1
|
Zhao L, Dong X, Liu X, Wang N, Eastoe CJ, Wei N, Xie C, Liu H, Han C, Hua T, Wang L. Extreme precipitation stable isotopic compositions reveal unexpected summer monsoon incursions in the Qilian Mountains. Sci Total Environ 2023; 900:165743. [PMID: 37495157 DOI: 10.1016/j.scitotenv.2023.165743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 07/16/2023] [Accepted: 07/21/2023] [Indexed: 07/28/2023]
Abstract
Isotope composition and moisture sources of precipitation are important for understanding water cycles and reconstructing paleoclimate. Based on 15-years' precipitation stable Isotope composition (δ18O and δ2H) from four stations of the Qilian Mountains, we found unique δ18O and δ2H features associated with the incursion of the summer monsoon over the Qilian Mountains, northwestern China. In 12 of the 15 years, similar seasonal variations of δ18O and δ2H confirmed a dominant source of moisture from Westerly circulation, and higher intercepts of the local meteoric water line (LMWL) indicated strong recycling of continental moisture. However, in August 2016 and 2018, extremely low slopes and intercepts of the LMWL, and more negative δ18O and δ2H revealed substantial contributions of the Asian summer monsoon to precipitation of the Qilian Mountains, with extremely heavy precipitation in August 2016. The column moisture flux, land-sea thermal contrast, correlations of precipitation δ18O with East Asian Summer Monsoon Index and Westerlies Index, HYSPLIT modeling results and precipitation δ18O along backward trajectories confirmed incursions of the summer monsoon in August 2016 and 2018. Our redefining of the boundary of the summer monsoon region confirmed the summer monsoon incursion zone can extend to the west of longitude 96°E and north of latitude 40°N in strong monsoon years, corresponding to boundaries of monsoon incursions in the mid-Holocene. Temperature correlated with precipitation δ18O at monthly and shorter time scales, but not for whole seasons or at yearly scale, revealing that summer monsoon incursions are therefore more likely than changing temperature to explain the multi-year cycles in the Qilian Mountains ice archives. Continent-scale shifts in atmospheric circulation strongly influence water resources in the Qilian mountains, and may change in frequency as climate warms. This study therefore has important implications for understanding water resources in the Qilian mountains in the past and into the future.
Collapse
Affiliation(s)
- Liangju Zhao
- Shaanxi Key Laboratory of Earth Surface System and Environmental Carrying Capacity, College of Urban and Environmental Sciences, Northwest University, Xi'an 710127, China.
| | - Xiying Dong
- Shaanxi Key Laboratory of Earth Surface System and Environmental Carrying Capacity, College of Urban and Environmental Sciences, Northwest University, Xi'an 710127, China
| | - Xiaohong Liu
- School of Geography and Tourism, Shaanxi Normal University, Xi'an 710119, China
| | - Ninglian Wang
- Shaanxi Key Laboratory of Earth Surface System and Environmental Carrying Capacity, College of Urban and Environmental Sciences, Northwest University, Xi'an 710127, China
| | - Christopher J Eastoe
- Department of Geosciences (retired), University of Arizona, Tucson, AZ 85721, USA
| | - Na Wei
- Climate Centre of Shaanxi Province, Xi'an 710049, China
| | - Cong Xie
- Shaanxi Key Laboratory of Earth Surface System and Environmental Carrying Capacity, College of Urban and Environmental Sciences, Northwest University, Xi'an 710127, China
| | - Hang Liu
- Shaanxi Key Laboratory of Earth Surface System and Environmental Carrying Capacity, College of Urban and Environmental Sciences, Northwest University, Xi'an 710127, China
| | - Chuntan Han
- Key Laboratory of Ecological Safety and Sustainable Development in Arid Lands, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Ting Hua
- Shaanxi Key Laboratory of Earth Surface System and Environmental Carrying Capacity, College of Urban and Environmental Sciences, Northwest University, Xi'an 710127, China
| | - Lixin Wang
- Department of Earth Sciences, Indiana University-Purdue University Indianapolis (IUPUI), Indianapolis, IN 46202, USA
| |
Collapse
|
2
|
Tan H, Chen X, Shi D, Rao W, Liu J, Liu J, Eastoe CJ, Wang J. Base flow in the Yarlungzangbo River, Tibet, maintained by the isotopically-depleted precipitation and groundwater discharge. Sci Total Environ 2021; 759:143510. [PMID: 33221005 DOI: 10.1016/j.scitotenv.2020.143510] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 10/26/2020] [Accepted: 10/27/2020] [Indexed: 06/11/2023]
Abstract
The extension-induced rift systems on the Tibetan Plateau (TP) may convey large amount of groundwater to rivers, but sources and flow paths of such groundwater are unknown. The Yarlungzangbo River (YR) is the only large river that traverses the southern Tibetan plateau from west to east, following one major suture zone that is cut by extensional normal faults. The faults could influence the flow paths of groundwater discharging to the river. In this study, O and H isotopes, major ions and 222Rn concentrations are analyzed along the YR, and interpreted in relation to structural geology and tectonics. The YR exhibits an abrupt change of isotopic and chemical compositions along with a large increase in flow where the middle reach intersects NE-SW-trending rifts. Low values of δD and δ18O and high concentrations of major ions and 222Rn in the middle reach show that waters are modified isotopically and chemically by a variety of possible water origins, such as recharge of high-altitude glacier melt and discharge from groundwater. Groundwater contributes 27 to 40% of the river flow in the middle reach. Isotopically-light meltwater from high-altitude glacier melt cannot account for the isotope composition of the present outflow of groundwater. The O and H isotope data in the YR and discharging groundwater can be well explained by the groundwater originated as paleo-precipitation during a cooler time, such as the late Pleistocene to early Holocene. The paleo-groundwater discharge can account for about 36 × 108 m3 water budget unbalance in the middle reach. The study provides the first clear isotope evidence for the source of groundwater discharge into a large river through favorable conduits in large-scale active tensile fault zones and confirms the regional scale of groundwater flow on the Tibetan Plateau. Understanding the characteristics and changes of streamflow and surface-groundwater circulation on the Tibetan Plateau will help to manage water resources under a changing environment.
Collapse
Affiliation(s)
- Hongbing Tan
- School of Earth Sciences and Engineering, Hohai University, Nanjing 210098, China.
| | - Xi Chen
- Institute of Surface-Earth System Science, Tianjin University, Tianjin 300072, China.
| | - Dongping Shi
- School of Earth Sciences and Engineering, Hohai University, Nanjing 210098, China
| | - Wenbo Rao
- School of Earth Sciences and Engineering, Hohai University, Nanjing 210098, China
| | - Jing Liu
- Institute of Surface-Earth System Science, Tianjin University, Tianjin 300072, China
| | - Jintao Liu
- College of Hydrology and Water Resources, Hohai University, Nanjing 210098, China
| | - Christopher J Eastoe
- Department of Geosciences, University of Arizona, Tucson, AZ 85721, United States
| | - Jiarong Wang
- College of Hydrology and Water Resources, Hohai University, Nanjing 210098, China
| |
Collapse
|
3
|
Wang W, Wei HZ, Jiang SY, Eastoe CJ, Guo Q, Lin YB. Adsorption Behavior of Metasilicate on N-Methyl d-Glucamine Functional Groups and Associated Silicon Isotope Fractionation. Langmuir 2016; 32:8872-8881. [PMID: 27499230 DOI: 10.1021/acs.langmuir.6b02388] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Significant isotope fractionation of silicon provides a powerful geochemical tracer for biological and physicochemical processes in terrestrial and marine environments. The exact mechanism involved in silicon uptake as part of the biological process is not well known. The silicon uptake in biological processes is investigated using silicate adsorption onto the N-methylglucamine functional group (sugarlike structure, abbreviated as L) of Amberlite IRA-743 resin as an analogue of the formation of silicate-sugar complexes in plants. This study provides new evidence that certain sugars can react readily with basic silicic acid to form sugar-silicate chelating complexes, and the equilibrium adsorption behavior of silicate can be well described by the Langmuir isotherm with a Gibbs free energy (ΔG) of -11.94 ± 0.21 kJ·mol(-1) at 293 K. The adsorption kinetics corresponds well to a first-order kinetic model in which the adsorption rate constant ka of 1.25 × 10(-4) s(-1) and the desorption rate constant kd of 4.00 × 10(-6) s(-1) are obtained at 293 K. Both ka and kd increase with increasing temperature. The bonding configurations of silicate-sugar complexes imply the principal coordination complex of hexacoordinated silicon (silicon/L = 1:3) in the liquid phase and the dominant tetracoordinated silicon in the solid phase. Similar to those of many natural processes, the biological uptake via the sugar-silicate chelating complexes favors the preferential enrichment of light Si isotopes into solids, and the Rayleigh model controls the dynamic isotope fractionation with an estimated silicon isotope fractionation factor (i.e., αsolid-solution = [Formula: see text]) of 0.9971. This study advanced the fundamental understanding of the dynamic isotope fractionation of silicon during silicon cycling from the lithosphere to the biosphere and hydrosphere in surficial processes.
Collapse
Affiliation(s)
- Wei Wang
- State Key Laboratory of Geological Processes and Mineral Resources, Faculty of Earth Resources, China University of Geosciences , Wuhan 430074, PR China
| | - Hai-Zhen Wei
- State Key Laboratory for Mineral Deposits Research, Department of Earth Sciences, Nanjing University , Nanjing 210023, PR China
| | - Shao-Yong Jiang
- State Key Laboratory of Geological Processes and Mineral Resources, Faculty of Earth Resources, China University of Geosciences , Wuhan 430074, PR China
- State Key Laboratory for Mineral Deposits Research, Department of Earth Sciences, Nanjing University , Nanjing 210023, PR China
| | - Christopher J Eastoe
- Department of Geosciences, University of Arizona , Tucson, Arizona 85721, United States
| | - Qi Guo
- State Key Laboratory of Geological Processes and Mineral Resources, Faculty of Earth Resources, China University of Geosciences , Wuhan 430074, PR China
| | - Yi-Bo Lin
- State Key Laboratory of Geological Processes and Mineral Resources, Faculty of Earth Resources, China University of Geosciences , Wuhan 430074, PR China
| |
Collapse
|
4
|
Eastoe CJ, Hess G, Mahieux S. Identifying recharge from tropical cyclonic storms, Baja California Sur, Mexico. Ground Water 2015; 53 Suppl 1:133-138. [PMID: 24635484 DOI: 10.1111/gwat.12183] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Accepted: 01/28/2014] [Indexed: 06/03/2023]
Abstract
Groundwater in the Todos Santos watershed in southern Baja California, and throughout the peninsula south of latitude 28°N, has values of (δ18 O‰, δD‰) ranging between (-8.3, -57) and (-10.9, -78). Such negative values are uncharacteristic of the site latitude near the sea level. Altitude effects do not explain the isotope data. Tropical depressions originating along the Pacific coast of North America yield rain with isotopic depletion; rain from these weather systems in southern Arizona commonly has δ18O values<-10‰ in comparison with amount-weighted mean summer and fall rain at -6‰. Isotope data indicate hurricane rain as the predominant source of recharge in southern Baja California, where named tropical depressions bring large rains (>50 mm) at least once every 2 to 3 years, and along the Pacific coast between Jalisco and Oaxaca.
Collapse
|
5
|
Abstract
The tritium input to groundwater, represented as volume-weighted mean tritium concentrations in precipitation, has been close to constant in Tucson and Albuquerque since 1992, and the decrease in tritium concentrations at the tail end of the bomb tritium pulse has ceased. To determine the future usefulness of tritium measurements in southwestern North America, volume-weighted mean tritium levels in seasonal aggregate precipitation samples have been gathered from 26 sites. The averages range from 2 to 9 tritium units (TU). Tritium concentrations increase with site latitude, and possibly with distance from the coast and with site altitude, reflecting local ratios of combination of low-tritium moisture advected from the oceans with high-tritium moisture originating near the tropopause. Tritium used alone as a tool for mapping aquifer volumes containing only pre-bomb recharge to groundwater will become ambiguous when the tritium in precipitation at the end of the bomb tritium pulse decays to levels close to the analytical detection limit. At such a time, tritium in precipitation from the last one to two decades of the bomb pulse will become indistinguishable from pre-bomb recharge. The threshold of ambiguity has already arrived in coastal areas with a mean of 2 TU in precipitation and will follow in the next three decades throughout the study region. Where the mean tritium level is near 5 TU, the threshold will occur between 2025 and 2030, given a detection limit of 0.6 TU. Similar thresholds of ambiguity, with different local timing possible, apply globally.
Collapse
Affiliation(s)
- C J Eastoe
- SAHRA, Department of Geosciences, University of Arizona, Tucson, AZ 85721, USA.
| | | | | | | |
Collapse
|
6
|
Abstract
Sulfate (S and O) isotopes used in conjunction with sulfate concentration provide a tracer for ground water contributions to base flow. They are particularly useful in areas where rock sources of contrasting S isotope character are juxtaposed, where water chemistry or H and O isotopes fail to distinguish water sources, and in arid areas where rain water contributions to base flow are minimal. Sonoita Creek basin in southern Arizona, where evaporite and igneous sources of sulfur are commonly juxtaposed, serves as an example. Base flow in Sonoita Creek is a mixture of three ground water sources: A, basin ground water with sulfate resembling that from Permian evaporite; B, ground water from the Patagonia Mountains; and C, ground water associated with Temporal Gulch. B and C contain sulfate like that of acid rock drainage in the region but differ in sulfate content. Source A contributes 50% to 70%, with the remainder equally divided between B and C during the base flow seasons. The proportion of B generally increases downstream. The proportion of A is greatest under drought conditions.
Collapse
Affiliation(s)
- Ailiang Gu
- Department of Geosciences, University of Arizona, Tucson, AZ 85721, USA.
| | | | | | | | | | | |
Collapse
|
7
|
Abstract
Analysis of a typical semiarid mountain system recharge (MSR) setting demonstrates that geochemical tracers help resolve the location, rate, and seasonality of recharge as well as ground water flowpaths and residence times. MSR is defined as the recharge at the mountain front that dominates many semiarid basins plus the often-overlooked recharge through the mountain block that may be a significant ground water resource; thus, geochemical measurements that integrate signals from all flowpaths are advantageous. Ground water fluxes determined from carbon-14 ((14)C) age gradients imply MSR rates between 2 x 10(6) and 9 x 10(6) m(3)/year in the Upper San Pedro Basin, Arizona, USA. This estimated range is within an order of magnitude of, but lower than, prior independent estimates. Stable isotopic signatures indicate that MSR has a 65% +/- 25% contribution from winter precipitation and a 35% +/- 25% contribution from summer precipitation. Chloride and stable isotope results confirm that transpiration is the dominant component of evapotranspiration (ET) in the basin with typical loss of more than 90% of precipitation-less runoff to ET. Such geochemical constraints can be used to further refine hydrogeologic models in similar high-elevation relief basins and can provide practical first estimates of MSR rates for basins lacking extensive prior hydrogeologic measurements.
Collapse
Affiliation(s)
- Arun K Wahi
- SAHRA, University of Arizona, Tucson, AZ 85721, USA.
| | | | | | | | | |
Collapse
|
8
|
Baillie MN, Hogan JF, Ekwurzel B, Wahi AK, Eastoe CJ. Quantifying water sources to a semiarid riparian ecosystem, San Pedro River, Arizona. ACTA ACUST UNITED AC 2007. [DOI: 10.1029/2006jg000263] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Matthew N. Baillie
- Department of Hydrology and Water Resources; University of Arizona; Tucson Arizona USA
- SAHRA; University of Arizona; Tucson Arizona USA
| | - James F. Hogan
- Department of Hydrology and Water Resources; University of Arizona; Tucson Arizona USA
- SAHRA; University of Arizona; Tucson Arizona USA
| | - Brenda Ekwurzel
- Department of Hydrology and Water Resources; University of Arizona; Tucson Arizona USA
- SAHRA; University of Arizona; Tucson Arizona USA
| | - Arun K. Wahi
- Department of Hydrology and Water Resources; University of Arizona; Tucson Arizona USA
- SAHRA; University of Arizona; Tucson Arizona USA
| | - Christopher J. Eastoe
- SAHRA; University of Arizona; Tucson Arizona USA
- Department of Geosciences; University of Arizona; Tucson Arizona USA
| |
Collapse
|
9
|
Eastoe CJ, Gu A, Long A. The origins, ages and flow paths of groundwater in Tucson basin: Results of a study of multiple isotope systems. Groundwater Recharge in a Desert Environment: The Southwestern United States 2004. [DOI: 10.1029/009wsa12] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
|