http://hdl.handle.net/10453/37630 2026-06-09T17:32:47Z http://hdl.handle.net/10453/195131 Title: Tracking spatiotemporal dynamics of dust aerosols in China: Emissions, transport, and mitigation insights. Authors: Che, Y; Yang, L; She, L; Leys, J; Yang, X Abstract: Dust aerosols, recognized as hazardous atmospheric pollutants, significantly impact air quality, human health, and ecosystems. Understanding the dust's spatiotemporal dynamics, sources, and transport paths is crucial, especially in China, as it is home to major dust sources in East Asia and frequently experiences severe dust events. Substantial dust aerosols are produced during dust events, leading to sharp increases in particulate matter concentrations and resulting in health and environmental issues in both the dust source regions and downwind populated areas. Building on this context, this study analyzes the spatiotemporal distribution of dust aerosols in China and its six subregions between 2000 and 2023 using MERRA-2 reanalysis data. Unlike previous studies that focus on climatic drivers and anthropogenic factors influencing dust aerosol trends, this study provides new insights into dust aerosol trends in large provincial cities (population 2-20 million) within the dust-prone "Three-North" region, from the perspective of dust emissions, fluxes, and transport processes. Furthermore, the combination of MERRA-2 simulations and backward (forward) trajectory analyses offers complementary strengths. The results show that (1) spring Dust Aerosol Optical Depth (DAOD) decreased 2000-2023, with the exception of the Taklamakan Desert, where both dust emissions and DAOD increased; (2) increased dust emissions from the Saryesik-Atyrau Basin in eastern Kazakhstan resulted in higher DAOD over the southern Jungger Basin; (3) Taklamakan Desert emissions remained high across all seasons, sustaining elevated DAOD within the Tarim Basin; (4) MERRA-2 fails to capture anthropogenic dust emissions from cropland of the North China Plain, while the back-trajectory analysis based on measurements of particulate matter less than 10 μg/m3 in several cities across the North China and Northeast China suggests dust emissions from this region. This finding highlights the need to improve dust emission parameterizations in reanalysis models like MERRA-2, particularly when studying the impact of anthropogenic activities on dust emissions and air quality. Overall, the study provides essential references for managing the health and environmental impacts of dust aerosols in large densely populated cities of China. 2025-12-05T00:00:00Z http://hdl.handle.net/10453/195080 Title: Spatiotemporal Variability of Atmospheric Pollutants in Syria: A Multi-Year Assessment Using Sentinel-5P Data Authors: Ayek, AAE; Zerouali, B; Srivastava, A; Loho, MA; Bailek, N; Santos, CAG Abstract: This study investigates the spatial and temporal dynamics of key air pollutants nitrogen dioxide (NO2), carbon monoxide (CO), methane (CH4), formaldehyde (HCHO), and the ultraviolet aerosol index (UVAI) over the period 2019 2024. Utilizing high-resolution remote sensing data from the Sentinel-5 Precursor satellite and its TROPOspheric Monitoring Instrument (TROPOMI) processed via Google Earth Engine (GEE), pollutant concentrations were analyzed, with spatial visualizations produced using ArcGIS Pro. The results reveal that urban and industrial hotspots notably in Damascus, Aleppo, Homs, and Hama exhibit elevated NO2 and CO levels, strongly correlated with population density, traffic, and industrial emissions. Temporal trends indicate significant pollutant fluctuations linked to external factors such as economic activities and regulatory measures. Methane concentrations have shown a steady increase, driven by intensified oil refining, biomass burning, and agricultural practices. Formaldehyde levels initially declined due to reduced industrial activity before experiencing a moderate rebound, though remaining below 2019 levels overall. The UV aerosol index demonstrated marked variability, predominantly influenced by wind-driven dust transport, desert dust storms, and localized anthropogenic emissions. These findings underscore the intricate interplay between economic dynamics and environmental processes, highlighting the critical need for robust air quality management strategies. 2025-01-01T00:00:00Z http://hdl.handle.net/10453/195005 Title: Fresh out of the seed coat: first leaves of germinants are equally heat tolerant but less cold tolerant than later life stages. Authors: Alvarez, PR; Jutta Imdahl, M; Cook, AM; Briceño, VF; Offord, CA; Nicotra, AB; Leigh, A Abstract: BACKGROUND AND AIMS: Plant photosystem thermal thresholds are regularly used as indicators for plant tolerance under extreme temperature scenarios. Photosystem tolerance can vary with species, leaf traits and environmental conditions. To date, most research into plant thermal tolerance has been conducted on established plants; likewise, leaf traits are routinely measured on fully expanded, adult leaves. To fully understand function and survival of plant communities, the first leaves of early life stages must be considered. METHODS: We sought to understand germinant photosystem thermal tolerance breadth through upper and lower critical temperature (Tcrit) thresholds, leaf mass per area (LMA) and leaf water content (LWC) for 22 species from three contrasting biomes - extreme desert and alpine, and benign coastal temperate. For seven of these species, we compared the relationship between these traits with those of older juvenile and adult life stages. KEY RESULTS: Biome of origin had no effect on germinant thermal thresholds. Thermal tolerance breadth (heat minus cold tolerance thresholds) varied significantly among germinant species, but not across the three life stages. However, although germinant heat tolerance within species was comparable to adult thermal tolerance, germinants were significantly less cold tolerant than adults. LMA was greater in older life stages than in germinants, LWC decreased across the life stages. LMA was greater in older life stages than in germinants and LWC decreased as LMA increased. CONCLUSIONS: In the first known study examining photosystem thermal tolerance breadth of newly emerged leaves of germinants, we found germinant PSII to be as heat tolerant as later life stages, but less cold tolerant, associated with their lower LMA and higher LWC. This demonstrates that not all physiological aspects of germinant tolerance are more vulnerable to thermal extremes than older life stages, with certain leaf traits potentially playing an important role in early survival. 2026-05-05T00:00:00Z http://hdl.handle.net/10453/194685 Title: Improved estimates of growth for wild Yellowtail Kingfish (Seriola lalandi) off eastern-Australia using multiple data sources Authors: Stewart, J; Stuart, S; Hughes, JM; Booth, DJ Abstract: Unbiased growth functions are imperative for stock assessment and sustainable management of fisheries. We present a case-study demonstrating implications of data collection biases from fishery-dependent sampling where length-selective fishing occurs. Yellowtail Kingfish Seriola lalandi supports substantial fisheries around the world and is the focus of a developing aquaculture industry. Estimating growth rates in wild populations has been challenging, with uncertainties around accurate estimates of length-at-age from which to model growth. Length-at-age data are generally derived from sectioned sagittal otoliths. We generated new estimates of growth rates for Yellowtail Kingfish from south-eastern Australia by excluding data for age classes not fully recruited to the fishery based on significance tests of normality and skewness. New length-at-age estimates for young fish were generated from dive surveys around offshore Fish Aggregation Devices (FADs) to inform early growth. Otolith-derived age classes younger than 5 years old were biased in terms of faster growing individuals being sampled. Length-selective biases from fishery dependent sampling results in over-estimation of the von Bertalanffy growth function parameter L∞ and under-estimation of the parameters K and t0. Revised growth function parameters of L∞ = 133.40 cm fork length, K = 0.13 year -1, and t0 = −1.20 years are substantially different from those used for stock assessment. We recommend that future studies of growth rates would benefit from more fishery-independent sampling, the collection of greater numbers of larger and older fish, and regular sampling and direct aging of young-of-the year fish recruiting to offshore FADs.