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Semidiurnal nonmigrating tides in low-latitude lower thermospheric NO: A climatology based on 20 years of Odin/SMR measurements

Grieco, Francesco; Orsolini, Yvan Joseph Georges Emile G.; Pérot, Kristell

The Sub-Millimetre Radiometer (SMR) on board the Odin satellite provides almost 20 years of nitric oxide (NO) measurements in the mesosphere and lower thermosphere (MLT) at equatorial crossing local solar times (LSTs) of 6 AM and 6 PM. In this study, we use Odin/SMR observations to estimate how lower thermospheric NO mixing ratios at low latitudes are affected by solar nonmigrating tides. Most of the previous studies based on satellite data have focused on the signatures of diurnal tides in the MLT and above, while we concentrate here on nonmigrating semidiurnal tides. To study the contribution of these tides to NO mixing ratio variations, we average pairs of NO measurements along ascending and descending orbital tracks at 107 km altitude over latitudes between −40°and +40°. We consider monthly climatologies of these pair-averages and analyse residuals with respect to their zonal mean. In this way, it is possible to study the effect of nonmigrating even-numbered tidal components, albeit there is a non-tidal component arising largely from quasi-stationary planetary waves. Spectral wave amplitudes are extracted using a Fourier transform as function of (apparent) zonal wavenumber with a focus around −30°, −20°and 30°latitudes. From our analysis, it appears that the semidiurnal (apparent) zonal wavenumber 4 arising from the SW6 and SE2 tides is dominant close to the equator (e.g., at −20°), except during some boreal summer months (June, July, August). On the other hand, wave-1 plays a more prominent role at subtropical latitudes, especially in the southern hemisphere, where it surpasses wave-4 during 7 months (March and May-to-October) at −30°. There is little observational evidence to date documenting the presence of the semidiurnal nonmigrating tides in NO in the low-latitude MLT. Our results hence provide one of the first evidences of the climatological signature of these tides in NO, in an altitude range that remains poorly observed.



Fluorine Mass Balance, including Total Fluorine, Extractable Organic Fluorine, Oxidizable Precursors, and Target Per- and Polyfluoroalkyl Substances, in Pooled Human Serum from the Tromsø Population in 1986, 2007, and 2015

Cioni, Lara; Plassmann, Merle; Benskin, Jonathan P.; Coelho, Ana Carolina; Nøst, Therese Haugdahl; Rylander, Karin Charlotta Maria; Nikiforov, Vladimir; Sandanger, Torkjel Manning; Herzke, Dorte

Of the thousands of per- and polyfluoroalkyl substances (PFAS) known to exist, only a small fraction (≤1%) are commonly monitored in humans. This discrepancy has led to concerns that human exposure may be underestimated. Here, we address this problem by applying a comprehensive fluorine mass balance (FMB) approach, including total fluorine (TF), extractable organic fluorine (EOF), total oxidizable precursors (TOP), and selected target PFAS, to human serum samples collected over a period of 28 years (1986, 2007, and 2015) in Tromsø, Norway. While concentrations of TF did not change between sampling years, EOF was significantly higher in 1986 compared to 2007 and 2015. The ∑12PFAS concentrations were highest in 2007 compared to 1986 and 2015, and unidentified EOF (UEOF) decreased from 1986 (46%) to 2007 (10%) and then increased in 2015 (37%). While TF and EOF were not influenced by sex, women had higher UEOF compared to men, opposite to target PFAS. This is the first FMB in human serum to include TOP, and it suggests that precursors with >4 perfluorinated carbon atoms make a minor contribution to EOF (0–4%). Additional tools are therefore needed to identify substances contributing to the UEOF in human serum.


A roadmap to estimating agricultural ammonia volatilization over Europe using satellite observations and simulation data

Abeed, Rimal; Viatte, Camille; Porter, William C.; Evangeliou, Nikolaos; Clerbaux, Cathy; Clarisse, Lieven; Van Damme, Martin; Coheur, Pierre-François; Safieddine, Sarah

Ammonia (NH3) is one of the most important gases emitted from agricultural practices. It affects air quality and the overall climate and is in turn influenced by long-term climate trends as well as by short-term fluctuations in local and regional meteorology. Previous studies have established the capability of the Infrared Atmospheric Sounding Interferometer (IASI) series of instruments, aboard the Metop satellites, to measure ammonia from space since 2007. In this study, we explore the interactions between atmospheric ammonia, land and meteorological variability, and long-term climate trends in Europe. We investigate the emission potential (Γsoil) of ammonia from the soil, which describes the soil–atmosphere ammonia exchange. Γsoil is generally calculated in-field or in laboratory experiments; here, and for the first time, we investigate a method which assesses it remotely using satellite data, reanalysis data products, and model simulations.

We focus on ammonia emission potential in March 2011, which marks the start of growing season in Europe. Our results show that Γsoil ranges from 2 × 103 to 9.5 × 104 (dimensionless) in fertilized cropland, such as in the North European Plain, and is of the order of 10–102 in a non-fertilized soil (e.g., forest and grassland). These results agree with in-field measurements from the literature, suggesting that our method can be used in other seasons and regions in the world. However, some improvements are needed in the determination of mass transfer coefficient k (m s−1), which is a crucial parameter to derive Γsoil.

Using a climate model, we estimate the expected increase in ammonia columns by the end of the century based on the increase in skin temperature (Tskin), under two different climate scenarios. Ammonia columns are projected to increase by up to 50 %, particularly in eastern Europe, under the SSP2-4.5 scenario and might even double (increase of 100 %) under the SSP5-8.5 scenario. The increase in skin temperature is responsible for a formation of new hotspots of ammonia in Belarus, Ukraine, Hungary, Moldova, parts of Romania, and Switzerland.


Increased contribution of biomass burning to haze events in Shanghai since China’s clean air actions

Fang, Wenzheng; Evangeliou, Nikolaos; Eckhardt, Sabine; Xing, Ju; Zhang, Hailong; Xiao, Hang; Zhao, Meixun; Kim, Sang-Woo

High levels of East Asian black carbon (BC) aerosols affect ecological and environmental sustainability and contribute to climate warming. Nevertheless, the BC sources in China, after implementing clean air actions from 2013‒2017, are currently elusive due to a lack of observational constraints. Here we combine dual-isotope-constrained observations and chemical-transport modelling to quantify BC’s sources and geographical origins in Shanghai. Modelled BC concentrations capture the overall source trend from continental China and the outflow to the Pacific. Fossil sources dominate (~70%) BC in relatively clean summer. However, a striking increase in biomass burning (15‒30% higher in a fraction of biomass burning compared to summer and 2013/2014 winter), primarily attributable to residential emissions, largely contributes to wintertime BC (~45%) pollution. It highlights the increasing importance of residential biomass burning in the recent winter haze associated with >65% emissions from China’s central-east corridor. Our results suggest clearing the haze problem in China’s megacities and mitigating climate impact requires substantial reductions in regional residential emissions, besides reducing urban traffic and industry emissions.

Springer Nature


Modelling PCB-153 in northern ecosystems across time, space, and species using the nested exposure model

Krogseth, Ingjerd Sunde; Breivik, Knut; Frantzen, Sylvia; Nilsen, Bente Merete; Eckhardt, Sabine; Nøst, Therese Haugdahl; Wania, Frank

There is concern over possible effects on ecosystems and humans from exposure to persistent organic pollutants (POPs) and chemicals with similar properties. The main objective of this study was to develop, evaluate, and apply the Nested Exposure Model (NEM) designed to simulate the link between global emissions and resulting ecosystem exposure while accounting for variation in time and space. NEM, using environmental and biological data, global emissions, and physicochemical properties as input, was used to estimate PCB-153 concentrations in seawater and biota of the Norwegian marine environment from 1930 to 2020. These concentrations were compared to measured concentrations in (i) seawater, (ii) an Arctic marine food web comprising zooplankton, fish and marine mammals, and (iii) Atlantic herring (Clupea harengus) and Atlantic cod (Gadus morhua) from large baseline studies and monitoring programs. NEM reproduced PCB-153 concentrations in seawater, the Arctic food web, and Norwegian fish within a factor of 0.1–31, 0.14–3.1, and 0.09–21, respectively. The model also successfully reproduced measured trophic magnification factors for PCB-153 at Svalbard as well as geographical variations in PCB-153 burden in Atlantic cod between the Skagerrak, North Sea, Norwegian Sea, and Barents Sea, but estimated a steeper decline in PCB-153 concentration in herring and cod during the last decades than observed. Using the evaluated model with various emission scenarios showed the important contribution of European and global primary emissions for the PCB-153 load in fish from Norwegian marine offshore areas.

Royal Society of Chemistry (RSC)


Regionally sourced bioaerosols drive high-temperature ice nucleating particles in the Arctic

Freitas, Gabriel Pereira; Adachi, Kouji; Conen, Franz; Heslin-Rees, Dominic; Krejci, Radovan; Tobo, Yutaka; Yttri, Karl Espen; Zieger, Paul

Primary biological aerosol particles (PBAP) play an important role in the climate system, facilitating the formation of ice within clouds, consequently PBAP may be important in understanding the rapidly changing Arctic. Within this work, we use single-particle fluorescence spectroscopy to identify and quantify PBAP at an Arctic mountain site, with transmission electronic microscopy analysis supporting the presence of PBAP. We find that PBAP concentrations range between 10−3–10−1 L−1 and peak in summer. Evidences suggest that the terrestrial Arctic biosphere is an important regional source of PBAP, given the high correlation to air temperature, surface albedo, surface vegetation and PBAP tracers. PBAP clearly correlate with high-temperature ice nucleating particles (INP) (>-15 °C), of which a high a fraction (>90%) are proteinaceous in summer, implying biological origin. These findings will contribute to an improved understanding of sources and characteristics of Arctic PBAP and their links to INP.

Springer Nature


Linking Nanomaterial-Induced Mitochondrial Dysfunction to Existing Adverse Outcome Pathways for Chemicals

Murugadoss, Sivakumar; Vrček, Ivana Vinković; Schaffert, Alexandra; Paparella, Martin; Pem, Barbara; Sosnowska, Anita; Stępnik, Maciej; Martens, Marvin; Willighagen, Egon L.; Puzyn, Tomasz; Cimpan, Mihaela-Roxana; Lemaire, Frauke; Mertens, Birgit; Dusinska, Maria; Fessard, Valérie; Hoet, Peter H.

The Adverse Outcome Pathway (AOP) framework plays a crucial role in the paradigm shift of toxicity testing towards the development and use of new approach methodologies. AOPs developed for chemicals are in theory applicable to nanomaterials (NMs). However, only subtle efforts have been made to integrate information on NM-induced toxicity into existing AOPs. In a previous study, we identified AOPs in the AOP-Wiki associated with the molecular initiating events (MIEs) and key events (KEs) reported for NMs in scientific literature. In a next step, we analyzed these AOPs and found that mitochondrial toxicity plays a significant role in several of them at the molecular and cellular levels. In this study, we aimed to generate hypothesis-based AOPs related to NM-induced mitochondrial toxicity. This was achieved by integrating science-based information collected on NM-induced mitochondrial toxicity into all existing AOPs in the AOP-Wiki, which already includes mitochondrial toxicity as a MIE/KE. The results showed that several AOPs in the AOP-Wiki related to the lung, liver, cardiovascular and nervous system, with extensively defined KEs and key event relationships (KERs), could be utilized to develop AOPs that are relevant for NMs. Our results also indicate that the majority of the studies included in our literature review were of poor quality, particularly in reporting NM physico-chemical characteristics, and NM-relevant mitochondrial MIEs were scarcely reported. This study highlights the potential role of NM-induced mitochondrial toxicity in human-relevant adverse outcomes and identifies useful AOPs in the AOP-Wiki for the development AOPs that are relevant for NMs.


Low-Cost Particulate Matter Sensors for Monitoring Residential Wood Burning

Hassani, Amirhossein; Schneider, Philipp; Vogt, Matthias; Castell, Nuria

Conventional monitoring systems for air quality, such as reference stations, provide reliable pollution data in urban settings but only at relatively low spatial density. This study explores the potential of low-cost sensor systems (LCSs) deployed at homes of residents to enhance the monitoring of urban air pollution caused by residential wood burning. We established a network of 28 Airly (Airly-GSM-1, SP. Z o.o., Poland) LCSs in Kristiansand, Norway, over two winters (2021–2022). To assess performance, a gravimetric Kleinfiltergerät measured the fine particle mass concentration (PM2.5) in the garden of one participant’s house for 4 weeks. Results showed a sensor-to-reference correlation equal to 0.86 for raw PM2.5 measurements at daily resolution (bias/RMSE: 9.45/11.65 μg m–3). High-resolution air quality maps at a 100 m resolution were produced by combining the output of an air quality model (uEMEP) using data assimilation techniques with the network data that were corrected and calibrated by using a proposed five-step network data processing scheme. Leave-one-out cross-validation demonstrated that data assimilation reduced the model’s RMSE, MAE, and bias by 44–56, 38–48, and 41–52%, respectively.


State of the Climate in 2022: The Arctic

Moon, Twila A.; Thoman, Richard L.; Druckenmiller, Matthew L.; Ahmasuk, Brandon; Backensto, Stacia A.; Ballinger, Thomas J.; Benestad, Rasmus; Berner, Logan T.; Bernhard, Germar H.; Bhatt, Uma S.; Bigalke, Siiri; Bjerke, Jarle W.; Brettschneide, Brian; Christiansen, Hanne H.; Cohen, Judah L.; Dechame, Bertrand; Derksen, Chris; Divine, Dmitry V; Drost Jensen, Caroline; Elias Chereque, Aleksandra; Epstein, Howard E.; Fausto, Robert S.; Fettweis, Xavier; Fioletov, Vitali E.; Forbes, Bruce C.; Frost, Gerald V.; Gerland, Sebastian; Goetz, Scott J.; Grooß, Jens-Uwe; Hanna, Edward; Hanssen-Bauer, Inger; Hendricks, Stefan; Holmes, Robert M.; Ialongo, Iolanda; Isaksen, Ketil; Johnsen, Bjørn; Jones, Timothy; Kaler, Robb S.A.; Kaleschke, Lars; Kim, Seong-Joong; Labe, Zachary M.; Lader, Rick; Lakkala, Kaisa; Lara, Mark J.; Lindsey, Jackie; Loomis, Bryant D.; Luojus, Kari; Macander, Matthew J.; Mamen, Jostein; Mankoff, Ken D.; Manney, Gloria L.; McAfee, Stephanie A.; McClelland, James W.; Meier, Walter N.; Moore, G. W. K.; Mote, Thomas L.; Mudryk, Lawrence; Müller, Rolf; Nyland, Kelsey E.; Overland, James E.; Parrish, Julia K.; Perovich, Donald K.; Petersen, Guðrún Nína; Petty, Alek; Phoenix, Gareth K.; Poinar, Kristin; Rantanen, Mika; Ricker, Robert; Romanovsky, Vladimir E.; Serbin, Shawn P.; Serreze, Mark C.; Sheffield, Gay; Shiklomanov, Alexander I.; Shiklomanov, Nikolay I.; Smith, Sharon L.; Spencer, Robert G. M.; Streletskiy, Dmitry A.; Suslova, Anya; Svendby, Tove Marit; Tank, Suzanne E.; Tedesco, Marco; Tian-Kunze, Xiangshan; Timmermans, Mary-Louise; Tømmervik, Hans; Tretiakov, Mikhail; Walker, Donald A.; Walsh, John E.; Wang, Muyin; Webster, Melinda; Wehrlé, Adrian; Yang, Daqing; Zolkos, Scott

American Meteorological Society


A regional modelling study of halogen chemistry within a volcanic plume of Mt Etna's Christmas 2018 eruption

Narivelo, Herizo; Hamer, Paul David; Marécal, Virginie; Surl, Luke; Roberts, Tjarda; Pelletier, Sophie; Josse, Béatrice; Guth, Jonathan; Bacles, Mickaël; Warnach, Simon; Wagner, Thomas; Corradini, Stefano; Salerno, Giuseppe; Guerrieri, Lorenzo

Volcanoes are known to be important emitters of atmospheric gases and aerosols, which for certain volcanoes can include halogen gases and in particular HBr. HBr emitted in this way can undergo rapid atmospheric oxidation chemistry (known as the bromine explosion) within the volcanic emission plume, leading to the production of bromine oxide (BrO) and ozone depletion. In this work, we present the results of a modelling study of a volcanic eruption from Mt Etna that occurred around Christmas 2018 and lasted 6 d. The aims of this study are to demonstrate and evaluate the ability of the regional 3D chemistry transport model Modèle de Chimie Atmosphérique de Grande Echelle (MOCAGE) to simulate the volcanic halogen chemistry in this case study, to analyse the variability of the chemical processes during the plume transport, and to quantify its impact on the composition of the troposphere at a regional scale over the Mediterranean basin.

The comparison of the tropospheric SO2 and BrO columns from 25 to 30 December 2018 from the MOCAGE simulation with the columns derived from the TROPOspheric Monitoring Instrument (TROPOMI) satellite measurements shows a very good agreement for the transport of the plume and a good consistency for the concentrations if considering the uncertainties in the flux estimates and the TROPOMI columns. The analysis of the bromine species' partitioning and of the associated chemical reaction rates provides a detailed picture of the simulated bromine chemistry throughout the diurnal cycle and at different stages of the volcanic plume's evolution. The partitioning of the bromine species is modulated by the time evolution of the emissions during the 6 d of the eruption; by the meteorological conditions; and by the distance of the plume from the vent, which is equivalent to the time since the emission. As the plume travels further from the vent, the halogen source gas HBr becomes depleted, BrO production in the plume becomes less efficient, and ozone depletion (proceeding via the Br+O3 reaction followed by the BrO self-reaction) decreases. The depletion of HBr relative to the other prevalent hydracid HCl leads to a shift in the relative concentrations of the Br− and Cl− ions, which in turn leads to reduced production of Br2 relative to BrCl.

The MOCAGE simulations show a regional impact of the volcanic eruption on the oxidants OH and O3 with a reduced burden of both gases that is caused by the chemistry in the volcanic plume. This reduction in atmospheric oxidation capacity results in a reduced CH4 burden. Finally, sensitivity tests on the composition of the emissions carried out in this work show that the production of BrO is higher when the volcanic emissions of sulfate aerosols are increased but occurs very slowly when no sulfate and Br radicals are assumed to be in the emissions. Both sensitivity tests highlight a significant impact on the oxidants in the troposphere at the regional scale of these assumptions.

All the results of this modelling study, in particular the rapid formation of BrO, which leads to a significant loss of tropospheric ozone, are consistent with previous studies carried out on the modelling of volcanic halogens.