ALBERT

Description: Land cover (LC) is an important terrestrial variable and key information for understanding the interaction between human activities and global change. As the cause and result of global environmental change, land cover change (LCC) influences the global energy balance and biogeochemical cycles. Continuous and dynamic monitoring of global LC is urgently needed. Effective monitoring and comprehensive analysis of LCC at the global scale is rare. Using the latest version of GLASS (The Global Land Surface Satellite) CDRs (Climate Data Records) from 1982 to 2015, we built the first set of CDRs to record the annual dynamics of global land cover (GLASS-GLC) at 5 km resolution using the Google Earth Engine (GEE) platform. Compared to earlier global LC products, GLASS-GLC is characterized by high consistency, more detailed classes, and longer temporal coverage. The average overall accuracy is 85 %. We implemented a systematic uncertainty analysis at the global scale. In addition, we carried out a comprehensive spatiotemporal pattern analysis. Significant changes and patterns at various scales were found, including deforestation and agricultural land expansion in the tropics, afforestation and forest expansion in northern high latitudes, land degradation in Asian grassland and reclamation in northeast China, etc. A global quantitative analysis of human factors showed that the average human impact level in areas with significant LCC was about 25.49 %. The anthropogenic influence has a strong correlation with the noticeable Earth greening. Based on GLASS-GLC, we can conduct long-term LCC analysis, improve our understanding of global environmental change, and mitigate its negative impact. GLASS-GLC will be further applied in Earth system modeling in order to facilitate research on global carbon and water cycling, vegetation dynamics and climate change.

Description: Land cover is the physical evidence on the surface of the Earth. As the cause and result of global environmental change, land cover change (LCC) influences the global energy balance and biogeochemical cycles. Continuous and dynamic monitoring of global LC is urgently needed. Effective monitoring and comprehensive analysis of LCC at the global scale are rare. With the latest version of GLASS (The Global Land Surface Satellite) CDRs (Climate Data Records) from 1982 to 2015, we built the first record of 34-year long annual dynamics of global land cover (GLASS-GLC) at 5 km resolution using the Google Earth Engine (GEE) platform. Compared to earlier global LC products, GLASS-GLC is characterized by high consistency, more detailed, and longer temporal coverage. The average overall accuracy for the 34 years each with 7 classes, including cropland, forest, grassland, shrubland, tundra, barren land, and snow/ice, is 82.81 % based on 2431 test sample units. We implemented a systematic uncertainty analysis and carried out a comprehensive spatiotemporal pattern analysis. Significant changes at various scales were found, including barren land loss and cropland gain in the tropics, forest gain in northern hemisphere and grassland loss in Asia, etc. A global quantitative analysis of human factors showed that the average human impact level in areas with significant LCC was about 25.49 %. The anthropogenic influence has a strong correlation with the noticeable vegetation gain, especially for forest. Based on GLASS-GLC, we can conduct long-term LCC analysis, improve our understanding of global environmental change, and mitigate its negative impact. GLASS-GLC will be further applied in Earth system modeling to facilitate research on global carbon and water cycling, vegetation dynamics, and climate change. This GLASS-GLC data set is related to the paper at doi:10.5194/essd-2019-23. It consists of one readme file and 34 GeoTIFF files of annual 5 km global maps from 1982 to 2015 in a WGS 84 projection.

Description: Author(s): Jian Wang, Wei Xie, Long Zhang, Dan Xu, Wenhui Liu, Jian Lu, Yinglei Wang, Jie Gu, Yan Chen, Xuechu Shen, and Zhanghai Chen We realize the evaporative cooling of a polariton gas and observe the formation of polariton condensate in a potential trap based on a ZnO microwire at room temperature. Due to the three-dimensional confinement, the system is characterized by a well-defined discrete spectrum of polariton states whic... [Phys. Rev. B 91, 165423] Published Wed Apr 22, 2015

Description: Author(s): Jie Li, Yunhua Wang, Zongtan Wang, Jie Tan, Biao Wang, and Yulan Liu Using the strain-dependent effective Hamiltonian and the geometric phase, Droth et al. [ Phys. Rev. B 94 , 075404 (2016) ] obtain an analytical expression for the electronic contribution to the piezoelectricity of planar hexagonal boron nitride ( h -BN). Their analytical results of piezoelectric constant... [Phys. Rev. B 98, 167403] Published Mon Oct 22, 2018

Description: Author(s): Yunhua Wang, Zongtan Wang, Jie Li, Jie Tan, Biao Wang, and Yulan Liu The lack of inversion symmetry in semiconducting transition metal dichalcogenide monolayers (TMDMs) enables a considerable intrinsic piezoelectricity, which opens prospects for atomically thin piezotronics and optoelectronics. Here, based on the tight-binding (TB) approach and Berry phase expression... [Phys. Rev. B 98, 125402] Published Tue Sep 04, 2018

Description: Author(s): Chen Wang, Jie Ren, and Jianshu Cao To study the full counting statistics of quantum heat transfer in a driven nonequilibrium spin-boson model, we develop a generalized nonequilibrium polaron-transformed Redfield equation with an auxiliary counting field. This enables us to study the impact of qubit-bath coupling ranging from weak to … [Phys. Rev. A 95, 023610] Published Mon Feb 13, 2017

Description: Author(s): Wen-Yuan Wang, Jie Liu, and Li-Bin Fu We present measure synchronization (MS) in a bosonic Josephson junction with spin-orbit coupling. The two atomic hyperfine states are coupled by a Raman dressing scheme, and they are regarded as two orientations of a pseudo-spin- 1 / 2 system. A feature specific to a spin-orbit-coupled (SOC) bosonic Jo… [Phys. Rev. A 92, 053608] Published Tue Nov 10, 2015