Academic literature on the topic 'Isfjorden'

Air temperature and specific humidity inversions and low-level jets were studied over two Svalbard fjords, Isfjorden and Kongsfjorden, applying three tethersonde systems. Tethersonde operation practices notably affected observations on inversion and jet properties. The inversion strength and depth were strongly affected by weather conditions at the 850 hPa level. Strong inversions were deep with a highly elevated base, and the strongest ones occurred in warm air mass. Unexpectedly, downward longwave radiation measured at the sounding site did not correlate with the inversion properties. Temperature inversions had lower base and top heights than humidity inversions, the former due to surface cooling and the latter due to adiabatic cooling with height. Most low-level jets were related to katabatic winds. Over the ice-covered Kongsfjorden, jets were lifted above a cold-air pool on the fjord; the jet core was located highest when the snow surface was coldest. At the ice-free Isfjorden, jets were located lower.

Light-absorbing aerosols (LAA) impact the atmosphere by heating it. Their effect in the Arctic was investigated during two summer Arctic oceanographic campaigns (2018 and 2019) around the Svalbard Archipelago in order to unravel the differences between the Arctic background and the local anthropic settlements. Therefore, the LAA heating rate (HR) was experimentally determined. Both the chemical composition and high-resolution measurements highlighted substantial differences between the Arctic Ocean background (average eBC concentration of 11.7 ± 0.1 ng/m3) and the human settlements, among which the most impacting appeared to be Tromsø and Isfjorden (mean eBC of 99.4 ± 3.1 ng/m3). Consequently, the HR in Isfjorden (8.2 × 10−3 ± 0.3 × 10−3 K/day) was one order of magnitude higher than in the pristine background conditions (0.8 × 10−3 ± 0.9 × 10−5 K/day). Therefore, we conclude that the direct climate impact of local LAA sources on the Arctic atmosphere is not negligible and may rise in the future due to ice retreat and enhanced marine traffic.

RÉSUMÉLa flore du Svalbard est riche de 184 espèces vasculaires. Cette flore est considérée commeexceptionnellement riche eu égard à l’emplacement de l’archipel. À l’occasion de l’expéditionau Spitzberg menée, en juillet 2018, conjointement par l’association Sibbaldia et la Sociétéd’Histoire naturelle et d’Ethnographie de Colmar, un programme de culture et de conservationex situ de plantes vasculaires a été mis en place en collaboration avec le jardin d’altitudedu Chitelet dans le massif vosgien. Les explorations botanistes ont été menées sur les zonesles plus accessibles de la rive sud de l’Isfjorden. Au total, ce travail a permis de récolteret de mettre en culture 134 échantillons correspondant à 91 espèces, soit environ 300 potsen culture. À partir d’une mise en culture le 23 juillet, au jardin d’altitude du Chitelet, la quasitotalitédes végétaux ont présenté une croissance au mois de septembre. À ce jour, seulementquatre espèces n’ont présenté aucun signe de reprise et ont péri.MOTS-CLÉS : Spitzberg, Isfjorden, botanique, récolte, plantes vivantes, jardin botanique,éducation, conservation, recherche.ABSTRACTThe flora of Svalbard accounts 184 vascular species. This flora is considered as exceptionallyrich despite to the northern location of the archipelago. During the expeditionto Spitzberg - conducted in July 2018 jointly by the Sibbaldia association andthe Society of Natural History and Ethnography of Colmar - a program of conservationand ex situ culture of vascular plants has was set up in collaboration with the altitudebotanical garden of Chitelet in the Vosges mountains. Fieldworks were carried outon the most accessible areas of the South bank of the Isfjorden. In total, this workallowed to collect and put in culture 134 samples corresponding to 91 species,about 300 pots in culture. Since July 23, almost all vascular plants showed growthin September. To date, only four species have shown no signs of recovery and haveperished.KEYWORDS