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Mountain glaciers are one of the most sensitive indicators of climate change. Reconstructing past glacier extents provides valuable insights into the climate change for specific regions where instrumental records are not enough and even absent. In the paper we mapped the outlines for 691 Little Ice Age (LIA) glaciers in terms of prominent moraines beyond contemporary glaciers in the Tanggula Mountains, central Tibetan Plateau (TP). Based on these glacier outlines, we reconstructed the ice thicknesses and surfaces for the LIA glaciers in the region. Accordingly, we calculated the equilibrium-line altitudes (ELAs) for contemporary and LIA glaciers. By comparing the ELAs between the contemporary and LIA glaciers, we estimated the LIA summer temperature decreases in different subregions of the Tanggula Mountains. Since the LIA, the ELA have risen by 35.6 ± 18.8 m, 26.1 ± 17.6 m, and 63.1 ± 38.6 m in the respective western, central, and eastern subregions of the Tanggula Mountains. Assuming no change in precipitation, the LIA summer temperature would decrease by 0.22 ± 0.12 °C, 0.14 ± 0.09 °C, and 0.34 ± 0.21 °C in the three subregions, respectively. Moreover, glaciers in the western, central, and eastern subregions have lost 13.3%, 23.9%, and 42.8% of their area, 15.4%, 25.3%, and 39.6% of their length, and 20.8%, 39.0%, and 61.0% of their volume, respectively. By compiling the LIA ELA data from previous studies, we also estimated the LIA summer temperature changes for other regions of the TP. The LIA ELA and summer temperature changes relative to the present showed a decreasing trend from the edges towards the interior on the TP. • LIA glaciers and summer climate were reconstructed at the Tanggula Mountains. • LIA summers were 0.22 ± 0.12 °C, 0.14 ± 0.09 °C, and 0.34 ± 0.21 °C cooler than present in three subregions. • Summer temperature change had a decreasing trend from the edges towards the interior on the Tibetan Plateau. [ABSTRACT FROM AUTHOR]

Studies of geochemical proxies, such as carbonate δ18O and TEX 86 , show that the Earth's climate has changed significantly during the Cretaceous Period. However, knowledge about the sea surface temperature (SST) history of the eastern Tethys is limited. Based on the calcareous nannofossil record of the Nirang section, Tethys Himalayas, this paper attempts to establish the biostratigraphic framework and SST evolution of the Cretaceous Period in the southern Tibet. A total of 131 species were identified from the studied succession. Twelve bioevents were recognized, allowing for early Albian to the early Campanian (CC8 to CC18 biozones) in the section. Meanwhile, a disconformity within 81–71 Ma was also identified. The SST evolution was analysed by the calcareous nannofossils modified temperature index (mTI), and the results reveal that the long-term SST changes in the Tethys Himalayas of southern Tibet experienced progressive warming from the early Albian to the early Turonian and the warm interval persisted until the early Campanian. Short-term warming and cooling events, e.g., rapid warming in the early and late Albian, subsequent cooling in the latest Albian and peak warmth at the Cenomanian–Turonian transition, are also recorded in the study area. The SST history of the Albian-Cenomanian in the eastern Tethys can be well correlated to the western Tethys (central Italy). However, the compilation of TEX 86 data indicates substantial global cooling during the Coniacian to Campanian. This study suggests that the northward drift of the Indian continent towards the equator is likely to be responsible for the sustained warmth in the Tethys Himalayas from the middle Turonian to the early Campanian. • Calcareous nannofossil biozones of Albian-early Campanian in Tethys Himalaya of southern Tibet is defined. • Based on mTI of nannofossils, long term history of Cretaceous palaeoclimate of eastern Tethys is reconstructed. • The SST history in Tethys Himalaya is controlled by changes of global palaeotemperature and regional palaeolatitude. [ABSTRACT FROM AUTHOR]

The tropopause plays an important role in climate change, particularly in Tibet with complex topography and climate change system. In this paper, the temperature and height of the Cold Point Tropopause (CPT) in Tibet are obtained and investigated from COSMIC (Constellation Observing System for Meteorology, Ionosphere and Climate) GPS Radio Occultation (RO) during June 2006–Feb 2014, which are compared with Lapse Rate Tropopause (LRT) from Atmospheric Infrared Sounder (AIRS/NASA). Furthermore, the impact of Gravity waves (GW) potential energy ( E p ) on the CPT-Temperature, CPT-Height, and the variation of stratospheric water vapor with GW E p variations are presented. Generally the coldest CPT temperature is in June–July–August (JJA) with −76.5 °C, resulting less water vapor into the stratosphere above the cold points. The temperature of the cold point increases up to −69 °C during the winter over the Tibetan Plateau (25–40°N, 70–100°E) that leads to increase in water vapor above the cold points (10 hPa). Mean vertical fluctuations of temperature are calculated as well as the mean gravity wave potential energy E p for each month from June 2006 to Feb 2014. Monthly E p is calculated at 5°×5° grids between 17 km and 24 km in altitude for the Tibetan Plateau. The E p raises from 1.83 J/Kg to 3.4 J/Kg from summer to winter with mean E p of 2.5 J/Kg for the year. The results show that the gravity waves affect the CPT temperature and water vapor concentration in the stratosphere. Water vapor, CPT temperature and gravity wave ( E p ) have good correlation with each other above the cold points, and water vapor increases with increasing E p . [ABSTRACT FROM AUTHOR]

• LUE-VPM produced better quality NPP than MODIS products. • PAR produced from high-resolution DEM can be used in regional NPP modelling. • The MODIS NPP is statistical different with the in-situ measurements in Zeku implementation. Accurate estimation of grassland Net Primary Productivity (NPP) is one of the most important steps in monitoring and further analysing the status of the grassland ecosystem. However, the quality of regional or even global grassland NPP estimations are commonly limited by the two most important input datasets: Photosynthetic Active Radiation (PAR) and climatic data, which make the NPP estimate unrepresentative or even inaccurate. This paper uses a Light Use Efficiency with Vegetation Photosynthesis Model (LUE-VPM) to estimate the high-quality grassland NPP in Zeku. By using the PAR data derived from high resolution DEM products and the improved land surface temperature data, the NPP produced by LUE-VPM shows that it is statistically the same as in situ converted NPP with a p-value of t -test equalling 0.90 (the RMSE between the two is 97.77 gC/m2), while MODIS NPP in Zeku is statically different from the all the in-situ sampling results with a p-value of t-text smaller than 0.03. The results of this paper provided a better estimate than MODIS NPP, and LUE-VPM can be used for the high-quality regional grassland NPP estimation when the quality of PAR data and climatic data improved. [ABSTRACT FROM AUTHOR]

Abstract: In recent years, disasters caused by Glacial Lake Outburst Floods (GLOFs) have taken place more frequently in Tibet than previously and have been the cause of considerable losses. Temperature fluctuations are believed a major influencing factor of GLOFs. However, if or how much climatic change influences GLOFs is a question that remains to be answered. In this paper, using 24 GLOFs related to 19 glacial lakes and temperature data from 14 meteorological stations, we explored the relationships between temperature variations on different temporal scales (annual, monthly, and daily) and GLOFs. There were three active periods for GLOFs in the 1960s, 1980s and 2000s in Tibet, when 16 of 24 GLOFs took place. All the studied GLOFs occurred in the ablation months (from May and September, and especially in July and August) and on ablation days with a monthly average temperature and daily average temperature that were both greater than 0 °C. Based on the analysis of monthly and daily temperature, GLOFs depend on the coupled influence of ablation temperature and accumulation temperature; even the accumulation temperature may be important. Based on this, temperature increments were defined, representing the change from accumulation to ablation temperature with a significant impact on GLOFs. There is an altitude effect on GLOFs, in that lakes at lower altitude generally burst earlier, whereas those at a higher altitude burst later. The monthly and daily increments increase according to a similar power-law form with elevation. [Copyright &y& Elsevier]

Abstract: Long-term high-resolution climate proxies are essential for understanding climate variability on the Tibetan Plateau (TP), where few long-term climate records are available. In this paper, we describe a summer (August) temperature reconstruction over the period 1385–2002 based on a tree-ring width chronology of Balfour spruce (Picea likiangensis var. balfouriana) on the southeastern TP created using the Regional Curve Standardization method. The reconstruction explains 44.7% of the variance in the instrumental temperature records during the calibration period (1962–2002), and captures temperature variability over a broad region of the TP. Warmer than average Augusts were found during the periods 1446–1494, 1509–1522, 1553–1567, 1797–1812, 1845–1905 and 1918–2002. Cooler than average Augusts occurred from 1385–1416, 1426–1445, 1495–1508, 1523–1552, 1568–1686, 1695–1718, 1725–1796, 1813–1844 and 1906–1917. A warming trend in the 20th century was unprecedented during the past six centuries. The reconstruction closely matched other tree-ring summer temperature reconstructions from neighboring regions, as well as patterns from ice-core δ18O data, and fluctuated in synchrony with Northern Hemisphere temperature reconstructions. [Copyright &y& Elsevier]

In this paper, we review evidence for a major biotic turnover across the Oligocene/Miocene in the Tibetan Plateau region. Based on the recent study of six well-preserved fossil sites from the Cenozoic Lunpola and Nima basins in the central Tibetan Plateau, we report a regional changeover from tropical/subtropical ecosystems in the Late Oligocene ecosystem (26–24 Ma) to a cooler, alpine biota of the Early Miocene (23–18 Ma). The Late Oligocene fossil biota, comprising of fish (climbing perch), insects and plants (palms), shows that the hinterland of the Tibetan Plateau was a warm lowland influenced by tropical humidity from the Indian Ocean. In the Early Miocene, the regional biota became transformed, with the evolution and diversification of the endemic primitive snow carp. Early Miocene vegetation was dominated by temperate broad-leaved forest with abundant conifers and herbs under a cool climate, and mammals included the hornless rhinoceros, Plesiaceratherium , a warm temperate taxon. This dramatic ecosystem change is due to a cooling linked to the uplift of Tibetan region, from a Late Oligocene paleo-elevation of no greater than 2300 m a.s.l. in the sedimentary basin to a paleo-elevation of about 3000 m a.s.l. Another factor was the Cenozoic global climatic deterioration toward to an ice-house world. • The Tibetan uplift had a profound impact on the evolution of terrestrial ecosystems. • The Oligocene subtropical ecosystem was replaced by a Miocene cooler biota in Tibet. • The Late Oligocene biota showed that the Tibetan hinterland was a warm lowland. • The Early Miocene biota eventually culminated in the present ecosystem of Tibet. • This dramatic ecosystem change is due to the cooling effect of the Tibetan Plateau. [ABSTRACT FROM AUTHOR]