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In the context of global warming, glaciers in the Asian High Mountains (AHMs) are shrinking at an accelerating rate. Projecting their future change is helpful for understanding the hydrological and climatic effects related to glacier retreat. Here, we projected glacier change in the AHMs from 1979 to 2100 under shared socioeconomic pathway (SSP) scenarios from the perspective of temperature, equilibrium-line altitude (ELA), and accumulation area. The annual mean temperature in the AHMs increased by 1.26°C from 1979 to 2014, corresponding to an increase of 210 m in the mean ELA and a decrease of 1.7×104 km2 in the glacier accumulation area. Under the SSP2-4.5 (SSP5-8.5) scenario, the annual mean temperature in the AHMs would increase by 2.84°C (3.38°C) in 2040–2060 relative to that in 1850–1900, leading to the mean ELA reaching an elevation of 5661 m (5777 m). The accumulation area in the AHMs decreased by 46.3% from 1995 to 2014 and was projected to decrease by 60.1% in 2040–2060. Moreover, the annual mean temperature in the AHMs was projected to increase by 3.76°C (6.44°C) in 2080–2100 relative to that in 1850–1900, corresponding to the ELA reaching an elevation of 5821 m (6245 m) and the accumulation area decreasing to 1.8×104 km2 (0.5×104 km2). These data suggest that the conditions for glacier development will disappear in most of the AHMs, except for extreme high-altitude regions in the Tianshan, Pamir, and Himalaya Mountains. Under the SSP2-4.5 (SSP5-8.5) scenario, when the global mean temperature increases 1.5°C (2°C) above pre-industrial levels, the annual mean temperature will increase by 2.12°C (2.86°C) and the accumulation area will decrease by 15% (48%) in the AHMs compared with that in 1995–2015. Therefore, a 1.5°C increase in global warming would keep 40% more of the glacial accumulation area (1.5×104 km2) in the AHMs compared to a 2°C increase in global warming. [ABSTRACT FROM AUTHOR]

The variation of freezing level height (FLH) is significantly indicated the cryosphere change under global warming. In this study, the FLH during boreal summer in the TP regions is investigated, with the leading mode of a mono-sign pattern both on interannual and interdecadal timescales. The interannual variation of the summer FLH is dominantly coupled with the summer Arctic Oscillation (AO). When the AO is in positive phase, positive geopotential height anomalies are prolonged in the mid-latitude and negative anomalies are present over the Arctic regions. Meanwhile, the westerly shifts northward and strengthened, preventing the cold air propagating southward. These conditions are beneficial for the surface and free-air temperature increasing and thus enhance the FLH over the TP. On the interdecadal timescale, the Pacific Decadal Oscillation (PDO) has mainly contributed to the variation of summer FLH. In the negative PDO phase, the warming sea surface temperature anomalies appear in the North Pacific, which could drive wave trains propagating eastward and induce high pressure around the northern TP. With the anomalous anticyclone from TP to western North Pacific, the southeasterly wind is prevalent in the TP. Consequently, the northern TP becomes warming remarkably and leads to the rising of FLH. This study provides an insight perspective for understanding the changes of FLH over the TP, which also suggests the influence on the cryosphere processes at multi-timescale variations. • The summer freezing level height (FLH) in the Tibetan Plateau (TP) shows interannual and interdecadal variations. • The interannual variation is dominantly coupled with the summer Arctic Oscillation. • The Pacific Decadal Oscillation has mainly contributed to the interdecadal component variation. • The results indicate the cryosphere processes changes in the TP at multi-timescales. [ABSTRACT FROM AUTHOR]

In recent years, rapid global warming has led to a dramatic cryosphere retreat and caused environmental disasters on the Tibetan Plateau (TP). To better understand the near-surface air temperature variation on the TP in response to global warming in the 21st century, we systematically detected temperature changes on the TP relative to global warming regarding warming time, warming amplitude, and elevation-dependent warming (EDW) using the multi-model ensemble (MME) means of 24 CMIP6 models. The results showed that the warming rate on the TP is 1.3–1.45 times more than that of mean global warming from 2015 to 2100, with the TP having already warmed by 1.5 °C above the pre-industrial levels in 2016/2015 and will warm by 2 °C by 2028/2027 under the Shared Socioeconomic Pathway (SSP) scenarios, SSP2–4.5 and SSP5–8.5. In addition, the warming amplitude on the TP in response to global warming levels of 1.5 and 2 °C would be 1.97 and 2.69 °C under the SSP2–4.5 scenario and 1.94 and 2.68 °C under the SSP5–8.5 scenario. Furthermore, EDW amplifies the warming amplitude at high elevations, mainly because of the decrease in surface albedo. The most sensitive warming amplitude in the cryosphere region, with an elevation of 5–5.5 km, would exceed 2.06, 2.79, 4.29, and 5.73 °C when global warming reaches 1.5, 2, 3, and 4 °C under the SSP5–8.5 scenario. This additional 0.56–1.73 °C warming in the high elevation relative to the global mean will intensify the cryosphere ablation on the TP. Thus, considering the projected larger warming trend and amplitude, the high-elevation region on the TP would be particularly sensitive and vulnerable, which is unfavorable for the TP from the perspective of the Paris Agreement warming target. • Temperature changes on the Tibetan Plateau (TP) are sensitive to global warming. • The warming rate of the TP is 1.3–1.45 times greater than the global mean during 2015–2100. • The TP has warmed by 1.5 °C in 2016 and will warm by 2 °C in 2028 under the SSP2–4.5. • The EDW phenomenon will continue to amplify the warming amplitude at high elevations. • As global warming reaches 2.0 °C, the mean warming over TP could be 2.7 °C, which would cause disastrous effects on the cryosphere. [ABSTRACT FROM AUTHOR]

Due to climate changes, most of the alpine glaciers have retreated dramatically during the past decades. Thus it is significant to predict the alpine glacier variability in the future for a better understanding of the impact of climate changes on water resource. In this paper, we perform the numerical simulation on Urumqi Glacier No.1 in the eastern Tianshan, central Asia (hereafter Glacier No.1 for short) by considering both the mass balance and ice flow. Given the shape of the Glacier No.1, the velocity of the glacier is obtained by solving a two-dimensional nonlinear Stokes equation and simulated result is in agreement with the observation. In order to predict the variability of Glacier No.1 in the next decades, a climatic scenario is constructed with a temperature rise rate as 0.17°C/10 a and precipitation as constant during the period of 2005-2070. The simulation shows that, the glacier terminus will retreat slowly and the glacier will thin dramatically before 2040, while after year 2040, the glacier terminus retreat will accelerate. This study confirms the increasing retreat rate of alpine glaciers under global warming. [ABSTRACT FROM AUTHOR]

[Display omitted] • During 2000–2019, snow cover days experienced a significant decreasing trend only in 13.1% of the Loess Plateau. • The effects of temperature and precipitation variations on the SCDs dynamics have clear spatial and monthly differences. • The EATI, the APVA and the SST in the NINO W region are three effective indictors of SCDs anomaly of the Loess Plateau. Identifying the large-scale teleconnection is of great practical significance to comprehend the formation mechanism of snow cover days (SCDs) anomalies and improve the disaster risk management of ecological construction on the Loess Plateau. Based on Terra Moderate Resolution Imaging Spectroradiometer (MODIS) snow cover days datasets from 2000 to 2020, we analyzed the spatiotemporal variation of SCDs on the Loess Plateau. Meanwhile, we identified the variability in large-scale atmospheric patterns associated with SCDs on the Loess Plateau. The results show that: in the past 20 years have revealed an interdecadal fluctuations of SCDs on the Loess Plateau. Spatially, the SCDs experienced a significant decreasing trend (p < 0.05) in only 13.1% of the regions, which were distributed in the Northern Earth-Rock Mountain and Hully and Gully Loess Region. The effects of climate-related factor variations on SCD dynamics showed obvious spatial and monthly differences. Specifically, SCDs dominated by precipitation were significantly positively correlated in the north-eastern part of the Loess Plateau. Temperature plays a decisive role in SCD dynamics in the southern part of the Loess Plateau. Among the influencing factors, the East Asian Trough Intensity (EATI), the Asian Polar Vortex Area index (APVA) and the sea surface temperature (SST) anomalies in the NINO W region are three effective indictors of SCDs anomaly. In January, with the deepening of East Asian Trough and low SST in the NINO W region (0°∼10°N, 140°E∼180°E), East Asian winter monsoon is relatively strengthening, temperature is lower on the Loess Plateau, leading to more SCDs in the southern study region. The bigger APVA, corresponding to more snow accumulation in December, could effectively prolong the SCDs dominated by precipitation on the Loess Plateau. The conclusions of this study have implications for excavating early warning information of snow cover anomalies on the Loess Plateau. [ABSTRACT FROM AUTHOR]