for the first pair of flights. In the BL, offshore declines in organic mass fraction and increases in sulfate mass fraction coincide with increasing hygroscopicity based on f(RH) measurements. Free troposphere measurements show a decline in N<100 nm, but other measured parameters are more variable when compared to the prominent offshore gradients seen in the BL. Pollution layers exist in the free troposphere, such as smoke plumes, that can potentially entrain into the BL. This work provides detailed case studies with a broad set of high-resolution measurements to further our understanding of the transition between continental and marine environments.

An exploratory framework to identify dust on photovoltaic panels in offshore floating solar power stations

Offshore floating solar power stations represent a new frontier in energy development. These stations maximize solar energy use, reduce land consumption and promote algae growth. However, moist marine air makes airborne particles like sand adhere more easily to PV panels, reducing photoelectric conversion efficiency and causing overheating and potential damage. Additionally, drones and fixed cameras face challenges due to complex maritime factors and complicating image analysis. To address these issues, this paper proposes an exploratory framework for identifying dust regions on photovoltaic panels specifically for offshore floating solar power stations. The framework aims to address how to accurately and reliably identify dust accumulation on PV panels, even in images with complex background interference. The framework is designed to be compatible with existing image recognition models and incorporates specialized enhancement modules to further improve recognition accuracy and efficiency. In this study, we utilized a dust feature enhancement module based on the HLS color space, combined with Mask R-CNN, to demonstrate the framework's feasibility and effectiveness. Experimental results show that, compared to a single Mask R-CNN, the framework significantly reduces misidentification and omission of dust areas, boosting the confidence level and effectively meeting the operational needs of offshore floating solar power stations.

Management of Plastic Wastes through Recent Advanced Pyrolysis Processes

Plastics are predominant in numerous sectors like packaging, agriculture, hardware, electronics, and many others. Annual plastic demand has been rapidly growing in the last few decades because of the increasing dependency on plastics. As a consequence, massive amounts of plastic waste are being generated every year. These plastic wastes are non-biodegradable, and hence their disposal poses a serious threat to the ecosystem and causes significant environmental problems such as endangering the safety of marine life, wildlife, air, water, and soil, etc. A large portion of plastic waste ends up in landfills, and only a small fraction is recycled. The continuous dependence on landfills as the main disposal method for plastic waste is costly and ineffective. Common solutions to plastic waste management are incineration and recycling; however, incineration emits harmful pollutants and greenhouse gases that contribute to ozone layer depletion and global warming; moreover, recycling is expensive and inefficient. As an alternative to recycling and incineration, the pyrolysis process can convert plastic wastes into more valuable fuel products. Pyrolysis is a thermal process that converts raw material into pyrolysis liquid, solid wax, and non-condensable gases in the absence of oxygen. This process is attractive because it is economical and energy-efficient, and it can be used to convert various types of plastic waste into valuable products. In recent years, there have been significant developments in pyrolysis applications in liquid fuel production from plastic wastes. This work reviews recent advances in and challenges for the pyrolysis process for converting plastic wastes into a valuable alternative fuel, focusing on studies of advanced pyrolysis processes published over the last five years. The paper also highlights the numerical modeling of pyrolysis of plastic wastes and the potential impact of pyrolysis on the future of sustainable waste-management practices of plastics.

The Role ofDrill Instructors andGender Integration at Recruit Training: Examining Intersections ofGender andIntegration inthe Recruit Training Environment.

Drill instructors (DIs) are responsible for executing their Services' recruit training programs and for training recruits. DIs assume a variety of roles, including teaching and developing practical skills and knowledge, mentoring, modeling appropriate behavior and attitudes, motivating recruits for success during and after recruit training, applying and instilling discipline, and ensuring the safety and welfare of recruits. This article examines two major research questions at the intersection of gender, gender-integrated training, and the DI role: (1) What differences exist in how DIs experience their role by gender? and (2) how does gender-integrated recruit training affect DIs' approach to training? This article draws from 87 semistructured interviews conducted with Service leaders, training cadre, and DIs in service of a broader Marine Corps interdisciplinary study on gender integration at recruit training. Interviews were conducted virtually and in-person with Marine Corps, Army, Navy, Air Force, and Coast Guard personnel from June to November 2021. Each interview was coded with initial and secondary codes developed through a flexible coding approach. Data were analyzed across and within relevant categories such as gender and Service to identify themes and patterns. Although the DI role was universally described as demanding and difficult, unique challenges for women consistently emerged from the data. The top reported challenges faced by female DIs were personnel shortages, work and family conflict, culture-driven sexism in the training environment from male peers and recruits, and pressure to excel above and beyond their male peers. In recruit training, DIs are responsible for executing gender-integrated practices. Service leaders, training cadre, and DIs described how gender integration practices affect their approach to the role and implementation of training, including addressing and dismantling sexism, shutting down recruit romantic relationships, training all recruits in an equal manner, knowing gender-specific grooming standards, increasing communication among DIs, and working with mixed-gender DI teams. Female DIs face additional challenges in and outside the role compared with their male peers, and some of these challenges are preventable. Staffing and personnel issues plague the female DI population and are a persistent and pervasive challenge to gender integration efforts. Women are a necessary and highly desirable population to fill the DI role, particularly as Services aim to expose recruits to leaders of both genders during their critical first training experience. DIs play an important role in ensuring the successful completion of recruit training, ultimately helping to build the future leaders of the military. The success of gender integration efforts depends on DIs' intentional approach to the process. Future research can build on this work by expanding the scope to other military training environments (beyond recruit training) and examining how DIs' own sociodemographic positions (e.g., gender, race, ethnicity, and sexual orientation) inform their perspective on and approach to equity in the training environment.

Regional Aerosol Optical Depth over Antarctica

Atmospheric aerosols greatly contribute to the uncertainty in current climate models, particularly presenting pronounced limitations in the Antarctic region. This study measures aerosol properties using data from several Antarctic AERONET sites (Escudero, Marambio, South Pole, Utsteinen, Vechernaya_Hill) and Zhongshan Station. We examined the spatial and temporal patterns of two specific aerosol properties: Aerosol Optical Depth (AOD) at 500 nm (τ500nm) and Ångström Exponent (AE) between 440 and 870 nm (α440−870nm). Our findings reveal τ500nm medians ranging from 0.02 to 0.09, with elevated values observed along the coastal regions compared to the interior of Antarctica. Regarding the AE, the medians of α440−870nm indicate that the coarse-mode particle aerosols are dominated at Escudero (approximately 0.54). In contrast, fine mode particles prevail at the other sites (over 0.97). Monthly mean τ500nm and the proportion of fine mode particles peaks during austral summer and autumn, suggesting increased marine biological sources. Moreover, analyzing the air mass back trajectories, we discovered marine air influences on Escudero, Marambio, Zhongshan, and Vechernaya_Hill, while Utsteinen and South Pole are primarily experiencing air originating from the Antarctic continent. These findings underscore the significant role of aerosol sources in regional AOD differences. Additionally, higher τ500nm were more associated with significantly negative direct aerosol radiative forcing at the bottom of the atmosphere (DARF-BOA). The direct aerosol radiative forcing at the top of the atmosphere (DARF-TOA) closely correlates with single-scattering albedo (SSA), where high (low) SSA generally results in negative (positive) forcing over Antarctica.

Broadband and filter radiometers at Ross Island, Antarctica: detection of cloud ice phase versus liquid water influences on shortwave and longwave radiation

Abstract. Surface radiometer data from Ross Island, Antarctica, collected during the austral summer 2015–2016 by the US Department of Energy Atmospheric Radiation Measurement (ARM) program West Antarctic Radiation Experiment (AWARE), are used to evaluate how shortwave and longwave irradiance respond to changing cloud properties as governed by contrasting meteorological regimes. Shortwave atmospheric transmittance is derived from pyranometer measurements, and cloud conservative-scattering optical depth is derived from filter radiometer measurements at 870 nm. With onshore flow associated with marine air masses, clouds contain mostly liquid water. With southerly flow over the Transantarctic Mountains, orographic forcing induces substantial cloud ice water content. These ice and mixed-phase clouds attenuate more surface shortwave irradiance than the maritime-influenced clouds and also emit less longwave irradiance due to colder cloud base temperature. These detected irradiance changes are in a range that can mean onset or inhibition of surface melt over ice shelves. This study demonstrates how basic and relatively low-cost broadband and filter radiometers can be used to detect subtle climatological influences of contrasting cloud microphysical properties at very remote locations.

Peatland Wildfires Enhance Nitrogen-Containing Organic Compounds in Marine Aerosols over the Western Pacific.

Peatland wildfires contribute significantly to the atmospheric release of light-absorbing organic carbon, often referred to as brown carbon. In this study, we examine the presence of nitrogen-containing organic compounds (NOCs) within marine aerosols across the Western Pacific Ocean, which are influenced by peatland fires from Southeast Asia. Employing ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) in electrospray ionization (ESI) positive mode, we discovered that NOCs are predominantly composed of reduced nitrogenous bases, including CHN+ and CHON+ groups. Notably, the count of NOC formulas experiences a marked increase within plumes from peatland wildfires compared to those found in typical marine air masses. These NOCs, often identified as N-heterocyclic alkaloids, serve as potential light-absorbing chromophores. Furthermore, many NOCs demonstrate pyrolytic stability, engage in a variety of substitution reactions, and display enhanced hydrophilic properties, attributed to chemical processes such as methoxylation, hydroxylation, methylation, and hydrogenation that occur during emission and subsequent atmospheric aging. During the daytime atmospheric transport, aging of aromatic N-heterocyclic compounds, particularly in aliphatic amines prone to oxidation and reactions with amine, was observed. The findings underscore the critical role of peatland wildfires in augmenting nitrogen-containing organics in marine aerosols, underscoring the need for in-depth research into their effects on marine ecosystems and regional climatic conditions.

Atmospheric chemistry of the coastal area is influenced by the convergence between the inland and marine air: Insight into carbonyl compounds

Marine biological activity has long been recognized to impact the atmospheric chemistry of coastal areas. In this work, we monitored the seasonal variation of carbonyl compounds in the coastal city of Qingdao, located in the north of China's coastline and the south of Jiaodong Peninsula, with the vast hinterland in the west. The mean total concentration of the 15 carbonyls varied significantly between seasons, with the highest observed in autumn (10.2 ± 6.2 ppbv), followed by spring (9.0 ± 3.0 ppbv), winter (6.4 ± 4.0 ppbv) and summer (3.4 ± 1.4 ppbv). Using bivariate analysis, the agricultural emissions from inland areas were responsible for the high levels of carbonyls in the autumn. In summer, clean and humid sea winds helped reduce the concentration of carbonyls, but they also brought air masses from vegetation, and marine organisms, which contributed to high levels of carbonyls in the spring of coastal areas. The observation-based chemistry box model found that the formation of formaldehyde and acetaldehyde was primarily controlled by the RO + O2 reaction, and alkenes oxidation was the main contributing factor. Based on the OH radical loss rate (LOH) and ozone formation potential (OFP) calculation, we found that autumn and spring seasons have significantly higher values of LOH and OFP than winter and summer due to the presence of high concentrations of carbonyl compounds. Therefore, it is believed that these carbonyl compounds primarily originate from agricultural activities, and marine air influences the atmospheric chemistry of the coastal areas.

Drivers of late Holocene ice core chemistry in Dronning Maud Land: the context for the ISOL-ICE project

Abstract. Within the framework of the Isotopic Constraints on Past Ozone Layer in Polar Ice (ISOL-ICE) project, we present initial ice core results from the new ISOL-ICE ice core covering the last millennium from high-elevation Dronning Maud Land (DML) and discuss the implications for interpreting the stable isotopic composition of nitrogen in ice core nitrate (δ15N(NO3-)) as a surface ultra-violet radiation (UV) and total column ozone (TCO) proxy. In the quest to derive TCO using δ15N(NO3-), an understanding of past snow accumulation changes, as well as aerosol source regions and present-day drivers of their variability, is required. We therefore report here the ice core age–depth model, the snow accumulation and ice chemistry records, and correlation analysis of these records with climate variables over the observational era (1979–2016). The ISOL-ICE ice core covers the last 1349 years from 668 to 2017 CE ± 3 years, extending previous ice core records from the region by 2 decades towards the present and shows excellent reproducibility with those records. The extended ISOL-ICE record of last 2 decades showed a continuation of the methane sulfonate (MSA−) increase from ∼ 1800 to present while there were less frequent large deposition events of sea salts relative to the last millennium. While our chemical data do not allow us to distinguish the ultimate (sea ice or the open ocean) source of sea salt aerosols in DML winter aerosol, our correlation analysis clearly suggests that it is mainly the variability in atmospheric transport and not the sea ice extent that explains the interannual variability in sea salt concentrations in DML. Correlation of the snow accumulation record with climate variables over the observational era showed that precipitation at ISOL-ICE is predominately derived from the South Atlantic with onshore winds delivering marine air masses to the site. The snow accumulation rate was stable over the last millennium with no notable trends over the last 2 decades relative to the last millennium. Interannual variability in the accumulation record, ranging between 2 and 20 cm a−1 (w.e.), would influence the ice core δ15N(NO3-) record. The mean snow accumulation rate of 6.5±2.4 cm a−1 (w.e.) falls within the range suitable for reconstructing surface mass balance from ice core δ15N(NO3-), highlighting that the ISOL-ICE ice core δ15N(NO3-) can be used to reconstruct either the surface mass balance or surface UV if the ice core δ15N(NO3-) is corrected for the snow accumulation influence, thereby leaving the UV imprint in the δ15N(NO3-) ice core record to quantify natural ozone variability.

Atmospheric gaseous mercury and associated health risk assessment in the economic capital of India.

Mercury cycling in coastal metropolitan areas on the west coast of India becomes complex due to the combined effects of both intensive domestic anthropogenic emissions and marine air masses. The present study is based on yearlong data of continuous measurements of gaseous elemental mercury (GEM) concentration concurrent with meteorological parameters and some air pollutants at a coastal urban site in Mumbai, on the west coast of India, for the first time. The concentration of GEM was found in a range between 2.2 and 12.3ng/m3, with a mean of 3.1 ± 1.1ng/m3, which was significantly higher than the continental background values in the Northern Hemisphere (~ 1.5ng/m3). Unlike particulates, GEM starts increasing post-winter to peak during the monsoon and decrease towards winter. July had the highest concentration of GEM followed by October, and a minimum in January. GEM exhibited a distinct diurnal cycle, mainly with a broad peak in the early morning, a narrow one by nightfall, and a minimum in the afternoon. The peaks and their timing suggest the origin of urban mobility and the start of local activities. A positive correlation between SO2, PM2.5, temperature, relative humidity, and GEM indicates that emissions from local industrial plants in the Mumbai coastal area. Principal component analysis (PCA) and cluster analysis (CA) confirm this fact. Monthly back trajectory analysis showed that air mass flows are predominantly from the Arabian Sea and local human activities. Assessment of human health risks by USEPA model reveals that the hazardous quotient, HQ < 1, implies negligible carcinogenic risk. GEM observations in Mumbai during the study period are below the World Health Organization's (WHO) safe limit (200ng/m3) for long-term inhalation.

Experimental and numerical simulation study on the heat transfer effect of anti-icing wave-plate separators in marine air intake systems

When navigating in cold sea areas, surface vessels such as hovercrafts and destroyers often encounter the issue of ice formation, caused by splashing waves and water droplets, which can clog the air intake filtration systems and lead to performance degradation and safety hazards for gas turbines. To address this problem, this paper proposes an anti-icing wave-plate separation structure (AWS), aiming to meet both the anti-icing and droplet filtration requirements within the intake duct. Utilizing numerical simulation methods, the paper calculates the performance of six different models with varying bending angles (θ) and spacings between waved plates (H1), and conducts experiments to measure the total pressure loss (ΔP) of model (f) under non-heating conditions. The experimental measurement results have demonstrated that the AWS structure exhibits a total pressure loss of less than 1000 Pa when designed for an inlet air velocity of 7 m/s. This meets the design requirements specified for ship air intakes. Numerical simulation results indicate that as H1 increases from 19 mm to 23 mm, the ΔP of the AWS decreases by 47.8 %, while the temperature difference between the inlet and outlet (ΔT) decreases by 26.7 %, with minimal impact on the comprehensive heat transfer coefficient (ξ). Conversely, reducing θ of the wave-plates from 36° to 21° decreases ΔP by 84.2 %, ΔT by 29.7 %, and increases ξ by 17 %. When designing the AWS, it is advisable to adjust θ and H1 based on the specific requirements of the vessel’s intake duct to ensure a larger ξ while meeting the actual needs of ΔP and ΔT.

Ethanol, acetaldehyde, and methanol in the gas phase and rainwater in different biomes and urban regions of Brazil

In the context of the increasing global use of ethanol biofuel, this work investigates the concentrations of ethanol, methanol, and acetaldehyde, in both the gaseous phase and rainwater, across six diverse urban regions and biomes in Brazil, a country where ethanol accounts for nearly half the light-duty vehicular fuel consumption. Atmospheric ethanol median concentrations in São Paulo (SP) (12.3 ± 12.1 ppbv) and Ribeirão Preto (RP) (12.1 ± 10.9 ppbv) were remarkably close, despite the SP vehicular fleet being ∼13 times larger. Likewise, the rainwater VWM ethanol concentration in SP (4.64 ± 0.38 μmol L−1) was only 26 % higher than in RP (3.42 ± 0.13 μmol L−1). This work demonstrated the importance of evaporative emissions, together with biomass burning, as sources of the compounds studied. The importance of biogenic emissions of methanol during forest flooding was identified in campaigns in the Amazon and Atlantic forests. Marine air masses arriving at a coastal site led to the lowest concentrations of ethanol measured in this work. Besides vehicular and biomass burning emissions, secondary formation of acetaldehyde by photochemical reactions may be relevant in urban and non-urban regions. The combined deposition flux of ethanol and methanol was 6.2 kg ha−1 year−1, avoiding oxidation to the corresponding and more toxic aldehydes. Considering the species determined here, the ozone formation potential (OFP) in RP was around two-fold higher than in SP, further evidencing the importance of emissions from regional distilleries and biomass burning, in addition to vehicles. At the forest and coastal sites, the OFP was approximately 5 times lower than at the urban sites. Our work evidenced that transition from gasoline to ethanol or ethanol blends brings the associated risk of increasing the concentrations of highly toxic aldehydes and ozone, potentially impacting the atmosphere and threatening air quality and human health in urban areas.

Insights into atmospheric trace gases, aerosols, and transport processes at a high-altitude station (2623 m a.s.l.) in Northeast Asia

As part of the efforts to understand long-range air pollution transport in Northeast Asia, a comprehensive field measurement campaign was conducted at the top of Changbai Mountain (2623 m a.s.l.) from 25th July to 21st August in 2021. The ambient concentrations of trace gases and chemical characteristics of fine particulate matter (PM2.5) were comparable to those at background or free tropospheric locations in China, but exceeded levels at corresponding sites in Europe and the United States. Well-defined diurnal variations were evident in most air pollutants, including carbon monoxide (CO), sulfur dioxide (SO2), and nitrogen oxide (NOx), reflecting the influence of boundary layer development and local anthropogenic activities. Ozone (O3) exhibited a unique diurnal distribution, with lower concentrations during the daytime and higher levels at nighttime, indicating a pronounced impact of downward transport of O3-rich air from the upper troposphere during the nighttime. During the campaign, organic carbon (OC) constituted the predominant component of PM2.5, comprising 43% of the total, while sulfate (SO42−) was the most abundant secondary inorganic component in PM2.5, accounting for 26%. Combining the analysis of air mass backward trajectories, we found that Changbai Mountain is primarily influenced by air masses originating from North Korea and the Sea of Japan, constituting 62% of the total, and local vegetation biological emissions and anthropogenic emissions in North Korea notably affect the observation site. Conversely, the secondary aerosol components were most abundant in marine air mass originating from the marginal seas of China and the strait between the Korean peninsula and southern Japan. Utilizing the Lagrangian photochemical trajectory model (LPTM), a significant increase in particulate SO42− concentrations was observed when air mass passed through the marginal seas of China, primarily due to SO2 oxidation reaction. This study contributes to an improved understanding of the atmospheric chemistry in the high-altitude regions of Northeast Asia and underscores the substantial role of secondary inorganic aerosol formation during the transport of marine air masses.

Recent Trends of Refrigerants for Marine Air Conditioning and Refrigeration Systems

Recent Trends of Refrigerants for Marine Air Conditioning and Refrigeration Systems

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.

Direct measurement of the inertial-convective subrange above ocean surface waves

The −5/3 power law over the inertial subrange of the turbulence kinetic energy spectrum is one of the most well-known concepts in fluid physics. Obukhov and Corrsin extended the original hypothesis to a passive tracer, leading to the concept of an inertial-convective subrange. These postulates have been empirically validated in the atmospheric turbulence over land but have not been comprehensively studied in the marine air flow. During a recent oceanic campaign, the platform FLIP was deployed with an array of sensors to measure the perturbation wind velocity, temperature, and water vapor. Using these data, a previous study found that Kolmogorov's hypothesized −5/3 was not universally valid over the ocean. Here, we continue that work to analyze the spectrum of temperature and water vapor to empirically evaluate the theoretical extension by Obukhov-Corrsin. For temperature, the observed spectra were too noisy for thorough analysis; our conjecture for the source of noise and its implications for near-surface observations of atmospheric turbulence are discussed. For water vapor, we found strong agreement with the previous analysis of the kinetic energy spectrum. These findings corroborate (1) the theoretical notion of the scalar energy dissipation subrange driven by the inertial motions in the marine boundary layer and (2) evidence for non-Kolmogorov turbulence in the high Reynolds flow immediately above ocean waves. Our analysis shows a strong relationship with distance from the wavy surface; using linear extrapolation, we find that divergence from −5/3 persists in the lowest 25 m of the atmosphere.

Design of a Passenger Ship Launch Using an Air Bag System

Ship launching is one of the stages of ship production before the ship is handed over to the owner, which marks the beginning of the ship's life. With the development of technology at this time, various launching methods have been developed, one of which is the launching method using an air bag system. Launching using air bags has many advantages compared to conventional launching methods that have been used so far. Pre-launch calculations are performed to avoid risks during the launch. Launching using air bags begins with calculating the weight plan of the ship launch and the preparation of the air bag layout. Using CB/T 3837:1998 Technological Requirements for Ship Upgrading or Launching Relying on Air Bags, Shipbuilding Industry Standard, and ISO 14409:2011 ships and marine technology-ship launching air bags, the number of air bag requirements and layout can be determined to support the ship launching process. The passenger ship, with an length overall of 62.80 metres, is planned to have a launch weight of 1058.881 tons. By using the QG6 high-bearing capacity air bag model with 6 layers of cord fabric with a diametre of one metre and a contact length between the air bag and the ship's body of ten metres, a total of 11 air bags are required in a linear arrangement to support the launch of a passenger ship. The distance between air bags is 2.07 metres to 5.736 metres, the longer the distance between air bags, the greater the load supported by each air bag.

Regional Controls on Climate and Weather Variability on the Southwest Coast of Peru

Southwestern Peru has an arid climate typical of subtropical west coasts bordering cold ocean currents. Mountain runoff is barely able to sustain urban needs and motivates this research. Using high-resolution satellite reanalysis products, the meso-scale climate and weather variability are explored via point-to-field regression. A time series spanning 1970–2022 of Tacna area (18 S, 70.2 W, 570 m) rainfall, potential evaporation, wind, and weather parameters were evaluated for thermodynamic and kinematic features. Although sea breezes draw marine air inland, they simultaneously generate low-level divergence and subsidence aloft. Potential evaporation in early summer causes water deficits that are rarely offset by late summer runoff from the Andes Mountains. Winter (May–September) showers from passing cold fronts are more frequent during El Niño. Warming of the tropical east Pacific accelerates subtropical westerly winds that lift over the coastal plains. Quasi-stationary Rossby wave patterns amplify transient troughs at 70 W, but the winter showers rarely exceed 4 mm/day due to low-level stability from negative heat fluxes over cool seawater offshore. Two winter wet spells were studied using satellite and surface data (July 2002, July 2009). Light showers were prominent in elevations from 400 to 900 m. An early summer dry spell was considered (November 2020), wherein southeast winds, coastal upwelling, and low dewpoint temperatures coincided with La Niña conditions. A rain-gauge transect showed that summer convection stays east of the Andes escarpment and seldom benefits the coastal plains. Thus, water resources in Tacna are strained beyond the carrying capacity.