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Atmospheric HONO Observed Over Global Biomass Burning Regions Using Satellite Observations of TROPOMI and GEMS
Get PDFNitrous acid (HONO) is a key tropospheric species primarily due to ist role as a source of the hydroxyl radical (OH), which is pivotal in breaking down pollutants and greenhouse gases and is also a key ingredient to photochemical air pollution. Recent HONO measurements from space in fresh biomass burning plumes offer the potential to inform about HONO formation mechanisms globally. However, research is needed to further develop, interpret, and evaluate the satellite retrievals. Here, we present a new global HONO column data set of 5.5 years from the TROPOspheric Monitoring Instrument (TROPOMI). We leverage the Covariance-Based Retrieval Algorithm to significantly improve the sensitivity to weak HONO signals over all biomass burning regions. Radiative transfer simulations for retrieving HONO columns indicate a strong dependence on plume height and smoke aerosols. Such information is mostly inaccessible from space for thick plumes but can be obtained from suborbital measurements during dedicated campaigns. We compare the TROPOMI HONO columns to aircraft observations from the BB-FLUX campaign. When explicitly accounting for aerosols, the satellite and aircraft data are in good agreement albeit with significant comparison uncertainty. We also evaluate the TROPOMI retrievals against HONO columns measured by IASI and discuss the differences. Next, we demonstrate the potential of geostationary satellites like the Geostationary Environment Monitoring Spectrometer to provide temporally resolved information on pyrogenic HONO. Finally, we find a close relationship between satellite HONO detections and fire intensity both in space and time, highlighting the likely dominance of HONO production during the flaming phase of the fires
DNA barcoding the Lake Edward basin: high taxonomic coverage of a tropical freshwater ichthyofauna.<iframe id="lQdLxFyX" frameborder="0" src="chrome-extension://ekhagklcjbdpajgpjgmbionohlpdbjgc/translateSandbox/translateSandbox.html" style="width: 0px; height: 0px; display: none;"></iframe>
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Engaging communities to safeguard ocean life: UNESCO Environmental DNA Expeditions
No full textOcean warming is reducing marine biodiversity, with changes observed all over the world. What does this mean for life on our planet, and what can we do to protect it? To protect ocean biodiversity, decisions must be based on sound science. That requires inventorying and monitoring the ocean. And because 70% of the planet s surface and 95% of the biosphere are ocean, we need all hands-on deck. UNESCO s citizen science eDNA Expeditions span 21 World Heritage marine sites around the world. This groundbreaking initiative demonstrates that people of every nation and of all ages can help document the ocean s rich biodiversity and the changes already underway. This report describes UNESCO s first global eDNA initiative, methods, and findings, including the many fascinating species identified. It includes on-the-ground stories of citizen science, inspiring readers to get involved in science and contribute to safeguarding our planet. Regular eDNA monitoring as described in this report can provide the critical information needed to actively manage and protect marine biodiversity and help reach the global target of protecting 30% of the ocean by 2030
Very High Energy Solar Energetic Particle Events and Ground Level Enhancement Events: Forecasting and Alerts
Get PDFA Ground Level Enhancement (GLE) event can be observed as an increase in the background of ground-based neutron monitor observations and is often associated with an increase of >500 MeV space-based proton flux measurements. GLE events begin as very high-energy SEP events associated with GeV protons. For such events to be detected at sea level, proton energies must exceed about 433 MeV. Since the increased flux of such particles can be a major problem to technology in space and on Earth and pose a threat for human health, developing real time warning systems is of great importance. GLE Alert++ is a product, built by the Athens Cosmic Ray Group of the National and Kapodistrian University of Athens, that issues alerts when a GLE event starts to register and is based on ground-based neutron monitor observations. From the space-based approach, the HESPERIA UMASEP-500 product, jointly developed within the framework of the EU HORIZON2020 HESPERIA project by the Universidad de Malaga, Spain and National Observatory of Athens, Greece, provides forecasts of GLE events and >500 MeV protons relying on GOES satellite Soft X-Ray and high energy proton observations. These two products are fully integrated as federated products on the ESA SWE Portal and are provided as part of the ESA Space Safety Program Space Weather Service Network. In this paper we present how the products were built, provide examples of their outputs as seen on the ESA SWE Portal, and show how the products complement each other and how using them together can in some instances provide more information for users of these services
A parametric study of solar wind properties and composition using fluid and kinetic solar wind models
Get PDFThe physical processes in the solar corona that shape the solar wind remain an active research topic. Modeling efforts have shown that energy and plasma exchanges near the transition region play a crucial role in modulating solar wind properties. Although these regions cannot be measured in situ, plasma parameters can be inferred from coronal spectroscopy and ionization states of heavy ions, which remain unchanged as they escape the corona. We introduce a new solar wind model extending from the chromosphere to the inner heliosphere, capturing thermodynamic coupling across atmospheric layers. By including neutral and charged particle interactions, we model the transport and ionization processes of the gas through the transition region and corona and into the solar wind. Instead of explicitly modeling coronal heating, we link its spatial distribution to large-scale magnetic field properties. Our results confirm that energy deposition strongly affects wind properties through key mechanisms involving chromospheric evaporation, thermal expansion, and magnetic flux expansion. For sources near active regions, the model predicts significant solar wind acceleration, with plasma outflows comparable to those inferred from coronal spectroscopy. For winds from large coronal holes, the model reproduces the observed anticorrelation between charge state and wind speed. However, the predicted charge state ratios are overall lower than observed. Inclusion of a population of energetic electrons enhances both heavy ion charge states and solar wind acceleration, improving agreement with observations
Feasibility of robust estimates of ozone production rates using a synergy of satellite observations, ground-based remote sensing, and models
Get PDFOzone pollution is secondarily produced through a complex, non-linear chemical process. Our understanding of the spatiotemporal variations in photochemically produced ozone (i.e., PO3) is limited to sparse aircraft campaigns and chemical transport models, which often carry significant biases. Hence, we present a novel satellite-derived PO3 product informed by bias-corrected TROPOspheric Monitoring Instrument (TROPOMI) HCHO, NO2, surface albedo data, and various models. These data are integrated into a parameterization that relies on HCHO, NO2, HCHO / NO2, jNO2, and jO1D. Despite its simplicity, it can reproduce ∼ 90 % of the variance in observationally constrained PO3, with minimal biases in moderately to highly polluted regions. We map PO3 across various regions with respect to July 2019 at a 0.1° × 0.1° spatial resolution, revealing accelerated values (> 8 ppbv h−1) for numerous cities throughout Asia and the Middle East, resulting from elevated ozone precursors and enhanced photochemistry. In Europe and the United States, such high levels are only detected over Benelux, Los Angeles, and New York City. PO3 maxima are observed in various seasons and are attributed to changes in photolysis rates, non-linear ozone chemistry, and fluctuations in HCHO and NO2. Satellite errors result in moderate errors (10 %–20 %) in PO3 estimates over cities on a monthly average basis, while these errors exceed 50 % in clean areas and under low light conditions. Using the current algorithm, we demonstrate that satellite data can provide valuable information for robust PO3 estimation. This capability expands future research through the application of data to address significant scientific questions about locally produced ozone hotspots, seasonality, and long-term trends
<i>Fasciola nyanzae</i>
No full textThe liver fluke Fasciola nyanzae infects the bile ducts of the enigmatic hippo (Hippopotamus amphibius) and can grow up to 9 cm in length. Its main intermediate host is the freshwater snail Radix natalensis, but invasive exotic species like Pseudosuccinea columella, and to a lesser extent Radix aff. plicatula, can also act as hosts. Historical studies describe notable liver damage, and a high infection prevalence in hippo populations. However, recent data on distribution and morbidity are lacking due to the vulnerable status of hippos, hindering postmortem investigations. Optimized molecular tools to monitor infections in snails and hippo dung present noninvasive alternatives to collect epidemiological data on F. nyanzae. The combined effect of invasive exotic snail species, climate change and increased use of agrochemicals can amplify disease transmission and thereby impact hippo populations throughout Africa