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Wang K.,Beijing Normal University | Wang K.,Joint Center for Global Change Studies | Ma Q.,Beijing Normal University | Ma Q.,Joint Center for Global Change Studies | And 3 more authors.
Journal of Geophysical Research Atmospheres | Year: 2015

Existing studies have shown that observed surface incident solar radiation (Rs) over China may have important inhomogeneity issues. This study provides metadata and reference data to homogenize observed Rs, from which the decadal variability of Rs over China can be accurately derived. From 1958 to 1990, diffuse solar radiation (Rsdif) and direct solar radiation (Rsdir) were measured separately, and Rs was calculated as their sum. The pyranometers used to measure Rsdif had a strong sensitivity drift problem, which introduced a spurious decreasing trend into the observed Rsdif and Rs data, whereas the observed Rsdir did not suffer from this sensitivity drift problem. From 1990 to 1993, instruments and measurement methods were replaced and measuring stations were restructured in China, which introduced an abrupt increase in the observed Rs. Intercomparisons between observation-based and model-based Rs performed in this research show that sunshine duration (SunDu)-derived Rs is of high quality and can be used as reference data to homogenize observed Rs data. The homogenized and adjusted data of observed Rs combines the advantages of observed Rs in quantifying hourly to monthly variability and SunDu-derived Rs in depicting decadal variability and trend. Rs averaged over 105 stations in China decreased at -2.9 W m-2 per decade from 1961 to 1990 and remained stable afterward. This decadal variability is confirmed by the observed Rsdir and diurnal temperature ranges, and can be reproduced by high-quality Earth System Models. However, neither satellite retrievals nor reanalyses can accurately reproduce such decadal variability over China. © 2015. American Geophysical Union. All Rights Reserved. Source

Agency: GTR | Branch: AHRC | Program: | Phase: Research Grant | Award Amount: 8.60K | Year: 2008

New research by the University of Bristol, led by Professor Robert Bickers, aims to help the development of a comprehensive picture of Chinese meteorological observations and practices in and around the South China Sea, dating back to the mid-19th century. It is a rare and exciting example of humanities research as a basis for solid scientific improvement. The work contributes to the Met Office Hadley Centres Atmospheric Circulation Reconstructions over the Earth [http://www.met-acre.org/] project, which advances research into the causes of climate change. The work is part of a global project attempting to reconstruct a series of weather conditions dating as far back as the mid-18th century. \n\nProfessor Bickers worked with Dr Rob Allan at the Met Office Hadley Centre and recent PhD graduate Dr Catherine Ladds at the Department of History at the University of Bristol, in this application of humanities scholarship to scientific research. Dr Ladds searched Chinese archives for information about meteorological practices and for records of climate conditions in 19th century East and South-East Asia that are outside of usual meteorological sources, specifically traditional and non-traditional humanities sources such as ships logbooks and unpublished data.\n\nThe research also informed a new understanding of the history of Chinese Maritime Customs meteorological activity, its role in China coast meteorology more widely, its standards and procedures for collecting and distributing data and the subsequent history of those records. Professor Bickerss findings are to be used by the Met Office Hadley Centre at Exeter. The research has helped broaden knowledge of East and South East Asian maritime and riverine surface observational weather data coverage, and contributed to helping to complete the global projects series of global weather reconstructions. It has resulted in the most comprehensive English language inventory of this field to date and the historical Chinese weather observations uncovered can in turn help to reconstruct the observations made at Chinese inland stations and around the South China Sea: the project can recover, image and digitise them.\n

Bougeault P.,European Center for Medium | Toth Z.,National Centers for Environmental Prediction | Bishop C.,U.S. Navy | Brown B.,U.S. National Center for Atmospheric Research | And 18 more authors.
Bulletin of the American Meteorological Society | Year: 2010

A major component of THORPEX, THORPEX Interactive Grand Global Ensemble (TIGGE) was initiated in 2005 at a workshop hosted by the European Center for Medium-Range Weather Forecasts (ECMWF). It was initiated to enhance collaboration on ensemble prediction, both internationally and between operational centers and universities and develop new methods to combine ensembles from different sources and to correct for systematic errors. The highest-priority data accumulated in the TIGGE archive are the ensemble forecasts generated routinely (operationally) at major forecast centers around the world. TIGGE has strong links with the North American Ensemble Forecast System (NAEFS), which synthesizes ensemble products from the National Centers for Environmental Prediction (NCEP) and the Meteorological Service of Canada (MSC). The Internet Data Distribution (IDD) system/Local Data Manager (LDM), an Internet-based distribution system has been developed by Unidata, which meets the TIGGE requirements. Source

Wang B.,Chinese Meteorological Administration | Ding L.,Chinese Meteorological Administration | Yang Y.,Chinese Meteorological Administration
Taiyangneng Xuebao/Acta Energiae Solaris Sinica | Year: 2012

SMARTS spectral model was used to calculate direct and global spectral irradiance under different atmosphere condition, which weighted by the spectral responsivity of the silicon photovoltaic detector, then was used to simulate the output of pyranometer or pyrheliometer made by silicon device. The responsivity of the simulated radiometer was computed by dividing the simulated output cumulative value by the spectral cumulative value in the range of 300-4000 nm in the same condition. By analyzing the corresponding data, it is concluded that the photovoltaic pyranometer can be used with error range below ±5%. The sensitivity of diffused radiometer and pyranometer would be better calibrated, respectively. The pyrheliometer was not suggested to use because of its great error. It is urgent to develop a standard light source which had been fully tested and could be reproducible indoors for the calibration of auto sunshine duration sensor. Source

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