Late quaternary climate, precipitation δ18O, and Indian monsoon variations over the Tibetan Plateau

Li, Jingmin; Ehlers, Todd A.; Werner, Martin; Mutz, Sebastian G.; Steger, Christian; Paeth, Heiko

doi:10.1016/j.epsl.2016.09.031

Cited by 31 publications

(19 citation statements)

References 52 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Unfortunately, quantitative estimates of precipitation changes on orbital timescales are rare and largely based on climate model results. For example, Li et al [] employed an atmospheric general circulation model to study climatic conditions over the Tibetan Plateau and bordering mountain ranges during the mid‐Holocene (6 ka B.P.) and the Last Glacial Maximum (LGM; 21 ka B.P.).…”

Section: Discussionmentioning

confidence: 83%

Testing monsoonal controls on bedrock river incision in the Himalaya and Eastern Tibet with a stochastic‐threshold stream power model

et al. 2017

View full text Add to dashboard Cite

10Be‐derived catchment average erosion rates from the Himalaya and Eastern Tibet show different relationships with normalized channel steepness index (ksn), suggesting differences in erosional efficiency of bedrock river incision. We used a threshold stream power model (SPM) combined with a stochastic distribution of discharges to explore the extent to which this observation can be explained by differences in the mean and variability of discharge between the two regions. Based on the analysis of 199 daily discharge records (record lengths 3–45 years; average 18.5 years), we parameterized monsoonal discharge with a weighted sum of two inverse gamma distributions. During both high‐ and low‐flow conditions, annual and interannual discharge variabilities are similarly low in each region. Channel widths for 36 rivers indicate, on average, 25% wider streams in Eastern Tibet than in the Himalaya. Because most catchments with 10Be data are not gauged, we constrained mean annual discharge in these catchments using gridded precipitation data sets that we calibrated to the available discharge records. Comparing 10Be‐derived with modeled erosion rates, the stochastic‐threshold SPM explains regional differences better than a simple SPM based on drainage area or mean annual runoff. Systematic differences at small ksn values can be reconciled with ksn‐dependent erosion thresholds, whereas substantial scatter for high ksn values persists, likely due to methodological limitations. Sensitivity analysis of the stochastic‐threshold SPM calibrated to the Himalaya indicates that changes in the duration or strength of summer monsoon precipitation have the largest effect on erosional efficiency, while changes in monsoonal discharge variability have almost no effect. The modeling approach presented in this study can in principle be used to assess the impact of precipitation changes on erosion.

show abstract

Section: Discussionmentioning

confidence: 83%

Testing monsoonal controls on bedrock river incision in the Himalaya and Eastern Tibet with a stochastic‐threshold stream power model

et al. 2017

View full text Add to dashboard Cite

show abstract

“…3.75 • × 3.75 • ; T63, ca. 1.9 • × 1.9 • in the case of Feng et al, 2016, and T106 in the case of Li et al, 2017 and. The studies performed are not limited to the last millennium (e.g.…”

Section: Echam5 Simulationsmentioning

confidence: 99%

“…The model seems able to reproduce the predominantly wetter conditions on much of the Tibetan Plateau, but predicts slightly drier conditions north of Chengdu, which is not reflected in local reconstructions. The modest mismatch between ECHAM5-predicted and proxy-based MH climate change in South Asia was also documented by Li et al (2017), whose simulations were conducted at a coarser (T106) resolution. Despite these model-proxy differences, we note that there are significant discrepancies among the proxy data themselves in neighbouring locations in the MH, highlighting caution in relying solely upon these data for regional palaeoclimate reconstructions.…”

Section: Comparison Of Simulated and Observed Precipitation Differencesmentioning

confidence: 99%

“…Li et al, 2017) instead of conducting the computationally more expensive fully coupled atmosphere-ocean GCM experiments. While the use of SST climatologies comes at the cost of capturing decadal-scale variability, and the results are ultimately biased towards the SST reconstructions the model is forced with; the simulated climate more quickly reaches an equilibrium state and the means of atmospheric variables used in this study do no change significantly after the relatively short spin-up period.…”

Section: Echam5 Simulationsmentioning

confidence: 99%

“…Yanites and Ehlers, 2012;Herman et al, 2013;Valla et al, 2011) but also global changes in precipitation and temperature (e.g. Otto-Bliesner et al, 2006;Li et al, 2017) that could influence catchment denudation in non-glaciated environments (e.g. Schaller and Ehlers, 2006;Glotzbach et al, 2013;Marshall et al, 2015).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Estimates of late Cenozoic climate change relevant to Earth surface processes in tectonically active orogens

et al. 2018

Self Cite

View full text Add to dashboard Cite

Abstract. The denudation history of active orogens is often interpreted in the context of modern climate gradients. Here we address the validity of this approach and ask what are the spatial and temporal variations in palaeoclimate for a latitudinally diverse range of active orogens? We do this using high-resolution (T159, ca. 80 × 80 km at the Equator) palaeoclimate simulations from the ECHAM5 global atmospheric general circulation model and a statistical cluster analysis of climate over different orogens (Andes, Himalayas, SE Alaska, Pacific NW USA). Time periods and boundary conditions considered include the Pliocene (PLIO, ∼ 3 Ma), the Last Glacial Maximum (LGM, ∼ 21 ka), mid-Holocene (MH, ∼ 6 ka), and pre-industrial (PI, reference year 1850). The regional simulated climates of each orogen are described by means of cluster analyses based on the variability in precipitation, 2 m air temperature, the intra-annual amplitude of these values, and monsoonal wind speeds where appropriate. Results indicate the largest differences in the PI climate existed for the LGM and PLIO climates in the form of widespread cooling and reduced precipitation in the LGM and warming and enhanced precipitation during the PLIO. The LGM climate shows the largest deviation in annual precipitation from the PI climate and shows enhanced precipitation in the temperate Andes and coastal regions for both SE Alaska and the US Pacific Northwest. Furthermore, LGM precipitation is reduced in the western Himalayas and enhanced in the eastern Himalayas, resulting in a shift of the wettest regional climates eastward along the orogen. The cluster-analysis results also suggest more climatic variability across latitudes east of the Andes in the PLIO climate than in other time slice experiments conducted here. Taken together, these results highlight significant changes in late Cenozoic regional climatology over the last ∼ 3 Myr. Comparison of simulated climate with proxy-based reconstructions for the MH and LGM reveal satisfactory to good performance of the model in reproducing precipitation changes, although in some cases discrepancies between neighbouring proxy observations highlight contradictions between proxy observations themselves. Finally, we document regions where the largest magnitudes of late Cenozoic changes in precipitation and temperature occur and offer the highest potential for future observational studies that quantify the impact of climate change on denudation and weathering rates.

show abstract

Hydroclimatic significance of stable isotopes in precipitation from glaciers of Garhwal Himalaya, Upper Ganga Basin (UGB), India

Verma

Kumar

Gupta

et al. 2018

Hydrological Processes

View full text Add to dashboard Cite

Stable isotopic composition of precipitation as preserved in continental proxy climate archives (e.g., ice cores, lacustrine sediments, tree rings, groundwater, and organic matter) can sensitively record fluctuations in local meteorological variables. These are important natural climatic tracers to understand the atmospheric circulation patterns and hydrological cycle and to reconstruct past climate from archives. Precipitation was collected at Dokriani Glacier to understand the response of glaciers to climate change in the Garhwal Central Himalaya, Upper Ganga Basin. The local meteoric water line deviates from the global meteoric water line and is useful for the identification of moisture source in the region. The data suggest different clusters of isotopic signals, that is, summer (June–September) and winter (November–April); the mean values of δ18O, δD, and d ‰ during summer are −13.03‰, −84.49‰, and 19.78 ‰, respectively, whereas during winter, the mean values of δ18O, δD, and d ‰ are −7.59‰, −36.28‰, and 24.46 ‰, respectively. Backward wind trajectory analysis ascertains that the major source of precipitation during summer is from the Indian Summer Monsoon and during winter from the westerlies. Regression analysis has been carried out in order to establish interrelationship between the precipitation isotopic signatures and meteorological variables such as air temperature, relative humidity, and precipitation. Temperature and precipitation have good correlation with the isotopic signatures of precipitation with R2 values >.5, suggesting that both temperature and amount effects prevail in the study region. Multiple regression analysis found strong relationships for both the seasons. The relationship of deuterium excess with δ18O, relative humidity, and precipitation are significant for the winter season. No significant relationships of deuterium excess were found with other meteorological variables such as temperature and radiation. The correlation and regression analysis performed are significant and valuable for interpretation of processes in the hydrological cycle as well as for interpretation of palaeoclimate records from the region.

show abstract

Late quaternary climate, precipitation δ18O, and Indian monsoon variations over the Tibetan Plateau

Cited by 31 publications

References 52 publications

Testing monsoonal controls on bedrock river incision in the Himalaya and Eastern Tibet with a stochastic‐threshold stream power model

Testing monsoonal controls on bedrock river incision in the Himalaya and Eastern Tibet with a stochastic‐threshold stream power model

Estimates of late Cenozoic climate change relevant to Earth surface processes in tectonically active orogens

Hydroclimatic significance of stable isotopes in precipitation from glaciers of Garhwal Himalaya, Upper Ganga Basin (UGB), India

Contact Info

Product

Resources

About