The role of the Arctic and Antarctic and their impact on global climate change: Further findings since the release of IPCC AR4, 2007

Changes in the climate of the Arctic and of the Antarctic have been of great concern to the international scientific and social communities since the release in 2007 of the Intergovernmental Panel on Climate Change Fourth Assessment Report (IPCC AR4). Since then, many new findings have been reported from observations and research carried out in the Arctic and Antarctic during the fourth International Polar Year (IPY). There is evidence that global warming is inducing rapid changes in the Arctic and Antarctic, in both a quantitative and qualitative sense, and that these regional changes could be used as indicators of global climate change. Declining Arctic sea ice could affect winter snowfall across much of the Northern Hemisphere by bringing harsher winters. Projections suggest that summertime Arctic sea ice will disappear by 2037. By the 2070s, the Antarctic ozone hole will recover to the level of the early 1980s, following the ban on the production of Freon earlier this century. With the loss of the shielding effect of the ozone hole, Antarctic surface temperatures will increase, ice sheets in East Antarctica will begin to melt, and the Antarctic sea ice will retreat. Therefore, sea level rise will become an increasingly serious issue this century. As sea surface temperature rises, the Southern Ocean will become less effective as a sink for atmospheric CO2 and the increase of surface CO2 will be faster than that in the atmosphere. Increased surface CO2 would lead to ocean acidification and affect ecological systems and food chains

Pre-stressed Bi-stable Hair Clip Mechanism for Faster Swimming Robots

Structural instability is a hazard that leads to catastrophic failure and is generally avoided through special designs. A trend, however, has emerged over the past decades pointing to the harnessing of mechanisms with instability. Inspired by the snapping of a hair clip, we are finessing the unique characteristics of the lateral-torsional buckling of beams and the snap-through of pre-buckled dome-like thin-wall structures in a new field: the in-plane prestressed mechanism. Analyses reveal how the 2D-3D assembly of an in-plane prestressed actuator (IPA) is achieved and how the post-buckling energy landscape is pictured. Combining them with soft robotics, we show that the inclusion of a bistable IPA can enormously enhance the performance of an underwater fish robot as well as inspire a finger-like soft gripper.Comment: Posted repeatedl

Characteristics of trace metals in marine aerosols and their source identification over the Southern Ocean

Atmospheric trace metals (Cu, Zn, Cd, Pb, Fe, V, and Cr), As, Al and Na in marine aerosols were studied over the Southern Ocean during the 28th Chinese National Antarctic Research Expedition. Fe was the most abundant of the analyzed trace metals, with an average concentration of 28.824 ng∙m-3. V and Zn concentrations were also high, and their average concentrations were 5.541 ng∙m-3 and 2.584 ng∙m-3, respectively. Although sea spray significantly influenced the marine aerosol particles measured (Na had the highest concentrations of the analyzed elements, with an average concentration of 2.65 μg∙m-3), multivariate analyses (enrichment factor and principal components analysis) indicated that most of the elements were not associated with oceanic sources. Over the Southern Ocean, Fe, Cd, As, Al and Cr in the aerosols mainly originated from crustal sources, while Cu, Pb, V and Zn originated from crustal sources and anthropogenic emissions. The enrichment factors (EFcrust) for most elements (Fe, Al, As, Cr, Cd, Cu and V) were much lower in the northern latitudes, indicating that when the sampling occurred closer to land the concentrations of these elements in aerosols were strongly affected by terrestrial crustal sources

Air pollution and timing of childbirth: a retrospective survey analysis based on birth registration data of Chinese newborns

ObjectivesCurrently, there is a lack of research on whether people will take action to avoid the harm of air pollution and the heterogeneous behavior of different groups. The goal of this paper is to examine the effects of air pollution on the resulting differential effects on newborns and the timing of pregnancy.MethodsBased on a survey of newborns in a total of 32 hospitals in 12 cities across China in 2011, and after matching with city-level air pollution data, a multiple regression statistical method is then used to examine how the pollution level in a certain period is related to the number of conceptions in that certain period, after controlling for region and season fixed effects.ResultsWe first demonstrate that exposure to air pollution during pregnancy is associated with a significant increase in adverse birth outcomes. Most importantly, the empirical results show that the number of conceptions decreased significantly during periods of severe air pollution.ConclusionEvidence suggests that air pollution may be causing some families to delay conception to reduce the possible adverse impact on neonatal outcomes. This helps us to understand the social cost of air pollution more, and then make more accurate environmental policies

Distributions of dissolved inorganic carbon and total alkalinity in the Western Arctic Ocean

The third Chinese National Arctic Research Expedition (3rd CHINARE-Arctic in 2008) was carried out from July to September 2008. During the survey, numerous sea water samples were taken for CO2 parameter measurement (including total alkalinity TA and total dissolved inorganic carbon DIC).The distribution of CO2 parameters in the Western Arctic Ocean was determined, and the controlling factors are addressed. The ranges of summertime TA, normalized TA (nTA), DIC and normalized DIC (nDIC) in the surface seawater were 1.757 - 2.229 μmol * kg(-1), 2.383 - 2.722 μmol * kg(-1), 1.681 - 2.034 μmol * kg(-1), 2.119 - 2.600 μmol * kg(-1), respectively. Because of dilution from ice meltwater, the surface TA and DIC concentrations were relatively low. TA in the upper 100 m to the south of 78±N had good correlation with salinity, showing a conservative behavior. The distribution followed the seawater-river mixing line at salinity >30, then followed the seawater mixing line (diluted by river water to salinity = 30) with the ice meltwater. The DIC distribution in the Chukchi Sea was dominated by biological production or respiration of organic matter, whereas conservative mixing dominated the mixed layer TA distribution in the ice-free Canada Basin

Marine biogenic aerosols and their effects on aerosol-cloud interactions over the Southern Ocean: a review

The Southern Ocean (SO) plays an important role in the global climate system. Changes in SO biogeochemistry and marine ecosystems may influence the distribution of atmospheric aerosols and clouds and impact the climate system. We reviewed current knowledge on the interactions between marine aerosols and clouds over the SO. We focused on marine primary and secondary organic aerosols and summarized their characteristics, processes and roles as cloud condensation nuclei and ice nuclei. We described in detail the interactions between the marine ecosystem, aerosols and clouds. We discussed marine productivity, formation of marine biogenic aerosols and interactions between aerosols, clouds and climate. We explored the impact of climate change on SO marine ecosystem productivity and aerosol–cloud–climate feedback. Marine biogenic aerosols could impact the radiation budget and oceanic low-level clouds over the SO. This study contributes towards an improved understanding of marine productivity, aerosol-cloud interactions and climate change in the SO. The SO may respond to climate change in varying degrees. More studies are urgently needed to support accurate forecasts of future changes in the SO

Summertime freshwater fractions in the surface water of the western Arctic Ocean evaluated from total alkalinity

As a quasi-conservative tracer, measures of total alkalinity (TA) can be utilized to trace the relative fractions of freshwater and seawater. In this study, based on the TA and related data collected during the third Chinese National Arctic Research Expedition (July—September 2008, 3rd CHINARE-Arctic) and the fourth Chinese National Arctic Research Expedition (July — September 2010, 4th CHINARE-Arctic), fractions of sea-ice meltwater, river runoff, and seawater within the surface water of the western Arctic Ocean were determined using salinity and TA relationships. The largest fraction of sea-ice meltwater was found around 75°N within the Canada Basin during both surveys, which is located at the ice edge. Generally, it was found that the fraction of river runoff was less than that of sea-ice meltwater. The river runoff, composed mainly of contributions from the Yukon River carried by Bering inflow water and the Mackenzie River, was influenced by the currents, leading to two peak areas of its fraction. Our results show that the dilution effect of freshwater carried by Bering inflow water during the 3rd CHINARE-Arctic in 2008 expedition period may be stronger than that during the 4th CHINARE-Arctic in 2010 expedition period. The peak area of sea-ice meltwater fraction during the 4th CHINARE-Arctic was different from that of the 3rd CHINARE-Arctic, corresponding to their sea-ice condition