Publications by authors named "Juan Andres Casquero-Vera"
There is a body of evidence that ultrafine particles (UFP, those with diameters ≤ 100 nm) might have significant impacts on health. Accordingly, identifying sources of UFP is essential to develop abatement policies. This study focuses on urban Europe, and aims at identifying sources and quantifying their contributions to particle number size distribution (PNSD) using receptor modelling (Positive Matrix Factorization, PMF), and evaluating long-term trends of these source contributions using the non-parametric Theil-Sen's method.
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- Atmospheric new particle formation (NPF) is the natural process of creating tiny particles (sub-10 nm) from gases, observed globally in various environments.
- Although these particles impact total and ultrafine particle concentrations, there is limited research on their health effects largely due to a lack of specific identifiers in existing data.
- This study introduces an automated machine learning algorithm that identifies NPF events from particle data across 65 global measurement sites from 1996 to 2023, facilitating future research on NPF.
This study aims to picture the phenomenology of urban ambient total lung deposited surface area (LDSA) (including head/throat (HA), tracheobronchial (TB), and alveolar (ALV) regions) based on multiple path particle dosimetry (MPPD) model during 2017-2019 period collected from urban background (UB, n = 15), traffic (TR, n = 6), suburban background (SUB, n = 4), and regional background (RB, n = 1) monitoring sites in Europe (25) and USA (1). Briefly, the spatial-temporal distribution characteristics of the deposition of LDSA, including diel, weekly, and seasonal patterns, were analyzed. Then, the relationship between LDSA and other air quality metrics at each monitoring site was investigated.
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- The study analyzed hourly particle number size distributions (PNSD) from 26 European sites and 1 in the US to understand urban ultrafine particles and their air quality impacts.
- Findings show that particle number concentrations (PNC) are highest in traffic areas compared to urban background and suburban locations, with noticeable increases as one moves from Northern to Southern Europe.
- Recommendations highlight the need for specific PNSD monitoring to accurately assess the health effects of nanoparticles, with calls for standardized measurement practices to ensure comparability across different sites.
The indirect effect of aerosols on climate through aerosol-cloud-interactions is still highly uncertain and limits our ability to assess anthropogenic climate change. The foundation of this uncertainty is in the number of cloud condensation nuclei (CCN), which itself mainly stems from uncertainty in aerosol sources and how particles evolve to become effective CCN. We analyze particle number size distribution (PNSD) and CCN measurements from an urban site in a two-step method: (1) we use an unsupervised clustering model to classify the main aerosol categories and processes occurring in the urban atmosphere and (2) we explore the influence of the identified aerosol populations on the CCN properties.
View Article and Find Full Text PDFUnderstanding the activation properties of aerosol particles as cloud condensation nuclei (CCN) is important for the climate and hydrological cycle, but their properties are not fully understood. In this study, the CCN activation properties of aerosols are investigated at two different sites in southern Spain: an urban background station in Granada and a high altitude mountain station in the Sierra Nevada National Park, with a horizontal separation of 21 km and vertical separation of 1820 m. CCN activity at the urban environment is driven by primary sources, mainly road traffic.
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