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Atmospheric feedbacks on Arctic summer sea-ice anomalies in ensemble simulations of a coupled regional climate model
Get PDFEnsemble simulations with the Arctic coupled regional climate model HIRHAM-NAOSIM have been analyzed to investigate atmospheric feedbacks to September sea-ice anomalies in the Arctic in autumn and the following winter. Different “low minus high ice” composites have been calculated using selected model runs and different periods. This approach allows us to investigate the robustness of the simulated regional atmospheric feedbacks to detected sea-ice anomalies. Since the position and strength of the September sea-ice anomaly varies between the different “low minus high ice” composites, the related simulated atmospheric patterns in autumn differ depending on the specific surface heat flux forcing through the ocean-atmosphere interface. However, irrespective of those autumn differences, the regional atmospheric feedback in the following winter is rather insensitive to the applied compositing. Neither the selection of simulations nor the considered period impacts the results. The simulated consistent large-scale atmospheric circulation pattern shows a wave-like pattern with positive pressure anomaly over the region of the Barents/Kara Seas and Scandinavia/western Russia (“Scandinavian-Ural blocking”) and negative pressure anomaly over the East Siberian/Laptev Seas
Research on governance of HFO use and carriage on ships in accordance with the Polar Code
Get PDFIn this paper, we discuss the environmental damages caused by the use and carriage of Heavy Fuel Oil (HFO) by ships in Arctic waters. We also review efforts made by major international and regional organizations in governing the use and carriage of HFO by ships in Arctic waters after implementation of the Polar Code, and analyze the obstacles and difficulties that lie ahead. By illustrating the features of the Arctic Council and the International Maritime Organization (IMO), which govern Arctic waters, we examine measures taken by these two organizations in tackling HFO issues. These include: assessing indigenous and local community’s reliance on HFO transportation in the Arctic, developing risk prevention measures for ships operating in Arctic waters, seeking economic alternatives to HFO that contribute to a greener economy, developing a package of HFO governance measures, strengthening cooperation between relevant international and regional organizations that govern HFO to provide suggestions for follow-up discussions on HFOs, and optimize governance by relevant organizations and determine a better global solution to governing the use and carriage of HFO by ships. In addition, we discuss the feasibility of an IMO-imposed HFO ban from the perspective of the Arctic governance to clearly grasp the path of its future development
Arctic warming and its influence on East Asian winter cold events: a brief recap
Get PDFThe rate of warming of Arctic surface temperature is about 2–3 times faster than the global mean surface warming. Increases of ice albedo feedback and water vapor as well as moisture intrusion from outside the Arctic all have major roles in this phenomenon. In contrast to this rapid Arctic warming, in recent decades, stronger cold air outbreaks have occurred more frequently during winter in East Asia than were recorded in the 1990s, resulting in severe socioeconomic impacts. A number of related studies have claimed the increased frequency of these stronger cold air outbreaks is linked to the amplified warming in the Arctic through complicated mechanisms. As there are time lags between the observed Arctic warming and East Asian cold weather response at various scales, understanding the entire chain of processes from the Arctic to East Asia has importance for forecasting winter weather in East Asia. There are two pathways linking Arctic warming with East Asian cold weather events. One is the synoptic-scale pathway in the lower troposphere via strengthening of the Siberian High initiated by Ural blocking. The other is the planetary-scale path through the stratosphere via activation of planetary waves and downward propagation, which weakens the polar vortex. This study briefly reviews the current understanding of the linkage mechanisms between Arctic warming and East Asian winter cold weather
Preliminary investigation of rubidium distribution in the Grove Mountains area, East Antarctica
Get PDFWe analyzed rock samples from the Grove Mountains in Antarctica to determine the distribution of rubidium (Rb) in that location. We collected samples from the Black Nunataks, Melvoldt Nunataks, Mason Peaks, Zakharoff Ridge, Mount Harding, and the northern Gale Escarpment. Geochemical analysis indicated that in some samples the amount of Rb was higher than 300 ppm. This suggests that rocks from the Grove Mountains are rich in Rb. Based on field observations and previous research, we speculate that mica and potash feldspar from moyite, granite gneiss, and felsic pegmatite are the primary carrier minerals of Rb. However, further research is necessary to confirm this speculation
Trends of summertime extreme temperatures in the Arctic
Get PDFExtreme temperature events can influence the natural environment and societal activities more so than mean temperature events. This study used daily data from 238 stations north of 60°N, obtained from the Global Summary of the Day dataset for the period 1979–2015, to investigate the trends of summertime extreme temperature. The results revealed most stations north of 60°N with trends of decrease in the number of cold days (nights) and increase in the number of warm days (nights). The regional average results showed trends of consistent decline (rise) of cold days and nights (warm days and nights) in Eurasia and Greenland. Similarly, the trends of the seasonal maximum and minimum values were most significant in these regions. In summer, of three indices considered (i.e., Arctic Oscillation, Arctic dipole, and El Niño–Southern Oscillation), the largest contributor to the trends of extreme temperature events was the Arctic dipole. Prevailing southerly winds in summer brought warm moist air across northern Eurasia and Greenland, conducive to increased numbers of warm days (nights) and decreased numbers of cold day (nights). Moreover, we defined extreme events using different thresholds and found the spatial distributions of the trends were similar
An analysis on Sino Russian cooperation in the Arctic in the BRI era
Get PDFOver the past decade Sino-Russian cooperation in the Arctic has emerged as one of the major topics of the Russia-China negotiations on how to expand their comprehensive strategic partnership and to bring it to a new level. China considers the Arctic region important for its economic interests and desires to be included in the development of the region and its economic potential. For Russia, the Arctic is a future strategic resource base that would replace the old depleting fields and assure Russia’s status as a major worldwide energy supplier. Despite many joint statements on deepening of the Sino-Russian cooperation in the development of the Arctic energy resources, the concrete results of these ambitious plans are few. Some joint projects were dropped, as China and Russia could not agree on the conditions of the deal, others are progressing very slowly and have an uncertain future. In 2017, China has expanded its “Belt and Road Initiative” (BRI) to the Arctic thus elevating the Sino-Russian cooperation in the Artcic to a higher level. How did the relationship between Russia and China evolve in the Arctic and how do Russia and China view and respond to the new Arctic dimension of the BRI? What factors limit the strategic rapprochement between China and Russia in the Arctic
An emic science of climate. Reindeer Evenki environmental knowledge and the notion of an “extreme process”
Get PDFHuman-environment relationships in Siberia and Northeast China.
Knowledge, rituals, mobility and politics among the Tungus peoples,followed by Vari
Occurrence of seabirds and marine mammals in the pelagic zone of the Patagonian Sea and north of the South Orkney Islands
Get PDFThe Patagonian Sea is one of the most productive ecosystems in the Southern Hemisphere. Unlike other coastal regions, however, few studies exist on the top predators in its pelagic zone. In March 2017, a survey of seabirds and marine mammals was carried out on board the R/V Puerto Deseado in the Patagonian Sea, which extends from the South Atlantic Ocean to the north of the South Orkney Islands, Antarctica. Four of the five oceanographic regimes described in this region were studied, and 23 seabird species and five marine mammal species were recorded. Great shearwater Puffinus gravis, Antarctic prion Pachyptila desolata, and fin whale Balaenoptera physalus were the most abundant species. In the 2615 km traveled, two hotspots for top predators were found, coinciding with frontal zones: one in the shelf-break front and the other in the Southern Front of the Antarctic Circumpolar Current. The highest bird diversity and the greatest cetacean concentrations were recorded in the polar regime in the presence of low ice-field debris (5%). The results suggest that at the end of the austral summer, the distribution of top predators in this section of the South Atlantic Ocean is highly unequal. Some oceanic areas have a few species aggregations which contrast with the vast pelagic areas that have scarce species presence and activity. The hotspots were associated with high-productivity areas, but it is likely that they were also facilitated by the time of year (post-reproductive season), as most of the species were concentrated and had fed prior to their migrations
Extreme events as ecosystems drivers: Ecological consequences of anomalous Southern Hemisphere weather patterns during the 2001/2002 austral spring-summer
Get PDFThe frequency and severity of extreme events associated with global change are both forecast to increase with a concomitant increase expected in perturbations and disruptions of fundamental processes at ecosystem, community and population scales, with potentially catastrophic consequences. Extreme events should thus be viewed as ecosystem drivers, rather than as short term deviations from a perceived ‘norm’. To illustrate this, we examined the impacts associated with the extraordinary weather pattern of the austral spring/summer of 2001/2002, and find that patterns of ocean-atmosphere interactions appear linked to a suite of extreme events in Antarctica and more widely across the Southern Hemisphere. In the Antarctic, the extreme events appear related to particular ecological impacts, including the substantial reduction in breeding success of Adélie penguins at sites in the Antarctic Peninsula as well as for Adélie penguin and snow petrel colonies in East Antarctica, and the creation of new benthic habitats associated with the disintegration of the Larsen B Ice Shelf. Other major impacts occurred in marine and terrestrial ecosystems at temperate and tropical latitudes. The suite of impacts demonstrates that ecological consequences of extreme events are manifested at fundamental levels in ecosystem processes and produce long-term, persistent effects relative to the short-term durations of the events. Changes in the rates of primary productivity, species mortality, community structure and inter-specific interactions, and changes in trophodynamics were observed as a consequence of the conditions during the 2001/2002 summer. Lasting potential consequences include reaching or exceeding tipping points, trophic cascades and regime shifts