http://www.igsnrr.cas.cn/xwzx/jxlwtj/201011/P020101104391081976901.pdf

A review of heavy metal contaminations in urban soils, urban road dusts and agricultural soils from China.

[1] Arctic amplification (AA) – the observed enhanced warming in high northern latitudes relative to the northern hemisphere – is evident in lower-tropospheric temperatures and in 1000-to-500 hPa thicknesses. Daily fields of 500 hPa heights from the National Centers for Environmental Prediction Reanalysis are analyzed over N. America and the N. Atlantic to assess changes in north-south (Rossby) wave characteristics associated with AA and the relaxation of poleward thickness gradients. Two effects are identified that each contribute to a slower eastward progression of Rossby waves in the upper-level flow: 1) weakened zonal winds, and 2) increased wave amplitude. These effects are particularly evident in autumn and winter consistent with sea-ice loss, but are also apparent in summer, possibly related to earlier snow melt on high-latitude land. Slower progression of upper-level waves would cause associated weather patterns in mid-latitudes to be more persistent, which may lead to an increased probability of extreme weather events that result from prolonged conditions, such as drought, flooding, cold spells, and heat waves.

Soil amendments for immobilization of potentially toxic elements in contaminated soils: A critical review.

Heavy metal pollution of coal mine-affected agricultural soils in the northern part of Bangladesh

Heavy metal contamination is a globally recognized environmental issue, threatening human life very seriously. Increasing population and high demand for food resulted in release of various contaminants into environment that finally contaminate the food chain. Edible plants are the major source of diet, and their contamination with toxic metals may result in catastrophic health hazards. Heavy metals affect the human health directly and/or indirectly; one of the indirect effects is the change in plant nutritional values. Previously, a number of review papers have been published on different aspects of heavy metal contamination. However, no related information is available about the effects of heavy metals on the nutritional status of food plants. This review paper is focused upon heavy metal sources, accumulation, transfer, health risk, and effects on protein, amino acids, carbohydrates, fats, and vitamins in plants. The literature about heavy metals in food plants shows that both leafy and nonleafy vegetables are good accumulators of heavy metals. In nonleafy vegetables, the bioaccumulation pattern was leaf > root ≈ stem > tuber. Heavy metals have strong influence on nutritional values; therefore, plants grown on metal-contaminated soil were nutrient deficient and consumption of such vegetables may lead to nutritional deficiency in the population particularly living in developing countries which are already facing the malnutrition problems.

The uptake and bioaccumulation of heavy metals by food plants, their effects on plants nutrients, and associated health risk: a review.

Multivariate analysis of heavy metal contamination in urban dusts of Xi’an, Central China

Global climate is influenced by the Arctic hydrologic cycle, which is, in part, regulated by sea ice through its control on evaporation and precipitation. However, the quantitative link between precipitation and sea ice extent is poorly constrained. Here we present observational evidence for the response of precipitation to sea ice reduction and assess the sensitivity of the response. Changes in the proportion of moisture sourced from the Arctic with sea ice change in the Canadian Arctic and Greenland Sea regions over the past two decades are inferred from annually averaged deuterium excess (d-excess) measurements from six sites. Other influences on the Arctic hydrologic cycle, such as the strength of meridional transport, are assessed using the North Atlantic Oscillation index. We find that the independent, direct effect of sea ice on the increase of the percentage of Arctic sourced moisture (or Arctic moisture proportion, AMP) is 18.2 ± 4.6% and 10.8 ± 3.6%/100,000 km2 sea ice lost for each region, respectively, corresponding to increases of 10.9 ± 2.8% and 2.7 ± 1.1%/1 °C of warming in the vapor source regions. The moisture source changes likely result in increases of precipitation and changes in energy balance, creating significant uncertainty for climate predictions.

https://www.pnas.org/content/pnas/113/1/46.full.pdf

Influence of sea ice on Arctic precipitation.

[1] We use data from Global Network of Isotopes in Precipitation (GNIP) database to explore how the atmosphere's meridional circulation cells control the latitudinal and seasonal distribution of δ18O and d-excess in precipitation. We demonstrate that the atmospheric general circulation (AGC) cells determine variations of zonally averaged isotopic composition of meteoric water; the local isotopic minimum near the equator coincides with the intertropical convergence (ITC), and two maxima on either side of the ITC coincide with the subtropical highs (STHs). Both the ITC and STHs migrate cum sole, as part of the systematic annual migration of the meridional cells. This migratory circulation pattern controls the phase of the annual oscillation of the precipitation δ18O. At latitudes equatorward of the STHs, δ18O reaches its maximum in the winter of the respective hemisphere and at higher latitudes in the summer. From the monthly latitudinal distribution of the vertical velocity at the 500-hPa level, we obtain the seasonal variations of the latitudinal positions of the subtropical moisture source regions and their climates. The sea surface temperature and relative humidity at the moisture source regions are used to predict seasonal changes of the d-excess of water vapor evaporated from the source regions. The GNIP data is consistent with the predicted phase of the d-excess. However, the observed magnitude of the seasonal oscillation is greater than the predicted values. This work provides a baseline for understanding the influence of subtropical moisture source regions and other climatological factors on the d-excess.

https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2008JD011279

Seasonality of isotopes in precipitation: A global perspective

Particulate-associated potentially harmful elements in urban road dusts in Xi’an, China

Abstract Understanding an isotopic evolution of a snowpack is important for both climate and hydrological studies, because the snowmelt is a significant component of groundwater and surface runoff in temperate areas. In this work, we studied oxygen and hydrogen isotopic evolution from new snow to snow profile and to meltwater through two winter seasons (1998 and 2001) at the Central Sierra Snow Laboratory, California, USA. The slopes of the δD vs. δ18O regression for the new snow are similar to that of the global meteoric water line (GMWL) of 8. However, this slope decreases in the snow profile and decreases further in the meltwater. We attribute this systematic slope changes to the isotopic exchange between ice and liquid water that is generated at the snow surface by melting and flows through the snowpack by percolation. A physically-based one-dimensional model, including melting of snow at the surface and isotopic exchange between percolating water and ice, was used to simulate isotopic variation of snowmelt in 2001. A successful simulation was obtained for the δD–δ18O slope of snowmelt (6.5), which is significantly lower than the slope of the meteoric water line (8.2) defined by the new snow. This result indicates that the liquid water evaporation should not be considered as the only process that yields slopes of the δD vs. δ18O relationship in surface water and groundwater. The d-excess of the snowmelt is changed from the original snow because of the δD–δ18O relationship controlled by ice–liquid exchange. With a δD–δ18O slope less than 8, the d-excess would be anti-correlated with δD or δ18O. The model is also used to examine how isotopic heterogeneity of a snowpack affects the isotopic redistribution in the pore water, ice and meltwater of the snowpack. The results show that isotopic heterogeneity of the snowpack may significantly affect the temporal changes in the δD–δ18O slopes, and a measured slope at a given time is a combined result of meteorological conditions, which affect both isotopic composition of the original snow and the process of snow metamorphism, and the melting history of the snowpack.

Eric S. Posmentier

Papers

Multivariate analysis of heavy metal contamination in urban dusts of Xi’an, Central China

Influence of sea ice on Arctic precipitation.

Seasonality of isotopes in precipitation: A global perspective

Particulate-associated potentially harmful elements in urban road dusts in Xi’an, China

Isotopic evolution of a seasonal snowcover and its melt by isotopic exchange between liquid water and ice