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Analysis of Rain Variability Using the Daily and Monthly Concentration Indexes in Southeastern Brazil

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Atmospheric and Climate Sciences 2017年第2期7卷 176-190页

作者： Jonas T. Nery Ana Claudia Carfan Javier Martin-Vide Department of Geography UNESP Ourinhos Brazil climatology group University of Barcelona Barcelona Spain

Daily and monthly rainfall was analyzed by the Concentration Index (CI) of [1] and the Annual Precipitation Concentration Index (PCI) of [2] in southeastern Brazil. About 120 rainfall stations were used in the period from 1976 to 2010. Data were obtained from the National Water Agency (ANA). These data were selected by observing their spatial and temporal distribution in the study area. In general, the Concentration Index and the Precipitation Concentration Index were consistent for the study of rainfall variability in the study area. High percentages of annual rainfall concentration in a few very rainy days can increase the risk of flooding and soil instability. In this work, a survey of the spatial and temporal patterns of daily and monthly rainfall concentration in southeast Brazil was conducted. The results showed a relatively homogeneous temporal distribution of daily rainfall in the study area. In addition, the Mann-Kendall test showed a clear trend towards a seasonal rainfall distribution.

关键词： Concentration Indices Variability Rain Southeast Brazil

Seasonal variability in tropical and subtropical convective and stratiform precipitation of the East Asian monsoon

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Science China Earth Sciences 2011年第10期54卷 1595-1603页

作者： HU Liang LI YaoDong SONG Yang DENG DiFei National Satellite Meteorological Center China Meteorological Administration Beijing 100081 China Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China Beijing Aviation Meteorological Institute Beijing 100085 China L M. Systems group Satellite Meteorology and Climatology Division National Oceanic andAtmospheric Administration Washington D C USA

Seasonal variations in tropical and subtropical convective and stratiform precipitation of the East Asian monsoon are analyzed using 10-year (1998-2007) Tropical Rainfall Measuring Mission (TRMM) precipitation radar (PR) rain products (2A25). Datasets from the Intergovernmental Panel on Climate Change Fourth Assessment Report (AR4) 24 general circulation models (GCMs) are evaluated using TRMM PR rain products in terms of their ability to simulate convective and stratiform precipitation and their deficiencies. The results show that Asian monsoon convective and stratiform precipitation increases significantly after onset of the summer monsoon, but the percentage of convective precipitation clearly decreases over tropical areas while it increases in subtropical regions. The GCMs simulate well the seasonal variation in the contribution of Asian monsoon subtropical convective precipitation to the total rainfall; however, the simulated convective precipitation amount is high while the simulated stratiform precipitation amount is low relative to TRMM measurements, especially over the Asian monsoon tropical region. There is simultaneous TRMM-observed convective and stratiform precipitation in space and time, but GCMs cannot simulate this relationship between convective and stratiform precipitation, resulting in the deficiency of stratiform precipitation simulations.

关键词： convective precipitation stratiform precipitation Asian monsoon seasonal variability

Extreme Wind Variability and Wind Map Development in Western Java,Indonesia

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International Journal of Disaster Risk Science 2022年第3期13卷 465-480页

作者： Muhammad Rais Abdillah Prasanti Widyasih Sarli Hafidz Rizky Firmansyah Anjar Dimara Sakti Faiz Rohman Fajary Robi Muharsyah Gian Gardian Sudarman Atmospheric Science Research group Faculty of Earth Science and TechnologyInstitut Teknologi BandungBandung40132Indonesia Structural Engineering Research group Faculty of Civil and Environmental EngineeringInstitut Teknologi BandungBandung40132Indonesia Center for Infrastructures and Built Environment Institut Teknologi BandungBandung40132Indonesia Civil Engineering Department Faculty of Civil and Environmental EngineeringInstitut Teknologi BandungBandung40132Indonesia Remote Sensing and Geographic Information Science Research group Faculty of Earth Sciences and TechnologyInstitut Teknologi BandungBandung40132Indonesia Center for Remote Sensing Institut Teknologi BandungBandung40132Indonesia Center for Climate Change and Information The Agency for MeteorologyClimatology and Geophysics of the Republic of Indonesia(BMKG)Jakarta10720Indonesia Subdivision for Executive Secretary Administration The Agency for MeteorologyClimatology and Geophysics of the Republic of Indonesia(BMKG)Jakarta10720Indonesia Earth Science Department Faculty of Earth Science and TechnologyInstitut Teknologi BandungBandung40132Indonesia

Wind-related disasters are one of the most frequent disasters in *** can cause severe damages of residential construction,especially in the world's most populated island of *** the characteristics of extreme winds is crucial for mitigating the disasters and for defining structural design *** study investigated the spatiotemporal variations of extreme winds and pioneered a design wind map in Indonesia by focusing on western *** on gust data observed in recent years from 24 stations,the extreme winds exhibit a clear annual cycle where northwestern and southeastern sides of western Java show out-of-phase relationship due to reversal ***,extreme wind occurrences are mostly affected by small-scale weather systems,regardless of seasons and *** build the wind map,we used bias-corrected gust from ERA5 and applied the Gumbel method to predict extreme winds with different return *** wind map highlights some drawbacks of the current national design standards,which use single wind speed values regardless of location and return *** a fundamental improvement for wind design,this study will benefit disaster risk mapping and other applications that require extreme wind speed distribution.

关键词： ERA5 reanalysis Extreme wind Mixed weather system Tropical climate

Global Radiation, Transmissivity and Bright Sunshine Hour Trend over Nagpur in Pre-Monsoon and Monsoon Seasons

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Atmospheric and Climate Sciences 2012年第2期2卷 206-209页

作者： Jyotsna Singh Manoj Kumar Bimal K. Bhattacharya Agriculture-Forestry and Environment group (AFEG) Space Applications Centre (ISRO) Ahmedabad India Center of Excellence in climatology Birla Institute of Technology Ranchi India

Global dimming term was introduced in 1990s which means the decline in global radiation. This decline was reported in several studies across the world. In the present study time series analysis of global radiation (1960-2003), transmissivity (1960-2003) and bright sunshine hours (1973-2003) has been done over Nagpur during pre-monsoon (March to May) and monsoon seasons (June-September). A significant decrease in global radiation and transmissivity has been reported for both the seasons and it was higher during pre-monsoon compared to monsoon. Bright sunshine hour has also shown good agreement with the previous trend with a significant trend on pre-monsoon months only. Mann Kendall test was performed to confirm the significance of reported trend.

关键词： Global Radiation Bright Sunshine Hour Transmissivity Global Dimming Mann Kendall Test

An Extreme Value Analysis of Wind Speed over the European and Siberian Parts of Arctic Region

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Atmospheric and Climate Sciences 2016年第2期6卷 205-223页

作者： Alexander Kislov Tatyana Matveeva Department of Meteorology and climatology Lomonosov Moscow State University Moscow Russia

Multiyear observed time series of wind speed for selected points of the Arctic region (data of station network from the Kola Peninsula to the Chukotka Peninsula) are used to highlight the important peculiarities of wind speed extreme statistics. How largest extremes could be simulated by climate model (the INM-CM4 model data from the Historical experiment of the CMIP5) is also discussed. Extreme value analysis yielded that a volume of observed samples of wind speeds are strictly divided into two sets of variables. Statistical properties of one population are sharply different from another. Because the common statistical conditions are the sign of identity of extreme events we therefore hypothesize that two groups of extreme wind events adhere to different circulation processes. A very important message is that the procedure of selection can be realized easily based on analysis of the cumulative distribution function. The authors estimate the properties of the modelled extremes and conclude that they consist of only the samples, adhering to one group. This evidence provides a clue that atmospheric model with a coarse spatial resolution does not simulate special mechanism responsible for appearance of largest wind speed extremes. Therefore, the tasks where extreme wind is needed cannot be explicitly solved using the output of climate model. The finding that global models are unable to capture the wind extremes is already well known, but information that they are members of group with the specific statistical conditions provides new knowledge. Generally, the implemented analytical approach allows us to detect that the extreme wind speed events adhere to different statistical models. Events located above the threshold value are much more pronounced than representatives of another group (located below the threshold value) predicted by the extrapolation of law distributions in their tail. The same situation is found in different areas of science where the data referring t

关键词： Extreme Wind Speed Analysis Arctic Circulation Modelled Extreme Wind Speed

Automated Soil Moisture Monitoring Wireless Sensor Network for Long-Term Cal/Val Applications

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Wireless Sensor Network 2012年第8期4卷 202-209页

作者： Aurelio Cano Jose Luís Anon Candid Reig Cristina Millán-Scheiding Ernesto López-Baeza Department of Electronic Engineering University of ValenciaValenciaSpain climatology from Satellites group University of ValenciaValenciaSpain Research Centre on Desertification-CIDE CSIC-University of ValenciaValenciaSpain

The design and development of a wireless sensor network for soil moisture measurement in an unlevelled 10 km × 10 km area, is described. It was specifically deployed for the characterization of a reference area, in campaigns of calibration and validation of the space mission SMOS (Soil Moisture and Ocean Salinity), but the system is easily extensible to monitor other climatic or environmental variables, as well as to other regions of ecological interest. The network consists of a number of automatic measurement stations, strategically placed following soil homogeneity and land uses criteria. Every station includes acquisition, conditioning and communication systems. The electronics are battery operated with the help of solar cells, in order to have a total autonomous system. The collected data is then transmitted through long radio links, with ling ranges above 8 km. A standard PC linked to internet is finally used in order to control the whole network, to store the data, and to allow the remote access to the real-time data.

关键词： Wireless Sensor Network Soil Moisture Monitoring SMOS Calibration/Validation Radio Frequency Links

Identifying Regional Prolonged Low Temperature Events in China

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Advances in Atmospheric Sciences 2011年第2期28卷 338-351页

作者：张宗婕钱维宏 Monsoon and Environment Research group Department of Atmospheric and Oceanic Sciences School of Physics Peking University

This study examined regional prolonged low temperature （PLT） events in China from the observational station data for the period 1960–2008 using the new criteria. The new definition of a site PLT event is that the daily minimum temperature does not exceed the 10th percentile threshold of the local daily minimum temperature climatology for at least 5 days at a station. The regional PLT event is defined as at least five adjacent stations exhibiting site PLT simultaneously for 5 d. Under the new definition, 552 regional PLT events were identified, and three indices： duration, extent, and intensity, as well as a comprehensive index （CI） were used to quantify the event severity. In addition, geographical patterns and temporal variations of regional PLT events were investigated using three event categories： strong, moderate, and weak. Spatially, strong events were mainly located in the north of Xinjiang and along the Yangtze River to the south of the Yangtze River; moderate events occurred in Xinjiang and south of the Yangtze River; and weak events occurred south of the Yellow River. The variation for the annual frequency of regional PLT events in China in the last 49 years showed a significant decreasing trend with a rate of-1.99 times per decade, and the significant transition decade was the 1980s.

关键词： regional prolonged low temperature extreme event duration index comprehensive index spatiotemporal variation

空间形态分区视角下的北京热脆弱性评估与缓解策略

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China City Planning Review 2023年第4期32卷 35-42页

作者：蔡智唐燕李娜娜 Demuzere Matthias School of Architecture Tsinghua UniversityBeijingP.R.China Institute of Urban Meteorology China Meteorological AdministrationBeijingP.R.China Urban climatology group Department of GeographyRuhr-University BochumBochumGermany

Against the backdrop of climate change,heat waves have become increasingly detrimental to cities,Urban morphology,a comprehensive reflection of material and non-material elements in the physical world,is closely related to environmental quality,thermal environment,population health,and other *** the perspective of urban morphological regions,this paper examines the characteristics of heat exposure,sensitivity,adaptability,and vulnerability ofthe main urban areas and its surrounding areas in Beijing,in combination with land surface temperature,air temper-ature,population characteristics,vegetation distribution,and other *** results indicate that the built-up areas ofBejing are dominated by compact classes,making them most vulnerable to heat waves due to the unfavorable thermal environment,high population density,a large proportion of young and old people,and sparse vegetation *** contrast,the open low-rise class shows the highest adaptive capacity due to better economic condition of the population and high vegetation *** paper provides mitigation strategies from angles of morphology optimization and policy guidance,and suggests that the assessment and analysis ofheat vulnerability based on urban morphology can provide a reference for climate change-oriented planning and design,and promote urban high-quality development and sustainable construction.

关键词： morphological regions urban morphology thermal environment heat vulnerability Bejing

Extreme Values of Wind Speed over the Kara Sea Based on the ERA5 Dataset

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Atmospheric and Climate Sciences 2021年第1期11卷 98-113页

作者： Alexander Kislov Tatyana Matveeva Department of Meteorology and climatology Faculty of Geography Lomonosov Moscow State University Moscow Russia Laboratory of Climate Institute of Geography Russian Academy of Sciences Moscow Russia

Extreme values of wind speed were studied based on the highly detailed ERA5 dataset covering the central part of the Kara Sea. Cases in which the ice coverage of the cells exceeded 15% were filtered. Our study shows that the wind speed extrema obtained from station observations, as well as from modelling results in the framework of mesoscale models, can be divided into two groups according to their probability distribution laws. One group is specifically designated as black swans, with the other referred to as dragons (or dragon-kings). In this study we determined that the data of ERA5 accurately described the swans, but did not fully reproduce extrema related to the dragons;these extrema were identified only in half of ERA5 grid points. Weibull probability distribution function (PDF) parameters were identified in only a quarter of the pixels. The parameters were connected almost deterministically. This converted the Weibull function into a one-parameter dependence. It was not clear whether this uniqueness was a consequence of the features of the calculation algorithm used in ERA5, or whether it was a consequence of a relatively small area being considered, which had the same wind regime. Extremes of wind speed arise as mesoscale features and are associated with hydrodynamic features of the wind flow. If the flow was non-geostrophic and if its trajectory had a substantial curvature, then the extreme velocities were distributed according to a rule similar to the Weibull law.

关键词： ERA5 Kara Sea Weibull Probability Distribution Function Wind Speed Hydrodynamics and Statistics of Extreme Events