Stable Isotopes In Precipitation Research Articles

The Effect of Convective/Advective Precipitation Partitions on the Precipitation Isotopes in the Monsoon Regions of China: A Case Study of Changsha

Abstract Convective/advective precipitation partitions refer to the divisions of precipitation that are either convective or advective in nature, relative to the total precipitation amount. These distinct partitions can have a significant influence on the stable isotope composition of precipitation. This study analyzed and compared the effect of precipitation partitions on δ18O in precipitation (δ18Op) by using daily precipitation stable isotope data from Changsha station and monthly precipitation stable isotope data from the Global Network of Isotopes in Precipitation (GNIP), under different time scales, time intervals (i.e., annual, warm season, and cold season), and precipitation intensities. The results showed that the correlation between the convective precipitation fraction (CPF) and total precipitation amount was influenced by the intensity of convection in different time intervals. On both the daily and monthly scales, the CPF decreased as the precipitation amount increased in the warm season, while it increased with increasing precipitation amount in the cold season. Regardless of the season, daily δ18Op at Changsha station consistently increased with an increase in daily CPF. On a daily scale, the effect of convective activity on δ18Op was stronger than that of the “precipitation amount effect” in the cold season, as compared to the situation in the warm season. As a result, the regression line slope between δ18Op and CPF increased with increasing precipitation intensity in the warm season, meaning that as the CPF increased, the δ18Op increased at a faster rate under higher precipitation intensity. Similarly, the slope increased with increasing precipitation intensity in the cold season. This suggests that precipitation intensity and convection intensity can affect the relationship between δ18Op and CPF. Our findings shed light on how different precipitation partitions affect stable isotope composition of precipitation, thus enhancing our understanding of the variability of precipitation stable isotopes in the monsoon regions of China. Significance Statement This study aims to better elucidate the influence of different precipitation partitions on precipitation stable isotopes. In the eastern monsoon region of China, stable isotopes in precipitation showed a robust positive relationship with convective precipitation faction. On a daily scale, the convective activity enhanced the influences of the “precipitation amount effect” on precipitation stable isotopes in the warm season and reduced such influences in the cold season. These results improve our understanding of stable isotopic variability of precipitation in the eastern monsoon region, China.

Effect of the North Atlantic Oscillation on stable isotopes of precipitation in Northern Europe

Effect of the North Atlantic Oscillation on stable isotopes of precipitation in Northern Europe

Dataset of stable isotopes of precipitation in the Eurasian continent

Abstract. Stable isotopes in precipitation can effectively reveal the process of atmospheric water circulation, serving as an effective tool for hydrological and water resource research, climate change, and ecosystem studies. The scarcity of stable isotope data in precipitation has hindered comprehension of the regional hydrology, climate, and ecology due to discontinuities on a temporal scale and unevenness on a spatial scale. To this end, we collated stable hydrogen and oxygen isotope data in precipitation from 842 stations in Eurasia from 1961 to 2022, totalling 51 752 data records. Stable isotopes in precipitation across various regions of Eurasia, as a whole, decrease with increasing latitude and distance from the coast. In the summer, stable isotopes in precipitation are relatively enriched, while in the winter, they are relatively depleted. In recent decades, the stable isotope values of Eurasian precipitation show an overall trend of increasing variation with the advancement of years, which is associated with global warming. Geographical location, underlying surface conditions, seasons, and atmospheric circulation are all factors that determine the characteristics of stable isotopes in precipitation. The dataset of stable isotopes in Eurasian precipitation provides a powerful tool for understanding changes in regional atmospheric water circulation and assists in conducting hydrological, meteorological, and ecological studies in related regions. The datasets are available at https://doi.org/10.17632/rbn35yrbd2.2 (Zhu, 2024).

Influence of Sub-Cloud Secondary Evaporation Effects on the Stable Isotopes in Precipitation of Urumqi Glacier No. 1, Eastern Tianshan

Influence of Sub-Cloud Secondary Evaporation Effects on the Stable Isotopes in Precipitation of Urumqi Glacier No. 1, Eastern Tianshan

Mechanisms of isotopic control of precipitation in the Yellow River source region

AbstractThe study of water vapour sources and water cycle patterns in the Yellow River source region is of great significance for ensuring water resource security in the arid and semi‐arid regions of northern China. We established a precipitation stable isotope observation system in the Yellow River source region for three consecutive years (2020–2022), systematically analysed the spatial and temporal distribution characteristics of precipitation stable isotopes 2H and 18O in the Yellow River source region and their interrelationships with environmental factors and topography, and explored the regional water vapour transport pathways by using the HYSPLIT model and combining with the global reanalysis data. The results show that: (1) the δ18O and δ2H values of precipitation in the Yellow River source region follow the seasonal pattern, with the first half of the year being richer than the second half of the year; (2) the spatial variations of δ18O of precipitation in the Yellow River source region show a low in the southwest and a high in the northeast; (3) the water vapour source in the source area is basically stable, and the complex transport paths and the cross‐effects of the local factors determine the stable isotope characteristics of the water, and the stable isotope characteristics of the water are determined by the cross‐effects of the local factors, because the source of the water vapour and the local factors such as the height will not change significantly in the short term. Since the source of water vapour and local elevation factors will not change significantly in the short term, the precipitation pattern in the source area of the Yellow River can be considered to be basically stable.

An Assessment of Six Years of Precipitation Stable Isotope and Tritium Activity Concentration Records at Station Sv. Urban, Eastern Slovenia

We present data from six years (January 2016–December 2021) of monitoring the isotope composition of precipitation at the Sv. Urban station in Eastern Slovenia. The 68 precipitation samples were collected as a monthly composite. The complete dataset (193 data pints) includes information on the stable isotope composition of hydrogen (δ2H) and oxygen (δ18O) and tritium activity concentration (A), obtained using isotope ratio mass spectrometry (IRMS) and liquid scintillation counting (LSC) following electrolytic enrichment (EE), respectively. The isotope data, together with meteorological data, are reported. Calculations of the deuterium excess (d-excess), monthly, seasonal, and annual unweighted and precipitation-weighted means and local meteoric water lines (LMWLs) were conducted. The mean values for δ2H, δ18O, d-excess, and A, weighted by precipitation, were −59.9‰, −8.81‰, 10.6‰, and 7.7 TU. The disparities between unweighted and precipitation-weighted δ2H, δ18O, d-excess, A, and LMWLs underscore the significance of non-uniformly distributed precipitation. Annual variations in slope and intercept of the LMWLs emphasize the importance of longer data records (48+ months) to capture consistent trends, while combining data over longer periods may distort accuracy due to distinct isotope differences between individual years related to the variability of climate conditions typical for Slovenia.

Role of stable isotopes in revealing moisture sources and rainfall variability in India

Precipitation is a crucial component of the water cycle and is essential for the livelihood of people and ecosystems; therefore, understanding precipitation parameters is vital. Stable isotopes in precipitation can provide important information on precipitation sources, atmospheric circulation patterns, and hydrological processes. In this study, stable isotopes in precipitation for four cities in India were analyzed, namely New Delhi, Hyderabad, Shillong, and Calicut, using data from the International Atomic Energy Agency (IAEA) Global Network for Isotopes in Precipitation (GNIP). The GNIP data were supplemented with in-situ measurements. Results showed the correlations between climate-related factors such as surface air temperature and precipitation levels with the stable isotope composition of precipitation. The relationships critically explore interannual variations in the isotope data over the last three decades. The Local Meteoric Water Line (LMWL) for New Delhi and Hyderabad had intercepts less than 10‰, implying a higher evaporation effect over precipitation, consistent with arid and semi-arid regions with increased altitude. The weighted average value of d-excess for southern and Himalayan points were 10.7 and 12.7, respectively, and the average value of δ¹⁸O were − 3.65 and − 5.84, and δ²H were − 16.8 and − 35.8. The d-excess value was significantly lower in the Northern part (New Delhi), with an average weighted value of 6.6. The key values include the isotopic composition of rainfall in different regions of India, the LMWL for different stations, the d-excess value, and the consistency of meteoric water lines with regional and global values. The results of this study provide valuable information on the variability of stable isotopes in precipitation in India. The study's outcomes can be compared with the isotopic composition of surface water and groundwater. This discovery offers more understanding of the isotopic differences that occur on a smaller scale during organized convection and the factors that affect them. As a result, it enhances our ability to decipher the paleoclimate data in arid, semi-arid, and subtropical monsoon regions.

Influence of below‐cloud evaporation on stable isotopes of precipitation in the Yellow River source region

AbstractThe study of below‐cloud evaporation effects under clouds in the Yellow River source region is of great significance for regional water resource generation as well as for water resource security in the arid and semi‐arid regions of northern China. In this study, we quantitatively assessed the evapotranspiration effect in the Yellow River source region from March to November based on the improved Stewart model. The study concluded that: (1) below‐cloud evaporation was slightly higher in summer than in other seasons (residual fractions of raindrop evaporation were 80.57% in summer, 81.12% in spring, and 84.2% in autumn, respectively); and (2) sub‐cloud evaporation diminishes with increasing altitude (residual fractions of raindrop evaporation were 83.09% in the western part of the area, 81.82% in the central part of the area, and 81.36% in the eastern part of the area, respectively). (3) The total linear index between study areas f and ∆d is 2.24, where f > 95%, it is 1.19; that is, the evaporation of raindrops increases by 1% and the reduction in the excess of mercury by about 2‰. (4) Local meteorological factors (temperature, precipitation, and relative humidity) and raindrop diameter have a cross‐influence on below‐cloud evaporation, with relative humidity having the most significant effect, with the highest correlation coefficient of 3.03 when relative humidity is less than 70%. The results of the study can provide a parameter basis for hydrological and climatic models in the Yellow River Basin.

Seasonal Variations of Modern Precipitation Stable Isotopes over the North Tibetan Plateau and Their Influencing Factors

Based on 360 event-based precipitation samples collected at six stations on the North Tibetan Plateau (NTP) in 2019–2020, we analyzed the influence of meteorological parameters, sub-cloud evaporation, moisture sources, and moisture transmission pathways on precipitation and its seasonal variations. The results show that precipitation δ18O, δ2H, and d-excess values show obvious seasonal variations, being depleted in winter and enriched in summer. Although temperature is an important variable that affects the change in δ18O values of precipitation, the results of the sub-cloud evaporation effect and moisture tracing show that differences in moisture sources caused by seasonal changes in large-scale water moisture transport are an important cause of seasonal changes in δ18O and d-excess of precipitation at NTP. Depleted δ18O and enriched d-excess in winter represent the source of moisture transported by the westerlies from the Mediterranean area and Central Asia. Enriched δ18O and d-excess values in summer precipitation are related to the temperature effect. In addition, the meridional motion of the atmospheric flow has an effect on the precipitation isotope values in the NTP. When the meridional circulation is enhanced, the water vapour from low latitudes is easily transported northwards, enriching the summer precipitation isotope values in the central and eastern parts of the plateau. This provides a new insight into the explanation of stable oxygen isotopes in climate proxies across the westerlies-dominated Tibetan Plateau.

Influence of atmospheric circulation on the stable isotope of precipitation in the monsoon margin region

Precipitation stable isotope is a good medium for studying the water cycle and atmospheric water vapor transport process. To better understand the influence and control mechanism of atmospheric circulation on the stable isotope of precipitation in the East Asian monsoon margin region. We set up observation points in the Shiyang River basin in the East Asian monsoon marginal region to observe precipitation isotopes and analyze the mechanism and process of the control of atmospheric circulation on precipitation isotopes in the monsoon marginal region. The results show that: The results show that the stable isotope of precipitation in the monsoon margin region is greatly affected by the local meteorological conditions, and there are obvious temperature effects. The main water vapor affecting the monsoon margin region throughout the year are west wind water vapor, southeast monsoon water vapor, plateau wind water vapor and local circulation water vapor. In July and August, 25.33% and 65% of the southeast monsoon water vapor reached the monsoon margin region, respectively. The variation of stable isotope of precipitation in the monsoon margin region is mainly controlled by the East Asian Monsoon and the Northwest Pacific Monsoon Trough, but is less dependent on the Westerly Wind and Plateau Wind.

Spatial and Temporal Variation Characteristics of Stable Isotopes in Precipitation and Their Relationships with Meteorological Factors in the Shiyang River Basin in China

Stable isotopes of precipitation play an important role in understanding hydrological and climatic processes of arid inland river basins. In order to better understand the difference of regional water cycle and precipitation patterns, precipitation samples were collected in Shiyang River Basin from June 2018 to May 2020, and spatial and temporal variation characteristics of stable isotopes in precipitation and their relationships with meteorological factors were discussed. The results showed that stable isotopes in precipitation showed seasonal variation characteristics, that δ2H and δ18O values were higher in summer and autumn and lower in winter and spring, and d-excess values were higher in spring and autumn and lower in winter and summer. Slopes and intercepts of the local meteoric water lines gradually increased with elevation increasing. δ18O significantly showed a positive correlation with temperature but a negative correlation with precipitation in summer. Contrary to below 15 hPa, δ18O significantly showed a negative correlation with water vapor pressure above 15 hPa. Due to the influence of meteorological factors, there are significant differences in stable isotopes of precipitation in arid inland river basins, which were more influenced by local moisture recycling in upstream area but by below-cloud secondary evaporation in mid-downstream area.

Simulating precipitation stable isotopes and tracking moisture sources in Qaidam Basin combining GCMs and HYSPLIT

Simulating precipitation stable isotopes and tracking moisture sources in Qaidam Basin combining GCMs and HYSPLIT

What causes site-specific intra-event variations of stable isotopes in precipitation in Beijing?

Stable oxygen isotope composition (δ18Op) and deuterium excess (dp) in precipitation carry important climate and hydrological information on the history of water from evaporation, transport to precipitation. This study aims to quantify the effect of potential factors on site-specific intra-event δ18Op and dp dynamics during three precipitation events in a mid-latitude region Beijing, China. The tested factors included moisture source (Ms) and upstream rainout fraction (Up) obtained by HYSPLIT backward trajectory model, radar reflectivity factor (Ze) that corresponds to raindrop size by weather radar, sub-cloud evaporation fractionation (fe) by an isotope-evaporation model, local precipitation amount (Lp) and precipitation intensity (I) by rain gauge, and relative location of the sampling sites (downwind or upwind). Intra-event δ18Op had an amplitude of 10.3‰, and 84% of the variance could be explained, in the descending order of importance, by Ms, site, Ze, fe and I. Intra-event dp had an amplitude of 16.5‰, and 57% of the variance could be explained by fe, site, Ms and I, in the descending order of importance. Absolute values of intra-event δ18Op and dp differed between two sites, 30 km apart, by up to 4.7‰ and 9.7‰, respectively. This site-specificity in δ18Op and dp was mainly caused by differences in rainout effects and I. This work provides new insights into separating the effects of various climatic and hydrological variables on high-frequency dynamics of δ18Op and dp.

Moisture sources and climatic effects controlling precipitation stable isotope composition in a western Mediterranean island (Pianosa, Italy)

The Mediterranean basin is indicated as a hot spot of climate change, which is an area whose climate is especially responsive to variations. The insular environment is one of the most threatened by the current climate change, especially in terms of drought events, with serious consequences for water scarcity and water stress. This issue is even enhanced in small islands, whose ecosystems are among more sensitive to climatic changes and water availability. The stable isotope composition of hydrogen (δ2H) and oxygen (δ18O) in precipitation is globally recognized as a powerful natural tracer in the water cycle and represents the starting point to investigate hydrological processes. The understanding of the prevailing factors that drive the isotopic variability of precipitation in the Mediterranean is therefore essential to unravel the hydrological processes and to ensure proper and sustainable management of potentially vulnerable resources to climate change. Here, we discuss the results of multi-year isotopic monitoring in the period 2014–2021 of monthly precipitation collected on Pianosa Island (Italy), a small island located in the northern Tyrrhenian (western Mediterranean). The lower slope and intercept of the Local Meteoric Water Line of the island compared to the Global Meteoric Water Line indicated warmer and drier climatic conditions, suggesting the existence of sub-cloud evaporation processes of raindrops during precipitation, especially in summer. The mean δ18O of precipitation was lower with respect to other sites placed at higher elevation in this Mediterranean region, due to the lack of summer precipitation which were generally enriched in heavy isotopes. Temperature and amount effects may explain part of the δ18O variability observed at the monthly and seasonal scale. An HYSPLIT-based moisture uptake analysis indicated the area between the western Mediterranean basin, Italy, and the Adriatic Sea as the region that supplied most of the humidity associated with monthly precipitation samples on Pianosa Island. Less moisture was picked from the northwestern areas of Europe, the North Atlantic Ocean, the proximal Atlantic Ocean, the Iberian Peninsula and North Africa. Consistently with the rainout effect, the higher the moisture fraction picked from the more proximal regions, the more positive the δ18O of precipitation occurring on Pianosa Island; conversely, the higher the percentage of moisture sourced from more distal regions, the more negative the δ18O. A multiple linear model was proposed to predict the δ18O of monthly precipitation from temperature, precipitation amount and moisture origin data, which explained 45% of the δ18O variability. The deuterium excess variability on the island was partly controlled by the local climatic variables, whose effect potentially modifies the original d-excess signature imprinted at the moisture source. No relationship was found between the precipitation deuterium excess and moisture sources, suggesting that more attention should be paid when using the deuterium excess as a tracer of moisture origin, especially in the Mediterranean.

Influence of Evaporating Under the Clouds on the Precipitation Stable Isotope in the Transition Zone Between Tibetan Plateau and Arid Region of China

Influence of Evaporating Under the Clouds on the Precipitation Stable Isotope in the Transition Zone Between Tibetan Plateau and Arid Region of China

Extreme precipitation stable isotopic compositions reveal unexpected summer monsoon incursions in the Qilian Mountains

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.

A Precipitation Isotopic Response in 2014–2015 to Moisture Transport Changes in the Central Himalayas

AbstractThe impact of moisture transport and sources on precipitation stable isotopes (δ18O and d‐excess) in the central Himalayas are crucial to understanding the climatic archives. However, this is still unclear due to the lack of in‐situ observations. Here we present measurements of stable isotopes in precipitation at two stations (Yadong and Pali) in the central Himalayas during 2014–2015. Combined with simulations from the dispersion model FLEXPART, we investigate effects on precipitation stable isotopes related to changes in moisture sources and convections in the region, and possible influence by El Niño. Our results suggest that the moisture supplies related to evaporation over northeastern India and moisture losses related to convective activities over the Bay of Bengal (BoB) and Bangladesh region play important roles in changes in δ18O and d‐excess in precipitation in the Yadong Valley. Outgoing longwave radiation and moisture flux divergence analysis further confirm that the contribution from continental evaporation dominates the moisture supply in the central Himalayas with a lesser contribution from convection over the BoB during the 2015 monsoon season compared with 2014. A change in the altitude effect is observed in 2015, which is more significant than the temperature and precipitation amount effect during the observation period. These findings provide valuable insights into climatic interpretations of paleo‐isotopic archives with an isotopic response to changes in moisture transport to the central Himalayas.

Atmospheric processes control the stable isotopic variability of precipitation in the middle–lower reaches of the Yangtze River Basin, East Asian monsoon region

Paleoclimatic records in the East Asian monsoon region (EAM) depend on precipitation isotopes as proxies for past hydroclimatic variability. However, the potential mechanisms controlling precipitation isotopic variability in this region remain poorly understood. This study collected daily precipitation isotopes in the middle-lower reaches of the Yangtze River Basin from 2017 to 2020 to explore how convective behaviors and moisture sources determining the variability of precipitation stable isotopes. Daily precipitation δ18O presented a weak inverse relationship with local precipitation amount and air temperature. Results of correlation analysis showed that the maximum correlation zones of precipitation δ18O between different cloud levels and outgoing long wave radiation were identified in the upstream regions such as the Indian Peninsula, BoB, and Indo-China Peninsula during the rainy season. Back-trajectory analysis showed that substantial water vapor from maritine sources in the Indian Ocean and the Bay of Bengal (BoB) largely contributed to the lower δ18O values during the rainy season (−7.5 ‰) because of intense rainout processes in the upstream sourced regions, demonstrated by significant regional correlation between precipitation δ18O and regional precipitation amount. The regional correlations were stronger in the upstream regions than the local influences, indicating that precipitation isotopes in this region are more influenced by regional convective processes in the upstream region during the rainy season. Using the modified Stewart model, the mean subcloud evaporation fraction estimated was greater in rainy season (24.1 % vs 36.1 % for HK and HZ, respectively) than that in dry season (15.1 % vs 19.9 % for HK and HZ, respectively). These findings highlight the importance of upstream processes in controlling precipitation isotopes in the EAM region and provide reliable evidence on the interpretation of monsoonal climate variability.

Predicting the spatial distribution of stable isotopes in precipitation using a machine learning approach: a comparative assessment of random forest variants

Stable isotopes of hydrogen and oxygen are important natural tracers with a wide variety of environmental applications (e.g., the exploration of the water cycle, ecology and food authenticity). The spatially explicit predictions of their variations are obtained through various interpolation techniques. In the present work, a classical random forest (RF) and two of its variants were applied. RF and a random forest version employing buffer distance (RFsp) were applied to each month separately, while a random forest model was trained using all data employing month and year as categorical variables (RFtg). Their performance in predicting the spatial variability of precipitation stable oxygen isotope values for 2008–2017 across Europe was compared. In addition, a comparison was made with a publicly available alternative machine learning model which employs extreme gradient boosting. Input data was retrieved from the Global Network of Isotopes in Precipitation (GNIP; no. of stations: 144) and other national datasets (no. of stations: 127). Comparisons were made on the basis of absolute differences, median, mean absolute error and Lin’s concordance correlation coefficient. All variants were capable of reproducing the overall trends and seasonal patterns over time of precipitation stable isotope variability measured at each chosen validation site across Europe. The most important predictors were latitude in the case of the RF, and meteorological variables (vapor pressure, saturation vapor pressure, and temperature) in the case of the RFsp and RFtg models. Diurnal temperature range had the weakest predictive power in every case. In conclusion, it may be stated that with the merged dataset, combining GNIP and other national datasets, RFsp yielded the smallest mean absolute error 1.345‰) and highest Lin’s concordance correlation coefficient (0.987), while with extreme gradient boosting (based on only the GNIP data) the mean absolute error was 1.354‰, and Lin’s concordance correlation coefficient was 0.984, although it produced the lowers overall median value (1.113‰), while RFsp produced 1.124‰. The most striking systematic bias was observed in the summer season in the northern validation stations; this, however, diminished from 2014 onward, the point after which stations beyond 55° N are available in the training set.

Diet and landscape characteristics drive spatial patterns of mercury accumulation in a high-latitude terrestrial carnivore.

Limited information exists on mercury concentrations and environmental drivers of mercury bioaccumulation in high latitude terrestrial carnivores. Spatial patterns of mercury concentrations in wolverine (Gulo gulo, n = 419) were assessed across a 1,600,000 km2 study area in relation to landscape, climate, diet and biological factors in Arctic and boreal biomes of western Canada. Hydrogen stable isotope ratios were measured in wolverine hair from a subset of 80 animals to assess the spatial scale for characterizing environmental conditions of their habitat. Habitat characteristics were determined using GIS methods and raster datasets at two scales, the collection location point and a 150 km radius buffer, which was selected based on results of a correlation analysis between hydrogen stable isotopes in precipitation and wolverine hair. Total mercury concentrations in wolverine muscle ranged >2 orders of magnitude from 0.01 to 5.72 μg/g dry weight and varied geographically, with the highest concentrations in the Northwest Territories followed by Nunavut and Yukon. Regression models at both spatial scales indicated diet (based on nitrogen stable isotope ratios) was the strongest explanatory variable of mercury concentrations in wolverine, with smaller though statistically significant contributions from landscape variables (soil organic carbon, percent cover of wet area, percent cover of perennial snow-ice) and distance to the Arctic Ocean coast. The carbon and nitrogen stable isotope ratios of wolverine muscle suggested greater mercury bioaccumulation could be associated with feeding on marine biota in coastal habitats. Landscape variables identified in the modelling may reflect habitat conditions which support enhanced methylmercury transfer to terrestrial biota. Spatially-explicit estimates of wet atmospheric deposition were positively correlated with wolverine mercury concentrations but this variable was not selected in the final regression models. These landscape patterns provide a basis for further research on underlying processes enhancing methylmercury uptake in high latitude terrestrial food webs.