143 research outputs found
Higher airborne pollen concentrations correlated with increased SARS-CoV-2 infection rates, as evidenced from 31 countries across the globe
No full textSARS-CoV-2 infections positively correlate with pollen concentrations (PNAS, 2021).
Daily data per country and examined region of:
1. Airborne pollen concentrations
2. SARS-CoV-2 infection rates
3. Air temperature
4. Relative humidity
5. Population density
6. Lockdown date
Higher airborne pollen concentrations correlated with increased SARS-CoV-2 infection rates, as evidenced from 31 countries across the globe
No full textSARS-CoV-2 infections positively correlate with pollen concentrations (PNAS, 2021).
Daily data per country and examined region of:
1. Airborne pollen concentrations
2. SARS-CoV-2 infection rates
3. Air temperature
4. Relative humidity
5. Population density
6. Lockdown date
CALIPSO Overpasses During Three Atmospheric Pollen Events Detected by Hirst-Type Volumetric Samplers in Two Urban Cities in Greece
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Open AccessArticle
CALIPSO Overpasses During Three Atmospheric Pollen Events Detected by Hirst-Type Volumetric Samplers in Two Urban Cities in Greece
by Archontoula Karageorgopoulou 1,*,Elina Giannakaki 1ORCID,Christos Stathopoulos 1,Thanasis Georgiou 2ORCID,Eleni Marinou 2ORCID,Vassilis Amiridis 2ORCID,Ioanna Pyrri 3ORCID,Maria-Christina Gatou 1,Xiaoxia Shang 4ORCID,Athanasios Charalampopoulos 5,Despoina Vokou 5 andAthanasios Damialis 5ORCID
1
Department of Environmental Physics and Meteorology, Faculty of Physics, University of Athens, 15784 Athens, Greece
2
Institute for Astronomy, Astrophysics, Space Applications and Remote Sensing, National Observatory of Athens, 15236 Athens, Greece
3
Department of Ecology and Systematics, Faculty of Biology, University of Athens, 15784 Athens, Greece
4
Finnish Meteorological Institute, Atmospheric Research Centre of Eastern Finland, 70211 Kuopio, Finland
5
Department of Ecology, School of Biology, Faculty of Sciences, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
*
Author to whom correspondence should be addressed.
Atmosphere 2025, 16(3), 317; https://doi.org/10.3390/atmos16030317
Submission received: 24 January 2025 / Revised: 24 February 2025 / Accepted: 5 March 2025 / Published: 10 March 2025
(This article belongs to the Special Issue Development of LIDAR Techniques for Atmospheric Remote Sensing (2nd Edition))
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Abstract
Vertically retrieved optical properties by Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) were investigated in the case of three selected events over Athens and Thessaloniki with documented high pollen concentrations. Hirst-type volumetric samplers were used to detect and characterize the pollen during the CALIPSO overpasses. Only cases with a total pollen concentration greater than 400 grains m−3 for at least two hours per day were considered severe pollen events, while model simulations were used to exclude the presence of other depolarizing aerosol types. This study provides mean values of lidar-derived optical properties inside the detected pollen layers; i.e., optical values represent the atmosphere with the presence of pollen, in urban cities of Greece. Specifically, three observed aerosol layers, one over Athens and two over Thessaloniki with particulate color ratios of 0.652 ± 0.194, 0.638 ± 0.362, and 0.456 ± 0.284, and depolarization ratios of 8.70 ± 6.26%, 28.30 ± 14.16%, and 8.96 ± 6.87%, respectively, were misclassified by CALIPSO as marine-dusty marine, dust, and polluted dust. In cases of intense pollen presence, CALIPSO vertical profiles and aerobiological monitoring methods may be used synergistically to better characterize the atmospheric pollen layers
Πρότυπα παραγωγής και ατμοσφαιρικής κυκλοφορίας γυρεοκόκκων στην ευρύτερη περιοχή Θεσσαλονίκης
No full textAirborne pollen grains were sampled in Thessaloniki by use of a Burkard volumetric trap, which operates daily, drawing a constant volume of air. It was found that the most abundant pollen grains belonged to the woody Cupressaceae, Oleaceae, Pinaceae, Quercus and Platanus and to the herbaceous Poaceae and Urticaceae. Pollen circulation extends from February to October, with the main pollen season occurring during March to May. Floral phenology and pollen production of Corylus avellana, Cupressus sempervirens, Olea europaea and Platanus orientalis were also studied during 2004 and 2005, under differing environmental conditions (elevation, exposure or both). Differences were observed in both flowering phenology and pollen production between sampling years but also between stations. It was found that at higher elevations and northern exposures pollen production was lower and flowering started or peaked later. The highest pollen production (per flower) was found in O. europaea, whereas the highest flower production (per inflorescence) was found in P. orientalis. The number of pollen or flowers produced - per floral unit - is mainly regulated by the size of floral units, for all taxa. Moreover, it was found that seasons of flowering phenology and pollen atmospheric circulation may coincide (O. europaea, C. sempervirens), but they could also be unsynchronised, with either earlier flowering (C. avellana) or later flowering (P. orientalis). Pollen atmospheric circulation is mainly related with wind (direction, speed and persistence) and with precipitations. Even the lowest values of the latter washed out airborne pollen. The relationship with wind persistence was always positive, as it frequently was for the interaction of wind speed-persistence. Moreover, it was found that the yearly concentrations of pollen are increasing for the majority of the taxa examined (12 out of 16) but also for the yearly total, during the last two decades. In average, the pollen atmospheric load doubles every decade. Few and non-systematic trends were observed in phenological traits of pollen circulation season (start, peak, end, duration). These increasing trends are accompanied to an increase in air temperature, which is the only meteorological factor (of the 19 examined in total) to present significant changesΣυλλέχθηκαν οι γυρεόκοκκοι στην ατμόσφαιρα της Θεσσαλονίκης με χρήση γυρεοπαγίδας Burkard, η οποία λειτουργεί σε συνεχή βάση, προσροφώντας σταθερό όγκο ατμοσφαιρικού αέρα. Βρέθηκε ότι οι αφθονότεροι γυρεόκοκκοι προέρχονται κυρίως από τα ξυλώδη Cupressaceae, Oleaceae, Pinaceae, Platanus και Quercus και από τα ποώδη Poaceae και Urticaceae. Η κυκλοφορία γυρεοκόκκων εκτείνεται Φεβρουάριο με Οκτώβριο, με την κορύφωσή της να σημειώνεται την περίοδο Μαρτίου-Μαΐου. Μελετήθηκαν επιπλέον η ανθική φαινολογία και η γυρεοπαραγωγή των Corylus avellana, Cupressus sempervirens, Olea europaea και Platanus orientalis κατά τα έτη 2004 και 2005, κάτω από διαφορετικές περιβαλλοντικές συνθήκες (υψόμετρο ή και έκθεση). Παρατηρήθηκαν διαφορές στη φαινολογία άνθησης και στη γυρεοπαραγωγή τόσο μεταξύ σταθμών όσο και μεταξύ ετών δειγματοληψίας. Η γυρεοπαραγωγή ήταν χαμηλότερη και η άνθηση ξεκινούσε ή κορυφωνόταν αργότερα σε βόρειες εκθέσεις ή σε μεγαλύτερα υψόμετρα. Την υψηλότερη γυρεοπαραγωγή (σε επίπεδο άνθους) σημείωσε το O. europaea, ενώ την υψηλότερη ανθοπαραγωγή (σε επίπεδο ταξιανθίας) το P. orientalis. Το μέγεθος της γυρεοπαραγωγής ή και της ανθοπαραγωγής ανά ανθική μονάδα καθορίζεται κυρίως από το μέγεθος των τελευταίων, σε όλα τα taxa. Προέκυψε ακόμη ότι οι εποχές άνθησης και ατμοσφαιρικής κυκλοφορίας γυρεοκόκκων μπορεί να συμβαδίζουν (O. europaea, C. sempervirens), αλλά μπορεί να είναι και ετεροχρονισμένες, με πρωθύστερη άνθηση (C. avellana) ή μεθύστερη άνθηση (P. orientalis). Η ατμοσφαιρική κυκλοφορία γυρεοκόκκων φαίνεται να σχετίζεται κυρίως με τον άνεμο (διεύθυνση, ταχύτητα και εμμονή), καθώς και με τα υδάτινα κατακρημνίσματα. Έστω και ελάχιστη παρουσία των δεύτερων μηδένιζε τις ατμοσφαιρικές συγκεντρώσεις γυρεοκόκκων. Η σχέση με την εμμονή του ανέμου ήταν πάντα θετική, όπως ήταν συνήθως και με την αλληλεπίδραση εμμονής-ταχύτητας. Επίσης, βρέθηκε ότι αυξάνονται οι ετήσιες ατμοσφαιρικές συγκεντρώσεις γυρεοκόκκων για 12 από 16 μελετώμενα taxa, όπως και για το ετήσιο σύνολο, στις τελευταίες δύο δεκαετίες. Κατά μέσο όρο, το ατμοσφαιρικό φορτίο διπλασιάζεται κάθε δεκαετία. Δεν παρατηρήθηκαν συστηματικές μεταβολές στα φαινολογικά χαρακτηριστικά κυκλοφορίας (έναρξη, κορύφωση, λήξη, διάρκεια). Αυτές οι αυξητικές τάσεις συνοδεύονται από αύξηση της θερμοκρασίας του αέρα, που αποτελεί και το μοναδικό μετεωρολογικό παράγοντα (από τους 19 συνολικά που μελετήθηκαν) με συστηματικές και σημαντικές αλλαγές
Bioaerosols in Urban Settings: Roles of Climate Change, Ecosystem Services and Human Health
No full textUrban environments constitute of spaces in which the majority of humankind reside, work and recreate [...
Is birch pollen season the footprint of birch flowering in Augsburg, Germany? Phenotypic plasticity and environmental drivers
No full text
Environmental factors: a “missing link” in COVID-19
No full textPURPOSE OF REVIEW: As demand for food and fiber, but also for negative emissions, brings most of the Earth’s land surface under management, we aim to consolidate the scientific progress of recent years on the climatic effects of global land use change, including land management, and related land cover changes (LULCC). RECENT FINDINGS: We review the methodological advances in both modeling and observations to capture biogeochemical and biogeophysical LULCC effects and summarize the knowledge on underlying mechanisms and on the strength of their effects. Recent studies have raised or resolved several important questions related to LULCC: How can we derive CO₂ fluxes related to LULCC from satellites? Why are uncertainties in LULCC-related GHG fluxes so large? How can we explain that estimates of afforestation/reforestation potentials diverge by an order of magnitude? Can we reconcile the seemingly contradicting results of models and observations concerning the cooling effect of high-latitude deforestation? Major progress has been achieved in understanding the complementarity of modeling, observations, and inventories for estimating the impacts of various LULCC practices on carbon, energy, and water fluxes. Emerging fields are the operationalization of the recently achieved integration of approaches, such as a full greenhouse gas balance of LULCC, mapping of emissions from global models to country-reported emissions data, or model evaluation against local biogeophysical observations. Fundamental challenges remain, however, e.g., in separating anthropogenic from natural land use dynamics and accurately quantifying the first. Recent progress has laid the foundation for future research to integrate the local to global scales at which the various effects act, to create co-benefits between global mitigation, including land-based carbon dioxide removal, and changes in local climate for effective adaptation strategies
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