Socio-spatial polarization and the (re-)distribution of deprived groups in world cities: A case study of Hong Kong

This paper draws on theoretical discussions of world cities to analyze socio-spatial polarization and (re-)distribution of deprived groups in Hong Kong in the 2000s. Intensifying global economic restructuring processes have induced socio-economic polarization, thereby producing deprived groups although the spatial outcomes may depend on the city-specific context. When local policies do not counteract the polarization trend, a spatial manifestation of widening socio-economic gaps can be expected. Intensified pro-growth policies adopted since Hong Kong’s return to Chinese rule in 1997 and during its economic recession in the early 2000s have worsened the impact of globalization-induced socio-economic and spatial restructuring. Census data from 2001 and 2011 show increasingly differentiated socio-economic profiles at the district level. The analysis offered in this study also points to a decreased socially mixed society in 2011 when the deprived groups lived in districts with less presence of the advantaged population.     

How well do ecosystem indicators communicate the effects of anthropogenic eutrophication?

Anthropogenic eutrophication affects the Mediterranean, Black, North and Baltic Seas to various extents. Responses to nutrient loading and methods of monitoring relevant indicators vary regionally, hindering interpretation of ecosystem state changes and preventing a straightforward pan-European assessment of eutrophication symptoms. Here we summarize responses to nutrient enrichment in Europe's seas, comparing existing time-series of selected pelagic (phytoplankton biomass and community composition, turbidity, N:P ratio) and benthic (macro flora and faunal communities, bottom oxygen condition) indicators based on their effectiveness in assessing eutrophication effects. Our results suggest that the Black Sea and Northern Adriatic appear to be recovering from eutrophication due to economic reorganization in the Black Sea catchment and nutrient abatement measures in the case of the Northern Adriatic. The Baltic is most strongly impacted by eutrophication due to its limited exchange and the prevalence of nutrient recycling. Eutrophication in the North Sea is primarily a coastal problem, but may be exacerbated by climatic changes. Indicator interpretation is strongly dependent on sea-specific knowledge of ecosystem characteristics, and no single indicator can be employed to adequately compare eutrophication state between European seas. Communicating eutrophication-related information to policy-makers could be facilitated through the use of consistent indicator selection and monitoring methodologies across European seas. This work is discussed in the context of the European Commission's recently published Marine Strategy Directive.     

The use of steroid markers to assess sewage contamination of the Black Sea

Analyses of faecal steroids in coastal sediments taken from throughout the Black Sea indicate chronic sewage contamination at some locations. These include Sochi, where concentrations of coprostanol up to 5400 ng g(-1) (dry wt) were recorded, and in the coastal areas adjacent to the Danube delta (2600 ng g(-1) dry wt). Comparatively high values of 5beta/(5beta+5alpha) isomeric ratios of cholestan-3-ol and cholestan-3-one are reported at these locations and are characteristic of sediments contaminated with sewage. Lower concentrations of coprostanol are reported for Bosphorus sediments (12-440 ng g(-1) dry wt) and in the region of Odessa (130-290 ng g(-1) dry wt). Isomeric ratios at these locations also confirm sewage as a significant contributor to steroids in the Bosphorus, but lower values of the ratios indicate only minor sewage inputs in Odessa. In contrast, steroid concentrations and compositions from most Ukrainian sites are characteristic of uncontaminated environments. To place these results into perspective, the range in levels of coprostanol in the Black Sea sediments compares to the lower to mid-range of concentrations reported for coastal sediments on a world-wide basis, with Black Sea sedimentary levels substantially below those previously reported for heavily impacted sites.     

Effects of Resolution,Cumulus Parameterization Scheme,and Probability Forecasting on Precipitation Forecasts in a High-Resolution Limited-Area Ensemble Prediction System

This study investigates the effects of horizontal resolution, cumulus parameterization scheme (CPS), and probability forecasting on precipitation forecasts over the Korean Peninsula from 00 UTC 15 August to 12 UTC 14 September 2013, using the limited-area ensemble prediction system (LEPS) of the Korea Meteorological Administration. To investigate the effect of resolution, the control members of the LEPS with 1.5- and 3-km resolution were compared. Two 3-km experiments with and without the CPS were conducted for the control member, because a 3-km resolution lies within the gray zone. For probability forecasting, 12 ensemble members with 3-km resolution were run using the LEPS. The forecast performance was evaluated for both the whole study period and precipitation cases categorized by synoptic forcing. The performance of precipitation forecasts using the 1.5-km resolution was better than that using the 3-km resolution for both the total period and individual cases. The result of the 3-km resolution experiment with the CPS did not differ significantly from that without it. The 3-km ensemble mean and probability matching (PM) performed better than the 3-km control member, regardless of the use of the CPS. The PM complemented the defect of the ensemble mean, which better predicts precipitation regions but underestimates precipitation amount by averaging ensembles, compared to the control member. Further, both the 3-km ensemble mean and PM outperformed the 1.5-km control member, which implies that the lower performance of the 3-km control member compared to the 1.5-km control member was complemented by probability forecasting.     

Petroleum and PAH contamination of the Black Sea

Concern has been expressed regarding the extent of contamination of the Black Sea. Analyses of coastal sediments taken from throughout the region indicate, however, that levels of petroleum hydrocarbons (2-300 microg g(-1) dry wt total hydrocarbons) are generally comparable to those encountered in the Mediterranean and are lower than concentrations reported for highly contaminated areas such as the Gulf, Hong Kong, Taiwan and New York Bight. Highest concentrations of total hydrocarbons (>100 microg g(-1) dry wt) were associated with discharges from Odessa, Sochi and the River Danube. Chronic/degraded petroleum was the major contributor at these sites. Samples from the Ukrainian coastline were comparatively clean (<10 microg g(-1) dry wt total hydrocarbons). Major contributions of fresh oil (as indicated by sigma n-C14-34) occur through the River Danube. Concerning total PAH, concentrations (7-638 ng g(-1) dry wt) compare to relatively unpolluted locations in the Mediterranean and are much lower than levels reported for polluted UK estuaries (e.g. Mersey, Tyne, Thames). Both pyrolytic and petrogenic PAH are present in most samples, although petroleum derived PAH are dominant at Sochi and pyrolytic sources are prevalent in the Bosphorus region. The absence of a correlation between total hydrocarbons and PAH (R2 = 0.04) indicates different primary sources for the two.     

Statistical distributions of singular vectors for tropical cyclones affecting Korea over a 10-year period

To investigate the statistical sensitivity distributions of tropical cyclone (TC) forecasts over the Korean Peninsula, total energy (TE) singular vectors (SVs) were calculated and evaluated over a 10-year period. TESVs were calculated using the fifth-generation Pennsylvania State University/National Center for Atmospheric Research Mesoscale Model (MM5) and its tangent linear and adjoint models with a Lanczos algorithm over a 48-h period. Chosen cases were 21 TCs that affected the Korean Peninsula among 230 TCs that were generated in the western North Pacific from 2001 to 2010. Sensitive regions indicated by TESVs were mainly located near mid-latitude troughs and TC centers but varied depending on TC track and environmental conditions such as subtropical high and mid-latitude trough. The cases were classified into three groups by clustering TC tracks based on the finite mixture model. The two groups that passed through the western and southern sea of the Korean Peninsula had maximally sensitive regions in the mid-latitude trough and largely sensitive regions around the TC center, while the other group that passed straight through the eastern sea of the Korean Peninsula had maximally sensitive regions near the northeastern region of the TC center. Vertically, the former two clustered groups had the westerly tilted TESVs and potential vorticity structures under the mid-latitude troughs at the initial time, indicating the TCs were in a baroclinic environment. Conversely, the straight-moving TCs were not in a baroclinic environment. Based on the results in the present study, the TCs moving toward a fixed verification region over the Korean Peninsula have different sensitivity regions and structures according to their moving tracks and characteristic environmental conditions, which may provide guidance for targeted observations of TCs affecting the Korean Peninsula.     

Re-study on recurrence period of Stokes wave train with high order spectral method

Owing to the Benjamin-Feir instability,the Stokes wave train experiences a modulation-demodulation process,and presents a recurrence characteristics.Stiassnie and Shemer researched the unstable evolution process and provided a theoretical formulation for the recurrence period in 1985 on the basis of the nonlinear cubic Schr dinger equation(NLS).However,NLS has limitations on the narrow band and the weak nonlinearity.The recurrence period is re-investigated in this paper by using a highly efficient High Order Spectral(HOS) method,which can be applied for the direct phaseresolved simulation of the nonlinear wave train evolution.It is found that the Stiassnie and Shemer’s formula should be modified in the cases with most unstable initial conditions,which is important for such topics as the generation mechanisms of freak waves.A new recurrence period formula is presented and some new evolution characteristics of the Stokes wave train are also discussed in details.     

The effect of optimization and the nesting domain on carbon flux analyses in Asia using a carbon tracking system based on the ensemble Kalman filter

To estimate the surface carbon flux in Asia and investigate the effect of the nesting domain on carbon flux analyses in Asia, two experiments with different nesting domains were conducted using the CarbonTracker developed by the National Oceanic and Atmospheric Administration. CarbonTracker is an inverse modeling system that uses an ensemble Kalman filter (EnKF) to estimate surface carbon fluxes from surface CO₂ observations. One experiment was conducted with a nesting domain centered in Asia and the other with a nesting domain centered in North America. Both experiments analyzed the surface carbon fluxes in Asia from 2001 to 2006. The results showed that prior surface carbon fluxes were underestimated in Asia compared with the optimized fluxes. The optimized biosphere fluxes of the two experiments exhibited roughly similar spatial patterns but different magnitudes. Weekly cumulative optimized fluxes showed more diverse patterns than the prior fluxes, indicating that more detailed flux analyses were conducted during the optimization. The nesting domain in Asia produced a detailed estimate of the surface carbon fluxes in Asia and exhibited better agreement with the CO₂ observations. Finally, the simulated background atmospheric CO₂ concentrations in the experiment with the nesting domain in Asia were more consistent with the observed CO₂ concentrations than those in the experiment with the nesting domain in North America. The results of this study suggest that surface carbon fluxes in Asia can be estimated more accurately using an EnKF when the nesting domain is centered in Asian regions.     

Historical record of metal accumulation and lead source in the southeastern coastal region of Korea

Concentrations of heavy metals and Pb isotopes were measured in the 1-M HCl leaching fraction of core sediments spanning the last 400 years. This sedimentary record of pollution history in metal concentrations shows a good correlation with the increases in industrialization, urbanization, and energy consumption since 1901s. Notably, the Pb concentration and the ²⁰⁷Pb/²⁰⁶Pb and ²⁰⁸Pb/²⁰⁶Pb ratios were constant before the 1910s (16.7 μg/g, 0.844, and 2.098, respectively), whereas they increased steadily up to 21.9 μg/g, 0.848, and 2.101 after the 1910s. The correlations between Pb isotope ratios (²⁰⁶Pb, ²⁰⁷Pb, and ²⁰⁸Pb) showed different linear regression trends for core sediments before and after the 1910s, indicating differences in Pb sources. Our interpretation suggests that the source of anthropogenic Pb in Korean coastal region and the Yellow Sea shelf was presumed to be Chinese coals or ores, which have also played a major role as sources of atmospheric particulate Pb.