On the Storms Passing Over Southern Baffin Island During Autumn 2005

Although strong storms affect all regions of the Arctic, little research has focused on the details of their structure and evolution—particularly of the storms passing over southern Baffin Island. Such storms form in a variety of locations and often occlude before passing over the region. To study these storms, a field project was conducted at Iqaluit, Nunavut, in the eastern Canadian Arctic in the autumn of 2005. We launched rawinsondes into six storm systems and made detailed measurements that included ice crystal structure and snow accumulation. The storms had quite different histories: some produced strong winds; some produced snow, while others produced rain and freezing precipitation; and three led to record-breaking temperatures. The types of precipitation particles varied greatly, but aggregates and rimed particles dominated. When comparing the six storms, we found numerous similarities between the surface and the vertical atmospheric conditions, but there were also distinct differences.Même si de mauvaises tempêtes s’abattent sur toutes les régions de l’Arctique, peu de recherches ont été effectuées pour connaître les détails de leur structure et de leur évolution, plus particulièrement en ce qui a trait aux tempêtes qui passent dans la région sud de l’île de Baffin. Ces tempêtes se forment dans divers endroits et souvent, elles se ferment avant de passer dans la région. Pour étudier ces tempêtes, des travaux ont été effectués sur le terrain même à Iqaluit, au Nunavut, dans l’est de l’Arctique canadien à l’automne 2005. Nous avons lancé des appareils de radiosondage-radiovent dans six tempêtes et avons pris des mesures détaillées portant notamment sur la structure des cristaux de glace et l’accumulation de neige. La formation des tempêtes était très différente : certaines produisaient des vents violents, d’autres produisaient de la neige, d’autres encore produisaient de la pluie et des précipitations givrantes, et trois tempêtes ont donné lieu à des températures record. Le type de particules de précipitation variait beaucoup, bien que les agrégats et les particules givrées dominaient. En comparant les six tempêtes, nous avons constaté qu’il existait de nombreuses similitudes entre les conditions à la surface et les conditions atmosphériques verticales, mais qu’il y avait aussi de nettes différences

The Wind Energy Potential of Iceland

AbstractDownscaling simulations performed with the Weather Research and Forecasting (WRF) model were used to determine the large-scale wind energy potential of Iceland. Local wind speed distributions are represented by Weibull statistics. The shape parameter across Iceland varies between 1.2 and 3.6, with the lowest values indicative of near-exponential distributions at sheltered locations, and the highest values indicative of normal distributions at exposed locations in winter. Compared with summer, average power density in winter is increased throughout Iceland by a factor of 2.0–5.5. In any season, there are also considerable spatial differences in average wind power density. Relative to the average value within 10 km of the coast, power density across Iceland varies between 50 and 250%, excluding glaciers, or between 300 and 1500 W m−2 at 50 m above ground level in winter. At intermediate elevations of 500–1000 m above mean sea level, power density is independent of the distance to the coast. In addition to seasonal and spatial variability, differences in average wind speed and power density also exist for different wind directions. Along the coast in winter, power density of onshore winds is higher by 100–700 W m−2 than that of offshore winds. Based on these results, 14 test sites were selected for more detailed analyses using the Wind Atlas Analysis and Application Program (WAsP)

Workshop on Raising Data using the RDBES and TAF (WKRDBESRaiseTAF; outputs from 2022 meeting)

41 páginasThe Workshop on Raising Data using the RDBES and TAF (WKRDBES-Raise&TAF) met online (26–30 of September 2022) to evaluate the use of the Regional Database and Estimation System (RDBES) format to reproduce the 2022 InterCatch input and output, identifying a Transparent Assessment Framework (TAF) structure to organize the intermediate steps and to propose standardized output formats. The main outcomes of WKRDBES-Raise&TAF were: · RDBES provides sufficient support for current national estimation protocols. However, some minor issues were reported that hampered an exact reproduction of the estimates. Therefore, adaptations of the data model should not be excluded completely. · All the input to stock assessment that InterCatch currently provides, could be reproduced. The participants started from the current stock extracts that can be downloaded from InterCatch. · A workflow was proposed with a national TAF repository for each country, a stock estimation repository and a stock assessment repository. The intermediate output of those repositories will be stored in an ‘intermediate output database’ and depending on the user role, you will get access to the relevant stages in this workflow. · The following requirements for the standard output formats were defined: they cannot be more restrictive than the InterCatch input and output format; they should present measures of uncertainty and sample sizes (for national estimates) and should have a configurable domain definition (for national estimates). Despite those successful outcomes, the current plan for transition to an operational system was concluded to be too optimistic. WKRDBES-Raise&TAF therefore recommends to the Working Group on Governance of the Regional Database and Estimation System (WGRDBESGOV) to revise the roadmap and allow RDBES to be in a test phase also for 2023. WKRDBES-Raise&TAF felt the need to test the proposed workflow on a small scale and therefore recommends to the WGRDBESGOV to arrange a workshop where two stocks (pok.27.3a46 (Saithe (Pollachius virens) in Subareas 4, 6 and Division 3.a (North Sea, Rockall and West of Scotland, Skagerrak and Kattegat) and wit.27.3a47d (Witch (Glyptocephalus cynoglossus) in Subarea 4 and Divisions 3.a and 7.d (North Sea, Skagerrak and Kattegat, eastern English Channel)) will be set up to go through the whole flow.Peer reviewe

Working Group on Nephrops Surveys (WGNEPS; outputs from 2022 meeting)

The Working Group on Nephrops Surveys (WGNEPS) is the international coordination group for Nephrops underwater television and trawl surveys within ICES. This report summarizes the national contributions on the results of the surveys conducted in 2022 together with time series covering all survey years, problems encountered, data quality checks and technological improvements as well as the planning for survey activities for 2023.In total, 21 surveys covering 26 functional units (FU’s) in the ICES area and 1 geographical subarea (GSA) in the Adriatic Sea were discussed and further improvements in respect to survey design and data analysis standardization and the use of most recent technology were reviewed. The first exploratory UWTV survey on the FU 25 Nephrops grounds was also presented to the group.The results of the evaluation of reference sets for FU3&4 Skagerrak/Kattegat were accepted following the process set down by the 2018 workshop (WKNEPS).An alternative method estimate Nephrops abundance was shown to the group using the recently published R package sdmTMB.The group agreed to hold a workshop in 2025 to address burrow size estimations to update correction factors and terms of reference for this to be agreed at next meeting.Automatic burrow detection based on deep learning methods continues to show promising results where datasets from multiple institutes were used.Plans are being progressed for an international Nephrops UWTV database to be established at the ICES data centre with a sub-grou