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The dataset contains summaries of the expeditions report carried out by the Amundsen science between July 4 and November 3, 2021. The 2021 Expedition Summary is an overview of the science activities undertaken aboard the CCGS Amundsen during the 2021 field season. This document is available in English, French and Inuktitut and targets anyone who wishes to get a general idea of expeditions’ objectives and activities, including partners and local communities. It is possible to consult the full report and complementary documents in the dataset: [**Arctic Expedition aboard the CCGS Amundsen (2020)**](https://catalogue.ogsl.ca/en/dataset/ca-cioos_906649c6-b01d-4916-a3e2-94bcde855daf). The core oceanographic data generated by the CTD-Rosette operations, as well as meteorological information (AVOS) and data collected using the Moving Vessel Profiler (MVP), the ship-mounted current meter (SM-ADCP) and the thermosalinograph (TSG) are available in the [**Polar Data Catalogue (PDC)**](https://www.polardata.ca/pdcsearch/?doi_id=12713). You can consult an [**interactive map**](https://data.amundsen.ulaval.ca/) including all the years of expeditions and the different trajectories (LEG) associated with them., Le jeu de données contient les résumés du rapport des expéditions réalisées par Amundsen science entre le 4 juillet et le 3 novembre 2021. Le résumé de l'expédition 2021 est un aperçu des activités scientifiques entreprises à bord du NGCC Amundsen en 2021. Ce document est disponible en anglais, en français et en inuktitut et s'adresse à toute personne qui souhaite avoir une idée générale des objectifs et des activités de l'expédition, y compris les partenaires et les communautés locales. Il est possible de consulter le rapport complet et les documents complémentaires dans le jeu de données : [**Expédition dans l'Arctique à bord du NGCC Amundsen (2020)**](https://catalogue.ogsl.ca/fr/dataset/ca-cioos_906649c6-b01d-4916-a3e2-94bcde855daf). Les principales données océanographiques générées par les opérations du CTD-Rosette, ainsi que les informations météorologiques (AVOS, Environnement Canada) et les données collectées à l'aide du Moving Vessel Profiler (MVP), du compteur de courant embarqué (SM-ADCP) et du thermosalinographe (TSG) sont disponibles dans le [**catalogue de données polaires (PDC)**](https://www.polardata.ca/pdcsearch/?doi_id=12713). Vous pouvez consulter une [**carte interactive**](https://data.amundsen.ulaval.ca/) comprenant toutes les années d'expéditions et les différents trajectoires (LEG) qui y sont associées.

Accurate glacial isostatic adjustment (GIA) models are required for correcting measurements of mass change in Antarctica and for improving knowledge of the sub-surface, especially in areas of large current ice loss such as the Amundsen Sea Embayment (ASE). Regionally, seismic and gravity data suggests lateral differences in viscosity (3D). Furthermore, mantle flow laws allow for a stress-dependent effective viscosity which changes over time (3D-s). In this study we investigate whether models with 3D/3D-s have significant effects on the uplift in the region. We use a finite element model with composite rheology consisting of diffusion and dislocation creep, forced by an ice deglaciation model starting in 1900. We use its uplift predictions as synthetic observations to test the performance of 1D model inversion in the presence of viscosity variations. Stress-dependent rheology results in lower viscosity beneath the load and a more localized uplift pattern. We demonstrate that the background stress from earlier ice load changes can both increase or decrease the influence of stress-induced effective viscosity changes. For the ASE, fitting 1D models to 3D model uplift results in a best fitting model with viscosity that represents the average of a large area, while for 3D-s rheology, local viscosity is more influential. 1D models are statistically indistinguishable from 3D/3D-s viscosity with current GPS stations. However, 3D and 3D-s models should be taken into account when accurate uplift and gravity rate patterns are needed, as uplift can differ up to 45% compared to 1D models in between existing GPS stations.

I 1903 seilte en liten hardangerjakt med en besetning på 7 mann ut Kristianiafjorden. Målet var å stadfeste beliggenheten av den magnetiske Nordpolen og å seile gjennom Nordvestpassasjen. Ekspedisjonens leder var Roald Amundsen, han hadde nøye planlagt ferden som stod framfor dem. I 1906, da Gjøa-mannskapet returnerte til Norge med suksess i bagasjen, ble de mottatt som nasjonale helter av en nasjon som nå var selvstendig. Dette danner bakgrunnen for oppgaven som tar for seg hvordan Gjøa-ekspedisjonen kunne benyttes i en nasjonsbyggende kontekst. Oppgavens mål er å få innsikt i hvordan avisenes fremstilling av ekspedisjonen bidro til nasjonsbygging i Norge, og hvordan ekspedisjonen ble brukt som instrument for å skape nasjonal identitet. Dette er gjort gjennom en analyse av syv norske aviser. For å tydeligere kunne se om og hvordan den norske fremstillingen kan betegnes som nasjonsbyggende, er også en kortere analyse av tre svenske aviser fra samme periode gjennomført. Norske aviser hadde en konsensus i nyhetsdekningen av ekspedisjonen, variasjoner avhengig av avisenes politiske grunnsyn var små. Avisene bærer preg av den rådende oppfatningen av at vitenskapelige prestasjoner hadde stor betydning for nasjonen. Den naturvitenskapelige delen av ekspedisjonen ble fremhevet, særlig i startfasen. Ved ekspedisjonens hjemkomst, ble vitenskapen derimot ofte overskygget av den sjømannsdåden og bragden som ble utført da Nordvestpassasjen ble gjennomført for første gang. De norske avisene var fulle av lovord om denne prestasjonen. Amundsen ble gjerne fremstilt som et symbol på den norske folkekarakteren. Nasjonalromantiske trekk, som å vise til den historiske «gullalderen» da Norge sist var selvstendige var også en gjenganger. Den samlede pressedekningen viser at den norske offentlighetens forhold til Amundsen var udelt positivt på dette punktet. Amundsen ble gjenstand for mye oppmerksomhet. Han ble i avisene beskrevet som den seirende øverstkommanderende i en krig mot naturen, og i en kappestrid mot andre nasjoner. I sammenligningen med de svenske avisene er det påfallende hvordan de norske avisene omtaler Amundsen og hans ekspedisjon. Den nasjonsbyggende retorikken synes tydelig. De norske avisenes dekning av ekspedisjonen la premissene for en heltedyrkelse av Amundsen. I Norge ble Amundsen kreditert med å ha gjennomført to store prestasjoner, disse ble omtalt på en måte som gjorde det tydelig at Gjøa-ekspedisjonen kan sees som en medvirkende del i nasjonsbyggingsprosessen i Norge.

Среди памятников острова Диксон важное значение имеют знаки, установленные в предполагаемых местах гибели Питера Тессема и Пауля Кнутсена — двух членов легендарной норвежской экспедиции Руала Амундсена на шхуне «Мод» в 1918–1920 гг. В статье показывается, как устанавливались места их гибели на острове. Оцениваются все версии, которые возникли у исследователей в разное время с 1920 по 1983 г. Рассказывается о судьбе памятных знаков на местах захоронений и перспективах их дальнейшего сохранения. Делается вывод, что важную роль в формировании пространства памяти сыграли профессиональное сообщество полярников и государство, а сами события, о которых идет речь, составляют коллективную память Арктики., Among the memorials of the Dikson island the signs established in places of assumed death of Peter Tessem and Paul Knutsen — two members of legendary Roald Amundsen’s expedition by the «Mod» schooner (1918–1920) are of the great importance. This article demonstrates how the places of their tragic deaths were being located on the island. The article deals with the evaluation process of the scientist’s versions within the period between 1920 and 1983. The article illustrates the memorial signs established on the places of the burials and assumes the perspectives of their further preservation. It is concluded that the important role in creation of the «memorial environment» belongs to the professional association of the polar researches and to the state, and the described events create the «collective memory of the Arctic».

West Antarctica, and particularly the Amundsen sector, has shown since the 1990s a large increase of mass loss related to coastal glacier acceleration in response to an increase of oceanic melt underneath ice shelves. Ice shelves play a buttressing role for ice-stream and increased oceanic melt therefore lead to ice shelves thinning and glacier acceleration, which contributes to sea level rise. West Antarctica is of particular concern because its configuration is prone to marine ice-sheet instability. It has been suggested that ice shelves weaken under large surface melt in a warmer climate (hydrofracturing), possibly leading to another kind of instability. Instabilities could be slowed down or compensated by future Surface Mass Balance (SMB) that consists mainly of snowfall, sporadic rainfall, and is slightly reduced by sublimation and runoff. The main objective of this PhD work is to model the atmospheric and oceanic processes that will most likely affect the future West Antarctic contribution to sea level rise.First, oceanic projections have been developed using the NEMO ocean model. The ocean circulation induced by ice-shelf basal melting affects the ocean response to future changes in surface winds. Therefore, models that do not represent ice-shelf cavities produce wrong warming patterns around Antarctica. A positive feedback between oceanic melting and grounding-line retreat has been identified and can increase melt rates by a factor of 2.5. These results are strong incentive to couple ocean and ice sheet models, although the projections proposed here are relatively idealized.To run SMB and surface melting projections, an atmospheric model with a fine representation of polar processes, including those related to the snowpack, is needed. MAR is found to be an appropriate tool to simulate the present-day surface climate in the Amundsen region. We find that none of the large climate modes of variability (ASL, SAM, ENSO) explains more than 50% of surface melt and SMB summer variance at the interannual timescale. The use of climate mode variability projections to estimate the future surface climate of West Antarctica is therefore not trivial.Forced by the CMIP5 multi-model mean under the RCP8.5 scenario, MAR predicts an increase of SMB by 30-40% for the end of the 21st century. This increase corresponds to 0.33 mm yr-1 of sea level drop down, which is higher than the current West Antarctic contribution of ~0.26 mm yr-1 from ice dynamics. Surface melt is also projected to increase by a factor of 5 to 15 over the Amundsen ice shelves, but most of it is projected to refreeze in the annual snow layer, so future melting should not have a strong contribution to SMB or hydrofracturing.To conclude we show that coupled ocean and ice sheet climate models are essential to simulate the future of Antarctica and Southern Ocean. A fine representation of surface melt and refreezing processes within the snowpack is also crucial as possible hydrofracturing is threatening in a warmer climate and it comes within a delicate equilibrium between snowfall, air temperature, and feedback related to albedo and humidity., Depuis les années 90, l’Antarctique de l’Ouest, dont le secteur d’Amundsen, affiche une importante perte de masse provenant principalement de l’accélération des glaciers côtiers en réponse à une fonte océanique plus conséquente sous les plateformes de glace. Ces plateformes sont généralement confinées est agissent comme un verrou pour l’écoulement. En subissant davantage de fonte basale, les plateformes deviennent fragiles et les glaciers en amont s’accélèrent, contribuant ainsi à augmenter le niveau des mers. L’avenir de l’Antarctique de l’Ouest est particulièrement préoccupant car sa configuration rend la calotte sujette à une instabilité marine. Par ailleurs, ces plateformes pourraient s’affaiblir sous l’effet d’une augmentation de la fonte de surface dans un climat plus chaud (hydrofracturation), rendant là aussi une instabilité possible. L’arrivée de ces instabilités pourrait être freinée ou compensée par l’évolution du bilan de masse de surface qui se compose majoritairement de précipitations neigeuses, sporadiquement augmenté par la pluie, et légèrement amoindri par la sublimation et le runoff. Cette thèse porte sur la modélisation de l’ensemble des processus atmosphériques et océaniques pouvant faire évoluer la contribution de l’Antarctique de l’Ouest au niveau des mers.Pour cela une projection océanique représentant les cavités sous-glaciaires a d’abord été réalisée avec le modèle NEMO. La circulation induite par la fonte océanique modifie la réponse de l’océan côtier à un futur changement de circulation atmosphérique, si bien qu’utiliser des modèles de climat ne représentant pas les cavités donne une indication faussée du réchauffement de l’océan autour de la calotte. Nous avons également mis en évidence une rétroaction positive entre la fonte sous-glaciaire et le retrait de la ligne d’échouage, entraînant une augmentation de la fonte jusqu’à 2.5 fois. Ces résultats indiquent la nécessité de coupler des modèles de calotte et d’océan pour établir des projections futures, même si les projections envisagées dans cette thèse restent relativement idéalisées.Pour établir des projections de bilan de masse de surface, il est nécessaire d’utiliser un modèle atmosphérique avec une représentation fine des processus polaires, notamment ceux liés au manteau neigeux. Ainsi nous avons utilisé le modèle atmosphérique régional MAR pour établir des projections dans le secteur d’Amundsen. Nous avons d’abord montré que MAR est approprié pour représenter le climat de surface observé en Antarctique de l’Ouest. Nous avons trouvé qu’aucun des modes climatiques (ASL, SAM, ENSO) n’expliquent plus de 50% de la variance de la fonte et du SMB en été à l’échelle interannuelle, et il est donc difficile d’utiliser des projections des modes climatiques comme indication de l’évolution du climat de surface.Forcé par le signal multi-modèle CMIP5 dans le scénario rcp85, MAR prévoit une augmentation du bilan de masse de surface de 30-40% d’ici 2100. Cette augmentation est équivalente à une baisse de 0.33 mm/an de niveau des mers, ce qui compenserait l’effet de la dynamique si celle-ci restait à son niveau actuel (0.26 mm/an). Ces projections indiquent également 5 à 15 fois plus de fonte de surface sur les plateformes du secteur Amundsen, mais la quasi-totalité de la fonte produite chaque année continue à regeler dans la couche de neige annuelle, et ne devrait donc contribuer de manière importante ni au bilan de masse de surface ni à l’hydrofracturation.Il ressort de ces travaux qu’un couplage océan/calotte dans les modèles de climat est primordial pour simuler le futur de l’Antarctique et de l’océan Austral. Une représentation fine des processus liés à la fonte de surface et au regel dans le névé est également essentielle car la possibilité d’hydrofracturation des plateformes dans un climat plus chaud relève d’un équilibre subtil entre l’augmentation de l’accumulation, de la température, et les rétroactions liées à l’albédo et à l’humidité.

International audience; The use of Lagrangian platforms and of Autonomous Underwater Vehicles (AUVs) in oceanography has increasedrapidly over the last decade along with the development of improved biological and chemical sensors. These vehicles provide new spatial and temporal scales for observational studies of the ocean. They offer a broad range of deployment and recovery capabilities that reduce the need of large research vessels. This is especially true for ice-covered Arctic ocean where surface navigation is only possible during the summer period. Moreover, safe underwater navigation in icy waters requires the capability of detecting sea ice on the surface (ice sheets). AUVs navigating in such conditions risk collisions, RF communication shadowing, and being trapped by ice keels. In this paper, an underwater sea-ice detection apparatus is described. The source is a polarized continuous wave (CW) diode-pumped solid-state laser (DPSS) module operating at 532 nm. The detector is composed of a polarizing beam splitter, which separates light of S and P polarization states and two photodetectors, one foreach polarized component. Since sea-ice is a strong depolarizer, the ratio P/S is an indicator of the presence or absence of sea-ice. The system is capable of detecting sea-ice at a distance of 12m. This apparatus is designed to be used by free drifting profiling floats (e.g., Argo floats), buoyancy driven vehicles (e.g., sea gliders) and propeller-driven robots (e.g., Hugin class AUV).

To commemorate one hundred years of Roald Amundsen's reaching the South Pole, we provide a summary of early explorations to Antarctica, in which botanists played an almost anonymous role. Based on multiple observations of vegetation they found and recorded, we review the knowledge available at the end of the nineteenth century to compare with contemporary scientific beliefs; connecting them with observations we have collected in field-work. Using the aerial photography from the end of the 1950s of sites we visited, it is noted that opportunities are arising for the understanding of colonization phenomena in areas where ice is retreating. Accounts of research on colonization of new ice-free areas are analyzed as well as how molecular genetics attempts to deduce the early settlements. Finally, an analysis of conservation in Antarctica is provided and its outlook discussed. Al conmemorar los 100 años de la llegada de Roald Amundsen al polo sur, queremos entregar un resumen de las primeras exploraciones a Antártica, en el cual participaban botánicos en forma casi anónima. Basados en las múltiples observaciones de la vegetación que ellos encontraron y registraron, se revisó el conocimiento disponible al final del siglo diecinueve para compararlo con nuestra visión; relacionándolo con lo que nosotros hemos encontrado ahora en nuestros terrenos. Usando fotografía aérea de finales de 1950 de sitios que nosotros hemos visitado, es evidente que nuevas áreas del conocimiento se abren frente a estos fenómenos donde ha retrocedido el hielo. Se señalan las investigaciones que se han desarrollado en el análisis de la colonización de las nuevas áreas libres de hielo y cómo la genética molecular intenta descifrar su establecimiento. Finalmente, se hace un análisis de la conservación en Antártica y se discute sobre las proyecciones de ella.

Primary productivity in the Amundsen Sea (Southern Ocean) is among the highest in Antarctica. The summer phytoplankton bloom in 2009 lasted for > 70 days in both the Pine Island and Amundsen Polynyas. Such productive blooms require a large supply of nutrients, including the trace metal iron (Fe). The organic complexation of dissolved Fe was investigated in the Amundsen Sea during the spring of 2009 to better understand the potential role of ligands in enhancing the local stock of dissolved Fe. The main sources of Fe and ligands to the Amundsen Sea are thought to be melting sea-ice and the Circumpolar Deep Water (CDW), which is modified (MCDW) on the continental shelf and upwells beneath the coastal glaciers and ice-shelves. Upwelling of relatively warm MCDW is also responsible for the rapid melting of the Pine Island Glacier (PIG) and surrounding ice-shelves, resulting in additional release of Fe into surface waters. At upwelling stations near ice shelves, organic ligands were nearly saturated with Fe, thus enhancing the stock of Fe and its availability to the phytoplankton community. However, ligands had little capacity to buffer additional Fe input from glacial melt. In these coastal upwelling regions, much of the glacial Fe supply is lost due to vertical export of Fe via scavenging and precipitation. Conversely, within the phytoplankton bloom in the nearby coastal polynyas, the uptake of Fe combined with the production of organic matter enhanced the abundance of relatively unsaturated organic ligands capable of stabilizing additional Fe supplied from glacial melt. These unsaturated dissolved organic ligands, combined with the continuous input of Fe (dissolved and particulate) from glacial melt, appear to favor the solubilization of Fe, thus increasing the stock of bioavailable Fe and fueling the phytoplankton bloom. (C) 2012 Elsevier Ltd. All rights reserved.

En el presente trabajo se han obtenido los patrones espaciales más frecuentes de los campos de anomalías de concentración de hielo marino (ACHM) en los mares de Amundsen, Bellingshausen y Weddell a partir de los valores medios mensuales de concentración de hielo marino provistos por la NASA Goddard Space Flight Center derivados del Scanning Multichannel Microwave Radiometer y Special Sensor Microwave/Imager para el período 1979 al 2000. Haciendo uso de la técnica de análisis de Componentes Principales (CPs) en modo-T rotadas Varimax, se obtienen seis CPs. Por lo tanto, se obtienen un total de 12 patrones con seis en modo directo (ACHM del mismo signo que la CP) y seis en inverso (ACHM de signo opuesto a la CP), que clasifican el 95,5% de los campos mensuales. Tres CPs describen los casos más frecuentes de inviernoprimavera (período con mayor concentración y expansión del hielo marino) y tres CPs corresponden a verano-otoño (menor concentración y retracción del campo de hielo). La primera y segunda CP representan situaciones de invierno y primavera. La segunda componente está rotada 30° en sentido horario con respecto a la primer componente y ambas presentan anomalías dipolares entre los mares a ambos lados de la península Antártica. Estas dos componentes presentan una recurrencia de aproximadamente 4 años en los que alternativamente el exterior del mar de Weddell tiene condiciones de hielo marino sobre lo normal cuando en el norte del mar de Amundsen las anomalías son negativas y viceversa. La condición más frecuente y con una recurrencia anual de verano-otoño (3ºCP) también es bipolar pero entre el interior del Weddell y la región del Amundsen-Bellingshausen costera por ser la región donde se presenta el hielo en esa época del año. Las componentes 4º, 5º y 6º refieren a condiciones de ACHM diferentes y no descriptas en la literatura. Por otra parte, las CPs de verano-otoño, fundamentales para la navegación antártica, muestran un cambio de comportamiento ocurrido a fines de los años 80s, en que los mares de Amundsen y Bellingshausen pasaron de tener mayores a menores concentraciones de hielo marino. La distribución espacial de ACHM durante las fases maduras tanto de El Niño muestra una gran variabilidad entre eventos y en algunos casos tiene comportamiento opuesto para diferentes eventos. Lo mismo ocurre para La Niña. La influencia del ciclo El Niño/Oscilación del Sur es clara solo para el invierno que sigue a la fase madura estival del El Niño o La Niña. In this paper the most frequent spatial patterns of sea ice concentration anomalies (SICA) over the Amundsen, Bellingshausen and Weddell Seas have been obtained from monthly mean values of sea ice concentrations provided by the Scanning Multichannel Microwave Radiometer and the Special Sensor Microwave/Imager of NASA Goddard Space Flight Center for the period 1979 2000. Using analysis of Principal Components (PCs) in T-Mode rotated Varimax, six PCs were obtained. Therefore, a total of 12 patterns were found with six in direct mode (SICA of the same sign that the PC) and six in inversely (SICA of opposite sign to the PC), that classify 95.5 % of the monthly fields. Three PCs describe the most frequent winter-spring cases (period with major concentration and expansion of sea ice) and three PCs correspond to summer-autumn (minor concentration and retraction of the field of ice). Winter-spring months have mainly situations close to the first and second PCs. The 2°PC shows a 30 ° counter wise rotation with respect to the 1°CP and both present dipole anomalies between the seas at both sides of the Antarctic Peninsula. These two components display a recurrence of approximately 4 years in which alternatively the exterior region of the Weddell Sea has conditions of sea ice above the mean values meanwhile, in the north of the Amundsen Sea, the anomalies are negative and vice versa. The most frequent condition with an annual summer - autumn recurrence (3ºCP) is also a dipole but between the interior of the Weddell and the coastal region of Amundsen-Bellingshausen because these is the region where the sea ice is presented in this epoch of the year. The 4 º, 5 º and 6 º components refer to different, and not descript in the literature, conditions of SICA. The summer-autumn PCs, fundamental for the Antarctic navigation, show a change of behavior occurred at the end of the 80s years, in that the Amundsen and Bellingshausen Seas passed of having bigger to minor concentrations of sea ice. The SICA spatial distribution during the mature phases El Niño showed great variability among events and in some cases have opposite behavior for different events. The same occur for La Niña. The influence of the ENSO cycle is relatively clear only for the winter that follows the summer mature phase of the El Niño or La Niña. Fil: Compagnucci, Rosa Hilda. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ciencias de la Atmósfera y los Océanos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Barreira, Sandra. Ministerio de Defensa. Armada Argentina. Servicio Meteorológico de la Armada; Argentina

Aquest treball té com a objectiu analitzar dues grans expedicions polars que es van fer a l’Antàrtida a principis del segle XX, liderades per Roald Amundsen i Robert Scott. L’essència del treball està en com dues expedicions que tenien el mateix fi en comú, el Pol Sud, van arribar a ser tant diferents una de l’altre. El resultat és que una va tenir èxit i l’altre va fracassar, ja que en una de les expedicions van acabar morint una part dels homes. Amb aquest anàlisis doncs, trec les conclusions sobre quins errors van cometre que els va dur al fracàs, com quins encerts van fer per aconseguir l’èxit.