Acricotopus indet. morphotype incurvatus: Description and genetics of a new Orthocladiinae (Diptera: Chironomidae) larval morphotype from the Tibetan Plateau

Zootaxa ◽  
2019 ◽  
Vol 4656 (3) ◽  
pp. 535-544
Author(s):  
ANDREAS LAUG ◽  
LADISLAV HAMERLÍK ◽  
STEN ANSLAN ◽  
STEFAN ENGELS ◽  
FALKO TURNER ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
High Mountain ◽  
The Tibetan Plateau ◽  
Mitochondrial Coi ◽  
Mountain Ranges ◽  
Central Tibetan Plateau ◽  
Peculiar Form ◽  
Close Proximity ◽  
Coi Sequences ◽  
Complex Formations

High mountain ranges such as the Tibetan Plateau with an average altitude above 4500 m are topographically complex formations. Elevational gradients, physiographic diversity and climatic heterogeneity have led to highly biodiverse ecosystems in these regions. Mountain ranges can be seen as cradles of evolution and harbour, due to their unique characteristics, a high number of highly adapted species. At the same time these areas are hard to access and therefore taxonomic information is limited. Here we describe a new Acricotopus (Diptera: Chironomidae: Orthocladiinae) larval morphotype occurring in lakes and ponds of differing salinity and water depths located on the Southern and Central Tibetan Plateau. The description is based on larvae and their genetics (ribosomal 18S, 28S and mitochondrial COI sequences) collected from a shallow pond in close proximity to the large saline lake Selin Co. Larvae of Acricotopus indet. morphotype incurvatus are characterized by a mentum with a cluster of lateral teeth, partially folded inwards, a mandible with a toothed lobe in addition to four inner teeth and a sclerotized plate positioned behind the mentum. Up to now, these morphological features have only been found in early instars of other Acricotopus species. The proposed morphotype name is inspired by the peculiar form of the mentum. 

scholarly journals Seasonality and spatial variability of dynamic precipitation controls on the Tibetan Plateau

2016 ◽  
Author(s):  
Julia Curio ◽  
Dieter Scherer
Keyword(s):  
Tibetan Plateau ◽  
Spatial Variability ◽  
Water Cycle ◽  
High Mountain ◽  
The Tibetan Plateau ◽  
Precipitation Distribution ◽  
Mountain Ranges ◽  
Boundary Layer Height ◽  
Dynamic Factors ◽  
Vertical Wind Speed

Abstract. The Tibetan Plateau (TP) is the origin of many large Asian rivers, which provide moisture for large regions in South and East Asia. Therefore, the water cycle on the TP and adjacent high mountain ranges and especially the precipitation distribution plays an important role for the water availability for billions of people in the regions downstream of the TP. Based on the High Asia Refined analysis (HAR) we analyse the influence of dynamic factors on precipitation, enhancing or suppressing precipitation development. We selected six precipitation controls, the horizontal and vertical wind speed at 300 hPa and in about two kilometres above ground, the atmospheric water transport, and the planetary boundary layer height. Focus of the study are the seasonality and the spatial variability of these precipitation controls and their dominant patterns. The results show that precipitation controls have different effects on precipitation in different regions and seasons. This depends mainly on the type of precipitation, convective or frontal/cyclonic precipitation. Additionally, the study reveals that the mid-latitude westerlies have a high impact on precipitation distribution on the TP and its surrounding year-round.

scholarly journals Seasonality and spatial variability of dynamic precipitation controls on the Tibetan Plateau

2016 ◽  
Vol 7 (3) ◽  
pp. 767-782 ◽  
Author(s):  
Julia Curio ◽  
Dieter Scherer
Keyword(s):  
Wind Speed ◽  
Tibetan Plateau ◽  
Spatial Variability ◽  
Water Cycle ◽  
High Mountain ◽  
The Tibetan Plateau ◽  
Dominant Type ◽  
Precipitation Distribution ◽  
Mountain Ranges ◽  
Vertical Wind Speed

Abstract. The Tibetan Plateau (TP) is the origin of many large Asian rivers, which provide water resources for large regions in south and east Asia. Therefore, the water cycle on the TP and adjacent high mountain ranges, in particular the precipitation distribution and variability play an important role for the water availability for billions of people in the downstream regions of the TP. The High Asia Refined analysis (HAR) is used to analyse the dynamical factors that influence precipitation variability in the TP region, including the factors resulting in the enhancement and suppression of precipitation. Four dynamical fields that can influence precipitation are considered: the 300 hPa wind speed and wind speed 2 km above ground, the 300 hPa vertical wind speed, and the atmospheric water transport. The study focusses on the seasonality and the spatial variability of the precipitation controls and their dominant patterns. Results show that different factors have different effects on precipitation in different regions and seasons. This depends mainly on the dominant type of precipitation, i.e. convective or frontal/cyclonic precipitation. Additionally, the study reveals that the midlatitude westerlies have a high impact on the precipitation distribution on the TP and its surroundings year-round and not only in winter.

scholarly journals Spatiotemporal patterns of High Mountain Asia's snowmelt season identified with an automated snowmelt detection algorithm, 1987–2016

2017 ◽  
Vol 11 (5) ◽  
pp. 2329-2343 ◽  
Author(s):  
Taylor Smith ◽  
Bodo Bookhagen ◽  
Aljoscha Rheinwalt
Keyword(s):  
Time Series ◽  
Tibetan Plateau ◽  
Climate Model ◽  
Single Point ◽  
Passive Microwave ◽  
Spatiotemporal Patterns ◽  
Signal Separation ◽  
High Mountain ◽  
The Tibetan Plateau ◽  
Microwave Data

Abstract. High Mountain Asia (HMA) – encompassing the Tibetan Plateau and surrounding mountain ranges – is the primary water source for much of Asia, serving more than a billion downstream users. Many catchments receive the majority of their yearly water budget in the form of snow, which is poorly monitored by sparse in situ weather networks. Both the timing and volume of snowmelt play critical roles in downstream water provision, as many applications – such as agriculture, drinking-water generation, and hydropower – rely on consistent and predictable snowmelt runoff. Here, we examine passive microwave data across HMA with five sensors (SSMI, SSMIS, AMSR-E, AMSR2, and GPM) from 1987 to 2016 to track the timing of the snowmelt season – defined here as the time between maximum passive microwave signal separation and snow clearance. We validated our method against climate model surface temperatures, optical remote-sensing snow-cover data, and a manual control dataset (n = 2100, 3 variables at 25 locations over 28 years); our algorithm is generally accurate within 3–5 days. Using the algorithm-generated snowmelt dates, we examine the spatiotemporal patterns of the snowmelt season across HMA. The climatically short (29-year) time series, along with complex interannual snowfall variations, makes determining trends in snowmelt dates at a single point difficult. We instead identify trends in snowmelt timing by using hierarchical clustering of the passive microwave data to determine trends in self-similar regions. We make the following four key observations. (1) The end of the snowmelt season is trending almost universally earlier in HMA (negative trends). Changes in the end of the snowmelt season are generally between 2 and 8 days decade−1 over the 29-year study period (5–25 days total). The length of the snowmelt season is thus shrinking in many, though not all, regions of HMA. Some areas exhibit later peak signal separation (positive trends), but with generally smaller magnitudes than trends in snowmelt end. (2) Areas with long snowmelt periods, such as the Tibetan Plateau, show the strongest compression of the snowmelt season (negative trends). These trends are apparent regardless of the time period over which the regression is performed. (3) While trends averaged over 3 decades indicate generally earlier snowmelt seasons, data from the last 14 years (2002–2016) exhibit positive trends in many regions, such as parts of the Pamir and Kunlun Shan. Due to the short nature of the time series, it is not clear whether this change is a reversal of a long-term trend or simply interannual variability. (4) Some regions with stable or growing glaciers – such as the Karakoram and Kunlun Shan – see slightly later snowmelt seasons and longer snowmelt periods. It is likely that changes in the snowmelt regime of HMA account for some of the observed heterogeneity in glacier response to climate change. While the decadal increases in regional temperature have in general led to earlier and shortened melt seasons, changes in HMA's cryosphere have been spatially and temporally heterogeneous.

scholarly journals Hypsugo stubbei sp. nov., a novel cryptic bat species of the genus Hypsugo (Vespertilionidae, Chiroptera, Mammalia) from Mongolia. Results of the Mongolian-German Biological Expeditions Since 1962, No. 347.

2021 ◽  
Author(s):  
Dietrich Dolch ◽  
Michael Stubbe ◽  
Nyamsuren Batsaikhan ◽  
Annegret Stubbe ◽  
Dirk Steinhauser
Keyword(s):  
High Mountain ◽  
Limited Data ◽  
Gene Encoding ◽  
Mountain Areas ◽  
Mitochondrial Coi ◽  
Subspecies Level ◽  
Western Palearctic ◽  
Close Proximity ◽  
Morphological Differences ◽  
Mitochondrial Nd1

The occurrence of two members of the genus Hypsugo, namely H. alaschanicus and H. savii caucasicus, have been reported for Mongolia in the literature. Due to various taxonomic reassignments within and between genera, the number of records for the genus Hypsugo in Mongolia is quite scarce and sometimes not resolved at species or subspecies level. Despite recognition of the two above-mentioned species, recent reports based on genetic analyses describe only new and further records of H. alaschanicus. Thus, it exists a large uncertainty regarding the occurrence and distribution of H. savii caucasicus in Mongolia. Here, our efforts in gaining a deeper understanding towards the occurrence and distribution of Hypsugo species in Mongolia are described. A combination of genetic and morphological analyses of collected material from Hypsugo specimens revealed the existence of a genetically largely distant Hypsugo clade. Therefore, a new and cryptic Hypsugo species is proposed which is named after Prof. Dr. Michael Stubbe for his continuous, long-standing and significant contributions into the biological exploration of Mongolia. Hypsugo stubbei sp. nov. differs by at least 8.4 % and 9 % to the closest Western Palearctic distributed H. cf. darwinii and H. savii as well as at least 11.3 % to the Easter Palearctic (including Mongolia) distributed H. alaschanicus based on the first 798 nucleotides of the gene encoding the mitochondrial ND1 (subunit one of NADH dehydrogenase). Neither a close proximity species based on the gene encoding the mitochondrial COI (cytochrome oxidase subunit one) could be found in publicly accessible nucleotide databases. While the cryptic H. stubbei sp. nov. reveals no obvious cranial and morphological differences, few external characteristics are dissimilar to both H. alaschanicus and H. savii (caucasicus). Currently, Hypsugo stubbei sp. nov. was found at four different locations in Mongolia. Among the 11 specimens captured, six facilitated a genetic assignment. Based on the current scarce data records, the species seems to occur mainly in the far west of Mongolia inhabiting semi-deserts and steppes up to high mountain areas. An overlapping distribution with H. alaschanicus cannot be excluded based on the limited data currently available.

scholarly journals Luminescence dating of lacustrine sediments from CUOE Lake on the central Tibetan Plateau

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Yandong Hou ◽  
Hao Long ◽  
Lei Gao ◽  
Ji Shen
Keyword(s):  
Tibetan Plateau ◽  
Lacustrine Sediments ◽  
Water Reservoir ◽  
Hard Water ◽  
Luminescence Dating ◽  
Coarse Grained ◽  
The Tibetan Plateau ◽  
Sediment Layer ◽  
Central Tibetan Plateau ◽  
Dating Method

AbstractLuminescence dating technology has been used for chronological constraints on lacustrine sediments due to the ubiquitous materials (e.g., quartz and feldspar) as dosimeters, and a relatively long dating range, compared with the commonly used radiocarbon dating method. However, quartz dating on the Tibetan Plateau may suffer from dim and unstable luminescence signals. In the current study, we investigate a lake-related outcrop from the shore of Cuoe Lake on the central Tibetan Plateau. Both coarse-grained quartz and K-feldspar fractions were extracted, and OSL and post-IR IRSL signals were measured from these fractions, respectively. Combining the stratigraphy analysis and dating results, this study shows that: (1) quartz appears to be unsuitable for dating because of very dim natural signals and even anomalous fading (average g-value: 4.30 ± 2.51 %/decade). The suitability of the applied pIRIR protocol measured at 150°C (pIRIR150) for K-feldspar samples was confirmed by a set of luminescence tests; (2) compared with the luminescence-based chronology, the 14C age of shells from the same sediment layer yielded older age by ~7 ka, which is likely attributed to hard water reservoir effect in Cuoe Lake; (3) the lake level reached its peak and maintained high-stand during the early Holocene (~9.4–7.1 ka). This study highlights the applicability of K-feldspar luminescence dating when the counterpart quartz OSL is insensitive and encounters anomalous fading.

Roof of the World: Tibet, Pamirs

2013 ◽  
Author(s):  
Mike Searle
Keyword(s):  
Tibetan Plateau ◽  
High Elevation ◽  
Tien Shan ◽  
Palm Tree ◽  
The Tibetan Plateau ◽  
Wet Season ◽  
North West ◽  
Mountain Ranges ◽  
The North ◽  
The World

The Tibetan Plateau is by far the largest region of high elevation, averaging just above 5,000 metres above sea level, and the thickest crust, between 70 and 90 kilometres thick, anywhere in the world. This huge plateau region is very flat—lying in the internally drained parts of the Chang Tang in north and central Tibet, but in parts of the externally drained eastern Tibet, three or four mountain ranges larger and higher than the Alps rise above the frozen plateau. Some of the world’s largest and longest mountain ranges border the plateau, the ‘flaming mountains’ of the Tien Shan along the north-west, the Kun Lun along the north, the Longmen Shan in the east, and of course the mighty Himalaya forming the southern border of the plateau. The great trans-Himalayan mountain ranges of the Pamir and Karakoram are geologically part of the Asian plate and western Tibet but, as we have noted before, unlike Tibet, these ranges have incredibly high relief with 7- and 8-kilometre-high mountains and deeply eroded rivers and glacial valleys. The western part of the Tibetan Plateau is the highest, driest, and wildest area of Tibet. Here there is almost no rainfall and rivers that carry run-off from the bordering mountain ranges simply evaporate into saltpans or disappear underground. Rivers draining the Kun Lun flow north into the Takla Makan Desert, forming seasonal marshlands in the wet season and a dusty desert when the rivers run dry. The discovery of fossil tropical leaves, palm tree trunks, and even bones from miniature Miocene horses suggest that the climate may have been wetter in the past, but this is also dependent on the rise of the plateau. Exactly when Tibet rose to its present elevation is a matter of great debate. Nowadays the Indian Ocean monsoon winds sweep moisture-laden air over the Indian sub-continent during the summer months (late June–September). All the moisture is dumped as the summer monsoon, the torrential rains that sweep across India from south-east to north-west.

scholarly journals Understanding precipitation recycling over the Tibetan Plateau using tracer analysis with WRF

2020 ◽  
Vol 55 (9-10) ◽  
pp. 2921-2937
Author(s):  
Yanhong Gao ◽  
Fei Chen ◽  
Gonzalo Miguez-Macho ◽  
Xia Li
Keyword(s):  
Tibetan Plateau ◽  
Land Surface ◽  
Precipitation Amount ◽  
Interaction Strength ◽  
Convective Precipitation ◽  
High Mountain ◽  
The Tibetan Plateau ◽  
Important Indicator ◽  
Precipitation Recycling ◽  
Atmosphere Interaction

Abstract The precipitation recycling (PR) ratio is an important indicator that quantifies the land-atmosphere interaction strength in the Earth system’s water cycle. To better understand how the heterogeneous land surface in the Tibetan Plateau (TP) contributes to precipitation, we used the water-vapor tracer (WVT) method coupled with the Weather Research and Forecasting (WRF) regional climate model. The goals were to quantify the PR ratio, in terms of annual mean, seasonal variability and diurnal cycle, and to address the relationships of the PR ratio with lake treatments and precipitation amount. Simulations showed that the PR ratio increases from 0.1 in winter to 0.4 in summer when averaged over the TP with the maxima centered at the headwaters of three major rivers (Yangtze, Yellow and Mekong). For the central TP, the highest PR ratio rose to over 0.8 in August, indicating that most of the precipitation was recycled via local evapotranspiration in summer. The larger daily mean and standard deviation of the PR ratio in summer suggested a stronger effect of land-atmosphere interactions on precipitation in summer than in winter. Despite the relatively small spatial extent of inland lakes, the treatment of lakes in WRF significantly impacted the calculation of the PR ratio over the TP, and correcting lake temperature substantially improved both precipitation and PR ratio simulations. There was no clear relationship between PR ratio and precipitation amount; however, a significant positive correlation between PR and convective precipitation was revealed. This study is beneficial for the understanding of land-atmosphere interaction over high mountain regions.

First mid-ocean ridge-type ophiolite from the Meso-Tethys suture zone in the north-central Tibetan plateau

2020 ◽  
Vol 132 (9-10) ◽  
pp. 2202-2220 ◽  
Author(s):  
Yue Tang ◽  
Qing-Guo Zhai ◽  
Sun-Lin Chung ◽  
Pei-Yuan Hu ◽  
Jun Wang ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Ocean Basin ◽  
Suture Zone ◽  
The Tibetan Plateau ◽  
Spreading Ridge ◽  
North Central ◽  
The North ◽  
Central Tibetan Plateau ◽  
Mid Ocean Ridge ◽  
Ocean Ridge

Abstract The Meso-Tethys was a late Paleozoic to Mesozoic ocean basin between the Cimmerian continent and Gondwana. Part of its relicts is exposed in the Bangong–Nujiang suture zone, in the north-central Tibetan Plateau, that played a key role in the evolution of the Tibetan plateau before the India-Asia collision. A Penrose-type ophiolitic sequence was newly discovered in the Ren Co area in the middle of the Bangong–Nujiang suture zone, which comprises serpentinized peridotites, layered and isotropic gabbros, sheeted dikes, pillow and massive basalts, and red cherts. Zircon U-Pb dating of gabbros and plagiogranites yielded 206Pb/238U ages of 169–147 Ma, constraining the timing of formation of the Ren Co ophiolite. The mafic rocks (i.e., basalt, diabase, and gabbro) in the ophiolite have uniform geochemical compositions, coupled with normal mid-ocean ridge basalt-type trace element patterns. Moreover, the samples have positive whole-rock εNd(t) [+9.2 to +8.3], zircon εHf(t) [+17 to +13], and mantle-like δ18O (5.8–4.3‰) values. These features suggest that the Ren Co ophiolite is typical of mid-ocean ridge-type ophiolite that is identified for the first time in the Bangong–Nujiang suture zone. We argue that the Ren Co ophiolite is the relic of a fast-spreading ridge that occurred in the main oceanic basin of the Bangong–Nujiang segment of Meso-Tethys. Here the Meso-Tethyan orogeny involves a continuous history of oceanic subduction, accretion, and continental assembly from the Early Jurassic to Early Cretaceous.

scholarly journals Summer Atmospheric Heat Sources over the Western–Central Tibetan Plateau: An Integrated Analysis of Multiple Reanalysis and Satellite Datasets

2019 ◽  
Vol 32 (4) ◽  
pp. 1181-1202 ◽  
Author(s):  
Zhiling Xie ◽  
Bin Wang
Keyword(s):  
Tibetan Plateau ◽  
Integrated Analysis ◽  
Mountain Range ◽  
The Tibetan Plateau ◽  
Heat Sources ◽  
Central Tibetan Plateau ◽  
New Finding ◽  
Highly Correlated ◽  
Atmospheric Heat ◽  
Heat Released

Multiple bias-corrected top-quality reanalysis datasets, gauge-based observations, and selected satellite products are synthetically employed to revisit the climatology and variability of the summer atmospheric heat sources over the Tibetan Plateau (TP). Verification-based selection and ensemble-mean methods are utilized to combine various datasets. Different from previous works, this study pays special attention to estimating the total heat source (TH) and its components over the data-void western plateau (70°–85°E), including the surface sensible heat (SH), latent heat released by precipitation (LH), and net radiation flux (RD). Consistent with previous studies, the climatology of summer SH (LH) typically increases (decreases) from southeast to northwest. Generally, LH dominates TH over most of the TP. A notable new finding is a minimum TH area over the high-altitude region of the northwestern TP, where the Karakoram mountain range is located. We find that during the period of 1984–2006, TH shows insignificant trends over the eastern and central TP, whereas it exhibits an evident increasing trend over the western TP that is attributed to the rising tendency of LH before 1996 and to that of RD after 1996. The year-to-year variation of TH over the central–eastern TP is highly correlated with that of LH, but that is not the case over the western TP. It is also worth noting that the variations of TH in each summer month are not significantly correlated with each other, and hence study of the interannual variation of the TP heat sources should consider the remarkable subseasonal variations.

scholarly journals The topographic evolution of the Tibetan Region as revealed by palaeontology

2020 ◽  
Author(s):  
Robert A. Spicer ◽  
Tao Su ◽  
Paul J. Valdes ◽  
Alexander Farnsworth ◽  
Fei-Xiang Wu ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Landscape Evolution ◽  
The Tibetan Plateau ◽  
Mountain Ranges ◽  
The Past ◽  
Complex Interactions ◽  
New Synthesis ◽  
The Rich ◽  
Topographic Evolution ◽  
East West

AbstractThe Tibetan Plateau was built through a succession of Gondwanan terranes colliding with Asia during the Mesozoic. These accretions produced a complex Paleogene topography of several predominantly east–west trending mountain ranges separated by deep valleys. Despite this piecemeal assembly and resultant complex relief, Tibet has traditionally been thought of as a coherent entity rising as one unit. This has led to the widely used phrase ‘the uplift of the Tibetan Plateau’, which is a false concept borne of simplistic modelling and confounds understanding the complex interactions between topography climate and biodiversity. Here, using the rich palaeontological record of the Tibetan region, we review what is known about the past topography of the Tibetan region using a combination of quantitative isotope and fossil palaeoaltimetric proxies, and present a new synthesis of the orography of Tibet throughout the Paleogene. We show why ‘the uplift of the Tibetan Plateau’ never occurred, and quantify a new pattern of topographic and landscape evolution that contributed to the development of today’s extraordinary Asian biodiversity.

Sign in / Sign up

Export Citation Format

Share Document