Detlev Helmig
Datos Biográficos
| ID | 8003322 |
|---|---|
| NOMBRE | Detlev Helmig |
| NOMBRES | Detlev |
| APELLIDO | Helmig |
| FIRMA | HELMIG D |
| AFILIACIONES | Institute of Arctic and Alpine Research |
| ORCID | 0000-0003-1612-1651 |
| VERIFICADO | Sí |
| TOTAL DE OBRAS | 113 |
| TOTAL DE CITAS | 0 |
| TOTAL COMO AUTOR | 24 |
| TOTAL COMO EDITOR | 89 |
| PRIMER AÑO DE PUBLICACIÓN | 2013 |
| AÑO MÁS RECIENTE DE PUBLICACIÓN | 2026 |
| ÍNDICE H | 0 |
Influence of warm and moist air intrusions on black carbon deposition and snowmelt in the central Arctic
In the central Arctic, warm and moist air intrusions (WAMIs) are increasingly prevalent during winter and spring, significantly affecting the near-surface energy budget. Here, we combine in situ observations from the 2019–2020 Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition with model simulations to investigate the role of WAMIs in transporting pollutants and enhancing black carbon (BC) wet deposition. S…
Airborne radioactivity in the New Mexico oil and gas development area of the Permian Basin
Airborne alpha radioactivity from both radon gas (gas-phase radioactivity) and radon progeny in particulates (particle-associated radioactivity) were investigated over 13 months (May 2023–May 2024) at a fixed site in Loving, NM (LNM), USA, located at the central-western edge of the Permian Basin where oil and gas (O&G) development has experienced rapid expansion over the past decade. Gas-phase, particle-associated, and total alpha radioactivity r…
Methane and volatile organic compounds and their influence on air quality in Boulder, Colorado
The Northern Colorado Front Range (NCFR) has a long history of air pollution problems, which include summertime ozone levels regularly exceeding the ozone National Ambient Air Quality Standard (NAAQS). The NCFR has been designated as a nonattainment area for the ozone NAAQS since 2007. Contributing factors to the elevated pollution buildup include meteorological conditions such as the mountain-valley thermal forcing that recirculates air enriched…
Modelling the coupled mercury-halogen-ozone cycle in the central Arctic during spring
Near-surface mercury and ozone depletion events occur in the lowest part of the atmosphere during Arctic spring. Mercury depletion is the first step in a process that transforms long-lived elemental mercury to more reactive forms within the Arctic that are deposited to the cryosphere, ocean, and other surfaces, which can ultimately get integrated into the Arctic food web. Depletion of both mercury and ozone occur due to the presence of reactive h…
Low ozone dry deposition rates to sea ice during the MosaiC field campaign
Dry deposition to the surface is one of the main removal pathways of tropospheric ozone (O3). We quantified for the first time the impact of O3 deposition to the Arctic sea ice on the planetary boundary layer (PBL) O3 concentration and budget using year-round flux and concentration observations from the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) campaign and simulations with a single-column atmospheric chemist…
Overview of the MosaiC expedition
With the Arctic rapidly changing, the needs to observe, understand, and model the changes are essential. To support these needs, an annual cycle of observations of atmospheric properties, processes, and interactions were made while drifting with the sea ice across the central Arctic during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition from October 2019 to September 2020. An international team desig…
Spatial and temporal variability of ozone along the Colorado Front Range occurring over 2 days with contrasting wind flow
Transport of pollution into pristine wilderness areas is of concern for both federal and state agencies. Assessing such transport in complex terrain is a challenge when relying solely on data from standard federal or state air quality monitoring networks because of the sparsity of network monitors beyond urban areas. During the Front Range air quality study, conducted in the summer of 2008 in the vicinity of Denver, CO, research-grade surface air…
Spatial distribution of atmospheric oil and natural gas volatile organic compounds in the Northern Colorado Front Range
Methane and nonmethane volatile organic compounds (VOCs) were monitored near Boulder in the Northern Colorado Front Range to investigate their spatial distribution and sources as a part of the Front Range Air Pollution and Photochemistry Experiment (FRAPPE) and the Deriving Information on Surface conditions from Column and Vertically Resolved Observations Relevant to Air Quality (DISCOVER-AQ) campaign, in summer 2014. A particular emphasis was th…
Atmospheric oil and natural gas hydrocarbon trends in the Northern Colorado Front Range are notably smaller than inventory emissions reductions
From 2008 to mid-2016, there was more than a 7-fold increase in oil production and nearly a tripling of natural gas production in the Colorado Denver–Julesburg Basin (DJB). This study utilized air samples collected at the Boulder Atmospheric Observatory (BAO) tower in southwestern Weld County in the DJB to investigate atmospheric mole fraction trends of methane and volatile organic compounds (VOCs). Elevated methane and propane mole fractions and…
The spatial legacy of Australian mercury contamination in the sediment of the Molonglo River
Mercury (Hg) contamination is an environmental concern as a by-product of legacy mining in Australia. Here we investigate the spatial and temporal distribution of Hg in the Molonglo River system in New South Wales, Australia, and assess the physical and chemical factors influencing that distribution. Mercury concentrations in sediment cores were measured in conjunction with 210Pb and 137Cs dating to establish historical contamination. This was do…
Have improvements in ozone air quality reduced ozone uptake into plants
Peak levels of ozone (O3)—quantified by concentration metrics such as accumulated O3 exposure over a threshold of 40 ppb (AOT40) and the sigmoidal-weighted cumulative exposure (W126)—have decreased over large parts of the United States and Europe in the last several decades. Past studies have suggested that these improvements in AOT40 and W126 indicate reductions in plant injury, even though it is widely recognized that O3 flux into leaves, not a…
Seasonal gaseous elemental mercury fluxes at a terrestrial background site in south-eastern Australia
Terrestrial air-surface exchange of mercury (Hg) forms an important component of the global Hg cycle, with drivers varying across spatial and temporal scales. These drivers include substrate properties, atmospheric chemistry, and meteorological factors. Vegetation uptake represents the dominant pathway of atmospheric Hg deposition to terrestrial surfaces. This study investigated the drivers of net ecosystem exchange of gaseous elemental mercury (…
Characterization, sources and reactivity of volatile organic compounds (VOCs) in Seoul and surrounding regions during Korus-AQ
The Korea-United States Air Quality Study (KORUS-AQ) took place in spring 2016 to better understand air pollution in Korea. In support of KORUS-AQ, 2554 whole air samples (WAS) were collected aboard the NASA DC-8 research aircraft and analyzed for 82 C1–C10 volatile organic compounds (VOCs) using multi-column gas chromatography. Together with fast-response measurements from other groups, the air samples were used to characterize the VOC compositi…
Observation-based modeling of ozone chemistry in the Seoul metropolitan area during the Korea-United States Air Quality Study (Korus-AQ)
The Seoul Metropolitan Area (SMA) has a population of 24 million and frequently experiences unhealthy levels of ozone (O3). In this work, measurements taken during the Korea-United States Air Quality Study (KORUS-AQ, 2016) are used to explore regional gradients in O3 and its chemical precursors, and an observationally-constrained 0-D photochemical box model is used to quantify key aspects of O3 production including its sensitivity to precursor ga…
A case study in competing methane regulations
The Canadian federal government and the Province of Alberta (the dominant oil and gas producing province) have released competing methane regulations for the oil and gas sector intended to take effect between January 2020–2023. Provisions in Canadian law could allow the provincial regulations to take precedent, but only if they are deemed to be equivalent in effect. This paper presents a comprehensive technical comparison of these upcoming regula…
Multi-decadal surface ozone trends at globally distributed remote locations
Extracting globally representative trend information from lower tropospheric ozone observations is extremely difficult due to the highly variable distribution and interannual variability of ozone, and the ongoing shift of ozone precursor emissions from high latitudes to low latitudes. Here we report surface ozone trends at 27 globally distributed remote locations (20 in the Northern Hemisphere, 7 in the Southern Hemisphere), focusing on continuou…
Evaluation of next generation emission measurement technologies under repeatable test protocols
Twelve next generation emission measurement (NGEM) technologies completed single-blind testing at the Methane Emissions Technology Evaluation Center in 2018. This is the first series of tests to evaluate a wide variety of NGEM solutions including handheld, mobile, and continuous monitoring methods using comparable, repeatable protocols. Results assess performance of detection, localization and quantification, albeit with limited statistical signi…
Factors controlling surface ozone in the Seoul Metropolitan Area during the Korus-AQ campaign
To understand the characteristics of air quality in the Seoul Metropolitan Area, intensive measurements were conducted under the Korea-United States Air Quality (KORUS-AQ) campaign. Trace gases such as O3, NOx, NOy, SO2, CO, and volatile organic compounds (VOCs), photochemical byproducts such as H2O2 and HCHO, aerosol species, and meteorological variables including planetary boundary layer height were simultaneously measured at Olympic Park in Se…
Mercury cycling in Australian estuaries and near shore coastal ecosystems
Mercury (Hg) sources to estuaries (natural and anthropogenic) as well as Hg concentrations in Australian nearshore marine environment fish are reviewed herein. The question of whether Australian estuaries have a Hg contamination problem is addressed. The Hg concentrations in fish, excluding sharks, tuna, barramundi and some stingrays, in estuaries and near-shore ecosystems with no discernable pollution sources are typically below 0.5 mg/kg wet we…
Potential of temperature- and salinity-driven shifts in diatom compatible solute concentrations to impact biogeochemical cycling within sea ice
Sea-ice algae are an important source of primary production in polar regions, yet we have limited understanding of their responses to the seasonal cycling of temperature and salinity. Using a targeted liquid chromatography-mass spectrometry-based metabolomics approach, we found that axenic cultures of the Antarctic sea-ice diatom, Nitzschia lecointei, displayed large differences in their metabolomes when grown in a matrix of conditions that inclu…
Air quality measurements in the western Eagle Ford Shale
The Eagle Ford Shale in southern Texas remains one of the most productive oil and gas regions in the US. Like the Permian Basin and Bakken Shale, ubiquitous natural gas flaring serves as an uncertain source of trace gas emissions within the Eagle Ford. A lack of ambient air quality data, especially in the western shale, impedes a thorough understanding of trace gas emissions within the shale and the subsequent local/regional air quality impacts. …
Investigation of factors controlling PM2.5 variability across the South Korean Peninsula during Korus-AQ
The Korea – United States Air Quality Study (May – June 2016) deployed instrumented aircraft and ground-based measurements to elucidate causes of poor air quality related to high ozone and aerosol concentrations in South Korea. This work synthesizes data pertaining to aerosols (specifically, particulate matter with aerodynamic diameters <2.5 micrometers, PM2.5) and conditions leading to violations of South Korean air quality standards (24-hr mean…
Long-term changes of regional ozone in China
The first Tropospheric Ozone Assessment Report (TOAR) provides information on present-day distributions and long-term trends of ozone metrics relevant for climate change, human health, and vegetation. However, only few results are available in TOAR for China due to limited long-term ozone observations. Here, we present an integrated analysis of long-term measurements of surface ozone from eight sites distributed in the North China Plain (NCP) and…
Air quality impacts from oil and natural gas development in Colorado
The rise of hydraulic fracturing techniques has fostered rapid growth of oil and natural gas (O&NG) extraction in areas across the United States. In the Denver-Julesburg Basin (DJB), which mostly overlaps with Weld County in the Northern Colorado Front Range (NCFR) north of the City of Denver Metropolitan Area (DMA), the well drilling has increasingly approached, and in many instances moved into urban residential areas. During the same time, the …
Urban greenhouse gas emissions from the Berlin area
Urban areas are recognised as a significant source of greenhouse gas emissions (GHG), such as carbon dioxide (CO2) and methane (CH4). The total amount of urban GHG emissions, especially for CH4, however, is not well quantified. Here we report on airborne in situ measurements using a Picarro G1301-m analyser aboard the DLR Cessna Grand Caravan to study GHG emissions downwind of the German capital Berlin. In total, five aircraft-based mass balance …
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Dimethyl sulfide control of the clean summertime Arctic aerosol and cloud
One year of aerosol particle observations from Alert, Nunavut shows that new particle formation (NPF) is common during clean periods of the summertime Arctic associated with attendant low condensation sinks and with the presence of methane sulfonic acid (MSA), a product of the atmospheric oxidation of dimethyl sulfide (DMS). The clean aerosol time periods, defined using the distribution of refractory black carbon number concentrations, increase i…
Global distribution and trends of tropospheric ozone
Tropospheric ozone plays a major role in Earth’s atmospheric chemistry processes and also acts as an air pollutant and greenhouse gas. Due to its short lifetime, and dependence on sunlight and precursor emissions from natural and anthropogenic sources, tropospheric ozone’s abundance is highly variable in space and time on seasonal, interannual and decadal time-scales. Recent, and sometimes rapid, changes in observed ozone mixing ratios and ozone …
A characterization of Arctic aerosols on the basis of aerosol optical depth and black carbon measurements
Aerosols, transported from distant source regions, influence the Arctic surface radiation budget. When deposited on snow and ice, carbonaceous particles can reduce the surface albedo, which accelerates melting, leading to a temperature-albedo feedback that amplifies Arctic warming. Black carbon (BC), in particular, has been implicated as a major warming agent at high latitudes. BC and co-emitted aerosols in the atmosphere, however, attenuate sunl…
Anatomy of wintertime ozone associated with oil and natural gas extraction activity in Wyoming and Utah
Winter maximum daily 8-hour average (MDA8) ozone concentrations in the Upper Green River Basin, Wyoming (UGRBWY) and the Uintah Basin, Utah (UBUT) have frequently exceeded 100 ppb in January, February and March, in the past few years. Such levels are well above the U.S. air quality standard of 75 ppb. In these two remote basins in the Rockies, local ozone precursor emissions result from intense oil and gas extraction activities that release metha…
Influence of oil and gas emissions on ambient atmospheric non-methane hydrocarbons in residential areas of Northeastern Colorado
The Northern Front Range (NFR) region of Colorado has experienced rapid expansion of oil and gas extraction from shale and tight sands reservoirs in recent years due to advances in hydraulic fracturing technology, with over 25,000 wells currently in operation. This region has also been designated as a federal ozone non-attainment area by the U.S. EPA. High ozone levels are a significant health concern, as are potential health impacts from chronic…
Long-term high frequency measurements of ethane, benzene and methyl chloride at Ragged Point, Barbados
Here we present high frequency long-term observations of ethane, benzene and methyl chloride from the AGAGE Ragged Point, Barbados, monitoring station made using a custom built GC-MS system. Our analysis focuses on the first three years of data (2005–2007) and on the interpretation of periodic episodes of high concentrations of these compounds. We focus specifically on an exemplar episode during September 2007 to assess if these measurements are …
From California dreaming to California data
Improved quantification of diverse CH4 sources at the urban scale is needed to guide local GHG mitigation strategies in the Anthropocene. Herein, we focus on landfill CH4 emissions in California, challenging the current IPCC methodology which focuses on a climate dependency for landfill CH4 generation (methanogenesis), but does not explicitly consider climate or soil dependencies for emissions. Relying on a comprehensive California landfill datab…
Snowpack-atmosphere gas exchanges of carbon dioxide, ozone, and nitrogen oxides at a hardwood forest site in northern Michigan
Snowpack-atmosphere gas exchanges of CO2, O3, and NOx (NO + NO2) were investigated at the University of Michigan Biological Station (UMBS), a mid-latitude, low elevation hardwood forest site, during the 2007–2008 winter season. An automated trace gas sampling system was used to determine trace gas concentrations in the snowpack at multiple depths continuously throughout the snow-covered period from two adjacent plots. One natural plot and one wit…
Climatology and atmospheric chemistry of the non-methane hydrocarbons ethane and propane over the North Atlantic
A record spanning ten years of non-methane hydrocarbon (NMHC) data from the Pico Mountain Observatory (PMO), Pico Island, Azores, Portugal, was analyzed for seasonal NMHC behavior, atmospheric processing, and trends, focusing on ethane and propane. The location of this site in the central North Atlantic, at an elevation of 2225 m asl, allows these data to be used to investigate the background conditions and pollution transport events occurring in…
Bacteria and fungi associated with isoprene consumption in soil
Isoprene is a reactive volatile organic compound released from the biosphere that can be abundant in the planetary boundary layer, where it can have a myriad of effects on atmospheric chemistry and secondary aerosol formation. There is currently a high degree of uncertainty in forecasts of how atmospheric isoprene concentrations will shift in response to anthropogenic land-use change and climate change. One source of this uncertainty is that stud…
Quantification and source apportionment of the methane emission flux from the city of Indianapolis
We report the CH4 emission flux from the city of Indianapolis, IN, the site of the Indianapolis Flux Experiment (INFLUX) project for developing, assessing, and improving top-down and bottom-up approaches for quantifying urban greenhouse gas emissions. Using an aircraft-based mass balance approach, we find that the average CH4 emission rate from five flight experiments in 2011 is 135 ± 58 (1σ) moles s-1 (7800 ± 3300 kg hr-1). The effective per cap…
Comparison of halocarbon measurements in an atmospheric dry whole air sample
The growing awareness of climate change/global warming, and continuing concerns regarding stratospheric ozone depletion, will require continued measurements and standards for many compounds, in particular halocarbons that are linked to these issues. In order to track atmospheric mole fractions and assess the impact of policy on emission rates, it is necessary to demonstrate measurement equivalence at the highest levels of accuracy for assigned va…
Distributions of air pollutants associated with oil and natural gas development measured in the Upper Green River Basin of Wyoming
Diffusive sampler monitoring techniques were employed during wintertime studies from 2009 to 2012 to assess the spatial distribution of air pollutants associated with the Pinedale Anticline and Jonah Field oil and natural gas (O&NG) developments in the Upper Green River Basin, Wyoming. Diffusive sampling identified both the extent of wintertime ozone (O3) episodes and the distributions of oxides of nitrogen (NOx), and a suite of 13 C5+ volatile o…
Ozone in the Atlantic Ocean marine boundary layer
In situ atmospheric ozone measurements aboard the R/V Ronald H. Brown during the 2008 Gas-Ex and AMMA research cruises were compared with data from four island and coastal Global Atmospheric Watch stations in the Atlantic Ocean to examine ozone transport in the marine boundary layer (MBL). Ozone measurements made at Tudor Hill, Bermuda, were subjected to continental outflow from the east coast of the United States, which resulted in elevated ozon…
The Global Atmosphere Watch reactive gases measurement network
Long-term observations of reactive gases in the troposphere are important for understanding trace gas cycles and the oxidation capacity of the atmosphere, assessing impacts of emission changes, verifying numerical model simulations, and quantifying the interactions between short-lived compounds and climate change. The World Meteorological Organization's (WMO) Global Atmosphere Watch (GAW) program coordinates a global network of surface stations s…
Diurnal cycle of ozone throughout the troposphere over Frankfurt as measured by Mozaic-Iagos commercial aircraft
Ozone is generally assumed to have weak diurnal variations in the free troposphere due to lower production rates than in the boundary layer, in addition to a much lower NO titration and the absence of dry deposition at the surface. However, this hypothesis has not been proven due to a lack of high frequency observations at multiple times per day. For the first time, we take benefit from the frequent O3 vertical profiles measured above Frankfurt i…
The changing face of lower tropospheric sulfur oxides in the United States
Sulfur oxides, sulfur dioxide and airborne sulfate, SOx, are short-lived species in the troposphere whose concentrations in air and precipitation have changed dramatically in association with fossil fuel combustion. The historic rise in concentration is coincident with the era of the so-called “Anthropocene.” Unlike concentrations of long-lived species such as carbon dioxide, atmospheric SOx in the United States (US) peaked between 1970 and 2005 …
Analysis of non-methane hydrocarbon data from a monitoring station affected by oil and gas development in the Eagle Ford shale, Texas
Within the last decade, unconventional oil and gas exploration in the US has become a new source of atmospheric hydrocarbons. Although a geographically dispersed source, field measurements in and downwind of a number of shale basins demonstrate the impact exploration activities have on ambient levels of hydrocarbons. Due to concerns related to ozone production, regulatory agencies are adding monitoring stations to better understand the potential …
Variability analyses, site characterization, and regional [OH] estimates using trace gas measurements from the Noaa Global Greenhouse Gas Reference Network
Trace gas measurements from whole air samples collected weekly into glass flasks at background monitoring sites within the NOAA Global Greenhouse Gas Reference Network program (with most of the sites also being World Meteorological Organization (WMO) Global Atmospheric Watch (GAW) stations) were used to investigate the variability-lifetime relationship for site characterization and to estimate regional and seasonal OH concentrations. Chemical spe…
Possible malfunction in widely used methane sampler deserves attention but poses limited implications for supply chain emission estimates
Estimates of methane emissions from natural gas production sites in the United States based on recent studies have been questioned due to possible malfunction of the Bacharach Hi Flow® Sampler (BHFS), the primary measurement instrument used for two out of five source types examined in those studies (equipment leaks and chemical injection pumps). Without assessing whether the BHFS malfunction occurred in those studies, we constrain the possible un…
The role of open lead interactions in atmospheric ozone variability between Arctic coastal and inland sites
Boundary layer atmospheric ozone depletion events (ODEs) are commonly observed across polar sea ice regions following polar sunrise. During March-April 2005 in Alaska, the coastal site of Barrow and inland site of Atqasuk experienced ODEs (O3< 10 nmol mol-1) concurrently for 31% of the observations, consistent with large spatial scale ozone depletion. However, 7% of the time ODEs were exclusively observed inland at Atqasuk. This phenomenon also o…
O3, CH4, CO2, CO, NO2 and NMHC aircraft measurements in the Uinta Basin oil and gas region under low and high ozone conditions in winter 2012 and 2013
Instrumented aircraft measuring air composition in the Uinta Basin, Utah, during February 2012 and January-February 2013 documented dramatically different atmospheric ozone (O3) mole fractions. In 2012 O3 remained near levels of ∼40 ppb in a well-mixed 500–1000 m deep boundary layer while in 2013, O3 mole fractions >140 ppb were measured in a shallow (∼200 m) boundary layer. In contrast to 2012 when mole fractions of emissions from oil and gas pr…
Analysis of local-scale background concentrations of methane and other gas-phase species in the Marcellus Shale
The Marcellus Shale is a rapidly developing unconventional natural gas resource found in part of the Appalachian region. Air quality and climate concerns have been raised regarding development of unconventional natural gas resources. Two ground-based mobile measurement campaigns were conducted to assess the impact of Marcellus Shale natural gas development on local scale atmospheric background concentrations of air pollution and climate relevant …
A decade of changes in nitrogen oxides over regions of oil and natural gas activity in the United States
Nitrogen oxides (NOx = NO2 + NO) are a highly regulated species that play a major role in the formation of photochemical smog. While NOx emissions are generally decreasing over the U.S. as a result of more stringent environmental policies and improved emissions control technologies, the shale oil and natural gas industry is reversing this rate of changes in certain regions. We present here a quantitative analysis of NOx levels over the seven main…
Air pollution impacts due to petroleum extraction in the Norwegian Sea during the Access aircraft campaign
Emissions from oil/gas extraction activities in the Arctic are already important in certain regions and may increase as global warming opens up new opportunities for industrial development. Emissions from oil/gas extraction are sources of air pollutants, but large uncertainties exist with regard to their amounts and composition. In this study, we focus on detailed investigation of emissions from oil/gas extraction in the Norwegian Sea combining m…
Environmental Science (106 obras) · Atmospheric chemistry and aerosols (80 obras) · Meteorology (80 obras) · Atmospheric and Environmental Gas Dynamics (79 obras) · Atmospheric sciences (77 obras) · Geology (76 obras) · Geography (70 obras) · Chemistry (62 obras) · Atmospheric Ozone and Climate (41 obras) · Ozone (40 obras)