Chinese Weather Research Articles

Could the Enhanced Forests Reduce Summer Warming in the Southern China?

We examined if the enhanced forests could modify thermal climatic conditions in the southwestern China and its surrounding regions. We used the continuous time-series of annual forests fraction obtained from He et al. (2017) and sensible heat flux and temperatures from the European Center for Medium- Range Weather Forecasts reanalysis (ERA-Interim) for 1982-2011. In the linear regression trend analysis, the forests fraction, area-averaged over the southwestern China, significantly increased by 15.46% over the three decades. Significantly negative correlations of surface sensible heat flux during the summer growing season (June through August, JJA) with the area-averaged time-series of annual forests fraction were shown in the southwestern China. Correspondingly, the significantly negative correlations of JJA temperature at 925hPa with the annual forests fraction were observed in the southwestern China as well as the surrounding regions propagated to the east. The spatial patterns of negative correlations between the thermal climatic variables and forests fraction were consistent with the difference patterns of sensible heat flux and temperatures between high-fraction and low-fraction years of forests in the southwestern China. The results indicated that the enhanced forests in the southwestern China could reduce thermal energy transfer from land to atmosphere during JJA and, consequently, lower atmospheric temperatures. Based on the temperature trend analysis using the Chinese weather station data, we inferred that the forest-induced cooling effect might be one of the factors of relatively less summer warming, even cooling, trends in the southern China.

Principal component analysis in an asymmetric norm

Principal component analysis (PCA) is a widely used dimension reduction tool in high-dimensional data analysis. In risk quantification in finance, climatology and many other applications, however, the interest lies in capturing the tail variations rather than variation around the mean. To this end, we develop Principal Expectile Analysis (PEC), which generalizes PCA for expectiles. It can be seen as a dimension reduction tool for extreme-value theory, where fluctuations in the τ-expectile level of the data are approximated by a low-dimensional subspace. We provide algorithms based on iterative least squares, derive bounds on their convergence time, and compare their performance through simulations. We apply the algorithms to a Chinese weather dataset and fMRI data from an investment decision study.

Principal Component Analysis in an Asymmetric Norm

Principal component analysis (PCA) is a widely used dimension reduction tool in the analysis of high-dimensional data. However, in many applications such as risk quantification in finance or climatology, one is interested in capturing the tail variations rather than variation around the mean. In this paper, we develop Principal Expectile Analysis (PEC), which generalizes PCA for expectiles. It can be seen as a dimension reduction tool for extreme value theory, where one approximates fluctuations in the τ-expectile level of the data by a low dimensional subspace. We provide algorithms based on iterative least squares, prove upper bounds on their convergence times, and compare their performances in a simulation study. We apply the algorithms to a Chinese weather dataset and fMRI data from an investment decision study.

Effects of the ground surface temperature anomalies over the Tibetan Plateau on the rainfall over northwestern China and western Mongolia in July

A significantly negative interannual relationship is identified between the ground surface temperature (GTS) over the Tibetan Plateau (TP) and the rainfall over northwestern China and western Mongolia (NWC-WM) through analyzing the Chinese weather station data, GPCP precipitation, and ERA-Interim reanalysis in July during 1980–2012. This relationship is verified by the model sensitivity experiments carried out by using RegCM4.1 during 1982–2011. The positive/negative GTS forcing of three different magnitudes is added in two key regions over the TP in RegCM4.1. One of the key regions covers the central and eastern TP (denoted as TPC). The other covers the northern and north slope of the TP (denoted as TPN). The model results suggest that when the GTS anomalies in either of the two key regions are negative (positive), the rainfall anomalies over NWC-WM are positive (negative), which is consistent with observations. Furthermore, rainfall anomalies over NWC-WM are more sensitive to the GTS anomalies over the TPN region than those over the southern TP. The model results also reveal that the negative (positive) GTS anomalies over region TPN mainly cause the decrease (increase) of the latent heat release related to rainfall (surface sensible heat) and descent (ascent) over the TPN region but ascent (descent) to the north of the TP between 40° and 50° N. In addition, the specific humidity between 40° and 50° N is increased (decreased). Therefore, the increase (decrease) in specific humidity and the ascent (descent) between 40° and 50° N cause the increase (decrease) in the rainfall over NWC-WM.

Developing the science product algorithm testbed for Chinese next-generation geostationary meteorological satellites: Fengyun-4 series

Fengyun-4A (FY-4A), the first of the Chinese next-generation geostationary meteorological satellites, launched in 2016, offers several advances over the FY-2: more spectral bands, faster imaging, and infrared hyperspectral measurements. To support the major objective of developing the prototypes of FY-4 science algorithms, two science product algorithm testbeds for imagers and sounders have been developed by the scientists in the FY-4 Algorithm Working Group (AWG). Both testbeds, written in FORTRAN and C programming languages for Linux or UNIX systems, have been tested successfully by using Intel/g compilers. Some important FY-4 science products, including cloud mask, cloud properties, and temperature profiles, have been retrieved successfully through using a proxy imager, Himawari-8/Advanced Himawari Imager (AHI), and sounder data, obtained from the Atmospheric InfraRed Sounder, thus demonstrating their robustness. In addition, in early 2016, the FY-4 AWG was developed based on the imager testbed—a near real-time processing system for Himawari-8/AHI data for use by Chinese weather forecasters. Consequently, robust and flexible science product algorithm testbeds have provided essential and productive tools for popularizing FY-4 data and developing substantial improvements in FY-4 products.

Interdecadal variability of the large-scale extreme hot event frequency over the middle and lower reaches of the Yangtze River basin and its related atmospheric patterns

Based on daily maximum temperature data from Chinese weather stations for the period 1960–2013, the characteristics of the interdecadal variability of large-scale extreme hot event (EHE) frequency ...

Assessing environmental factors associated with regional schistosomiasis prevalence in Anhui Province, Peoples\u2019 Republic of China using a geographical detector method

BackgroundSchistosomiasis is a water-borne disease caused by trematode worms belonging to genus Schistosoma, which is prevalent most of the developing world. Transmission of the disease is usually associated with multiple biological characteristics and social factors but also factors can play a role. Few studies have assessed the exact and interactive influence of each factor promoting schistosomiasis transmission.MethodsWe used a series of different detectors (i.e., specific detector, risk detector, ecological detector and interaction detector) to evaluate separate and interactive effects of the environmental factors on schistosomiasis prevalence. Specifically, (i) specific detector quantifies the impact of a risk factor on an observed spatial disease pattern, which were ranked statistically by a value of Power of Determinate (PD) calculation; (ii) risk detector detects high risk areas of a disease on the condition that the study area is stratified by a potential risk factor; (iii) ecological detector explores whether a risk factor is more significant than another in controlling the spatial pattern of a disease; (iv) interaction detector probes whether two risk factors when taken together weaken or enhance one another, or whether they are independent in developing a disease. Infection data of schistosomiasis based on conventional surveys were obtained at the county level from the health authorities in Anhui Province, China and used in combination with information from Chinese weather stations and internationally available environmental data.ResultsThe specific detector identified various factors of potential importance as follows: Proximity to Yangtze River (0.322) > Land cover (0.285) > sunshine hours (0.256) > population density (0.109) > altitude (0.090) > the normalized different vegetation index (NDVI) (0.077) > land surface temperature at daytime (LSTday) (0.007). The risk detector indicated that areas of schistosomiasis high risk were located within a buffer distance of 50 km from Yangtze River. The ecological detector disclosed that the factors investigated have significantly different effects. The interaction detector revealed that interaction between the factors enhanced their main effects in most cases.ConclusionProximity to Yangtze River had the strongest effect on schistosomiasis prevalence followed by land cover and sunshine hours, while the remaining factors had only weak influence. Interaction between factors played an even more important role in influencing schistosomiasis prevalence than each factor on its own. High risk regions influenced by strong interactions need to be targeted for disease control intervention.

Possible Fengyun-1C debris fall

A fall of small objects took place on 27th April 2012 in Wargowo village near Oborniki, about 25km NW from Poznań (Poland). There was only one eye-witness of the fall, who found two separate pieces (ca. 2.7cm and ca. 2cm), with several small additional fragments. After microscopic observations and chemical analysis a meteoritic origin of these objects was excluded. They are identified as space debris, therefore man-made. The most probable source of the observed fall was space debris 35127 Fengyun 1C DEB, created during destruction of the Chinese weather satellite Fengyun-1C (FY-1C).

A velocity dealiasing scheme for C-band weather radar systems

A dealiasing algorithm for radar radial velocity observed by C-band Doppler radars is presented as an extension of an existing S-band dealiasing algorithm. This has operational significance in that many portable and many commercial broadcast radars, as well as approximately one half of the Chinese weather radar network (CINRAD), are C-band radars. With a wavelength of about 5 cm, the Nyquist interval of C-band radars is just about one half that of S-band radars (wavelength of about 10 cm) and thus has more velocity folding. The proposed algorithm includes seven modules to remove noisy data, find the starting radials, dealias velocities, and apply least squares error checking in both the radial and azimuth directions. The proposed velocity dealiasing method was applied to one widespread rain case and three strong convective cases from radars operating in China. It was found that, on average, 92.95% of the aliased radial velocity data could be correctly de-aliased by the algorithm, resulting in 96.65% of the data being valid.

Weather risk and the viability of weather insurance in China's Gansu, Shaanxi, and Henan provinces

PurposeThe purpose of this paper is to investigate weather risks facing Chinese farmers, and to determine whether farmers would have a preference for weather insurance over other types of agricultural insurance.Design/methodology/approachThe data are based on 1,564 farm households surveyed in Shaanxi, Henan, and Gansu provinces in Central China between October 2007 and 2008.FindingsResults suggest that the greater risk for farmers is drought followed by excessive rain. Heat is less critical as a risk but more significant than cool weather. Results suggest a strong interest in precipitation insurance with 50 and 44 percent of respondents indicating strong interest in the product. Supplementary results indicate that interest is equal between planting, cultivating, and harvesting. Furthermore, results suggest that farmers are willing to adopt new ideas, and where possible action has already been taken to self‐insure through diversification and other means.Research limitations/implicationsThis research is based on primary data gathered in China. However, the authors are limited in the access to Chinese weather station data to illustrate how weather insurance operates. Instead, the authors use weather data from the weather station in Ashland, Kansas which has similarities to the wheat growing regions of China. While the example is for illustrative purposes only, the authors cannot claim that it actually represents premiums that might actually be found in China.Practical implicationsThe Chinese Government has within the past year authorized an investigation into agricultural insurance. The burst of research and applications of weather insurance in both developed and developing countries suggest that a wide array of applications could be feasible in China. The results are encouraging because they suggest that farmers in China would have an interest in purchasing weather insurance.Originality/valueThe authors believe that this is the first study conducted on weather insurance in China. The survey instrument is designed to specifically determine what weather risks are important to Chinese farmers and the interest that farmers would have in using such a product.

A preliminary investigation on the topology of Chinese climate networks

Complex networks have been studied across many fields of science in recent years. In this paper, we give a brief introduction of networks, then follow the original works by Tsonis et al (2004, 2006) starting with data of the surface temperature from 160 Chinese weather observations to investigate the topology of Chinese climate networks. Results show that the Chinese climate network exhibits a characteristic of regular, almost fully connected networks, which means that most nodes in this case have the same number of links, and so-called super nodes with a very large number of links do not exist there. In other words, though former results show that nodes in the extratropical region provide a property of scale-free networks, they still have other different local fine structures inside. We also detect the community of the Chinese climate network by using a Bayesian technique; the effective number of communities of the Chinese climate network is about four in this network. More importantly, this technique approaches results in divisions which have connections with physics and dynamics; the division into communities may highlight the aspects of the dynamics of climate variability.

UNDERSTANDING CHINA'S ANTISATELLITE TEST

In discussing China's January 2007 hit-to-kill intercept of the Chinese weather satellite FengYun-1C, most American analysts sought the “message” for the United States—either by asserting that China's test was a deliberate step toward a comprehensive counterspace capability to offset U.S. conventional military superiority or an attempt to force the United States to the negotiating table on “the prevention of an arms race in outer space.” Chinese officials, after a long silence, eventually claimed the test was an “experiment” that was “not targeted at any country.” We traveled to China several times in 2007 and had a series of conversations with Chinese individuals knowledgeable about the history of this particular antisatellite program and with access to information about the decision-making process prior to and after the final test. These discussions were off the record, not for attribution, given the sensitivity of the subject. They reflected the views of some of the key institutions involved in the test from the State, the Communist Party, the People's Liberation Army, and aerospace experts involved in debris calculations. The information conveyed to us suggests that American commentators tend to place much greater importance on the United States as a driver in China's decision to develop the technology and conduct the test than do the Chinese.

Ontology-based fuzzy event extraction agent for Chinese e-news summarization

Abstract An Ontology-based Fuzzy Event Extraction (OFEE) agent for Chinese e-news summarization is proposed in this article. The OFEE agent contains Retrieval Agent (RA), Document Processing Agent (DPA) and Fuzzy Inference Agent (FIA) to perform the event extraction for Chinese e-news summarization. First, RA automatically retrieves Internet e-news periodically, stores them into the e-news repository, and sends them to DPA for document processing. Then, the DPA will utilize the Chinese Part-of-speech (POS) tagger provided by Chinese knowledge information processing group to process the retrieved e-news and filter the Chinese term set by Chinese term filter. Next, the FIA and Event Ontology Filter (EOF) extract the e-news event ontology based on the Chinese term set and domain ontology. Finally, the Summarization Agent (SA) will summarize the e-news by the extracted-event ontology. By the simulation, the proposed method can summarize the Chinese weather e-news effectively.

Who Was Responsible for the Weather? Moral Meteorology in Late Imperial China

Previous articleNext article No AccessPolitics, Policy, and Decision MakingWho Was Responsible for the Weather? Moral Meteorology in Late Imperial ChinaMark ElvinMark Elvin Search for more articles by this author PDFPDF PLUS Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by Osiris Volume 13, Number 11998Beyond Joseph Needham: Science, Technology, and Medicine in East and Southeast Asia Published for the History of Science Society Article DOIhttps://doi.org/10.1086/649286 Views: 24Total views on this site Citations: 10Citations are reported from Crossref Copyright 1999 The History of Science Society, Inc.PDF download Crossref reports the following articles citing this article:Sabine Kink The Explanations of Snow in the Taixi shuifa 泰西水法 (Hydromethods of the Great West, 1612) and Their Reception beyond the Ming–Qing Transition, Monumenta Serica 70, no.11 (Jun 2022): 165–207.https://doi.org/10.1080/02549948.2022.2061159Theresa Ventura ‘A Drought so Extraordinary’: The 1911 ENSO and Disaster Nationalism in the American Colonial Philippines, (May 2022): 345–376.https://doi.org/10.1007/978-3-030-98198-3_11Fiona Williamson The “cultural turn” of climate history: An emerging field for studies of China and East Asia, WIREs Climate Change 11, no.33 (May 2020).https://doi.org/10.1002/wcc.635Jerry C. Zee Machine Sky: Social and Terrestrial Engineering in a Chinese Weather System, American Anthropologist 122, no.11 (Jan 2020): 9–20.https://doi.org/10.1111/aman.13360Lei Sun, A.J. Faas Social production of disasters and disaster social constructs, Disaster Prevention and Management: An International Journal 27, no.55 (Nov 2018): 623–635.https://doi.org/10.1108/DPM-05-2018-0135Chris Courtney Governing Disasters: A Comparative Analysis of the 1931, 1954 and 1998 Middle-Yangzi Floods in Hubei, (Oct 2016): 67–102.https://doi.org/10.1057/978-1-137-02285-1_4Norman Harry Rothschild Why is it Necessary for Naked Savages to Drum and Dance? Early Tang Imperial Responses to a Sogdian Hibernal Festival, Fudan Journal of the Humanities and Social Sciences 8, no.11 (Feb 2015): 65–80.https://doi.org/10.1007/s40647-015-0061-3Kathryn Jean Edgerton-Tarpley From “Nourish the People” to “Sacrifice for the Nation”: Changing Responses to Disaster in Late Imperial and Modern China, The Journal of Asian Studies 73, no.22 (Feb 2014): 447–469.https://doi.org/10.1017/S0021911813002374 N. Harry Rothschild Sovereignty, Virtue, and Disaster Management: Chief Minister Yao Chong's Proactive Handling of the Locust Plague of 715–16, Environmental History 17, no.44 (Sep 2021): 783–812.https://doi.org/10.1093/envhis/ems078Tirthankar Roy ‘THE LAW OF STORMS’: EUROPEAN AND INDIGENOUS RESPONSES TO NATURAL DISASTERS IN COLONIAL INDIA, c. 1800-1850, Australian Economic History Review 50, no.11 (Mar 2010): 6–22.https://doi.org/10.1111/j.1467-8446.2009.00269.x

The impacts of potential climate change and climate variability on simulated maize production in China

This study assessed the impacts of potential climate change on maize yields in China, using the CERES-Maize model under rainfed and irrigated conditions, based on 35 maize modeling sites in eastern China that characterize the main maize regions. The Chinese Weather Generator was developed to generate a long time series of daily climate data as baseline climate for 51 sites in China. Climate change scenarios were created from three equilibrium general circulation models: the Geophysical Fluid Dynamics Laboratory model, the high-resolution United Kingdom Meteorological Office model, and the Max Planck Institute model. At most sites, simulated yields of both rainfed and irrigated maize decreased under climate change scenarios, primarily because of increases in temperature, which shorten maize growth duration, particularly the grain-filling period. Decreases of simulated yields varied across the general circulation model scenarios. Simulated yields increased at only a few northern sites, probably because maize growth is currently temperature-limited at these relatively high latitudes. To analyze the possible impacts of climate variability on maize yield, we specified incremental changes to variabilities of temperature and precipitation and applied these changes to the general circulation model scenarios to create sensitivity scenarios. Arbitrary climate variability sensitivity tests were conducted at three sites in the North China Plain to test maize model responses to a range of changes (0%, +10%, and +20%) inthe monthly standard deviations of temperature and monthly variation coefficients of precipitation. The results from the three sites showed that incremental climate variability caused simulated yield decreases, and the decreases in rainfed yield were greater than those of irrigated yield.

チベット高原における降水量補正の重要性について

Precipitation in the monsoon season on the Tibetan Plateau occurs as rain or snow depending on the elevation and temperature conditions. Point measurements of precipitation may not describe the accurate spatial distribution if systematic-error corrections of precipitation measurement are not applied. Precipitation data at 5 points intensively observed in the Tanggula basin (33°N, 92°E) were corrected, and the characteristics of the spatial distribution of precipitation are discussed. The largest correction was required for wind-induced loss of solid precipitation. The average ratio of corrected and measured precipitation was 1.38. An obvious increase of precipitation toward the south and higher elevations was found. Three years of precipitation data at two Chinese weather stations located north and south of the Tanggula basin were also corrected by the same methods. The ratio of corrected versus measured precipitation showed a clear annual variation, nearly constant at around 1.2 times in the monsoon season, but some months showed increase of more than 1.5 times in the non-monsoon season. Recycling of water between the atmosphere and land surface may strongly prevail in the Tibetan Plateau, which means that the corrected higher precipitation amounts directly correspond to a greater evaporation (or sensible heat source).