Publikasjoner

VOC measurements 2022

Solberg, Sverre; Claude, Anja; Reimann, Stefan

This report documents the EMEP VOC monitoring carried out in 2022. The levels of the measured in 2022 are presented as well as the 2022-status and history of the VOC programme. The geographical pattern of the species in Europe is discussed as well as the long-term trend during the last 20 years.

NILU

VOCers skjebne i inneluft - en ukjent verden. NILU F

Wisthaler, A.

Volatile Methyl Siloxanes in Polar Regions

Krogseth, Ingjerd Sunde; Warner, Nicholas Alexander

Volatile organic compounds in the museum environment - a PTR-TOF pilot study on canvas samples. NILU F

Mikoviny, T.; Eichler, P.; Müller, M.; Grøntoft, T.; Wisthaler, A.

Volatile Organic Compounds of Diverse Origins and Their Changes Associated With Cultivar Decay in a Fungus-Farming Termite

Vidkjær, Nanna Hjort; Schmidt, Suzanne; Davie-Martin, Cleo Lisa; Silué, Kolotchèlèma Simon; Koné, N'golo Abdoulaye; Rinnan, Riikka; Poulsen, Michael

Fungus-farming termites cultivate a Termitomyces fungus monoculture in enclosed gardens (combs) free of other fungi, except during colony declines, where Pseudoxylaria spp. stowaway fungi appear and take over combs. Here, we determined Volatile Organic Compounds (VOCs) of healthy Macrotermes bellicosus nests in nature and VOC changes associated with comb decay during Pseudoxylaria takeover. We identified 443 VOCs and unique volatilomes across samples and nest volatilomes that were mainly composed of fungus comb VOCs with termite contributions. Few comb VOCs were linked to chemical changes during decay, but longipinocarvone and longiverbenone were only emitted during comb decay. These terpenes may be involved in Termitomyces defence against antagonistic fungi or in fungus-termite signalling of comb state. Both comb and Pseudoxylaria biomass volatilomes contained many VOCs with antimicrobial activity that may serve in maintaining healthy Termitomyces monocultures or aid in the antagonistic takeover by Pseudoxylaria during colony decline. We further observed a series of oxylipins with known functions in the regulation of fungus germination, growth, and secondary metabolite production. Our volatilome map of the fungus-farming termite symbiosis provides new insights into the chemistry regulating complex interactions and serves as a valuable guide for future work on the roles of VOCs in symbioses.

John Wiley & Sons

Volatile siloxanes in the European Arctic: assessment of sources and spatial distribution.

Warner, N.; Evenset, A.; Christensen, G.; Gabrielsen, G.W.; Borgå, K.; Leknes, H.

Volcanic ash and SO2 in the 2008 Kasatochi eruption: Retrievals comparison from different IR satellite sensors.

Corradini, S.; Merucci, L.; Prata, F.; Piscini, A.

Volcanic ash infrared signature: porous non-spherical ash particle shapes compared to homogeneous spherical ash particles.

Kylling, A.; Kahnert, M.; Lindqvist, H.; Nousiainen, T.

Volcanic dust characterization by EARLINET during Etna's eruptions in 2001-2002.

Wang, X.; Boselli, A.; D'Avino, L.; Pisani, G.; Spinelli, N.; Amodeo, A.; Chaikovsky, A.; Wiegner, M.; Nickovic, S.; Papayannis, A.; Perrone, M.R.; Rizi, V.; Sauvage, L.; Stohl, A.

Volcanoes and aviation.

Zehner, C.; Theys, N.; Prata, F.; Davies, I.

Vortex-averaged Arctic ozone depletion in the winter 2002/2003.

Christensen, T.; Knudsen, B.M.; Streibel, M.; Andersen, S.B.; Benesova, A.; Braathen, G.; Claude, H.; Davies, J.; De Backer, H.; Dier, H.; Dorokhov, V.; Gerding, M.; Gil, M.; Henchoz, B.; Kelder, H.; Kivi, R.; Kyrö, E.; Litynska, Z.; Moore, D.; Peters, G.; Skrivankova, P.; Stübi, R.; Turunen, T.; Vaughan, G.; Viatte, P.; Vik, A.F.; von der Gathen, P.; Zaitcev, I.

Vulkansk aske - den norske modellen.

Tørseth, K.

Vulnerability and resilience of the carbon exchange of a subarctic peatland to an extreme winter event

Parmentier, Frans-Jan W.; Rasse, Daniel; Lund, Magnus; Bjerke, Jarle W.; Drake, Bert G.; Weldon, Simon Mark; Tømmervik, Hans; Hansen, Georg Heinrich

Extreme winter events that damage vegetation are considered an important climatic cause of arctic browning—a reversal of the greening trend of the region—and possibly reduce the carbon uptake of northern ecosystems. Confirmation of a reduction in CO2 uptake due to winter damage, however, remains elusive due to a lack of flux measurements from affected ecosystems. In this study, we report eddy covariance fluxes of CO2 from a peatland in northern Norway and show that vegetation CO2 uptake was delayed and reduced in the summer of 2014 following an extreme winter event earlier that year. Strong frost in the absence of a protective snow cover—its combined intensity unprecedented in the local climate record—caused severe dieback of the dwarf shrub species Calluna vulgaris and Empetrum nigrum. Similar vegetation damage was reported at the time along ~1000 km of coastal Norway, showing the widespread impact of this event. Our results indicate that gross primary production (GPP) exhibited a delayed response to temperature following snowmelt. From snowmelt up to the peak of summer, this reduced carbon uptake by 14 (0–24) g C m−2 (~12% of GPP in that period)—similar to the effect of interannual variations in summer weather. Concurrently, remotely-sensed NDVI dropped to the lowest level in more than a decade. However, bulk photosynthesis was eventually stimulated by the warm and sunny summer, raising total GPP. Species other than the vulnerable shrubs were probably resilient to the extreme winter event. The warm summer also increased ecosystem respiration, which limited net carbon uptake. This study shows that damage from a single extreme winter event can have an ecosystem-wide impact on CO2 uptake, and highlights the importance of including winter-induced shrub damage in terrestrial ecosystem models to accurately predict trends in vegetation productivity and carbon sequestration in the Arctic and sub-Arctic.