Glacier changes on the Tibetan Plateau derived from Landsat imagery: mid-1970s – 2000–13

The spatial‐temporal changes in terrestrial water storage (TWS) over the Tibetan Plateau (TP) and six selected basins during 2003–2014 were analyzed by applying the Gravity Recovery and Climate Experiment data and the extended Variable Infiltration Capacity‐glacier model, including the upstream of Yangtze (UYA), Yellow (UYE), Brahmaputra (UB), and Indus river basins and the Inner TP and the Qaidam Basin. The possible causes of TWS changes were investigated from the perspective of surface water balance and TWS components through multisource data and the Variable Infiltration Capacity‐glacier model. There was a strong spatial heterogeneity in changes of Gravity Recovery and Climate Experiment TWS in the TP—with apparent mass accumulation in central and northern TP and a sharp decreasing trend in southern and northwestern TP. The TWS changes in the TP were mostly attributed to variations in precipitation and evapotranspiration from the perspective of land‐surface water balance. Precipitation played a dominant role on the TWS accumulation in the UYA and UYE, while evapotranspiration had a more important role than precipitation in TWS depletion in the UB. From the perspective of TWS components, the TWS increase in the UYA and UYE was mainly caused by an increase in soil moisture, whereas the decrease in TWS in the UB was mostly due to glacier mass loss. TWS was accumulating from March through August in southeastern TP while from November to April/May in northwestern TP. The seasonal variations of TWS are highly modulated by the large‐scale climate system, atmospheric moisture flux, and precipitation regime over the TP.

Section: 1029/2018jd029552mentioning

confidence: 82%

Changes in Terrestrial Water Storage During 2003–2014 and Possible Causes in Tibetan Plateau

Meng

et al. 2019

“…Therefore, the debris cover is also unlikely to be the major cause of nearly stable glacier state in our study area. Previous studies have reported that glaciers/ice caps in the Inner Tibetan Plateau and East Kunlun Mountain were nearly stable in the early 21st century (Brun et al, ; Gardner et al, ; Neckel et al, ; Yao et al, ; Ye et al, , ). Such glacier state is not contradictory to the global warming because the climate there is extreme cold and dry and is nearly free of anthropogenic influence.…”

Section: Discussionmentioning

confidence: 97%

Anomalous Glacier Changes in the Southeast of Tuomuer‐Khan Tengri Mountain Ranges, Central Tianshan

Ding

et al. 2018

Central Tianshan (CTS) plays a prominent role in maintaining the vulnerable ecosystem in Central Asia. Rivers originating from it have high proportions of the runoffs contributed by glacier meltwater. In this study, the glacier mass balance in the catchments of Muzart and Karayulun rivers, CTS, was estimated by a geodetic method based on Advanced Land Observing Satellite/Panchromatic Remote-sensing Instrument for Stereo Mapping images and Shuttle Radar Topography Mission (SRTM) digital elevation model (DEM). The results revealed that at the west and east glacial centers in the study area, the 2000-2011 mass loss rates were À0.03 ± 0.17 and À0.06 ± 0.17 m w.e./a, respectively, considerably lower than other CTS zones. In order to ascertain this stable glacier state, we also performed a geodetic measurement based on TerraSAR-X add-on for Digital Elevation Measurement (TanDEM-X) images and SRTM DEM (2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010)(2011)(2012), and the results are similar (0.01 ± 0.17 and À0.04 ± 0.17 m w.e./a, respectively). The glacier thickness change around the regional snowline was close to zero. The strong capability of cold storage and the temperature drop in the early 21st century may account for the anomalous mass changes. Despite slight overall mass changes, obvious thinning was observed on many exposed glacier feet. This study indicates that the glacier melting can be effectively controlled if the rising trend of temperatures is reversed; furthermore, the land surface hydrological model should be calibrated with geodetic glacier mass balance measurement when it is used to simulate the streamflow trend in the headwater basin.Although in-site glaciological measurement is a highly accurate way of estimating glacier thickness changes, it is labor-intensive and its spatial coverage is limited (Racoviteanu et al., 2007). In comparison, geodetic LI ET AL. 6840

“…Climate change in the Tibetan Plateau (TP), the so called “Third pole warming”, threatens the vast reservoir of glacier and snow, whose current melting affects one fifth of the world's population (Gao et al, ). Glacier area on the plateau decreased from 44,366 ± 2,827 km 2 in the 1970s to 42,210 ± 1,621 km 2 in 2001 and 41,137 ± 1,616 km 2 in 2013 illustrated by the Landsat satellite images (Ye et al, ). As a result, the endorheic water storage in the inner TP increases remarkably (Wang et al, ).…”

Section: Introductionmentioning

confidence: 99%

Nonmonsoon Precipitation Dominates Groundwater Recharge Beneath a Monsoon‐Affected Glacier in Tibetan Plateau

Kong

Wang

et al. 2019

Groundwater recharge is poorly understood beneath the glacier due to the complex sampling conditions, although it is sensitive to the global change. Here we carried out the sampling and isotopic analysis on groundwater, ice‐melt water, river, and precipitation through a hydrological year at the lowest glacier of Mingyong in Hengduan Mountains, Southeastern Tibetan Plateau. The precipitation during the monsoon seasons (Pm) are more depleted in heavy isotopes than precipitation during the nonmonsoon seasons (Pnm) due to the influence of monsoon. The ice‐melt water and groundwater points are both found located left above the local meteoric water line (δ2H = 8.0δ18O + 8.0) and form lines of δ2H = 6.3δ18O – 10.0 and δ2H = 4.2δ18O – 37.6, respectively. However, their mean isotopic values are both larger than the weighted annual mean of precipitation isotopes. All of the phenomena above points to the occurring of refreezing process after excluding the evaporation process. A theoretical model is built to confirm the refreezing process that causes the lower slope of ice‐melt water line. The groundwater line is explained as a mixing line with ice‐melt water and precipitation with contributions of 46 ± 22% and 54 ± 22%, respectively. For the precipitation contribution, we propose a plausible conceptual model that groundwater comes primarily from Pnm (41 ± 17%), and minor from Pm (13 ± 17%). In this context, it is equivalent to 87 ± 28% groundwater recharged by Pnm because the glacier is mainly accumulated from Pnm. The findings highlight the importance of the Pnm recharging groundwater even in the monsoon‐affected glacial regions.