Subjects: Geosciences >> Geography submitted time 2024-04-29 Cooperative journals: 《干旱区研究》
Abstract： By using stable isotope data of atmospheric precipitation from September 2018 to May 2020 in the Taxkorgan River Basin Valley and meteorological data such as temperature, precipitation, and relative humidity from representative weather stations within the valley, this study analyzed the variation in δ18O, δ2H, and deuterium excess (d-excess) of precipitation. The influencing factors were explored, and the water vapor transport pathways of atmospheric precipitation in the valley were traced and analyzed using the hybrid single- particle Lagrangian integrated trajectory model (HYSPLIT). Results show that the δ2H and δ18O values of precipitation gen#2;erally present a seasonal pattern of enrichment in summer and depletion in winter, showing a significant tempera#2;ture effect (1.33‰·℃- 1), but no significant precipitation effect was observed. The local meteoric water line is δ2H=7.63δ18O-3.55, which shows distinct arid climate characteristics. The HYSPLIT simulation results indicate that the water vapor of precipitation in the study basin is mainly influenced by the westerly circulation and local water vapor recycling, with local water vapor evaporation accounting for 54.09% in the summer half-year and the long-distance transport of the western route accounting for 45.53% in the winter half-year. Water vapor from the Indian Ocean in August can bypass the Tibetan Plateau and reach the study area. These findings can provide a reference basis for water resource management and climate response in the Taxkorgan River Basin Valley.
Subjects: Geosciences >> Geography submitted time 2024-03-01 Cooperative journals: 《干旱区研究》
Abstract： The scarcity of water resources is the most critical natural factor impeding high-quality economic andsocial development and ecological security in Xinjiang. This paper systematically analyzes trends inprecipitation, atmospheric water resources, and surface water resources in Xinjiang. It also establishes theconversion relationship between different water resources in Xinjiang. The findings reveal that annualprecipitation water resources amount to 2717.12×108 m3, with water vapor input reaching 21115×108 m3, resultingin a net water vapor income of 347.5×108m3. Between 1961 and 2022, Xinjiang experienced a 12.5% increase inprecipitation conversion. The annual total water resources in Xinjiang is 912.3 × 108 m3, where surface waterresources constituted 864.1 × 108 m3 from 2001 to 2020, resulting in a water yield coefficient of 0.32. Theobserved trends show a significant increase in annual precipitation in Xinjiang, a slight decrease in total watervapor input, a marginal increase in net water vapor income, and a significant increase in precipitation conversionbetween 1961 and 2022. Although surface water resources in Xinjiang are abundant, the water yield coefficientexhibited a weak fluctuating decreasing trend from 2001 to 2020. Nevertheless, prominent issues persist in waterresources research in Xinjiang, including insufficient studies on precipitation water resource volumes,understanding of cloud water resource characteristics, and continuous monitoring of the physical process of cloudprecipitation. To address these challenges, it is imperative to conduct comprehensive scientific field experimentson cloud precipitation physics, including strengthening research on the physical processes of cloud precipitation,refining cloud water resource assessments, and examining precipitation efficiency and water increase effectswithin typical cloud systems. These studies will aid in developing cloud water resources and air- groundwaterresources joint control technology for arid areas.
Subjects: Geosciences >> Atmospheric Sciences submitted time 2023-06-28 Cooperative journals: 《干旱区地理》
Abstract：2021年4月2日塔里木盆地北缘拜城县出现突破历史同期极值的灾害性暴雪。利用ERA5高分辨率再分析资料、自动气象站观测资料和FY-2G卫星资料，分析了极端暴雪天气环流异常、多尺度环流特征及物理机制。结果表明：（1）高层伊朗高压及低纬东风气流的异常导致中亚低涡与高原低涡异常结合，加强了低层异常东风气流，东风急流引导南海、孟加拉湾暖湿空气沿河西走廊到达塔里木盆地中部，使得水汽辐合及垂直上升运动加强，在地面辐合线触发下，产生极端降雪天气。地面冷高压稳定维持，导致塔里木盆地持续降温，而拜城位于海拔1000 m以上的浅山区，二者共同作用，造成拜城4月降水相态仍然为雪。（2）垂直位温梯度和西风异常导致湿斜压不稳定发展，形成低层锋生和高层及近地面湿位涡异常，而锋生作用和湿位涡异常又通过垂直运动变化影响降雪的发生发展。对于拜城而言，起决定作用的是中层的上升运动及300~500 hPa的垂直风切变。（3）中尺度云团不断发展并向东北移动经过拜城县上空，增加了降雪持续时间和降雪强度，移动方向和传播方向的一致性则决定了中尺度云团生消演变特征。研究结果可加深对塔里木盆地局地极端暴雪成因的认知，为精确预报、精准服务提供科学支撑。
Subjects: Geosciences >> Geography submitted time 2022-12-14 Cooperative journals: 《干旱区研究》
Abstract：
The arid regions of Central Asia, which are“upstream”of China in terms of their influence on weather and climate, are characterized by a general shortage of water resources and the fragility of ecosystems. The atmospheric water cycle is the key link in the transformation of water resources and ecosystems in this region. In this study, we reassessed the temporal and spatial variation of water cycle elements, such as atmospheric water vapor content, water vapor budget, precipitation, and actual evaporation, in the arid region and subregions of Central Asia, from 1979 to 2018. The results of our analysis show clear spatial differences in the water cycle elements of Central Asia. Precipitation and actual evaporation are high in mountainous areas, such as Tianshan Mountains and Pamir and surrounding oasis areas, and low in the desert plain areas, whereas atmospheric water vapor content shows an opposite pattern. In terms of temporal changes, from 1979 to 2018, the water vapor content in Central Asia showed a weak decreasing trend, with obvious regional differences in the rate of change. Water vapor content in the surrounding areas of the Aral Sea decreased significantly, whereas in most of the areas of the Xinjiang and Tianshan Mountains, it increased significantly. Zonal transport is the main mode of water vapor transport in Central Asia, compared with the relatively weak meridional transport. Large differences were found in the water vapor budget over different regions; the water vapor transport tended to decrease in the western and northern boundaries and increased in the eastern and southern boundaries. Water vapor revenue and expenditure showed an increasing trend in northwestern Central Asia, southern Central Asia, the Pamir Plateau, and the Tianshan Mountains and a decreasing trend in northern Central Asia and most of Xinjiang. In contrast to the change in water vapor transport, the precipitation in Central Asia increased from 1979 to 2018, with an increase of 4.14 mm·(10a)-1 and a large interannual fluctuation. The significant increasing trend of precipitation is distributed in northern Central Asia and most of the Xinjiang and Tianshan Mountains, whereas there was a significant decreasing trend in northwestern and southern Central Asia. The actual evaporation in Central Asia showed a slight increasing trend, increasing significantly in the northern part of Central Asia, the Tianshan Mountains, and Pamir but decreasing significantly in the Caspian Sea area, Aral Sea, southern Central Asia, and southern Xinjiang. In terms of seasonal variation, the temporal and spatial distribution of seasonal and annual variations of water cycle elements was generally consistent. The results of our analysis contribute to a better understanding of the evolution and mechanism of the atmospheric water cycle in the arid regions of Central Asia.
Subjects: Geosciences >> Geography submitted time 2022-03-28 Cooperative journals: 《干旱区研究》
Abstract：21世纪初有研究提出我国西北尤其是新疆气候出现暖湿化的论断，但针对不同时间尺度下新疆气候暖湿化特征还缺乏明确结论。基于新疆区域观测的气候水文资料，结合近年来发表的新成果，对中国新疆区域历史时期至年代际尺度暖湿化特征进行了全面梳理和对比分析，综合评估了新疆气候暖湿化在不同时间尺度下的演变特征。结果表明：（1）过去千年和百年新疆气候主要呈暖干-冷湿的水热配置特征，近百年存在显著的年代际变化特征，其中20世纪80年代以来经历了明显的暖湿化过程，但变幅未超出历史各时段的变率范围；（2）1961年以来北半球中高纬度地区气候总体呈暖湿化特征，其中新疆及以北西伯利亚地区、欧洲北部等均有明显的暖湿化特征，新疆连接着发生暖湿化的高纬度地区和青藏高原地区，说明气候暖湿化并不是新疆所独有的，但新疆气候增湿过程在同中纬度地区具有独特性；（3）19612019年新疆气候年际温湿以暖湿-暖干配置为主，20世纪90年代之后新疆年及季节多呈暖湿配置；增暖增湿速率在逐气候态时段增强，但在当前时段有减缓趋势，说明增温增湿趋势有阶段性特征，并呈非线性增加态势。虽然近30 a以来新疆气候暖湿化趋势明显，变暖程度逐渐增强，蒸发需求旺盛，但降水增加绝对量并不大，当前的增湿特征并不能改变新疆的干旱气候环境。研究成果为不同空间尺度下新疆气候和暖湿化评估提供重要的科学基础。
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