REVA · Reality of a UV window during the geomagnetic excursion event of Mono Lake-Laschamps and possible link to the disappearance of the Neanderthals
Horizon 2020 — Marie Skłodowska-Curie Actions
- Duration
- 2021-05-01 → 2023-04-30
- EU contribution
- €196,708
- Participants
- 1
- Scheme
- MSCA-IF
Lines connect the coordinator with its partners.
Results in brief
Reality of a UV window during the geomagnetic excursion event of Mono Lake-Laschamps and possible link to the disappearance of the Neanderthals
This Marie Skłodowska Curie Action (MSCA) action is titled ‘Reality of a UV Window during the Laschmap Geomagentic Excursion’. The project investigates the possibility of destruction/thinning of the ozone layer and thereby formation of a ‘window’ in Earth’s atmosphere for the penetration of UV rays during major changes in the Earth’s magnetic field (i.e., Geomagnetic Excursions). This topic is important for both science and society as such geomagnetic excursion events are likely to also occur in the future. The penetration of UV radiation into the troposphere during such events can have major implications for the environment, ecology, and above all for life on the planet. So far, it had remained unclear if such events could trigger the formation of UV windows or not. The overall objective is to investigate geomagnetic excursions in the past caused a massive depletion of the ozone layer or not creating UV windows.
Data: CORDIS, © European Union
Project objective
The Earth is constantly subjected to cosmic radiation, the intensity of which, at the level of the upper atmosphere and the Earth's surface, depends on the strength of the magnetic field (MF) surrounding our planet. Over geological timescales, there have been periods of collapse of the magnetic dipole moment, and therefore of the MF, which can be associated with changes in the polarity of the dipole or with simple geomagnetic excursions (GE). GE events (typically lasting ~1ka to ~10ka) generate an increase in cosmic bombardment in the upper atmosphere and, ultimately, through chemical effects the destruction/thinning of the ozone layer. During these periods UV radiation can penetrate deeper into the atmosphere, while it is otherwise absorbed by the ozone layer. Yet, the reality of such a UV ""window” has never been attested by natural observations, which if present during GE events in the future would have significant environmental and above all human consequences. This is plausibly foreseen in a short term as the intensity of Earth’s MF has decreased (~20%) over the past 150 years and with an accelerated rate in the last decades (> ~10 times the normal). The aim of this project is, therefore, to test the reality of a UV window during the Mono Lake-Laschamps (~ -40 ka) GE event, which by its magnitude, its globality and the possible implications for human evolution (being contemporaneous with the disappearance of the Neanderthals), is an example of a remarkable case study. Here, by measuring stable isotopic composition of sulfur (S) at high resolution (<200 years) in ice cores taken in Antarctica, we will leverage peculiar aspects of atmospheric chemistry of the S-33 isotope. In the absence of ozone, the interaction between SO2 and UV radiation, through photochemical processes, generates mass-independent (Δ) signatures. We propose to trace a possible UV ""window"" by analyzing the evolution of the observed ΔS-33 anomaly and model the extent of depletion of ozone layer.""
Original text from CORDIS.
Participants
- CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE CNRS · ParisCoordinatorFrance
Links
Data: CORDIS, © European Union