•A thermal inversion pushed smoke plume 70km away from wildfire.•The air quality in a city 70km from the forest fire was seriously affected.•A significant loss of visibility and ashes deposition were ...observed in the city.•The radiative forcing estimated in the city indicated strong aerosol absorption.•Over 40μgm−3 of PM reached the alveolar area of the population in the city.
Display omitted
This study shows the influence of two large wildfires (one of which was the largest wildfire ever recorded in the region of Castilla y León) in the north-west of the Iberian Peninsula upon the atmospheric air quality of the city of León, Spain, at approximately 70km from the fires, on days with a strong subsidence inversion associated with high pressures. The vertical dispersion of the smoke plume was inhibited and this caused an increase in the particulate matter (PM) in the atmosphere. During this event, average values of up to 1700±600particlescm−3 were registered, most of which corresponding to the smallest fraction of the fine mode. On the other hand, the count median diameter of the fine mode (CMDf) increased gradually from 0.09 to 0.14μm. The PM10 and PM2.5 reached hourly values of 89 and 36μgm−3, respectively. This study also estimates the changes in the optical properties of the particles as well as the associated radiative forcing. The presence of an important load of absorbing aerosols was detected, with instantaneous radiative atmospheric forcing up to +134.6Wm−2. The estimations of the respirable fractions showed in healthy adults high levels of mass concentration of the aerosol that reaches the bronchioles and alveoli (up to 43μgm−3).
Mineral dust from arid areas is a major component
of global aerosol and has strong interactions with climate and
biogeochemistry. As part of the Chemistry-Aerosol Mediterranean Experiment
(ChArMEx) ...to investigate atmospheric chemistry and its impacts in the
Mediterranean region, an intensive field campaign was performed from mid-June
to early August 2013 in the western basin including in situ balloon-borne
aerosol measurements with the light optical aerosol counter (LOAC). LOAC is a
counter/sizer that provides the aerosol concentrations in 19 size classes
between 0.2 and 100 µm, and an indication of the nature of the
particles based on dual-angle scattering measurements. A total of 27 LOAC
flights were conducted mainly from Minorca Island (Balearic Islands, Spain)
but also from Ile du Levant off Hyères city (SE France) under 17 light
dilatable balloons (meteorological sounding balloons) and 10 boundary layer
pressurised balloons (quasi-Lagrangian balloons). The purpose was to document
the vertical extent of the plume and the time evolution of the concentrations
at constant altitude (air density) by in situ observations. LOAC measurements
are in agreement with ground-based measurements (lidar, photometer), aircraft
measurements (counters), and satellite measurements (CALIOP) in the case of
fair spatial and temporal coincidences. LOAC has often detected three modes
in the dust particle volume size distributions fitted by lognormal laws at
roughly 0.2, 4 and 30 µm in modal diameter. Thanks to the
high sensitivity of LOAC, particles larger than 40 µm were
observed, with concentrations up to about 10−4 cm−3. Such large
particles were lifted several days before and their persistence after
transport over long distances is in conflict with calculations of dust
sedimentation. We did not observe any significant evolution of the size
distribution during the transport from quasi-Lagrangian flights, even for the
longest ones (∼ 1 day). Finally, the presence of charged particles is
inferred from the LOAC measurements and we speculate that electrical forces
might counteract gravitational settling of the coarse particles.
Atmospheric and in‐water solar radiation, including UVR‐B, UVR‐A and PAR, as well as chromophoric dissolved organic matter absorption aCDOM(λ) in surface waters were monthly measured from November ...2007 to December 2008 at a coastal station in the Northwestern Mediterranean Sea (Bay of Marseilles, France). Our results showed that the UVR‐B/UVR–A ratio followed the same trend in the atmosphere and at 2 m depth in the water (P < 0.0001) with an increase (eight‐fold higher) during summer. The low diffuse attenuation coefficients for downward irradiance Kd(λ) of UVR‐B, UVR‐A and PAR indicated that the waters were highly transparent throughout the year. The relationships between aCDOM(λ) and Kd(λ) in this oligotrophic system suggested that CDOM contributed to UVR attenuation in the UVA domain, but also played a significant role in PAR attenuation. Mean UV doses received in the mixed layer depth were higher by a factor 1.4–33 relative to doses received at fixed depths (5 and 10 m) in summer (stratified period), while the inverse pattern was found in winter (mixing period). This shows the importance of taking into account the vertical mixing in the evaluation of UVR effects on marine organisms.
The wavelengths 305 and 380 nm have been chosen as biologically effective wavelengths for the induction of DNA damages (CPDs) and photorepairs (PERs) respectively. The ratio of the mean doses received within the mixed layer at 305 and 380 nm Q in % = H(m,305)/H(m,380) × 100 along with the mixed layer depth (Zm) are presented. Q ratio can be considered as an indicator of changes in the balance between DNA damages (CPDs) and repairs (PERs). Clearly, Q increased with the stratification of the water column.
Air pollution prediction assists residents in planning activities and avoiding regions with elevated pollution levels. This study employed Random Forest (RF), Extreme Gradient Boosting (XGB), and ...Histogram-Based Gradient Boosting (HistGB) based models to evaluate PM10 under 10-year average meteorological conditions (2012–2021) for Rocklea monitoring station in Queensland, Australia. The meteorological normalisation method adjusted air pollution data was assessed by removing weather-related effects to focus on the impact of human activities. By comparing observed and meteorologically normalised PM10 values, the impact of weather and human activities was assessed. The performance of these models was evaluated through k-Fold cross-validation, with a particular emphasis on their ability to predict PM10 concentrations accurately. Contrary to initial expectations, the RF model exhibited superior performance compared to XGB and HistGB, demonstrating the highest accuracy and consistency in predicting PM10 levels. This result underscores the effectiveness of the RF model in environmental air quality prediction. A key insight from our analysis was the role of weather-related factors in influencing PM10 levels. While the observed PM10 values showed a general decreasing trend from 2012 to 2021, except for an anomaly in 2019, the meteorologically normalised values remained relatively stable. This finding suggests that weather variations, rather than human activities, have been the more significant influence on the observed trend in PM10 levels over the past decade. The consistent meteorologically normalised values further reinforce the importance of considering natural meteorological variability in air quality studies.
Display omitted
•Machine learning based models were employed to evaluate PM10 levels.•RF showcased the highest accuracy in predicting PM10 concentrations.•Meteorological normalisation highlighted weather's impact on PM10 levels.•Observed PM10 showed a decreasing trend from 2012 to 2021, except for 2019.•Normalised values suggest weather influenced the PM10 more than human activities.
The aerosol radiative effect in the long-wave (LW) spectral range is sometimes not taken into account in atmospheric aerosol forcing studies at local scale because the LW aerosol effect is assumed to ...be negligible. At regional and global scale this effect is partially taken into account: aerosol absorption is taken into account but scattering is still neglected. However, aerosols with strong absorbing and scattering properties in the LW region, like mineral dust, can have a non-negligible radiative effect in the LW spectral range (both at surface and top of the atmosphere) which can counteract their cooling effect occurring in the short-wave spectral range. The first objective of this research is to perform a sensitivity study of mineral dust LW radiative forcing (RF) as a function of dust microphysical and optical properties using an accurate radiative transfer model which can compute vertically resolved short-wave and long-wave aerosol RF. Radiative forcing simulations in the LW range have shown an important sensitivity to the following parameters: aerosol load, radius of the coarse mode, refractive index, aerosol vertical distribution, surface temperature and surface albedo. The scattering effect has been estimated to contribute to the LW RF up to 18% at the surface and up to 38% at the top of the atmosphere. The second objective is the estimation of the short-wave and long-wave dust RF for 11 dust outbreaks observed in Barcelona. At the surface, the LW RF varies between +2.8 and +10.2 W m−2, which represents between 11 and 26% (with opposite sign) of the SW component, while at the top of the atmosphere the LW RF varies between +0.6 and +5.8 W m−2, which represents between 6 and 26% (with opposite sign) of the SW component.
The present study investigates the radiative effects of dust aerosols in the Mediterranean region during summer 2012 using a coupled regional aerosol–atmosphere–ocean model (CNRM-RCSM5). A prognostic ...aerosol scheme, including desert dust, sea salt, organic, black-carbon and sulphate particles, has been integrated to CNRM-RCSM5 in addition to the atmosphere, land surface and ocean components. An evaluation of this aerosol scheme of CNRM-RCSM5, and especially of the dust aerosols, has been performed against in situ and satellite measurements, showing its ability to reproduce the spatial and temporal variability of aerosol optical depth (AOD) over the Mediterranean region in summer 2012. The dust vertical and size distributions have also been evaluated against observations from the TRAQA/ChArMEx campaign. Three simulations have been carried out for summer 2012 with CNRM-RCSM5, including the full prognostic aerosol scheme, only monthly-averaged AOD means from the aerosol scheme or no aerosols at all, in order to focus on the radiative effects of dust particles and the role of the prognostic scheme. Surface short-wave aerosol radiative forcing variability is found to be more than twice as high over regions affected by dust aerosols, when using a prognostic aerosol scheme instead of monthly AOD means. In this case downward surface solar radiation is also found to be better reproduced according to a comparison with several stations across the Mediterranean. A composite study over 14 stations across the Mediterranean, designed to identify days with high dust AOD, also reveals the improvement of the representation of surface temperature brought by the use of the prognostic aerosol scheme. Indeed the surface receives less radiation during dusty days, but only the simulation using the prognostic aerosol scheme is found to reproduce the observed intensity of the dimming and warming on dusty days. Moreover, the radiation and temperature averages over summer 2012 are also modified by the use of prognostic aerosols, mainly because of the differences brought in short-wave aerosol radiative forcing variability. Therefore this first comparison over summer 2012 highlights the importance of the choice of the representation of aerosols in climate models.
•Evaluation of the role of aerosols in the spatiotemporal variability of photovoltaic productivity in a large area.•Evaluation of regional climate model simulations for photovoltaic energy ...modeling.•Different tracking systems for the photovoltaic generators are considered.•The results show a non-negligible effect of aerosols in photovoltaic production.
The increase in the photovoltaic energy installed capacity over the world leads to the need of a better understanding of solar resource and its variability. The aim of this work is to assess the influence of aerosols on photovoltaic energy production from seasonal to multi-decadal time scales. For this purpose we use various coupled aerosol-climate simulations that take into account the complex spatial and temporal patterns of natural and anthropogenic aerosols over the Euro-Mediterranean domain.
The results show that aerosols strongly influence the spatial pattern, seasonal cycle and long-term trend of PV production. The most affected area is Central Europe where sensitivity of PV production to aerosols is higher. The annual production loss due to aerosols ranges from no impact to -16% in The Netherlands, with variation depending on the area and on the typology of the tracking system. The summer production loss can even reach -20% over regions of Africa and Syria-Iraq.
We conclude that aerosols cannot be neglected in the assessment of PV production at large time scales over the Euro-Mediterranean area. Besides, the potential increase in energy due to reduction in the anthropogenic aerosols is shown in the simulation of the brightening period over Europe, with an increase of 2000 kWhkWp in a PV lifetime for the most affected areas. It illustrates the evolution that PV potential could follow in highly polluted areas through the effective implementation of pollution control measures.
Characteristics and radiative forcing of the aerosol and ozone fields of two configurations of the Centre National de Recherches Météoroglogiques (CNRM) and Cerfacs climate model are analyzed over ...the historical period (1850–2014), using several Coupled Model Intercomparison Project 6 (CMIP6) simulations. CNRM‐CM6‐1 is the atmosphere‐ocean general circulation model including prescribed aerosols and a linear stratospheric ozone scheme, while the Earth System Model CNRM‐ESM2‐1 has interactive tropospheric aerosols and chemistry of the midtroposphere aloft. The representations of aerosols and ozone in CNRM‐CM6‐1 are issued from simulations of CNRM‐ESM2‐1, and this ensures some comparability of both representations. In particular, present‐day anthropogenic aerosol optical depths are similar (0.018), and their spatial patterns correspond to those of reference data sets such as MACv2 and MACv2‐SP despite a negative bias. Effective radiative forcings (ERFs) have been estimated using 30‐year fixed sea surface temperature simulations (piClim) and several calls to the radiative scheme. Present‐day anthropogenic aerosol ERF, aerosol‐radiation ERF, and aerosol cloud ERF are fully within CMIP5 estimates and, respectively, equal to
−1.10,
−0.36, and
−0.81 W m
−2 for CNRM‐CM6‐1 and
−0.21,
−0.61, and
−0.74 W m
−2 for CNRM‐ESM2‐1. Additional CMIP6‐type piClim simulations show that these differences are mainly due to the interactivity of the aerosol scheme whose impact is confirmed when assessing the response of both climate model configurations to rising CO
2. Present‐day stratospheric ozone ERF, equal to
−0.04 W m
−2, is in agreement with that of the CMIP6 ozone. No trend appears in the ozone ERF over the historical period although the evolution of the total column ozone is correctly simulated.
Plain Language Summary
The manuscript documents the Météo‐France Centre National de Recherches Météorologiques aerosol‐chemistry modeling contributions to the sixth Coupled Model Intercomparison Project that supports the sixth IPCC Assessment Report of climate change. It establishes that their results are suitable for use by the scientific community in the analysis of the sixth Coupled Model Intercomparison Project experiments. The authors provide an evaluation of the model performance in both present‐day and historical (1850–2014) contexts, as well as a detailed analysis of the model calculated effective radiative forcing due to ozone and aerosols.
Key Points
The representations of aerosol and ozone in the CMIP6 CNRM‐CM6‐1 and CNRM‐ESM2‐1 models is described
Present‐day and historical aerosol and ozone distributions are assessed, as well as their effective radiative forcing (ERF)
The present‐day anthropogenic aerosol ERF (‐1.10 W m
−2 for CNRM‐CM6‐1) is sensitive to the interactivity of aerosols
In spring, the Mediterranean Sea, a well-stratified low-nutrient–low-chlorophyll region, receives atmospheric deposition by both desert dust from the Sahara and airborne particles from anthropogenic ...sources. Such deposition translates into a supply of new nutrients and trace metals for the surface waters that likely impact biogeochemical cycles. However, the relative impacts of the processes involved are still far from being assessed in situ. After summarizing the knowledge on dust deposition and its impact on the Mediterranean Sea biogeochemistry, we present in this context the objectives and strategy of the PEACETIME project and cruise. Atmospheric and marine in situ observations and process studies have been conducted in contrasted areas encountering different atmospheric deposition context, including a dust deposition event that our dedicated “fast-action” strategy allowed us to catch. Process studies also include artificial dust seeding experiments conducted on board in large tanks in three ecoregions of the open waters of the Mediterranean Sea for the first time. This paper summarizes the work performed at sea and the type of data acquired in the atmosphere, at the air–sea interface and in the water column. An overview of the results presented in papers of this special issue (and in some others published elsewhere) is presented.
We analyse the airborne measurements of above-cloud aerosols from
the AErosol, RadiatiOn, and CLOuds in southern Africa (AEROCLO-sA) field
campaign performed in Namibia during August and ...September 2017. The study
aims to retrieve the aerosol above-cloud direct radiative effect (DRE) with
well-defined uncertainties. To improve the retrieval of the aerosol and
cloud properties, the airborne demonstrator of the Multi-Viewing,
Multi-Channel, Multi-Polarization (3MI) satellite instrument, called the
Observing System Including PolaRisation in the Solar Infrared Spectrum
(OSIRIS), was deployed on-board the SAFIRE (Service des Avions Français Instrumentés pour la Rechercheen Environnement) Falcon 20 aircraft during 10
flights performed over land, over the ocean, and along the Namibian coast.
The airborne instrument OSIRIS provides observations at high temporal and
spatial resolutions for aerosol above clouds (AACs) and cloud properties.
OSIRIS was supplemented with the Photomètre Léger Aéroporté
pour la surveillance des Masses d'Air version 2 (PLASMA2). The combined
airborne measurements allow, for the first time, the validation of AAC algorithms previously developed for satellite
measurements. The variations in the aerosol properties are consistent with
the different atmospheric circulation regimes observed during the
deployment. Airborne observations typically show strong aerosol optical
depth (AOD; up to 1.2 at 550 nm) of fine-mode particles from biomass burning (extinction Ångström exponent varying between 1.6 and 2.2), transported above bright stratocumulus decks (mean cloud top around 1 km above mean sea level), with cloud optical thickness (COT) up to 35 at 550 nm. The above-cloud visible AOD retrieved with OSIRIS agrees within 10 % of the PLASMA2 sun photometer measurements in the same environment. The single scattering albedo (SSA) is one of the most influential parameters on the AAC DRE calculation that remains largely uncertain in models. During the AEROCLO-sA campaign, the average SSA obtained
by OSIRIS at 550 nm is 0.87, which is in agreement within 3 %, on average, with previous polarimetric-based satellite and airborne retrievals. The strong absorption of the biomass burning plumes in the visible range is generally
consistent with the observations from the Aerosol Robotic Network (AERONET)
ground-based sun photometers. This, however, shows a significant
increase in the particles' absorption at 440 nm in northern Namibia and
Angola, which indicates more absorbing organic species within the observed
smoke plumes. Biomass burning aerosols are also vertically collocated, with
significant amounts of water content up to the top of the plume at around 6 km height in our measurements. The detailed characterization of aerosol and cloud properties, water vapour, and their uncertainties obtained from OSIRIS and PLASMA2 measurements allows us to study their impacts on the AAC DRE. The high-absorbing
load of AAC, combined with high cloud albedo, leads to unprecedented
DRE estimates, which are higher than previous satellite-based estimates. The average AAC DRE calculated from the airborne measurements in the visible range is +85 W m−2 (standard deviation of 26 W m−2), with instantaneous
values up to +190 W m−2 during intense events. These high DRE
values, associated with their uncertainties, have to be considered as new
upper cases in order to evaluate the ability of models to reproduce the radiative impact of the aerosols over the southeastern Atlantic region.
PDF
