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BEGIN:VEVENT
DTSTART;VALUE=DATE:20260219
DTEND;VALUE=DATE:20260220
DTSTAMP:20260517T141651Z
CREATED:20260219T143338Z
LAST-MODIFIED:20260517T141651Z
UID:140620-1771459200-1771545599@www.a3veen.nl
SUMMARY:Measurement of a lithium plume from the uncontrolled re-entry of a Falcon 9 rocket - publication
DESCRIPTION:A 10-fold enhancement of lithium atoms was detected at 96 km altitude by a resonance lidar at Kühlungsborn\, Germany\, approximately 20 hours after the uncontrolled re-entry of a Falcon 9 upper stage. \nThe upper-atmospheric extension of the ICOsahedral Nonhydrostatic (ICON – a unified modeling system for global numerical weather prediction and climate studies) general circulation model\, nudged to ECMWF\, was used to calculate winds. Backwards trajectories\, including wind variability as measured by radar\, traced air masses to the Falcon 9 re-entry path at 100 km altitude\, west of Ireland. The study ‘Measurement of a lithium plume from the uncontrolled re-entry of a Falcon 9 rocket‘ presents the first measurement of upper-atmospheric pollution resulting from space debris re-entry and the first observational evidence that the ablation of space debris can be detected by ground-based lidar. The analysis of geomagnetic conditions\, atmospheric dynamics\, and ionospheric measurements supports the claim that the enhancement was not of natural origin. Our findings demonstrate that identifying pollutants and tracing them to their sources is achievable\, with significant implications for monitoring and mitigating space emissions in the atmosphere. \nLinks:\nMetals from spacecraft reentry in stratospheric aerosol particles – publication
URL:https://www.a3veen.nl/event/measurement-of-a-lithium-plume-from-the-uncontrolled-re-entry-of-a-falcon-9-rocket-publication/
CATEGORIES:Astronomie,Bibliotheek,Fysica,kennis,Klimaat
END:VEVENT
BEGIN:VEVENT
DTSTART;VALUE=DATE:20240301
DTEND;VALUE=DATE:20240302
DTSTAMP:20260421T120954Z
CREATED:20240301T125313Z
LAST-MODIFIED:20260421T120954Z
UID:139669-1709251200-1709337599@www.a3veen.nl
SUMMARY:Hoe verder met de Aziatische hoornaar? – Beleidsadvies - publicatie
DESCRIPTION:De Aziatische hoornaar / geelpoothoornaar is een invasieve exoot\, die zich sinds 2003 vanuit Zuidwest-Frankrijk snel over grote delen van Europa verspreid heeft. \nDe soort heeft in 2017 ook Nederland via Vlaanderen bereikt. Het aantal nesten in Nederland en Vlaanderen stijgt nog steeds explosief\, jaarlijks met een factor zeven\, wat in 2023 resulteerde in meer dan 500 nesten in Nederland en meer dan 6400 in Vlaanderen. De soort vangt ook honingbijen en leidt daarom tot grote zorgen onder imkers. Daarom staat de soort op de Europese Unielijst van te bestrijden invasieve exoten. Nut en noodzaak van bestrijding zou heroverwogen moeten worden. De provincie Zeeland loopt hierin voorop. EIS Kenniscentrum Insecten adviseert in het rapport ‘Hoe verder met de Aziatische hoornaar? – Beleidsadvies‘ overheden na te denken over een toekomst met de Aziatische hoornaar\, in plaats van luchtkastelen van totale uitroeiing na te jagen en daar tientallen miljoenen in te investeren. Goede voorlichting aan de bevolking (inclusief imkers) over de redenen van de gemaakte keuzes is hierin van groot belang. \nLinks:\nStop de hetze tegen de Aziatische hoornaar \nStrijd tegen Aziatische hoornaar is schadelijk voor biodiversiteit
URL:https://www.a3veen.nl/event/hoe-verder-met-de-aziatische-hoornaar-beleidsadvies-publicatie/
CATEGORIES:Bibliotheek,Biodiversiteit,Biologie,kennis,Natuur
END:VEVENT
BEGIN:VEVENT
DTSTART;VALUE=DATE:20230907
DTEND;VALUE=DATE:20230908
DTSTAMP:20260517T133704Z
CREATED:20230907T131529Z
LAST-MODIFIED:20260517T133704Z
UID:140618-1694044800-1694131199@www.a3veen.nl
SUMMARY:Metals from spacecraft reentry in stratospheric aerosol particles - publication
DESCRIPTION:Large increases in the number of low earth orbit satellites are projected in the coming decades [L. Schulz\, K.-H. Glassmeier\, Adv. Space Res. 67\, 1002–1025 (2021)] withperhaps 50\,000 additional satellites in orbit by 2030 [GAO\, Large constellations of satellites: Mitigating environmental and other effects (2022)]. \nWhen spent rocketbodies and defunct satellites reenter the atmosphere\, they produce metal vapors that condense into aerosol particles that descend into the stratosphere. So far\, models of spacecraft reentry have focused on understanding the hazard presented by objects that survive to the surface rather than on the fate of the metals that vaporize. Here\, the research shows that metals that vaporized during spacecraft reentries can be clearly measured instratospheric sulfuric acid particles. Over 20 elements from reentry were detected and were present in ratios consistent with alloys used in spacecraft. The mass of lithium\, aluminum\, copper\, and lead from the reentry of spacecraft was found to exceed the cosmic dust influx of those metals. About 10% of stratospheric sulfuric acid particles larger than 120 nm in diameter contain aluminum and other elements from spacecraft reentry. Planned increases in the number of low earth orbit satellites within the next few decades could cause up to half of stratospheric sulfuric acid particles to contain metals from reentry. The influence of this level of metallic content on the properties of stratospheric aerosol is unknown. \nLinks:\nMetals from spacecraft reentry in stratospheric aerosol particles \nMeasurement of a lithium plume from the uncontrolled re-entry of a Falcon 9 rocket – publication
URL:https://www.a3veen.nl/event/metals-from-spacecraft-reentry-in-stratospheric-aerosol-particles-publication/
CATEGORIES:Astronomie,Bibliotheek,kennis,Klimaat
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