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101.
Ultraviolet radiation (UV) and ozone can greatly affect human health and the Earth's ecological environment. By deploying a UV radiometer aboard a stratospheric balloon released at Qaidam (QDM) during the Asian summer monsoon (ASM) period in 2019, we provided in situ measurement of the UV profiles from the surface to the upper troposphere and lower stratosphere over the Tibetan Plateau (TP), China, for the first time. Based on two in situ UV profiles accompanied by four ozonesonde measurements, this study exhibited detailed variations of downwelling UV and vertical ozone distributions over the TP during the ASM period. The UV differences between the surface and stratospheric balloon flight altitudes were 16.7, 15.8, 12.6 and 18.0 Wm?2 during the four ozonesonde launches. Due to the diurnal variations in photochemical production and the stratosphere-troposphere exchange, the integrated ozone columns below 30 km ranged from 184.4 to 221.6 DU from four ozonesonde measurements. A positive correlation between UV attenuation and ozone column was exhibited under low cloud cover and clear sky conditions. The results of this study are expected to improve our understanding of UV and ozone properties, as well as their potential effects on terrestrial ecosystems and living environments over this significant plateau.  相似文献   
102.
利用2000年3月~2017年1月Terra卫星反演的最新版本C06的MODIS气溶胶光学厚度(AOD)、NCEP fnl全球业务分析数据、CMAP降水、CERES SYN1deg Ed4月平均资料、NCEP/NCAR再分析资料等,依据区域平均AOD距平的显著年际变化特征,将历年AOD划分为5个不同的污染等级,并探讨了不同污染等级的局地成因及其与季风环流的联系.结果表明,夏季中国东部地区AOD异常偏大与地面风速小、中高层季风环流系统不利于气溶胶扩散有关.气溶胶污染最重(最轻)时,气溶胶与到达地面的太阳短波辐射、地面气温、风速及降水存在密切联系;在其他污染等级下,除了与到达地面的短波辐射有密切关系外,与其他量的联系并不明显.气溶胶污染严重时,到达地面的太阳短波辐射相对减小,地面气温异常偏低,低层大气冷却,地面风速减小,地面降水呈现南多北少的变化特征;反之,气溶胶污染较轻时,到达地面的太阳短波辐射相对增加,地面气温异常偏高,低层大气加热,地面风速增大,地面降水呈现南少北多的变化特征.  相似文献   
103.
Today, the world's energy needs are still supplied mainly from fossil fuel based resources. This is true for electricity generation as well, thus making the power sector responsible for 45% of greenhouse gas emissions. The present climate crisis has made it necessary to minimise emissions in power generation, with low-carbon energy sources taking on greater significance in recent years. However, most low-carbon sources have inherent problems, like intermittency and high capital expenditure. A suitable alternative is carbon capture and storage (CCS) technology which allows continued fossil fuel-based electricity generation at much lower rates of emission. Two approaches are possible in the deployment of CCS technology. The first is to introduce new power plants equipped for carbon dioxide (CO2) capture, while systematically shutting down existing coal power plants. Another is to retrofit existing power plants for CO2 capture. These approaches are compared in this work. The study shows that allowing CCS retrofitting of existing power plants can reduce the overall cost requirement significantly. In addition, a sensitivity analysis is also done to study the effect of nuclear energy on the overall energy mix.  相似文献   
104.
2015/2016年海洋和大气环流异常对中国夏季降水的影响   总被引:1,自引:1,他引:0  
肖莺  任永建  杜良敏 《自然资源学报》2016,31(12):1995-2004
利用1981年1月-2016年8月中国160个气象站降水量资料和NCEP/NCAR资料,对比分析了2015/2016年的主要海洋和大气环流异常及其对夏季降水的影响。结果表明:1)2015和2016年夏季降水异常分布有着明显的差异。2015年夏季降水呈南多北少特点;2016年夏季降水明显增多,尤其是北方地区,且呈现经向型分布。2)热带印度洋-太平洋海温状况监测显示,2015年海温异常表现为El Niño发展年、热带印度洋全区一致模态海温偏暖、印度洋偶极子正位相;2016年海温异常表现为El Niño结束年、热带印度洋全区一致模态海温偏暖、印度洋偶极子负位相。3)2015年,受热带印度洋-太平洋海温异常影响,使得夏季西太平洋副高偏强、偏南,再配合中高纬冷空气活跃,西风急流轴位置偏南,导致我国降水北少南多。4)2016年,受El Niño衰减、印度洋偶极子负位相影响,副高偏北;叠加印度洋海温偏暖的“充电器”效应,副高偏强;同时冷空气偏北偏弱,西风急流轴位置偏北,导致长江中下游及以北区域降水偏多。  相似文献   
105.
Box core samples BC26 and BC36 from geologically different settings were examined to test the hypothesis that autochthonous microbial communities from polymetallic-nodule-rich Central Indian Basin sediments actively participate in immobilising metal ions. The bottom water dissolved oxygen concentration was reported to be 4.2–4.3 mL·L?1 in the northern siliceous ooze (BC26) and 4.1–4.2 mL·L?1 in the southern pelagic red clay (BC36); the sedimentation rates for these regions were 0.834 and 0.041 cm·kyr?1, respectively. An onboard experiment, conducted under oxic and sub-oxic conditions with 100 μmol of Mn, Co and Ni, showed that microbial immobilisation under sub-oxic conditions was higher than in azide-treated controls in BC26 for Mn, Co and Ni at 30, 2 and 4 cm below sea floor (bsf), respectively, after 45 days. The trend in immobilisation was BC 26>BC 36, Co>Mn>Ni under oxic conditions and Mn>Co>Ni under sub-oxic conditions. The depth of maximum immobilisation for Co in BC26 under sub-oxic conditions coincided with the yield of cultured Co-tolerant bacteria and Ni only with organic carbon at 4 cm bsf. This study demonstrates that the organic carbon content and bioavailable metal concentrations in sediments regulate microbial participation in metal immobilisation.  相似文献   
106.
107.
近10年中国大陆MODlS遥感气溶胶光学厚度特征   总被引:1,自引:0,他引:1  
应用2001-2010年MODIS大气气溶胶光学厚度(AOD)资料,分析中国550nmAOD年和季节平均分布。还选取了10个代表性区域,分析AOD变化特征。这些分析建立起了近10年来中国气溶胶光学厚度的气候学特征:中国年平均AOD空间区域分布中心大体呈现两低两高。两低中心位于植被覆盖度高和人烟稀少的(1)黑龙江和内蒙古东北高纬度地区(-0.2);(2)川、滇与青藏高原交界的西南高海拔地区(0.1-0.2)。一个AOD低值带(0.2-0.3)连接这两个低中心,呈东北西南走向跨过中国大陆。在此低值带两侧,各有一片AOD高值中心(-0.8):(1)人口密集和工业化发展带来的大量人为气溶胶形成了一个覆盖了华北、长江流域(从四川盆地,两湖地区到长三角)到华南珠江三角洲相联的大片高AOD中心区域;(2)以沙尘为主的自然气气溶胶造就了西北塔克拉玛干沙漠及周边高AOD区。中国AOD这一两低两高区域分布特征基本保持四季不变,但其中心强度呈现各自区域性季节变化。中国春季AOD高值区的面积最大,其次是夏季,然后是秋季,面积最小的是冬季。南方AOD月变化规律多为双峰型,即3-5和8-9月出现2次高峰,5-7月从南向北先后出现波谷,变化规律与季风响应。北方为单峰型,6-7月为高峰,11到来年2月为低谷。用弱季风年(2002)和强季风年(2003)季风影响区域气象条件和气溶胶数据对比分析表明,大陆AOD的月空间分布和变化与季风气候,以及风速、风向、降水、温度和湿度等的变化有关。  相似文献   
108.
The issue of solid waste management in Indian country is multidimensional in scope because it affects more than just regulatory concerns. There are more than 550 federally recognized Alaska Native and American Indian Tribes in the United States. Tribes are sovereign nations that have a special relationship to the federal government and a unique legal status. The environmental problems faced by tribes are many, and it is only fair that tribes, as sovereigns, specify the levels of protection on their lands. The one-size-fits-all regulatory approach to environmental problems and solid waste management in particular does not work and often leads to conflict between tribes and the federal and state governments. Inherent tensions also exist between tribes and various levels of government concerning jurisdiction of lands and managing solid waste. These intergovernmental relationships are often complex and present unique challenges to all. More research needs to be done on targeting resources to meet the capacity-building needs of tribes, as well as the overall environmental management needs of Indian country under the federal trust obligation. Successful intergovernmental relationships can be fostered through partnership arrangements between tribes and federal, state, and local governments. In the area of solid waste such partnerships have worked. It requires that all levels of government deal with tribes with careful consideration of their cultural, historic, and socioeconomic aspects, which are often intertwined.  相似文献   
109.
Reliable catch information is scarce for most sharks and rays worldwide, with almost half of the stocks considered to be Data Deficient due to limited species-specific catch statistics. Western Australia (WA) hosts a diverse number of shark and ray species, some of which are considered to be threatened with extinction at a global level. Commercial catch statistics only account for shark and ray landings. The present study used the best available information to reconstruct unaccounted and unreported catches for 47 shark and ray taxa to better understand the impact of fishing. For some species, there was good agreement between reconstructed catches and reported landings, but overall reconstructed catches were 57% higher than those derived from official statistics alone, underestimating the actual extraction level for many species. The reconstructed catch time series provide the basis for the assessment of all species of sharks and rays captured in WA, including protected species that interact with commercial and recreational fisheries.Supplementary informationThe online version of this article (10.1007/s13280-020-01495-6) contains supplementary material, which is available to authorised users.  相似文献   
110.
近10年中国大陆MODIS遥感气溶胶光学厚度特征   总被引:13,自引:0,他引:13  
应用2001—2010年MODIS大气气溶胶光学厚度(AOD)资料,分析中国550 nm AOD年和季节平均分布。还选取了10个代表性区域,分析AOD变化特征。这些分析建立起了近10年来中国气溶胶光学厚度的气候学特征:中国年平均AOD空间区域分布中心大体呈现两低两高。两低中心位于植被覆盖度高和人烟稀少的(1)黑龙江和内蒙古东北高纬度地区(~0.2);(2)川、滇与青藏高原交界的西南高海拔地区(0.1~0.2)。一个AOD低值带(0.2~0.3)连接这两个低中心,呈东北西南走向跨过中国大陆。在此低值带两侧,各有一片AOD高值中心(~0.8):(1)人口密集和工业化发展带来的大量人为气溶胶形成了一个覆盖了华北、长江流域(从四川盆地,两湖地区到长三角)到华南珠江三角洲相联的大片高AOD中心区域;(2)以沙尘为主的自然气气溶胶造就了西北塔克拉玛干沙漠及周边高AOD区。中国AOD这一两低两高区域分布特征基本保持四季不变,但其中心强度呈现各自区域性季节变化。中国春季AOD高值区的面积最大,其次是夏季,然后是秋季,面积最小的是冬季。南方AOD月变化规律多为双峰型,即3—5和8—9月出现2次高峰,5—7月从南向北先后出现波谷,变化规律与季风响应。北方为单峰型,6—7月为高峰,11到来年2月为低谷。用弱季风年(2002)和强季风年(2003)季风影响区域气象条件和气溶胶数据对比分析表明,大陆AOD的月空间分布和变化与季风气候,以及风速、风向、降水、温度和湿度等的变化有关。  相似文献   
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