Climate Change and Air Pollution Relationships. Lessons from a Subtropical Desert Region

The Atacama Desert is the dryest desert on Earth. Atmospheric, ocean, and topographic forcings preserve an exceptional hyper-arid environment. As a product of anthropogenic and natural emissions, PM10 and PM2.5 atmospheric concentrations have been observed to exceed international standards in urban areas where about 1.5 million people live. This research starts by describing the climate dynamics in northern Chile along with the primary anthropogenic emission sources of PM10, PM2.5, and gaseous precursor pollutants. Then, air quality levels across urban areas are evidenced. As a major source of natural PM, the unexplored mineral dust cycle of the Atacama desert is studied from satellite retrievals of aerosols properties. Two areas in the Antofagasta region are identified as predominant sources of dust, where links with reanalysed wind patterns are reported. This study is followed by the analysis of the relationship between PM10-PM2.5 levels and atmospheric ventilation from observational and modelled datasets. Because of the significant link found between both, especially in coastal areas, a wheater-driven model for PM events, with atmospheric ventilation as the most significant input variable, is pro- posed for the coastal city of Antofagasta. Finally, the future of the Atacama Desert, comprising atmospheric and oceanic regional forcings and future PM10-PM2.5 levels, is explored from the UKESM1 model. The South Pacific Anticyclone is already extending and intensifying during the austral summertime. The above leads to increasing upwelling-favourable winds and coastal upwelling intensity of the Humboldt system at the surface ocean, enhancing atmospheric stability. However, a decline is simulated at deeper ocean layers. PM10-PM2.5 are both projected to increase under the SSP370 and SSP585 climate change experiments during the 21st Century. This increasing trend is more abrupt under the SSP370 than the SSP585 experiment due to increased SO2 and dust emissions and the absence of mitigation measurements. Policy implications are dis- cussed, and future academic research is proposed, including implications beyond academia

Analysing the PMIP4-CMIP6 collection: a workflow and tool (pmip_p2fvar_analyzer v1)

Experiment outputs are now available from the Coupled Model Intercomparison Project's sixth phase (CMIP6) and the past climate experiments defined in the Palaeoclimate Modelling Intercomparison Project's fourth phase (PMIP4). All of this output is freely available from the Earth System Grid Federation (ESGF). Yet there is overhead in analysing this resource that may prove complicated or prohibitive. Here we document the steps taken by ourselves to produce ensemble analyses covering past and future simulations. We outline the strategy used to curate, adjust the monthly calendar aggregation and process the information downloaded from the ESGF. The results of these steps were used to perform analysis for several of the initial publications arising from PMIP4. We provide post-processed fields for each simulation, such as climatologies and common measures of variability. Example scripts used to visualise and analyse these fields are provided for several important case studies

Health and Safety Effects of Airborne Soil Dust in the Americas and Beyond

Risks associated with dust hazards are often underappreciated, a gap between the knowledge pool and public awareness that can be costly for impacted communities. This study reviews the emission sources and chemical, physical, and biological characteristics of airborne soil particles (dust) and their effects on human and environmental health and safety in the Pan-American region. American dust originates from both local sources (western United States, northern Mexico, Peru, Bolivia, Chile, and Argentina) and long-range transport from Africa and Asia. Dust properties, as well as the trends and interactions with criteria air pollutants, are summarized. Human exposure to dust is associated with adverse health effects, including asthma, allergies, fungal infections, and premature death. In the Americas, a well-documented and striking effect of soil dust is its association with Coccidioidomycosis, commonly known as Valley fever, an infection caused by inhalation of soil-dwelling fungi unique to this region. Besides human health, dust affects environmental health through nutrients that increase phytoplankton biomass, contaminants that diminish water supply and affect food (crops/fruits/vegetables and ready-to-eat meat), spread crop and marine pathogens, cause Valley fever among domestic and wild animals, transport heavy metals, radionuclides and microplastics, and reduce solar and wind power generation. Dust is also a safety hazard to road transportation and aviation, in the southwestern US where blowing dust is one of the deadliest weather hazards. To mitigate the harmful effects, coordinated regional and international efforts are needed to enhance dust observations and prediction capabilities, soil conservation measures, and Valley fever and other disease surveillance. © 2023. The Authors