How much we know about precipitation climatology over Tianshan Mountains––the Central Asian water tower

npj Climate and Atmospheric Science, Journal Year: 2024, Volume and Issue: 7(1)

Published: Jan. 18, 2024

Abstract Tianshan Mountains are the headwater regions for central Asia rivers, providing water resources ecological protection and economic development in semiarid regions. Due to scarce observations, hydroclimatic characteristics of Precipitation (TMP) measured over highland (>1500 m) remain be revealed. Here, we show TMP belongs a monsoon-like climate regime, with distinct annual range high ratio summer-to-yearly rainfall, exhibits six abrupt changes, dividing cycle into precipitation sub-seasons. Over past 60 years, yearly has significantly increased by 17.3%, dramatic increase winter (135.7%). The displays significant 40-day climatological intra-seasonal oscillation (CISO) summer. CISO’s wet phase results from confrontation eastward propagating mid-tropospheric Balkhash Lake Low southward migrating Mongolian High. sudden changes two circulation systems trigger TMP’s shaping CISO. Emerging scientific issues also discussed.

Language: Английский

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Mesoscale convective systems in the third pole region: Characteristics, mechanisms and impact on precipitation

Frontiers in Earth Science, Journal Year: 2023, Volume and Issue: 11

Published: April 12, 2023

The climate system of the Third Pole region, including (TP) and its surroundings, is highly sensitive to global warming. Mesoscale convective systems (MCSs) are understood be a vital component this system. Driven by monsoon circulation, surface heating, large-scale local moisture supply, they frequently occur during summer mostly over central eastern TP as well in downstream regions. Further, MCSs have been highlighted important contributors total precipitation efficient rain producers affecting water availability (seasonal precipitation) potential flood risk (extreme densely populated multi-decadal satellite observations high-resolution model datasets has made it possible study role under-observed balance. However, usage different methods for MCS identification focuses on specific subregions currently hamper systematic consistent assessment played their impact headwaters Here, we review observational studies region within common framework elucidate main characteristics, underlying mechanisms, seasonal extreme precipitation. We also identify major knowledge gaps provide suggestions how these can addressed using recently published datasets. Three identified 1) feedback other components system, 2) changing future 3) basin-scale drought risks associated with changes frequency intensity. A particularly promising tool address convection-permitting simulations. Therefore, evaluation existing historical simulations an urgent requirement reliable change assessments.

Language: Английский

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Human-induced warming accelerates local evapotranspiration and precipitation recycling over the Tibetan Plateau

Communications Earth & Environment, Journal Year: 2024, Volume and Issue: 5(1)

Published: July 20, 2024

Abstract The Tibetan Plateau faces changing precipitation and environmental conditions affecting alpine ecosystems downstream freshwater sustainability. While aerosol influence has been highlighted, how human-induced greenhouse warming impacts the plateau’s moisture recycling remains unclear. Here we show that Plateau’s recent changes result from enhanced convergence offset decline in monsoon- westerly-associated transport based on 40-year Lagrangian simulations water budget analyses. Local evapotranspiration is observed to increase faster percentage than precipitation, a trend expected continue future scenarios according climate projections. Greenhouse gas emission causes widespread wetting while weakening southerly monsoons across Himalayas, heightening sensitivity of thereby local land surface changes. This exacerbates vulnerability cycle high mountain Asia, calling for proactive management address potential risks ensure food security Asia.

Language: Английский

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Climatology of near-surface wind speed from observational, reanalysis and high-resolution regional climate model data over the Tibetan Plateau

Climate Dynamics, Journal Year: 2023, Volume and Issue: 62(2), P. 933 - 953

Published: Sept. 16, 2023

Abstract As near-surface wind speed plays a role in regulating surface evaporation and thus the hydrological cycle, it is crucial to explore its spatio-temporal characteristics. However, in-situ measurements are scarce over Tibetan Plateau, limiting understanding of climate across this high-elevation region. This study explores climatology Plateau by using for first time homogenized observations together with reanalysis products regional model simulations. Measuring stations center west plateau at higher elevations display mean standard deviation, confirming that increases increasing altitude. By exploring characteristics focus on seasonal cycle through cluster analysis, three regions distinct regimes can be identified: (1) central characterized high elevation; (2) eastern peripheral areas plateau; (3) Qaidam basin, topographic depression strongly influenced blocking effect surrounding mountainous terrain. Notably, ERA5 reanalysis, improvements horizontal, vertical, temporal spacing, physics data assimilation, demonstrates closer agreement measured conditions than predecessor ERA-Interim. It successfully reproduces identified regimes. newest ERA5-Land product does not show compared ERA5, most likely because they share parametrizations. Furthermore, two dynamical downscalings analyzed here fail capture observed statistics exhibit notable biases discrepancies also when investigating diurnal variations. Consequently, these high-resolution downscaling do add value reproducing Plateau.

Language: Английский

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Evaluating and Correcting Temperature and Precipitation Grid Products in the Arid Region of Altay, China

Remote Sensing, Journal Year: 2024, Volume and Issue: 16(2), P. 283 - 283

Published: Jan. 10, 2024

Temperature and precipitation are crucial indicators for investigating climate changes, necessitating precise measurements rigorous scientific inquiry. While the Fifth Generation of European Centre Medium-Range Weather Forecasts Atmospheric Reanalysis (ERA5), ERA5 Land Surface (ERA5-Land), China Meteorological Forcing Dataset (CMFD) temperature products widely used worldwide, their suitability Altay region arid semi-arid areas has received limited attention. Here, we as study area, utilizing meteorological station data implementing residual revision method coefficient to rectify inaccuracies in monthly records from ERA5-Land, ERA5, CMFD. We evaluate accuracy these datasets before after correction using bias, Taylor diagrams, root-mean-square error (RMSE) metrics. Additionally, employ Tropical Rainfall Measuring Mission satellite (TRMM) a benchmark assess performance CMFD correction. The results revealed significant differences capture capabilities region. Overall, exhibit substantial errors not directly suitable research. However, applied methods. After this revision, showed significantly improved capabilities, especially ERA5-Land. In terms temperature, post-revision-CMFD (CMFDPR) demonstrated better capabilities. All three weaker mountainous regions compared plains. Notably, post-revision-ERA5 (ERA5PR) seemed unsuitable capturing Concerning rain, CMFDPR, post-revision-ERA5-Land (ERA5-LandPR) ERA5PR outperformed TRMM precipitation. CMFDPR ERA5-LandPR both outperform ERA5PR. summary, effectively compensated sparse distribution stations region, providing reliable support studying change areas.

Language: Английский

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High resolution Tibetan Plateau regional reanalysis 1961-present

Scientific Data, Journal Year: 2024, Volume and Issue: 11(1)

Published: May 3, 2024

Abstract With the rapid global warming in recent decades, Tibetan Plateau (TP) has suffered severe impacts, such as glacier retreat, glacial lake expansion, and permafrost degradation, which threaten lives properties of local downstream populations. Regional Reanalysis (RR) is vital for TP due to limitations observations. In this work, a 62-year (1961–2022) long atmospheric regional reanalysis with spatial resolution 9 km (convective gray-zone scale) temporal 1 hour over (TPRR) was developed using Weather Research Forecasting (WRF) model, combined re-initialization method, spectral nudging (SN), several optimizations. TPRR forced by ERA5 at hourly intervals. outperforms ERA5, realistically capturing climatological characteristics seasonal variations precipitation T2m (air temperature 2m above ground level). Moreover, better reproduces frequency intensity precipitation, well diurnal cycle precipitation. This study also quantifies wetting trend 0.0071 mm/year amid TPRR.

Language: Английский

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Can ERA5 reanalysis data characterize the pre-storm environment?

Atmospheric Research, Journal Year: 2023, Volume and Issue: 297, P. 107108 - 107108

Published: Nov. 13, 2023

Language: Английский

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Development and Application of a New Convective Entrainment Rate Parameterization for Improving Precipitation Simulation Over the Tibetan Plateau and Its Surrounding Areas

Journal of Advances in Modeling Earth Systems, Journal Year: 2025, Volume and Issue: 17(1)

Published: Jan. 1, 2025

Abstract The Tibetan Plateau (TP) significantly impacts the global climate. TP's unique geographical conditions make it one of areas with largest precipitation biases in numerical models. overestimation and distribution models are closely related to parameterization convection processes over TP. In light this, a new deep convective entrainment rate suitable for region is developed based on observational data applied Grell‐Freitas Ensemble Scheme Weather Research Forecasting Model. scheme reduces simulated TP, decreasing from 29.4% default 11.8%. physical mechanism behind improved simulation results as follows: first, closer observed results. Second, terms cloud macrophysics, increases rate, top height depth clouds, decreases number grids updrafts vertical layers surface. Third, microphysics, increased water content weakens intensity precipitation. All these mechanisms ultimately reduce accumulated amount, providing an optimized modeling tool weather climate research which also aids better assessing cycle resource reserves “Asian Water Tower.”

Language: Английский

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Unraveling the Distinct Roles of Snowmelt and Glacier‐Melt on Agricultural Water Availability: A Novel Indicator and Its Application in a Glacierized Basin of China’s Arid Region

Water Resources Research, Journal Year: 2025, Volume and Issue: 61(1)

Published: Jan. 1, 2025

Abstract Mountain runoff is a vital water source for irrigation in global arid regions. Investigating the roles of major mountain components such as snowmelt and glacier‐melt, on downstream availability important understanding resource security. Snowmelt glacier‐melt have different timing availability. However, their potentially distinct impacts supplies been seldom investigated previously. This study proposes novel indicator, Irrigation Dependence Component ( IDC ), to assess individual impact availability, considering supply, demand relationship. Applying Yarkant River basin (YRB) China’s region, mainly fed by from northern Tibetan Plateau, reveals that, despite being primary contributor total YRB, generally more reliant due seasonal variations supply/demand Further sensitivity tests under 48 climate scenarios indicate that significantly increases drier climates, while decreases warms, implying increased importance future, especially conditions during transition season. Additionally, crucial role anthropogenic factors, including changes planting area use efficiency, influencing highlighted improved estimation. provides implications how cryosphere resources management an efficient indicator further studies glacierized basins globally.

Language: Английский

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Calibrating the simulated summer precipitation trend over the southern slope of the Tibetan Plateau in CMIP6 models using a sub-selection method

Advances in Climate Change Research, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 1, 2025

Language: Английский

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