西北太平洋大气海洋对东北亚冷夏形成的影响

通过对东北亚夏季气温场与全球海温场的SVD分析,得出东北亚冷夏的产生与西北太平洋海温场有着密切的联系,普查120a来东北亚冷夏年西北太平洋海温距平状况,发现该区域93%为负距平.对1881-1999年西北太平洋海温指数NWP及Nino3.4序列与东北亚夏季气温序列的相关分析得出,西北太平洋海温与东北亚冷夏的关系较El Nino与之的关系要直接得多.从西北太平洋影响东北亚夏季气温的机理来看,西北太平洋海洋与大气环流共同对东北亚夏季气温产生着影响,当夏季西北太平洋吸收的短波辐射较少,海温距平为负,向大气释放的潜热通量较少,而500hPa位势高度场偏低时,东北亚发生冷夏的可能性较大.     

Natural radionuclides distribution and environmental impacts of ferruginous sand-siltstone (raw material) and their manufactured Ahmer oxide used as wall paints

Commercially known Ahmer oxide paints are prepared from raw material mainly composed of red iron oxides (hematite) and iron oxyhydroxides. The raw material used in manufacturing of Ahmer oxide comes from some localities in southwest Sinai such as Abu Thor, Allouga, and El lehian. The adsorption of uranium and other radioelements on iron oxides could make the raw material (red iron oxides) and their products environmentally hazardous. The studied samples were subjected to radiometric analysis using NaI (Tl) gamma-ray spectrometer. The average activity concentration of U, Th, Ra, and K are 108.7, 458.8, 88.8, and 627.5?Bq?kg^?1, respectively in raw material and 136.4, 14.6, 58.3, and 95.9?Bq?kg^?1 in Ahmer oxide. High values of activity concentrations of ²³⁸U, ²²⁶Ra, and ⁴⁰K were recorded in Allouga and El lehian raw material. High radioactivities of Allouga and El lehian raw material are mainly attributed to the presence of torbernite, zircon, and monazite, in addition to adsorbed elemental uranium in Ahmer oxide. absorbed dose rate (D), annual effective dose equivalent, radium equivalent activity (Ra_eq), external hazard index (H_ex), and internal hazard index (H_in), as well as representative gamma index (Iγ) were determined from the activity concentrations of ²²⁶Ra, ²³²Th, and ⁴⁰K. Some of the studied samples do not satisfy the universal standards.     

Evaluation of the influence of El Niño–Southern Oscillation on air quality in southern China from long-term historical observations

•Strong ENSO influence on AOD is found in southern China region. •Low AOD occurs in El Niño but high AOD occurs in La Niña events in southern China. •Angstrom exponent anomalies reveals the circulation pattern during each ENSO phase. •ENSO exerts large influence (70.5%) on annual variations of AOD during 2002–2020. •Change of anthropogenic emissions is the dominant driver for AOD trend (2002–2020). Previous studies demonstrated that the El Niño–Southern Oscillation (ENSO) could modulate regional climate thus influencing air quality in the low-middle latitude regions like southern China. However, such influence has not been well evaluated at a long-term historical scale. To filling the gap, this study investigated two-decade (2002 to 2020) aerosol concentration and particle size in southern China during the whole dynamic development of ENSO phases. Results suggest strong positive correlations between aerosol optical depth (AOD) and ENSO phases, as low AOD occurred during El Niño while high AOD occurred during La Niña event. Such correlations are mainly attributed to the variation of atmospheric circulation and precipitation during corresponding ENSO phase. Analysis of the angstrom exponent (AE) anomalies further confirmed the circulation pattern, as negative AE anomalies is pronounced in El Niño indicating the enhanced transport of sea salt aerosols from the South China Sea, while the La Niña event exhibits positive AE anomalies which can be attributed to the enhanced import of northern fine anthropogenic aerosols. This study further quantified the AOD variation attributed to changes in ENSO phases and anthropogenic emissions. Results suggest that the long-term AOD variation from 2002 to 2020 in southern China is mostly driven (by 64.2%) by the change of anthropogenic emissions from 2002 to 2020. However, the ENSO presents dominant influence (70.5%) on year-to-year variations of AOD during 2002–2020, implying the importance of ENSO on varying aerosol concentration in a short-term period.     

金华旱涝趋势统计分析

根据对旱涝自身变化及其与太阳黑子活动，厄尔尼诺事件关系的分析，，得出了金华旱涝趋势的几点认识：（1）在未来的十几年之内，金华站将从涝年占优势的阶段转入旱年占优势的阶段；（2）在太阳黑子活动22年的磁周期转变年前后，金华站3年平均年降水量明显偏多；（3）在春季型厄尔尼诺事件的当年和夏季型厄尔尼诺事件的次年，金华站年降水量偏多；（4）厄尔尼诺事件的结束时间若超过5月1日，那么次年金华站年降水量偏多；（5）厄尔尼诺事件的强度越大，对金华站年降水量的影响也越大；（6）在太阳黑子活动22年磁周期转变年前后的厄尔尼诺事件的次年，金华站年降水量明显偏多。这些认识对长期及超长期的旱涝趋势预测具有重要的现实意义。     

Multiple impact pathways of the 2015–2016 El Niño in coastal Kenya

The 2015–2016 El Niño had large impacts globally. The effects were not as great as anticipated in Kenya, however, leading some commentators to call it a ‘non-event’. Our study uses a novel combination of participatory Climate Vulnerability and Capacity Analysis tools, and new and existing social and biophysical data, to analyse vulnerability to, and the multidimensional impacts of, the 2015–2016 El Niño episode in southern coastal Kenya. Using a social-ecological systems lens and a unique dataset, our study reveals impacts overlooked by conventional analysis. We show how El Niño stressors interact with and amplify existing vulnerabilities to differentially impact local ecosystems and people. The policy significance of this finding is that the development of specific national capacities to deal with El Niño events is insufficient; it will be necessary to also address local vulnerabilities to everyday and recurrent stressors and shocks to build resilience to the effects of El Niño and other extremes in climate and weather.Electronic supplementary materialThe online version of this article (10.1007/s13280-020-01321-z) contains supplementary material, which is available to authorized users.     

Risk and the neoliberal state: why post-Mitch lessons didn't reduce El Salvador's earthquake losses

Although El Salvador suffered light losses from Hurricane Mitch in 1998, it benefited from the increased international aid and encouragement for advance planning, especially mitigation and prevention interventions. Thus, one would have supposed, El Salvador would have been in a very advantageous position, able more easily than its economically crippled neighbours, Honduras and Nicaragua, to implement the 'lessons of Mitch'. A review of the recovery plan tabled by the El Salvador government following the earthquakes of early 2001 shows that despite the rhetoric in favour of 'learning the lessons of Mitch', very little mitigation and prevention had actually been put in place between the hurricane (1998) and the earthquakes (2001). The recovery plan is analysed in terms of the degree to which it deals with root causes of disaster vulnerability, namely, the economic and political marginality of much of the population and environmental degradation. An explanation for the failure to implement mitigation and preventive actions is traced to the adherence by the government of El Salvador to an extreme form of neoliberal, free market ideology, and the deep fissures and mistrust in a country that follow a long and bloody civil war.     

Rapid Assessment of Soil Erosion in the Rio Lempa Basin, Central America, Using the Universal Soil Loss Equation and Geographic Information Systems

Soil erosion is a severe problem for many developing regions that lack adequate infrastructure to combat the problem. The authors established a first-order method for prioritizing areas to be examined and remediated using preexisting data and expert knowledge where data are lacking. The Universal Soil Loss Equation was applied to the Rio Lempa Basin in Central America using geographic information systems and remote sensing technologies, and the estimated erosion rates were compared with sediment delivery ratios. Spatial analysis indicates that agriculture on very steep slopes contributes only a small fraction to the total estimated soil erosion, whereas agriculture on gentle and moderately steep slopes contributes a large fraction of the erosion. Although much of the basin is in El Salvador, the greatest estimated amount of erosion is from Honduras. Data quality and availability were impaired by a lack of coordination among agencies and across countries. Several avenues for improving the authors’ methods are described.     

1997/1998厄尔尼诺与江苏气象灾害及对农业影响的分析

１９９７／１９９８厄尔尼诺事件在１９９７～１９９８年冬春给江苏省带来严重气象灾害， 导致三麦、油菜减产近３成。夏季长江出现仅次于１９５４年的全流域性特大洪涝， 形势十分严峻。本文以大量翔实的数据与灾情资料， 分析了厄尔尼诺与江苏气象灾害的密切关系， 提请人们关注厄尔尼诺， 预防气象灾害。     

Emergency and institutional crisis in Peru during El Nino 1982-1983

From December 1982 through July 1983, Peru was plagued by disastrous consequences of El Nino/Southern Oscillation phenomenon. While the northern part of the country was devastated by torrential rains and floods, central Andean Peru endured landslides and flash floods, the southern Altiplano suffered a severe drought. Hazard preparedness was nonexistent, and official disaster relief uncoordinated and slow in coming. Administrative inefficiency magnified the stress upon the populations under disaster conditions. Provisions of disaster training from specialized international organizations is recommended as a preventive measure and as a policy to improve catastrophe-coping abilities in developing nations.     

Effect of El Nĩno on demographic,morphological, and chemical parameters in turtle-grass (Thalassia testudinum): an unexpected test of indicators

We examined the response of demographic, morphological, and chemical parameters of turtle grass (Thalassia testudinum), to much-higher-than-normal rainfall associated with an El Niño event in the winter of 1997–1998. Up to 20 inches of added rain fell between December 1997 and March 1998, triggering widespread and persistent phytoplankton blooms along the west coast of Florida. Water-column chlorophyll concentrations estimated from serial SeaWiFS imagery were much higher during the El Niño event than in the previous or following years, although the timing and magnitude of phytoplankton blooms varied among sites. Seagrass samples collected in 1997, 1998, and 1999 provided an excellent opportunity to test the responsiveness of Thalassia to decline and subsequent improvement of water quality and clarity in four estuaries. Using a scoring technique based on temporal responsiveness, spatial consistency, and statistical strength of indicators, we found that several morphological parameters (Thalassia shoot density, blade width, blade number, and shoot-specific leaf area) were responsive and consistent measures of light stress. Some morphological parameters, such as rhizome apex density, responded to declines and subsequent improvement in water clarity, but lacked the statistical discriminating power necessary to be useful indicators. However, rhizome sugar, starch, and the total carbohydrate concentrations also exhibited spatially and temporally consistent variation as well as statistical strength. Because changes in shoot density, as well as water clarity, affect rhizome carbohydrate levels, a composite metric based on Thalassia shoot density and rhizome carbohydrate levels together is probably more useful than either parameter alone as an indicator of seagrass health.