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India’s Arctic Policy: a critical appraisal
Full text linkAfter much procrastination, the Indian government has released its much awaited and delayed Arctic Policy document on 17 March 22 with the theme being “Building a Partnership for Sustainable Development”. It has been 15 years since India commenced its scientific research in the Arctic region and this policy document, charting out the direction that India aspires to assume will be keenly examined by the diverse stakeholders of the region. Despite being an Arctic Council observer for nearly a decade, India continues to view the Arctic from a mere scientific prism and yet again missed on the opportunity to elucidate her geo-economic, geostrategic, economic and geopolitical aspirations in the hugely vital region. There is no gainsaying that the research bases discreetly also act as pillars of geopolitical engagement and indirectly this scientific diplomacy ushers in peace and prevent conflict situations yet a holistic national policy enunciating a roadmap and vision for dealing in a region which has eight sovereign states, thirteen sovereign states as observers, various intergovernmental and inter-parliamentarian outfits, NGOs and a complex governance structure was much awaited
On the horizon: What to watch in 2022
Full text linkThe world in 2021 continued to roil with the ongoing COVID-19 pandemic, intensifying
competition between the world’s major powers, questions of trust inside many of the
world’s leading democracies, and natural disasters made more intense by the effects
of climate extremes. As we look to what is on the horizon in 2022, we contend with a
geopolitical situation of greater uncertainty than at any time since the end of the Cold
War. The Wilson Center strives to provide policymakers with industry-leading expertise
that is trustworthy, nonpartisan, and rooted in the values expressed in our congressional
charter: “symbolizing and strengthening the fruitful relation between the world of
learning and the world of public affairs.” In this spirit, we present On the Horizon –
What to Watch in 2022
Climate Change 2022 - Impacts, Adaption and Vulnerability. Summary for Policymakers
Full text linkThis Summary for Policymakers (SPM) presents key findings of the Working Group II (WGII) contribution to the Sixth Assessment Report (AR6) of the IPCC1. The report builds on the WGII contribution to the Fifth Assessment Report (AR5) of the IPCC, three Special Reports2, and the Working Group I (WGI) contribution to the AR6 cycle.
This report recognizes the interdependence of climate, ecosystems and biodiversity3, and human societies (Figure SPM.1) and integrates knowledge more strongly across the natural, ecological, social and economic sciences than earlier IPCC assessments. The assessment of climate change impacts and risks as well as adaptation is set against concurrently unfolding non-climatic global trends e.g., biodiversity loss, overall unsustainable consumption of natural resources, land and ecosystem degradation, rapid urbanisation, human demographic shifts, social and economic inequalities and a pandemic.
The scientific evidence for each key finding is found in the 18 chapters of the underlying report and in the 7 cross-chapter papers as well as the integrated synthesis presented in the Technical Summary (hereafter TS) and referred to in curly brackets {}. Based on scientific understanding, key findings can be formulated as statements of fact or associated with an assessed level of confidence using the IPCC calibrated language4. The WGII Global to Regional Atlas (Annex I) facilitates exploration of key synthesis findings across the WGII regions
Effects of sea ice melt water input on phytoplankton biomass and community structure in the eastern Amundsen Sea
Full text linkSea ice melt water and circumpolar deep water (CDW) intrusion have important impacts on the ecosystem of the Amundsen Sea. In this study, samples of nutrients and phytoplankton pigments from nine stations in the eastern Amundsen Sea were collected during the austral summer. Based on in-situ hydrological observations, sea ice density data from satellite remote sensing, and chemical taxonomy calculations, the relationships between environmental factors and phytoplankton biomass and community structure were studied. The results showed that with increasing latitude, the contribution of sea ice melt water (MW%) and the stability of the water body increased, and the depth of the mixed layer (MLD) decreased. The integrated concentration of chlorophyll a (Chl-a) ranged from 21.4 mg·m−2 to 148.4 mg·m−2 (the average value was 35.7±53.4 mg·m−2). Diatoms (diatoms-A [Fragilariopsis spp., Chaetoceros spp., and Proboscia spp.] and diatoms-B [Pseudonitzschia spp.]) and Phaeocystis antarctica were the two most widely distributed phytoplankton groups and contributed 32%±16% and 28%±11%, respectively, of the total biomass. The contributions of Dinoflagellates, Chlorophytes, Cryptophytes, the high-iron group of P. antarctica, and Diatom group A were approximately 17%±8%, 15%±13%, 9%±6%, 5%±9%, and 3%±7%, respectively. The area with the highest phytoplankton biomass was located near the ice-edge region, with a short time lag (Tlag) between sampling and complete sea ice melt and a high MW%, while the area with the second-highest Chl-a concentration was located in the area affected by the upwelling of CDW, with thorough water mixing. Vertically, in the area with a short Tlag and a shallow MLD, the phytoplankton biomass and proportion of diatoms decreased rapidly with increasing water depth. In contrast, in the region with a long Tlag and limited CDW upwelling, the phytoplankton community was dominated by a relatively constant and high proportion of micro phytoplankton, and the phytoplankton biomass was low and relatively stable vertically. Generally, the phytoplankton community structure and biomass in the study area showed high spatial variation and were sensitive to environmental changes
Inventory of unintentional POPs emission from anthropogenic sources in Antarctica
Full text linkIn spite of remote location and very limited human activities, Antarctica is affected by persistent organic pollutants (POPs). POPs investigation in Antarctica has a comparatively long history, but there are still large knowledge gaps in assessment of their emission into environment. In the paper the results of the first inventory of unintentional POPs emission from anthropogenic sources in Antarctica for modern period and preliminary estimate for the late 1980s are presented. Assessment of dioxin/furans (PCDD/Fs) emission in different media, as well as polychlorinated biphenyls (PCBs) and hexachlorobenzene (HCB) in air is based on methodology of emission factors and indicators of human activity. The following sources of POPs emission have been estimated: power generation and heating, waste incineration, mobile sources and open burning of waste (in the past). According to the data obtained, annual PCDD/Fs air emission for modern period comprises 60.74 mg toxic equivalent (TEQ), PCBs – 5.09 mg TEQ, and HCB – 457.6 mg. Additionally 2.5 mg TEQ of dioxin/furans is released to residues, so total PCDD/Fs emission is amounted 63.23 mg TEQ. Waste incineration makes the greatest contribution to POPs emission (96% of PCDD/Fs, 98% of PCBs and 36% of HCB air emission). In late 1980s open burning of waste was the major source of POPs. Retrospective assessment shows that over a 30-year period air emissions of PCDD/Fs decreased about 13 times, PCBs—15 times and HCB—57 times, primarily due to the prohibition of open burning of waste in compliance with the Protocol on Environmental Protection to the Antarctic Treaty requirements
Variability of size-fractionated chlorophyll a in the high-latitude Arctic Ocean in summer 2020
Full text linkThe size structure of phytoplankton has considerable effects on the energy flow and nutrient cycling in the marine ecosystem, and thus is important to marine food web and biological pump. However, its dynamics in the high-latitude Arctic Ocean, particularly ice-covered areas, remain poorly understood. We investigated size-fractionated chlorophyll a (Chl a) and related environmental parameters in the highly ice-covered Arctic Ocean during the summer of 2020, and analyzed the relationship between Chl a distribution and water mass through cluster analysis. Results showed that inorganic nutrients were typically depleted in the upper layer of the Canada Basin region, and that phytoplankton biomass was extremely low (mean= 0.05 ± 0.18 mg·m−3) in the near-surface layer (upper 25 m). More than 80% of Chl a values were <0.1 mg·m−3 in the water column (0–200 m), but high values appeared at the ice edge or in corresponding ice areas on the shelf. Additionally, the mean contribution of both nanoplankton (2–20 μm) (41%) and picoplankton (<2 μm) (40%) was significantly higher than that of microplankton (20–200 μm) (19%). Notably, the typical subsurface chlorophyll maximum (0.1 mg·m−3) was found north of 80°N, where the concentration of sea ice reached approximately 100%. The Chl a profile results showed that the deep chlorophyll maximum of total-, micro-, nano-, and picoplankton was located at depth of 40, 39, 41, and 38 m, respectively, indicating that nutrients are the primary factor limiting phytoplankton growth in the ice-covered Arctic Ocean during summer. These phenomena suggest that, despite the previous literatures pointing to significant light limitation under the Arctic ice, the primary limiting factor for phytoplankton in summer is still nutrient
Particle dynamics revealed by 210Po/210Pb disequilibria around Prydz Bay, the Southern Ocean in summer
Full text linkSeawater samples were collected around Prydz Bay in summer of 2014, dissolved and particulate 210Po and 210Pb were measured to reveal the disequilibrium characteristics and particle dynamics. Our results show that the distribution of 210Po and 210Po/210Pb activity ratio in the upper water is mainly affected by biological absorption or particle adsorption. An abnormal excess of 210Po relative to 210Pb was observed in the surface water at stations P1-2 and P2-2, which is likely to be the horizontal transport of water mass with high DPo/DPb)A.R. and TPo/TPb)A.R.. In this study, the removal of particulate 210Po is mainly controlled by the scavenging of dissolved 210Po and the two have a linear positive correlation with the salinity, a negative linear correlation with the content of dissolved oxygen and a reciprocal relationship with the content of POC. The export flux of POC at 100 m is estimated to be 1.8–4.4 mmol·m−2·d−1 (avg. 2.9 mmol·m−2·d−1) based on 210Po/210Pb disequilibria, with the highest value in the shelf, which is consistent with the distribution of biological productivity
The evaluation of biological productivity by triple isotope composition of oxygen trapped in ice-core bubbles and dissolved in ocean: a review
Full text linkThe 17O anomaly of oxygen (Δ17O, calculated from δ17O and δ18O) trapped in ice-core bubbles and dissolved in ocean has been respectively used to evaluate the past biosphere productivity at a global scale and gross oxygen production (GOP) in the mixed layer (ML) of ocean. Compared to traditional methods in GOP estimation, triple oxygen isotope (TOI) method provides estimates that ignore incubation bottle effects and calculates GOP on larger spatial and temporal scales. Calculated from TOI of O2 trapped in ice-core bubbles, the averaged global biological productivities in past glacial periods were about 0.83–0.94 of the present, and the longest time record reached 400 ka BP (thousand years before the present). TOI-derived GOP estimation has also been widely applied in open oceans and coastal oceans, with emphasis on the ML. Although the TOI method has been widely used in aquatic ecosystems, TOI-based GOP is assumed to be constant at a steady state, and the influence of physical transports below the ML is neglected. The TOI method applied to evaluate past total biospheric productivity is limited by rare samples as well as uncertainties related to O2 consumption mechanisms and terrestrial biosphere’s hydrological processes. Future studies should take into account the physical transports below the ML and apply the TOI method in deep ocean. In addition, study on the complex land biosphere mechanisms by triple isotope composition of O2 trapped in ice-core bubbles needs to be strengthened
Concentration maxima of methane in the bottom waters over the Chukchi Sea shelf: implication of its biogenic source
Full text linkKnowledge about the distribution of CH4 remains insufficient due to the scarcity of data in the Arctic shelves. We conducted shipboard observations over the Chukchi Sea shelf (CSS) in the western Arctic Ocean in September 2012 to obtain the distribution and source characteristics of dissolved CH4 in seawater. The oceanographic data indicated that a salinity gradient generated a pronounced pycnocline at depths of 20–30 m. The vertical diffusion of biogenic elements was restricted, and these elements were trapped in the bottom waters. Furthermore, high CH4 concentrations were measured below the pycnocline, and low CH4 concentrations were observed in the surface waters. The maximum concentrations of nutrients simultaneously occurred in the dense and cold bottom waters, and significant correlations were observed between CH4 and 2 3 SiO , 3 4 PO , 2 NO , and 4 NH (p < 0.01, n= 44). These results suggest that the production of CH4 in the CSS has a similar trend as that of nutrient regeneration and is probably associated with the degradation of organic matter. The high primary productivity and high concentration of organic matter support the formation of biogenic CH4 in the CSS and the subsequent release of CH4 to the water column