Temporal variations of stable isotopes in precipitation from Yungui Plateau: Insights from moisture source and rainout effect

2021 ◽  
Keyword(s):  
Meteoric Water ◽  
East Asian Monsoon ◽  
Precipitation Amount ◽  
Correlation Coefficients ◽  
Temporal Variations ◽  
Monsoon Period ◽  
Factors Affecting ◽  
Water Line ◽  
Moisture Source ◽  
Meteoric Water Line

Abstract Long-term continuous monitoring of precipitation isotopes has great potential to advance our understanding of hydrometeorological processes that determine stable isotope variability in the monsoon regions. This study presents 4–year daily precipitation isotopes from Yungui Plateau in southwestern China that is influenced by Indian summer monsoon and East Asian monsoon. The local meteoric water line (LMWL, δ2H=8.12 δ18O+11.2) was firstly established at the Tengchong (TC) site, which was close to the global meteoric water line (GMWL, δ2H=8 δ18O+10) indicating little secondary sub–cloud evaporation in the falling rain. Precipitation δ18O values exhibited significant inverse relationships with precipitation amount (r = −0.42), air temperature (r = −0.43), and relative humidity (r = −0.41) with lower correlation coefficients throughout the entire period, which indicated that precipitation isotopic variability in TC could not be well explained by the local meteorological factors but influenced by other combined factors of regional precipitation amount and upstream rainout. Precipitation δ18O values showed a clear V–shaped trend throughout the observation period, characterized by higher δ18O values during the pre–monsoon period whereas lower values during the post–monsoon period. This seasonal variation of precipitation δ18O values was associated with the seasonal movement of the Intertropical convergence zone and seasonal changes in moisture transport. Combined with backward trajectory analysis, precipitation δ18O values were estimated by a Rayleigh distillation model showing that upstream rainout processes from Bay of Bengal (BoB) towards land (Myanmar), and recycling moisture over land were key factors affecting the isotopic compositions of the TC precipitation. These findings could enhance our understanding of atmospheric dynamics and moisture source in the monsoon regions and will potentially facilitate the interpretation of numerous isotopic proxy records from this region.

Stable Isotopic Variability of Daily Precipitation from Yungui Plateau of Southwest China: Insights from Moisture Source and Rainout Effect

2021 ◽  
Author(s):  
huawu Wu ◽  
Congsheng Fu ◽  
Cicheng Zhang ◽  
Zhongwang Wei ◽  
Xinping Zhang
Keyword(s):  
Meteoric Water ◽  
Southwest China ◽  
Hydrological Cycle ◽  
East Asian Monsoon ◽  
Precipitation Amount ◽  
Southwest Monsoon ◽  
Winter Period ◽  
Data Set ◽  
Water Line ◽  
Meteoric Water Line

Abstract Long-term continuous monitoring of precipitation isotopes has great potential to advance our understanding of mechanisms that determine stable isotope variability in hydrological processes of monsoon regions. This study presents a 4-year daily data set of precipitation isotopes from Yungui Plateau of southwest China, influenced by southwest monsoon and East Asian monsoon. The local meteoric water line [LMWL, δ2H=8.12 (±0.04) δ18O+11.2(±0.4)] was established at the Tengchong (TC) site, which was similar to the global meteoric water line (GMWL, δ2H=8 δ18O+10) indicating little secondary sub-cloud evaporation in the falling rain. Precipitation δ18O exhibited significant inverse relationships with precipitation amount (r = -0.42) and air temperature (r = -0.43) throughout the entire period, which indicated that precipitation isotopic variability largely depended on the local meteorological conditions. Precipitation δ18O values are characterized by remarkably seasonal variability: In the summer monsoon period, moisture sources primarily originated from BoB source towards TC site experiencing local moisture recycling over land. The air masses were derived from the northern region of Africa and East Asia with the longest transporting distance and cyclonic activity over the source region in the Fall-winter period characterized with the depleted δ18O values. Precipitation δ18O at the TC site was estimated by a Rayleigh fractionation model considering rainout over BoB and land (Myanmar) during the vapor advection, and local recycling processes consistent with the observed precipitation δ18O values. These findings enhance our understanding of hydrological cycle in the Southwest monsoon regions and will potentially facilitate the interpretation of numerous isotopic proxy records from this region.

scholarly journals Isotopes of oxygen-18 and deuterium in precipitation in Slovakia / Izotopy kyslíka-18 A deutéria v zrážkach na Slovensku

2012 ◽  
Vol 60 (4) ◽  
pp. 265-276 ◽  
Author(s):  
Ladislav Holko ◽  
Michal Dóša ◽  
Juraj Michalko ◽  
Martin Šanda
Keyword(s):  
Isotopic Composition ◽  
Air Temperature ◽  
Meteoric Water ◽  
Precipitation Amount ◽  
Data Series ◽  
Water Line ◽  
Temperature And Precipitation ◽  
Meteoric Water Line ◽  
The Mean ◽  
Available Information

The article synthesizes available information on isotopic composition of precipitation in Slovakia (the Western Carpathians). Monthly δ18O data from eleven stations and period 1988-1997 were used to investigate correlations among the stations, altitude, air temperature and precipitation amount effects. The mean annual altitude and air temperature gradients of δ18O in precipitation were 0.21‰/100 m and 0.36‰/1°C, respectively. Maps of spatial distribution of mean annual δ18O in precipitation based on both gradients were constructed. The two maps do not significantly differ for the majority of Slovakia. δ2H data were available for only three stations. Local meteoric water line derived for the station with the longest data series (δ2H = = 7.86δ18O + 6.99) was close to the Global Meteoric Water line. Its parameters in periods 1991-1993 and 1991-2008 did not change. The study indicates that a more detailed monitoring of isotopic composition of precipitation in mountains should be carried out in the future. The highest station exhibited very small seasonal variability of δ18O in precipitation compared to other Slovak stations. The second highest mountain station had significantly higher deuterium excess than the neighboring stations located in the valley. In some analyses the data from the nearest stations situated abroad (Vienna, Krakow) were used.

scholarly journals Long-Term Isotope Records of Precipitation in Zagreb, Croatia

Water ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 226 ◽  
Author(s):  
Ines Krajcar Bronić ◽  
Jadranka Barešić ◽  
Damir Borković ◽  
Andreja Sironić ◽  
Ivanka Lovrenčić Mikelić ◽  
...  
Keyword(s):  
Meteoric Water ◽  
Isotope Composition ◽  
Eastern Mediterranean ◽  
Meteorological Data ◽  
Precipitation Amount ◽  
Monthly Precipitation ◽  
Air Masses ◽  
Water Line ◽  
Meteoric Water Line

The isotope composition of precipitation has been monitored in monthly precipitation at Zagreb, Croatia, since 1976. Here, we present a statistical analysis of available long-term isotope data (3H activity concentration, δ2H, δ18O, and deuterium excess) and compare them to basic meteorological data. The aim was to see whether isotope composition reflected observed climate changes in Zagreb: a significant increase in the annual air temperature and larger variations in the precipitation amount. Annual mean δ18O and δ2H values showed an increase of 0.017‰ and 0.14‰ per year, respectively, with larger differences in monthly mean values in the first half of the year than in the second half. Mean annual d-excess remained constant over the whole long-term period, with a tendency for monthly mean d-excess values to decrease in the first half of the year and increase in the second half due to the influence of air masses originating from the eastern Mediterranean. Changes in the stable isotope composition of precipitation thus resembled changes in the temperature, the circulation pattern of air masses, and the precipitation regime. A local meteoric water line was obtained using different regression methods, which did not result in significant differences between nonweighted and precipitation-weighted slope and intercept values. Deviations from the Global Meteoric Water Line GMWL (lower slopes and intercepts) were observed in two recent periods and could be explained by changes in climate parameters. The temperature gradient of δ18O was 0.33‰/°C. The tritium activity concentrations in precipitation showed slight decreases during the last two decades, and the mean A in the most recent period, 2012–2018, was 7.6 ± 0.8 Tritium Units (TU).

scholarly journals Seasonal and Inter-Annual Variations of Stable Isotopic Characteristics of Rainfall and Cave Water in Shennong Cave, Southeast China, and Its Paleoclimatic Implication

2021 ◽  
Vol 9 ◽  
Author(s):  
Ye Tian ◽  
Haiwei Zhang ◽  
Rui Zhang ◽  
Fan Zhang ◽  
Zeyuan Liang ◽  
...  
Keyword(s):  
Oxygen Isotope ◽  
Summer Monsoon ◽  
Meteoric Water ◽  
El Nino ◽  
Monsoon Precipitation ◽  
Southeast China ◽  
Water Line ◽  
Moisture Source ◽  
Meteoric Water Line ◽  
June July

Speleothem calcite stable oxygen isotope (δ18OC) is one of the most widely used proxies in paleoclimate research, and understanding its seasonal-annual variability is very significant for palaeoclimate reconstruction. Five-year precipitation and karst cave water from 2016 to 2021 were monitored in Shennong cave, Jiangxi Province, Southeast China. The local meteoric water line (LMWL) is δD = 8.20 × δ18O + 13.34, which is similar to the global meteoric water line. The stable hydrogen and oxygen isotope (δD and δ18O) characteristics of precipitation and cave water were studied. δ18O and δD of precipitation and cave water show obvious seasonal variations. Lower precipitation δ18O and δD generally occur during summer and autumn compared with higher δ18O and δD values during winter and spring. Meanwhile, low precipitation δ18O values do not only appear in June–July when precipitation is the highest of the year but also appear in August–September when precipitation is limited. The back-trajectory analysis of monsoon precipitation moisture sources shows that the moisture uptake regions vary little on inter-annual scales; the water vapor of rainfall in June–July comes from the South China Sea and the Bay of Bengal, while the moisture source in August–September is mainly from the West Pacific and local area. The El Niño-Southern Oscillation is an important factor affecting the value of δ18O by modulating the percentage of summer monsoon precipitation in the annual precipitation and moisture source. The relationship between amount-weighted monthly mean precipitation δ18O and Niño-3.4 index shows that the East Asian summer monsoon (EASM) intensifies during La Niña phases, resulting in more precipitation in monsoon season (May to September, MJJAS) and lower δ18O values, and vice versa during El Niño phases.

scholarly journals Characteristics and moisture sources of the stable isotopes in precipitation in the monsoon marginal region of north-central China

2021 ◽  
Author(s):  
Yiping Zhang ◽  
Junliang Xu ◽  
Yafei Yan ◽  
Wei Su ◽  
Zhiqiang Shi ◽  
...  
Keyword(s):  
Meteoric Water ◽  
Precipitation Amount ◽  
Central China ◽  
Positive Temperature ◽  
North Central ◽  
Water Line ◽  
Moisture Sources ◽  
Meteoric Water Line ◽  
Δd And Δ18o ◽  
Marginal Region

The stable hydrogen and oxygen isotopes in precipitation (δD and δ18O, respectively) are important source signatures for understanding the hydrological cycle and paleoclimatic reconstruction. In this study, 32 precipitation samples were collected from April to October 2014 at the Luya Mountain summit, a representative site in the monsoon marginal area of north-central China. The isotopic signatures of precipitation exhibited strong seasonal variations ranging from -185.61‰ to -18.50‰ and -25.51‰ to -4.59‰ for δD and δ18O, respectively, which were relatively higher in August and lower in September. The local meteoric water line was δD=(7.95±0.16) δ18O+(15.79±1.77) (R2 = 0.988, N = 32, p < 0.001), which had a similar slope but higher intercept than that of the global meteoric water line, indicating that the precipitation in this area is mainly sourced from the ocean surface transported via monsoons. Additionally, the secondary evaporated water by continental recycled moisture was identified by the significantly higher deuterium excess value (16.09‰). Backward trajectories generated via the Hybrid Single-Particle Lagrangian Integrated Trajectory model indicated seasonal moisture transport changes in the studied monsoonal marginal region, in which the main moisture sources were the Westerly winds in April, the Pacific Ocean in July, and the Indian Ocean in September. Secondary evaporated water from the alpine ecosystem may also influence the local atmospheric water cycle throughout the year. Positive temperature-isotopic signature effect (δD and δ18O) was observed in the cold season (before mid-May); however, the precipitation amount effect was observed in the monsoon season from June to August, and both effects became vague across the entire period. These findings suggest that the stable isotope compositions of precipitation can be utilized to determine the moisture sources in the monsoon marginal region of north-central China and potentially be utilized to reconstruct the precipitation signals in this region.

scholarly journals Characteristics of Stable Isotopes in Precipitation and Their Moisture Sources in the Guanling Region, Guizhou Province

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Jialu Wang ◽  
Weijie Li ◽  
Yong Wang ◽  
Jiaojiao Zhang ◽  
Shizhen Xiao
Keyword(s):  
Stable Isotopes ◽  
Meteoric Water ◽  
Guizhou Province ◽  
Monsoon Period ◽  
Water Line ◽  
Meteoric Water Line ◽  
National Centre ◽  
Winter Half ◽  
Summer Half ◽  
Environmental Prediction

Environmental prediction is one of the crucial means for social sustainable development. Based on the continuous sampling of atmospheric precipitation in Guanling County, Guizhou Province, China, from March 2016 to February 2017, and combining the reanalyzed data of the National Centre for Environmental Prediction/National Centre for Atmospheric Research with the Hybrid Single-Particle Lagrangian Integrated Trajectory model, this paper analyzed the variations of δ2H and δ18O in precipitation at the synoptic scale in the Guanling region. The results showed that the variations of δ2H, δ18O, and d-excess values in precipitation exhibited remarkable seasonal variability. The stable isotopic values in precipitation in the winter half-year were higher than those in the summer half-year. The meteoric water line of the winter half-year was close to the annual meteoric water line. The results showed that there was more than one fundamental source of moisture. It was affected by the winter monsoon period, which is longer than the summer monsoon period, so the local evaporation of water vapor participating in the water circulation had a greater impact. With the increase of precipitation, the intercept and slope of the meteoric water line gradually decreased, which indicated that the secondary evaporation was weak under the effect of stable isotope subcloud cluster. The correlations of precipitation δ18O with temperature T and precipitation P vary with time scales. As the time scale decreased, the correlation between δ18O and the temperature and precipitation improved. When P  ≤ 5 mm and 10°C < T ≤ 30°C, the most sensitive changes in stable isotopes were observed. In the study area, the backward trajectory model showed that the moisture in the winter half of the year was mainly from the transportation of the westerlies wind, replenishment, and local reevaporation of near-source ocean water, while the water in the summer half of the year mainly came from the transportation of water from the ocean at low latitudes.

scholarly journals Contrasting Water Use Strategies of Tamarix ramosissima in Different Habitats in the Northwest of Loess Plateau, China

Water ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2791
Author(s):  
Pengyan Su ◽  
Mingjun Zhang ◽  
Deye Qu ◽  
Jiaxin Wang ◽  
Yu Zhang ◽  
...  
Keyword(s):  
Soil Water ◽  
Water Use ◽  
Loess Plateau ◽  
Meteoric Water ◽  
Water Source ◽  
Water Sources ◽  
Tamarix Ramosissima ◽  
Water Line ◽  
Meteoric Water Line ◽  
Utilization Ratio

As a species for ecological restoration in northern China, Tamarix ramosissima plays an important role in river protection, flood control, regional climate regulation, and landscape construction with vegetation. Two sampling sites were selected in the hillside and floodplain habitats along the Lanzhou City, and the xylems of T. ramosissima and potential water sources were collected, respectively. The Bayesian mixture model (MixSIAR) and soil water excess (SW-excess) were applied to analyze the relationship on different water pools and the utilization ratios of T. ramosissima to potential water sources in two habitats. The results showed that the slope and intercept of local meteoric water line (LMWL) in two habitats were smaller compared with the global meteoric water line (GMWL), which indicated the existence of drier climate and strong evaporation in the study area, especially in the hillside habitat. Except for the three months in hillside, the SW-excess of T. ramosissima were negative, which indicated that xylems of T. ramosissima are more depleted in δ2H than the soil water line. In growing seasons, the main water source in hillside habitat was deep soil water (80~150 cm) and the utilization ratio was 63 ± 17% for T. ramosissima, while the main water source in floodplain habitat was shallow soil water (0~30 cm), with a utilization ratio of 42.6 ± 19.2%, and the water sources were different in diverse months. T. ramosissima has a certain adaptation mechanism and water-use strategies in two habitats, and also an altered water uptake pattern in acquiring the more stable water. This study will provide a theoretical basis for plant water management in ecological environment protection in the Loess Plateau.

scholarly journals Global perspective of local meteoric water lines based on daily and monthly data: a consideration of climate types

2021 ◽  
Author(s):  
Yang Song ◽  
Shengjie Wang ◽  
Athanassios Argiriou ◽  
Mingjun Zhang ◽  
Yudong Shi
Keyword(s):  
Least Squares ◽  
Meteoric Water ◽  
Major Axis ◽  
Ordinary Least Squares ◽  
Weighted Regression ◽  
Precipitation Data ◽  
Monthly Data ◽  
Water Line ◽  
Meteoric Water Line ◽  
Event Based

The stable hydrogen and oxygen isotopes as well as their correlation in precipitation have been widely investigated for the understanding of various hydrological processes. Monthly precipitation data were usually recommended in order to establish a linear relationship between the stable hydrogen and oxygen isotope ratios (also known as local meteoric water lines or LMWL for a specific location); however, the LMWL based on daily (or event-based) precipitation data is usually different from that using monthly data. Based on 83 sampling stations across the world from 2000 to 2017, local meteoric water lines were calculated using daily (or event-based) precipitation data (n=9354) and corresponding monthly data (n=1895), respectively; multiple regression methods were used, including ordinary least squares, reduced major axis and major axis regressions as well as their precipitation-weighted counterparts. The global meteoric water line from daily data is δ2H = (7.72 ± 0.02) δ18O + (6.84 ± 0.15) (n=9354, r2=0.96) and from monthly data is δ2H = (7.81 ± 0.04) δ18O+(7.61 ± 0.32) (n=1895, r2=0.96). The stations used in this study were grouped into five climate types, according to the Köppen Climate classification. The precipitation-weighted regression may increase the long-term receptiveness of LMWL using daily-based (or event-based) samples, not only for arid regions, but also for cold regions. When only relatively short-term isotopic records in event-based precipitation samples are available, which is usual in modern hydrological studies, the weighted regression (especially precipitation weighted ordinary least squares regression, PWLSR) is helpful to create a respective local meteoric water line.

scholarly journals Tracing groundwater salinization processes in coastal aquifers: a hydrogeochemical and isotopic approach in the Na-Cl brackish waters of northwestern Sardinia, Italy

2013 ◽  
Vol 17 (7) ◽  
pp. 2917-2928 ◽  
Author(s):  
G. Mongelli ◽  
S. Monni ◽  
G. Oggiano ◽  
M. Paternoster ◽  
R. Sinisi
Keyword(s):  
Coastal Aquifers ◽  
Meteoric Water ◽  
Major Ions ◽  
Mediterranean Islands ◽  
Rock Interaction ◽  
Water Line ◽  
Brackish Waters ◽  
Meteoric Water Line ◽  
The Mediterranean ◽  
Water Rock Interaction

Abstract. Throughout the Mediterranean, salinization threatens water quality, especially in coastal areas. This salinization is the result of concomitant processes related to both seawater intrusion and water–rock interaction, which in some cases are virtually indistinguishable. In the Nurra region of northwestern Sardinia, recent salinization related to marine water intrusion has been caused by aquifer exploitation. However, the geology of this region records a long history from the Palaeozoic to the Quaternary, and is structurally complex and comprises a wide variety of lithologies, including Triassic evaporites. Determining the origin of the saline component of the Jurassic and Triassic aquifers in the Nurra region may provide a useful and more general model for salinization processes in the Mediterranean area, where the occurrence of evaporitic rocks in coastal aquifers is a common feature. In addition, due to intensive human activity and recent climatic change, the Nurra has become vulnerable to desertification and, in common with other Mediterranean islands, surface water resources periodically suffer from severe shortages. With this in mind, we report new data regarding brackish and surface waters (outcrop and lake samples) of the Na-Cl type from the Nurra region, including major ions and selected trace elements (B, Br, I, and Sr), in addition to isotopic data including δ18O, δD in water, and δ34S and δ18O in dissolved SO4. To identify the origin of the salinity more precisely, we also analysed the mineralogical and isotopic composition of Triassic evaporites. The brackish waters have Cl contents of up to 2025 mg L−1 , and the ratios between dissolved ions and Cl, with the exception of the Br / Cl ratio, are not those expected on the basis of simple mixing between rainwater and seawater. The δ18O and δD data indicate that most of the waters fall between the regional meteoric water line and the global meteoric water line, supporting the conclusion that they are meteoric in origin. A significant consequence of the meteoric origin of the Na-Cl-type water studied here is that the Br / Cl ratio, extensively used to assess the origin of salinity in fresh water, should be used with care in carbonate aquifers that are near the coast. Overall, δ34S and δ18O levels in dissolved SO4 suggest that water–rock interaction is responsible for the Na-Cl brackish composition of the water hosted by the Jurassic and Triassic aquifers of the Nurra, and this is consistent with the geology and lithological features of the study area. Evaporite dissolution may also explain the high Cl content, as halite was detected within the gypsum deposits. Finally, these Na-Cl brackish waters are undersaturated with respect to the more soluble salts, implying that in a climate evolving toward semi-arid conditions, the salinization process could intensify dramatically in the near future.

Sign in / Sign up

Export Citation Format

Share Document