Search

The abundant precipitation over Pamirs Plateau (PP) in spring and winter plays a vital role in the water resources over the arid areas of Central Asia. Understanding the moisture sources and water vapour transportation associated with precipitation are very important, but there were few studies investigating the moisture sources of PP. We used a Lagrangian model driven with the Weather Research and Forecasting output to analyse the moisture sources at Northern Pamirs Plateau (NPP) and Southern Pamirs Plateau (SPP) in spring 2016, 2009 and 2001, and in winter 2016, 2010 and 2017, as the seasonal precipitation in PP was the largest, median and lowest during 2001 to 2018, and the precipitation in spring and winter was much higher than that in summer and autumn. The moisture sources from four regions were quantified: Atlantic‐Europe‐Africa, Arctic‐Northern Asia, Indian Ocean, and moisture recycling from the PP. Atlantic‐Europe‐Africa and Indian Ocean are the dominant moisture source regions in spring and winter, which contribute more than 70% to the total moisture affecting the precipitation at PP. The contributions of Indian Ocean are higher at SPP than those at NPP in spring and winter. The contributions from Arctic‐Northern Asia and PP are generally low, except that the moisture from PP region contributed 19% to the spring precipitation at NPP, indicating the importance of a local moisture source in enhancing the spring precipitation at NPP. The moisture contributions originating from the different source regions show great differences between winter and spring. The moisture transportation is affected by westerlies, and the zonal winds in spring affect the moisture transportation, while the meridional winds over the Arabian Peninsula mainly affect the moisture transportation in winter. [ABSTRACT FROM AUTHOR]

Large amounts of carbon in alpine sediments have been expected to be sensitive to climate change, but how carbon accumulation responds to climate change remains unclear. Thus, we explored the impact of different factors on the carbon accumulation rate (CAR) of alpine sediments by combining a variety of climatic variables, vegetation data and erosion indicators based on two alpine sediment successions on Taibai Mountain, the highest peak in central and eastern mainland China. One succession is near the modern treeline (Paomaliang Swamp, PML) and the other is located at the upper forest line (Sanqing Chi, SQC, a small lake). We used our previously published organic carbon content data and for the first time calculated the CAR, and further used pollen and physicochemical indicators to quantify the contributions from climate, vegetation and soil. We found that their contributions varied during different periods and between the two sediment successions. For the PML succession, from 5850 to 4000 calendar years before present (cal. a BP), the CAR was low, which was related to low annual temperatures, low vegetation cover and strong soil erosion. From 4000 to 2400 cal. a BP, a high CAR coincided with high annual temperatures, high vegetation cover and weak soil erosion. From 2400 to 200 cal. a BP, the CAR decreased, mainly attributed to low vegetation cover. Local vegetation cover had major impacts on the CAR in the SQC succession during the Middle–Late Holocene. In general, the local factor interpretation rate in SQC (83%) was higher than that of PML (47%), related to the vegetation stability of continuous forest and the treeline. This study highlights the important role of the local environment in determining carbon accumulation in the alpine region. [ABSTRACT FROM AUTHOR]