10 research outputs found
Clean air policies are key for successfully mitigating Arctic warming
A tighter integration of modeling frameworks for climate and air quality is urgently needed to assess the impacts of clean air policies on future Arctic and global climate. We combined a new model emulator and comprehensive emissions scenarios for air pollutants and greenhouse gases to assess climate and human health co-benefits of emissions reductions. Fossil fuel use is projected to rapidly decline in an increasingly sustainable world, resulting in far-reaching air quality benefits. Despite human health benefits, reductions in sulfur emissions in a more sustainable world could enhance Arctic warming by 0.8 °C in 2050 relative to the 1995–2014, thereby offsetting climate benefits of greenhouse gas reductions. Targeted and technically feasible emissions reduction opportunities exist for achieving simultaneous climate and human health co-benefits. It would be particularly beneficial to unlock a newly identified mitigation potential for carbon particulate matter, yielding Arctic climate benefits equivalent to those from carbon dioxide reductions by 2050
Spatial and seasonal variability of the mass concentration and chemical composition of PM2.5 in Poland
Influence of bitumen fractional composition on the physical and mechanical properties of cationic emulsion
Long-term evolution of the impacts of ozone air pollution on agricultural yields in Europe: a modelling analysis for the 1990-2010 period
The evolution of potential detrimental impacts of ozone pollution for wheat crop yields over Europe over the 1990 — 2010 period is assessed on the basis of ozone exposure (using the Accumulated Ozone over a Threshold, AOT40) or ozone dose (using the Phytotoxic Ozone Dose, POD).
Substantial decrease of exposure is found on average over Europe, leading to wheat crop yield losses being reduced from 18.2 % to 10.2 % between 1990 and 2010 according to AOT40 trends. However, because of compensation between opposite trends for ozone peaks and ozone background, but also because of trends in other environmental factors, the actual ozone dose does not change significantly. So that wheat crop yield losses derived with the POD metric are estimated to 14.9 % and 13.3 % in 1990 and 2010, respectively
Interannual variation and trends in air pollution over Europe due to climate variability during 1958–2001 simulated with a regional CTM coupled to the ERA40 reanalysis
Investigation of global particulate nitrate from the AeroCom phase III experiment
An assessment of global particulate nitrate and ammonium aerosol
based on simulations from nine models participating in the Aerosol Comparisons between
Observations and Models (AeroCom) phase III study is presented. A budget
analysis was conducted to understand the typical
magnitude, distribution, and diversity of the aerosols and their precursors
among the models. To gain confidence regarding model performance, the model results
were evaluated with various observations globally, including ground station
measurements over North America, Europe, and east Asia for tracer
concentrations and dry and wet depositions, as well as with aircraft
measurements in the Northern Hemisphere mid-to-high latitudes for tracer
vertical distributions. Given the unique chemical and physical features of
the nitrate occurrence, we further investigated the similarity and
differentiation among the models by examining (1) the pH-dependent NH3
wet deposition; (2) the nitrate formation via heterogeneous chemistry on the
surface of dust and sea salt particles or thermodynamic equilibrium
calculation including dust and sea salt ions; and (3) the nitrate coarse-mode
fraction (i.e., coarse/total). It is found that HNO3, which is simulated
explicitly based on full O3-HOx-NOx-aerosol chemistry by all
models, differs by up to a factor of 9 among the models in its global
tropospheric burden. This partially contributes to a large difference in
NO3−, whose atmospheric burden differs by up to a
factor of 13. The atmospheric burdens of NH3 and
NH4+ differ by 17 and 4, respectively. Analyses
at the process level show that the large diversity in atmospheric burdens of
NO3−, NH3, and
NH4+ is also related to deposition processes. Wet
deposition seems to be the dominant process in determining the diversity in
NH3 and NH4+ lifetimes. It is critical to
correctly account for contributions of heterogeneous chemical production of
nitrate on dust and sea salt, because this process overwhelmingly controls
atmospheric nitrate production (typically > 80 %) and determines
the coarse- and fine-mode distribution of nitrate aerosol
Model evaluation of short-lived climate forcers for the Arctic Monitoring and Assessment Programme: a multi-species, multi-model study
While carbon dioxide is the main cause for global warming, modeling short-lived climate forcers (SLCFs) such as methane, ozone, and particles in the Arctic allows us to simulate near-term climate and health impacts for a sensitive, pristine region that is warming at 3 times the global rate. Atmospheric modeling is critical for understanding the long-range transport of pollutants to the Arctic, as well as the abundance and distribution of SLCFs throughout the Arctic atmosphere. Modeling is also used as a tool to determine SLCF impacts on climate and health in the present and in future emissions scenarios.
In this study, we evaluate 18 state-of-the-art atmospheric and Earth system models by assessing their representation of Arctic and Northern Hemisphere atmospheric SLCF distributions, considering a wide range of different chemical species (methane, tropospheric ozone and its precursors, black carbon, sulfate, organic aerosol, and particulate matter) and multiple observational datasets. Model simulations over 4 years (2008–2009 and 2014–2015) conducted for the 2022 Arctic Monitoring and Assessment Programme (AMAP) SLCF assessment report are thoroughly evaluated against satellite, ground, ship, and aircraft-based observations. The annual means, seasonal cycles, and 3-D distributions of SLCFs were evaluated using several metrics, such as absolute and percent model biases and correlation coefficients. The results show a large range in model performance, with no one particular model or model type performing well for all regions and all SLCF species. The multi-model mean (mmm) was able to represent the general features of SLCFs in the Arctic and had the best overall performance. For the SLCFs with the greatest radiative impact (CH4, O3, BC, and SO), the mmm was within ±25 % of the measurements across the Northern Hemisphere. Therefore, we recommend a multi-model ensemble be used for simulating climate and health impacts of SLCFs.
Of the SLCFs in our study, model biases were smallest for CH4 and greatest for OA. For most SLCFs, model biases skewed from positive to negative with increasing latitude. Our analysis suggests that vertical mixing, long-range transport, deposition, and wildfires remain highly uncertain processes. These processes need better representation within atmospheric models to improve their simulation of SLCFs in the Arctic environment. As model development proceeds in these areas, we highly recommend that the vertical and 3-D distribution of SLCFs be evaluated, as that information is critical to improving the uncertain processes in models