Strengthening the three-dimensional comprehensive observation system of multi-layer interaction on the Tibetan Plateau to cope with the warming and wetting trend

Changes in the water cycle on the Tibetan Plateau(TP)have a significant impact on local agricultural production and livelihoods and its downstream regions.Against the background of widely reported warming and wetting,the hydrological cycle has accelerated and the likelihood of extreme weather events and natural disasters occurring(i.e.,snowstorms,floods,landslides,mudslides,and ice avalanches)has also intensified,especially in the highelevation mountainous regions.Thus,an accurate estimation of the intensity and variation of each component of the water cycle is an urgent scientific question for the assessment of plateau environmental changes.Following the transformation and movement of water between the atmosphere,biosphere and hydrosphere,the authors highlight the urgent need to strengthen the three-dimensional comprehensive observation system(including the eddy covariance system;planetary boundary layer tower;profile measurements of temperature,humidity,and wind by microwave radiometers,wind profiler,and radiosonde system;and cloud and precipitation radars)in the TP region and propose a practical implementation plan.The construction of such a three-dimensional observation system is expected to promote the study of environmental changes and natural hazards prevention.

Construction of a Comprehensive Observation Network for Natural-Resource Elements in Heihe River Basin,NW China

The construction of a comprehensive observation platform for natural-resource elements would provide data support for studies of dynamic changes in various natural resources,and could serve the needs of natural-resource management and the construction of ecological civilization during a period of global change.As the second-largest inland river basin in NW China,the Heihe River Basin(HRB)lies in the central part of the Silk Road Economic Belt,consequently,pilot studies of resource management in the basin are urgently needed.This paper describes the construction of a comprehensive natural-resource elements observation network in the HRB to meet requirements for natural-resource management,based on natural-resource and Earth-system science.Based on current observations and research,thirteen observation stations were established in different river basins through integration with existing stations,reconstruction and upgrading,and new construction.The main types of land-surface resources in the HRB(grassland,forests,rivers,lakes,deserts,wetlands,and farmland)were included in the observation network constructed for the monitoring of natural-resource elements.Long-term,continuous,and stable observation can yield key data concerning coupling processes,trends of change,and rates of change in natural resources.This is of great significance in improving cognitive ability,scientific management,and strategic decision-making regarding natural resources in the HRB,and can provide a reference paradigm for the observation of and research into natural resources in other basins.

Analysis on the Observation Data of Three Profiles across the Qilian Mountain-Haiyuan Fault Zone

By analyzing GPS, leveling and gravity observation data from the Minle, Huazangsi and Shagouhe profiles across the Qilian Mountain-Haiyuan fault during 2005 - 2009, the changes of these data and activity characteristics of the main faults in different time are obtained. The results show that the Changma-Erbo, Maomaoshan, Zhunglanghe and Haiyuan faults have been active in recent years. The relationship between the vertical displacement and mobile gravity data is analyzed, and the results reveal the gravity changes are mainly due to mass transfer. The results of GPS observation show that the direction of the horizontal movement velocity was almost along the fault strike in 2006 - 2007, while the horizontal velocity deviated from the fault direction in 2007 - 2008, characterized by increased eastward displacement. Further analysis upon removal of the linear trend on the time series of the N and E coordinate values of the continuous observation stations of the Crustal Movement Observation Network of China near the three profiles reveals that the Wenchuan earthquake had an effect on the observations in 2007 - 2008. Comparing the gravitational changes in 2008 - 2009 with the Bouguer gravity anomaly background, we find that the area near Minle profile is in the stage of adjustment and recovery, while the anomaly is not completely recovered around Huazangsi and Shagouhe profiles.

Phase Two of the Integrative Monsoon Frontal Rainfall Experiment(IMFRE-II)over the Middle and Lower Reaches of the Yangtze River in 2020

Phase Two of the Integrative Monsoon Frontal Rainfall Experiment(IMFRE-II)was conducted over the middle and lower reaches of the Yangtze River during the period 16 June to 19 July 2020.This paper provides a brief overview of the IMFRE-II field campaign,including the multiple ground-based remote sensors,aircraft probes,and their corresponding measurements during the 2020 mei-yu period,as well as how to use these numerous datasets to answer scientific questions.The highlights of IMFRE-II are:(1)to the best of our knowledge,IMFRE-II is the first field campaign in China to use ground-based,airborne,and spaceborne platforms to conduct comprehensive observations over the middle and lower reaches of the Yangtze River;and(2)seven aircraft flights were successfully carried out,and the spectra of ice particles,cloud droplets,and raindrops at different altitudes were obtained.These in-situ measurements will provide a“cloud truth”to validate the ground-based and satellite-retrieved cloud and precipitation properties and quantitatively estimate their retrieval uncertainties.They are also crucial for the development of a warm(and/or cold)rain conceptual model in order to better understand the cloud-to-rain conversion and accretion processes in mei-yu precipitation events.Through an integrative analysis of ground-based,aircraft,and satellite observations and model simulations,we can significantly improve our cloud and precipitation retrieval algorithms,investigate the microphysical properties of cloud and precipitation,understand in-depth the formation and dissipation mechanisms of mei-yu frontal systems,and improve cloud microphysics parameterization schemes and model simulations.

Continuous and comprehensive atmospheric observations in Beijing:a station to understand the complex urban atmospheric environment

Due to profound impact on climate and human health,air quality has attracted attention from all levels of the civil society.The key step in the provision of required tools for the society to tackle the complex air quality problem is to characterize it in a comprehensive manner with a long-term perspective.Here,we describe a continuous and comprehensive observation station and its accompanying state-ofthe-art instrumentation that was established to investigate the complex urban atmospheric environment in a rapidly developing Chinese Megacity.The station,located in downtown Beijing,aims to study air quality by identifying the major atmospheric pollutants and key processes determining their formation and loss mechanisms.A few hundreds of parameters are continuously measured with the state-of-the-art instruments,including trace gas concentrations,aerosol particle size distributions,and mass concentrations,covering aerosol particle chemical composition from molecules to micrometer-sized aerosol particles.This produced long-term,comprehensive big data with around 1�10^(11)bytes per year.In this paper,we provide an overview on the facilities of the station,the instrumentation used,the workflow of continuous observations and examples of results from 2018 to 2019 and a basis for establishing a modern long-term,comprehensive atmospheric urban observation station in other megacities.

A review of the ecohydrology discipline: Progress, challenges, and future directions in China

In recent decades, the ecohydrology discipline was developed to provide theoretical and technical foundations for the protection and restoration of complex ecological systems(e.g., mountains, rivers, forests, farmlands, and lakes), and to further ecological civilization construction and green development in China. In this study, the progress and challenges of the ecohydrology discipline are elaborated, and the future development directions are proposed according to international scientific frontiers and national ecological civilization construction demands. Overall, the main discipline directions are to develop new ecohydrological monitoring methods, to comprehensively understand ecohydrological mechanisms and their basic theories, to promote integration of multi-scale and multi-variable models by considering both terrestrial and aquatic ecosystems, and to encourage multidisciplinary integration, particularly with the social sciences. Furthermore, the future research interests in China include: combining multi-source information, constructing comprehensive monitoring systems, studying spatiotemporal patterns of key ecohydrological variables and their variation characteristics, developing integrated models of ecological, hydrological, and economic processes, estimating their uncertainty;and conducting interdisciplinary studies that include the natural and social sciences. The application prospects in China are further explored for a variety of ecosystems, including forests, grasslands, rivers, lakes, wetlands, farmlands, and cities. This study will provide a reference to support the development of the ecohydrology discipline in China, and will provide a solid theoretical and technical foundation for the implementation of national ecological civilization construction.