Relative Impacts of Sea Ice Loss and Atmospheric Internal Variability on the Winter Arctic to East Asian Surface Air Temperature Based on Large-Ensemble Simulations with NorESM2

To quantify the relative contributions of Arctic sea ice and unforced atmospheric internal variability to the “warm Arctic, cold East Asia”(WACE) teleconnection, this study analyses three sets of large-ensemble simulations carried out by the Norwegian Earth System Model with a coupled atmosphere–land surface model, forced by seasonal sea ice conditions from preindustrial, present-day, and future periods. Each ensemble member within the same set uses the same forcing but with small perturbations to the atmospheric initial state. Hence, the difference between the present-day(or future) ensemble mean and the preindustrial ensemble mean provides the ice-loss-induced response, while the difference of the individual members within the present-day(or future) set is the effect of atmospheric internal variability. Results indicate that both present-day and future sea ice loss can force a negative phase of the Arctic Oscillation with a WACE pattern in winter. The magnitude of ice-induced Arctic warming is over four(ten) times larger than the ice-induced East Asian cooling in the present-day(future) experiment;the latter having a magnitude that is about 30% of the observed cooling. Sea ice loss contributes about 60%(80%) to the Arctic winter warming in the present-day(future) experiment. Atmospheric internal variability can also induce a WACE pattern with comparable magnitudes between the Arctic and East Asia. Ice-lossinduced East Asian cooling can easily be masked by atmospheric internal variability effects because random atmospheric internal variability may induce a larger magnitude warming. The observed WACE pattern occurs as a result of both Arctic sea ice loss and atmospheric internal variability, with the former dominating Arctic warming and the latter dominating East Asian cooling.

Traffic Maps and Smartphone Trajectories to Model Air Pollution, Exposure and Health Impact

In this study, we explored to combine traffic maps and smartphone trajectories to model traffic air pollution, exposure and health impact. The approach was step-by-step modeling through the causal chain: engine emission, traffic density versus traffic velocity, traffic pollution concentration, exposure along individual trajectories, and health risk. A generic street with 100 km/h speed limit was used as an example to test the model. A single fixed-time trajectory had maximum exposure at velocity of 45 km/h at maximum pollution concentration. The street population had maximum exposure shifted to a velocity of 15 km/h due to the congestion density of vehicles. The shift is a universal effect of exposure. In this approach, nearly every modeling step of traffic pollution depended on traffic velocity. A traffic map is a super-efficient pre-processor for calculating real-time traffic pollution exposure at global scale using big data analytics.

Public Perception Survey Study on Air Quality Issues in Wuhan, China

In 2013, a survey on air quality (AQ) was conducted in Wuhan, China. The aim was to investigate public awareness of air pollution, and its epidemiological effect. This survey targeted both suburban and central city regions of Wuhan city, between August and December of 2013, where it engaged 1225 participants. Approximately 65% perceived AQ in Wuhan to be “bad”. Over 95% recognized a causal association between air pollution and human health. About 65% were unaware of any action taken by the government to mitigate the air pollution situation. 84% indicated that the government should shut down highly polluting enterprises, while 95% expressed willingness to reduce private use of vehicles if required. The results demonstrate that the citizens of Wuhan are concerned about air pollution issues, and agree that improving AQ is the obligation of all citizens. Further, they called for concrete actions to improve AQ. The survey emphasized the need for better education and more activities to raise environmental awareness. The innovative aspects of this survey were the exploration of participants’ perceptions of AQ issues and the survey results may influence local government to impose stricter regulations, and to develop more effective programs involving citizens.

Towards seamless environmental prediction-development of Pan-Eurasian EXperiment(PEEX)modelling platform

The Pan-Eurasian Experiment Modelling Platform(PEEX-MP)is one of the key blocks of the PEEX Research Programme.The PEEX MP has more than 30 models and is directed towards seamless envir-onmental prediction.The main focus area is the Arctic-boreal regions and China.The models used in PEEX-MP cover several main components of the Earth’s system,such as the atmosphere,hydrosphere,pedosphere and biosphere,and resolve the physicalchemicalbiological processes at different spatial and temporal scales and resolutions.This paper introduces and discusses PEEX MP multi-scale modelling concept for the Earth system,online integrated,forward/inverse,and socioeconomical modelling,and other approaches with a particular focus on applications in the PEEX geographical domain.The employed high-performance com-puting facilities,capabilities,and PEEX dataflow for modelling results are described.Several virtual research platforms(PEEXView,Virtual Research Environment,Web-based Atlas)for handling PEEX modelling and observational results are introduced.The over-all approach allows us to understand better physical-chemicalbiological processes,Earth’s system interactions and feedbacks and to provide valuable information for assessment studies on evaluating risks,impact,consequences,etc.for population,envir-onment and climate in the PEEX domain.This work was also one of the last projects of Prof.Sergej Zilitinkevich,who passed away on 15 February 2021.Since the finalization took time,the paper was actually submitted in 2023 and we could not argue that the final paper text was agreed with him.

中国的酸化问题——一项基于重庆—广州森林监测点研究结果的评估

中国经济的快速增长一直伴随着污染的加剧。本文在现场观测和文献研究的基础上讨论了酸性降水及其先兆的范围和影响。目前酸性降水的主要原因是二氧化硫的排放,但氮氧化物的排放也在增加。中国污染最严重地区的硫化合物沉降比东欧和中欧经受严重污染的地区要高。中国南部很多地区的土壤和土壤水看来已经被酸化。这些地区的污染已经影响了森林和其他植物的生命力,特别是在位于和靠近城市地区的地方。地表水的酸化似乎在近期不会成为主要的区域性问题,但一些地区的河流,目前虽仅接受少量的酸沉降,却对酸化显得较敏感。

Verification and Improvement of the Ability of CFSv2 to Predict the Antarctic Oscillation in Boreal Spring

The boreal spring Antarctic Oscillation(AAO)has a significant impact on the spring and summer climate in China.This study evaluates the capability of the NCEP's Climate Forecast System,version 2(CFSv2),in predicting the boreal spring AAO for the period 1983-2015.The results indicate that CFSv2 has poor skill in predicting the spring AAO,failing to predict the zonally symmetric spatial pattern of the AAO,with an insignificant correlation of 0.02 between the predicted and observed AAO Index(AAOI).Considering the interannual increment approach can amplify the prediction signals,we firstly establish a dynamical-statistical model to improve the interannual increment of the AAOI(DY AAOI),with two predictors of CFSv2-forecasted concurrent spring sea surface temperatures and observed preceding autumn sea ice.This dynamical-statistical model demonstrates good capability in predicting DY AAOI,with a significant correlation coeffcient of 0.58 between the observation and prediction during 1983-2015 in the two-year-out cross-validation.Then,we obtain an improved AAOI by adding the improved DY AAOI to the preceding observed AAOI.The improved AAOI shows a significant correlation coeffcient of 0.45 with the observed AAOI during 1983-2015.Moreover,the unrealistic atmospheric response to March-April-May sea ice in CFSv2 may be the possible cause for the failure of CFSv2 to predict the AAO.This study gives new clues regarding AAO prediction and short-term climate prediction.

Projected Changes in Eurasian and Arctic Summer Cyclones under Global Warming in the Bergen Climate Model

Using the coupled ocean-atmosphere Bergen Climate Model,and a Lagrangian vorticity-based cyclone tracking method,the authors investigate current climate summer cyclones in the Northern Hemisphere and their change by the end of the 21st century,with a focus on Northern Eurasia and the Arctic.The two scenarios A1B and A2 for increasing greenhouse gas concentrations are considered.In the model projections,the total number of cyclones in the Northern Hemisphere is reduced by about 3% 4%,but the Arctic Ocean and adjacent coastal re-gions harbour slightly more and slightly stronger summer storms,compared to the model current climate.This in-crease occurs in conjunction with an increase in the high-latitude zonal winds and in the meridional tempera-ture gradient between the warming land and the ocean across Northern Eurasia.Deficiencies in climate model representations of the summer storm tracks at high lati-tudes are also outlined,and the need for further model inter-comparison studies is emphasized.

Influence of solar wind energy flux on the interannual variability of ENSO in the subsequent year

Previous studies have tended to adopt the quasi-decadal variability of the solar cycle （e.g.sunspot number （SSN） or solar radio flux at 10.7 cm （F10.7） to investigate the effect of solar activity on El Ni（n）o-Southern Oscillation （ENSO）.As one of the major terrestrial energy sources,the effect of solar wind energy flux in Earth＇s magnetosphere （Ein） on the climate has not drawn much attention,due to the big challenge associated with its quantitative estimation.Based on a new Ein index estimated by three-dimensional magnetohydrodynamic simulations from a previous study,this study reveals that Ein exhibits both quasi-decadal variability （periodic 11-year） and interannual （2-4 years） variability,which has rarely before been detected by SSN and F10.7.A significant interannual relationship between the annual mean Ein and subsequent early-winter ENSO is further revealed.Following high Ein,the sea level pressure in the subsequent early winter shows significant positive anomalies from Asia southward to the Maritime Continent,and significant negative anomalies over the Southeast and Northeast Pacific,resembling the Southern Oscillation.Meanwhile,significant upper-level anomalous convergence and divergence winds appear over the western and eastern Pacific,which is configured with significant lower-level anomalous divergence and convergence,indicating a weakening of the Walker circulation.Consequently,notable surface easterly wind anomalies prevail over the eastern tropical Pacific,leading to El Ni（n

Simulated and projected relationship between the East Asian winter monsoon and winter Arctic Oscillation in CMIP5 models

Interdecadal change in the relationship between the East Asian winter monsoon(EAWM)and the Arctic Oscillation(AO)has been documented by many studies.This study,utilizing the model outputs from phase 5 of the Coupled Model Intercomparison Project(CMIP5),evaluates the ability of the coupled models in CMIP5 to capture the intensified relationship between the EAWM and winter AO since the 1980s,and further projects the evolution of the EAWM–AO relationship during the 21st century.It is found that the observed evolution of the EAWM–AO relationship can be reproduced well by some coupled models(e.g.,GFDL-ESM2M,GISS-E2-H,and MPI-ESM-MR).The coupled models’simulations indicate that the impact of winter AO on the EAWM-related circulation and East Asian winter temperature has strengthened since the 1980s.Such interdecadal change in the EAWM–AO relationship is attributed to the intensified propagation of stationary planetary waves associated with winter AO.Projections under the RCP4.5 and RCP8.5 scenarios suggest that the EAWM–AO relationship is significant before the 2030s and after the early 2070s,and insignificant during the 2060s,but uncertain from the 2030s to the 2050s.

Plastic litter in the European Arctic:What do we know?

Despite an exponential increase in available data on marine plastic debris globally,information on levels and trends of plastic pollution and especially microplastics in the Arctic remains scarce.The few available peer-reviewed scientific works,however,point to a ubiquitous distribution of plastic particles in all environmental compartments,including sea ice.Here,we review the current state of knowledge on the sources,distribution,transport pathways and fate of meso-and microplastics with a focus on the European Arctic and discuss observed and projected impacts on biota and ecosystems.

Levels and trends of poly-and perfluoroalkyl substances in the Arctic environment-An update

Poly-and perfluoroalkyl substances(PFASs)are important environmental contaminants globally and in the early 2000s they were shown to be ubiquitous contaminants in Arctic wildlife.Previous reviews by Butt et al.and Letcher et al.have covered studies on levels and trends of PFASs in the Arctic that were available to 2009.The purpose of this review is to focus on more recent work,generally published between 2009 and 2018,with emphasis on PFASs of emerging concern such as perfluoroalkyl carboxylates(PFCAs)and short-chain perfluoroalkyl sulfonates(PFSAs)and their precursors.Atmospheric measurements over the period 2006e2014 have shown that fluorotelomer alcohols(FTOHs)as well as perfluorobutanoic acid(PFBA)and perfluoroctanoic acid(PFOA)are the most prominent PFASs in the arctic atmosphere,all with increasing concentrations at Alert although PFOA concentrations declined at the Zeppelin Station(Svalbard).Results from ice cores show generally increasing deposition of PFCAs on the Devon Ice cap in the Canadian arctic while declining fluxes were found in a glacier on Svalbard.An extensive dataset exists for long-term trends of long-chain PFCAs that have been reported in Arctic biota with some datasets including archived samples from the 1970s and 1980s.Trends in PFCAs over time vary among the same species across the North American Arctic,East and West Greenland,and Svalbard.Most long term time series show a decline from higher concentrations in the early 2000s.However there have been recent(post 2010)increasing trends of PFCAs in ringed seals in the Canadian Arctic,East Greenland polar bears and in arctic foxes in Svalbard.Annual biological sampling is helping to determine these relatively short term changes.Rising levels of some PFCAs have been explained by continued emissions of long-chain PFCAs and/or their precursors and inflows to the Arctic Ocean,especially from the North Atlantic.While the effectiveness of biological sampling for temporal trends in long-chain PFCAs and PFSAs has been demonstrated,this does not apply to the C4eC8ePFCAs,perfluorobutane sulfonamide(FBSA),or perfluorobutane sulfonate(PFBS)which are generally present at low concentrations in biota.In addition to air sampling,sampling abiotic media such as glacial cores,and annual sampling of lake waters and seawater would appear to be the best approaches for investigating trends in the less bioaccumulative PFASs.

Plastic ingestion and associated additives in Faroe Islands chicks of the Northern Fulmar Fulmarus glacialis

Northern Fulmars(Fulmarus glacialis)are a pelagic seabird species distributed at northern and polar latitudes.They are often used as an indicator of plastic pollution in the North Sea region,but data are lacking from higher latitudes,especially when it comes to chicks.Here,we investigated amounts of ingested plastic and their characteristics in fulmar chicks from the Faroe Islands.Plastic particles(≥1 mm)in chicks of two age classes were searched using a digestion method with KOH.In addition,to evaluate if additive tissue burden reflects plastic ingestion,we measured liver tissue concentrations of two pollutant classes associated with plastic materials:polybrominated diphenyl ethers(PBDEs)and several dechloranes,using gas chromatography with high-resolution mass spectrometry.The most common shape was hard fragment(81%)and the most common polymer was polyethylene(73%).Plastic contamination did not differ between either age class,and we found no correlation between neither the amount and mass of plastic particles and the concentration of additives.After comparison with previous studies on adult fulmars,we do not recommend using chicks for biomonitoring adults because chicks seem to ingest more plastics than adults.