Monthly Mean Minimum Temperature Research Articles

SPATIO-TEMPORAL ANALYSIS OF HEAT INDEX IN THE OUTDOOR ENVIRONMENT IN UYO, AKWA IBOM STATE, NIGERIA

The study analysed spatio-temporal analysis of heat index in the outdoor environment in Uyo, Akwa Ibom State, Nigeria. The study made use of meteorological data including minimum and maximum temperature, relative humidity, wind speed and solar radiation from 1985 to 2021 obtained from NiMet. Both descriptive and inferential statistics were used for the data analysis. Results showed that both minimum and maximum temperatures in Uyo increased with increasing time while the monthly mean minimum and maximum temperature decreased from January to December. The mean total heat index continued to rise at the rate of 0.13381 in Uyo. The mean total heat index increased at the rate of 0.1998 in the dry season and 0.0968 in the rainy season in Uyo. The study concluded that the air temperature and relative humidity in Uyo are increasing from 1985 to 2021 while solar radiation and wind speed are slightly decreasing. However, the heat index in Uyo was increasing from 1985 to 2021 and as a result the human comfort in the outdoor environment becomes a challenge. The study thus recommended that the menace of increasing heat index in Uyo should be critically looked at so that the human comfort can be improved. Also, afforestation programme should be encouraged to decrease the heat in the outdoor environment

Investigation of Global Warming Case of Antalya

Antalya is one of the most important cities of Turkey in terms of agriculture, tourism and population. In this study, the global warming case of Antalya was investigated by using the monthly mean maximum, monthly mean minimum and monthly mean temperature data of Elmalı, Korkuteli, Antalya, Manavgat and Gazipaşa meteorology stations between 1970 and 2017. For this aim, trend analyses were performed by Mann Kendall Rank Correlation method and beginnings of trends were determined. Run, interquartile range and autocorrelation tests were applied before trend analysis test. 99.99% confidence interval was used for all tests. Run test results indicated that the data is homogenous. According autocorrelation test results, there is not autocorrelation in tha data except monthly mean minimum temperature data of Antalya station for August. Therefore, prewhitening was used for monthly mean minimum temperature data of Antalya station for August. The 12-month average value of the increasing trend was calculated as 98.33% for the mean temperature, 88.33% for the mean maximum temperature and 80% for the mean minimum temperature. The 12-month average value of the statistically significant increasing trend was calculated as 10% for the mean temperature, 5% for the mean minimum temperature and 0% for the mean maximum temperature. If 95% confidence level was used for Mann-Kendall test, the 12-month average value of the statistically significant increasing trend was calculated as 61.9% for the mean temperature, 34.5% for the mean maximum temperature and 51.2% for the mean minimum temperature. These results show that there is global warming in Antalya. The beginnings of statistically significant trends vary between 1992 and 2009. While water consumption is increasing due to increase in agriculture, tourism and population in Antalya, the global warming detected in this study shows that both water consumption and losses in water resources will increase further. Precautions are suggested in the results section.

Analysis of the annual pollen integral in Albuquerque, New Mexico, shows a negative trend with temperatures for Juniper, Cottonwood, Elm, and Mulberry

The goal of this study is to determine if the annual pollen integral (APIn) for the top tree allergens in the City of Albuquerque is correlated with meteorological variables. This analysis would be the first of its kind for this area. We used 17 consecutive years from 2004 to 2020 and data collected by the city of Albuquerque using a Spore Trap (Burkard) volumetric air sampler in a location designed to represent a typical desert environment. The pollen studied include Juniper, Elm, Ash, Cottonwood, and Mulberry. We found a negative linear correlation with early summer temperatures of the previous year and APIn for Elm, Cottonwood, and Mulberry, and early fall temperatures for Juniper. Linear regression models developed for Elm, Cottonwood, and Mulberry used the monthly mean maximum temperature for the month of June of the prior year as the independent variable to yield a R squared statistic (R2) of 0.88, 0.91 and 0.78, respectively. For Juniper, the average monthly mean minimum temperature for the previous September and October served as the independent variable and yielded the R2 value of 0.80. We also observed a positive trend for the annual maximum temperature over time and a negative trend for the total APIn. Summers in New Mexico are hot and dry, and they may be getting hotter and drier because of climate change. Our analysis predicts that climate change in this area may lead to reduced allergies if temperatures continue to increase and if precipitation patterns remain the same.

Simulation and Evaluation of Hydrothermal Conditions in Crop Growth Period: A Case Study of Highland Barley in the Qinghai-Tibet Plateau

WXGEN, a weather generator model based on stochastic process theory and mathematical statistics, was widely used in hydrological monitoring models, crop yield estimation models and derived fields of meteorological data. In this study, we used WXGEN to evaluate the simulation accuracy of hydrothermal conditions in the highlands of the Qinghai–Tibet Plateau. Results showed that: (1) The Markovian chain transfer parameters P(W|D) and P(W|W) of each station were between 0.03–0.30 and 0.12–0.74, which was basically consistent with the temporal and spatial distribution of actual precipitation; (2) In the thermal data simulation, more than 96% of the meteorological stations passed the 0.05 level in three different significance tests of monthly mean minimum and maximum temperature and solar radiation, and the measured deviations of simulated annual mean temperature and solar radiation were 0.686 °C and 1.65 MJ/m2, respectively. In all, 94% of the stations in the hydrological simulation passed the monthly precipitation significance test; (3) The simulated vs. measured deviations of annual precipitation, heavy rain days and wet days were 8.04 mm, 1.023 d and 8.374 d, respectively; (4) The simulation of extreme hydrothermal conditions that may affect the yield of highland barley was very close to the measured situation, and the R2 of simulation and measured value was all above 0.85. The simulation of freezing damage was less accurate, but also higher than 0.85.

Responses of radial growth of Pinus sylvestris var. mongolica and Larix gmelinii to climate change

In the context of global warming, the increases of temperature may affect tree growth and thus disturb ecosystem balance. In this study, we explored the main limiting factors for radial growth of Pinus sylvestris var. mongolica and Larix gmelinii in the Mohe area of Greater Khingan Mountains by using growth-climate response function analysis and moving correlation analysis, as well as the interspecific difference of the responses of radial growth to rapid warming. The results showed that the radial growth of P. sylvestris var. mongolica and L. gmelinii was affected by both temperature and precipitation. P. sylvestris var. mongolica was more sensitive to climate change than L. gmelinii, and its sensitivity to climate factors was more stable than L. gmelinii. The radial growth of P. sylvestris var. mongolica was significantly positively correlated with the monthly mean temperature and the monthly mean minimum temperature of the growing season, while that of L. gmelinii was significantly positively correlated with the monthly mean temperature and the monthly mean maximum temperature of winter. Precipitation in winter promoted the growth of P. sylvestris var. mongolica, whereas precipitation in the late growing season of the previous year inhibited the radial growth of L. gmelinii. After the rapid warming in 1990, the limiting effect of precipitation on P. sylvestris var. mongolica changed from negative to significantly positive, with the inhibition effect of high temperature being greater than the promotion effect. The inhibitory effect of high temperature on L. gmelinii was enhanced, and the limiting effect of precipitation on L. gmelinii was also enhanced after heating up. The growth rate decreased significantly, with obvious difference being observed in the correlations between the growth rate of two species with temperature and precipitation. Our results could provide scientific basis for forest ecosystem management and protection in Greater Khingan Mountains.

Natural History of a Highly Medically Important Snake, Russell's Viper (Daboia russelii), in a Human-Dominated Indian Rural Landscape

Venomous snakes are a public health concern in India, where they kill tens of thousands of people annually. Russell's Vipers are the major culprit, but despite their clinical significance, there is virtually no information on their ecology. I used radiotelemetry for a 9-mo period to study the spatial and behavioral ecology of a population of Russell's Vipers (Daboia russelii) in a human-dominated rural landscape in Karnataka, India. Russell's Vipers spent a substantial amount of time in plantations, which make up a significant proportion of the landscape. Snakes were the least active in March, a dry month with the hottest monthly mean maximum temperatures recorded; and spatial activity comparatively increased in late fall-early winter and May, corresponding with the timing of mating activities and the end of the dry season, respectively. Russell's Vipers basked throughout the year, but basking behavior was more frequent in January and February, when the monthly mean minimum temperatures were the lowest. The probability of observing a snake basking increased with decreasing minimum temperatures. Similarly, the snakes were found in ambush foraging postures during daytime throughout the year, and the odds of observing diurnal foraging increased with increasing minimum temperatures and was affected by an interaction between maximum temperature and sex. Overall, the data indicate that this tropical viper actively thermoregulates and is to some extent diurnal. This study provides the first quantitative field-based natural history information on Russell's Vipers, one of the most medically important snakes in the world.

Time series analysis of climate variables using seasonal ARIMA approach

The dynamic structure of climate is governed by changes in precipitation and temperature and can be studied by time series analysis of these factors. This paper describes investigation of time series and seasonal analysis of the monthly mean minimum and maximum temperatures and the precipitation for the Bhagirathi river basin situated in the state of Uttarakhand, India. The data used is from the year 1901–2000 (100 years). The seasonal ARIMA (SARIMA) model was used and forecasting was done for next 20 years (2001–2020). The auto-regressive (p) integrated (d) moving average (q) (ARIMA) model is based on Box Jenkins approach which forecasts the future trends by making the data stationary and removing the seasonality. It was found that the most appropriate model for time series analysis of precipitation data was SARIMA(0,1,1) (0,1,1)12 (with constant) and of temperature data was SARIMA(0,1,0) (0,1,1)12 (with constant). The model prediction results show that the forecast data fits well with the trend in the data. However, over-predictions are found in extreme rainfall events and temperature results. The information of pattern and trends can assist as a prediction tool for development of better water management practices in the area.

The m-delay Autoregressive Model with Application

The classical autoregressive (AR) model has been widely applied to predict future data using m past observations over five decades. As the classical AR model required m unknown parameters, this paper implements the AR model by reducing m parameters to two parameters to obtain a new model with an optimal delay called as the m-delay AR model. We derive the m-delay AR formula for approximating two unknown parameters based on the least squares method and develop an algorithm to determine optimal delay based on a brute-force technique. The performance of the m-delay AR model was tested by comparing with the classical AR model. The results, obtained from Monte Carlo simulation using the monthly mean minimum temperature in Perth Western Australia from the Bureau of Meteorology, are no significant difference compared to those obtained from the classical AR model. This confirms that the m-delay AR model is an effective model for time series analysis.

Fenologia, biometria e precocidade de plantas de caju arbóreo do Cerrado (<i>Anacardium othonianum</i> Rizz.)

O presente trabalho teve como objetivos analisar o comportamento fenológico do caju arbóreo do Cerrado (Anacardium othonianum Rizz.), relacionando a fenologia às condições meteorológicas do período e do local estudado, obtendo-se também dados biométricos das plantas, a fim de selecionar plantas precoces e indicá-las para um estudo de melhoramento genético, de forma a contribuir para uma futura domesticação da espécie. A pesquisa foi desenvolvida em populações de caju da espécie Anacardium othonianum Rizz., oriundas das regiões norte, oeste, centro-leste do Estado de Goiás, um município do Tocantins e um da Bahia, e implantadas na área da Escola de Agronomia da Universidade Federal de Goiás (EA/UFG), em Goiânia - GO. Entre os períodos de 2012 e 2013 foram coletados dados mensais das fenofases de folhação, floração e frutificação. Para fins de estabelecer correlação, as médias mensais de temperatura máxima, temperatura mínima, temperatura média, umidade relativa, precipitação e insolação foram coletadas na Estação Evaporimétrica de Primeira Classe da EA/UFG. Dados biométricos como altura e diâmetro das plantas também foram realizadas de forma mensal. Nos meses de março, abril e maio há maior ocorrência de emissão de folhas novas; já para a floração o pico ocorreu no mês de julho, não apresentando correlação com nenhum dos dados climáticos relacionados. A altura das plantas variou entre 4,0 cm a 380,0 cm e o diâmetro de caule de 1,5 mm a 94 mm. Apenas três plantas produziram frutos durante o período de estudo. Progênies da UFG e da região de São Miguel do Passa Quatro se destacaram quanto à precocidade e produção de frutos, podendo ser indicadas para um futuro trabalho de melhoramento genético.

THE SPATIO-TEMPORAL VARIATIONS OF WIND SPEED DURING HARMATTAN SEASON IN NORTHEASTERN NIGERIA

Wind speed is the principal climatic element that drives the Marmaton season in West African sub region. It drives the season by conveying huge amount of dust across the Northeastern Nigeria. The presence of dust in the atmosphere brought by the Northeast trade winds during the Harmattan season plays a vital role in absorbing and scattering solar radiation. The study examines the spatial and temporal variations of wind speed in Northeastern Nigeria during the Harmattan season with the sole aim of ascertaining its variability, patterns and trends from1984 to 2014. Descriptive and statistics such as mean, standard deviation, coefficient of variation, and time series analysis with ArcGIS 10.3 was used in examine the temporal and spatial variations of wind speed from 1984–2014 in six synoptic stations of Northeastern Nigeria. The findings show that wind speed varied both temporally and spatially in the last three decades. The pattern of variations in the six synoptic stations shows rising trends within the study years. It was also found that latitude playing a crucial role in determining the speed of the wind in the study area and as the speed of the wind increases with increasing latitude.
 Keywords: Wind speed, Harmattan, Season, Northeast, Variation and ITD.
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Winter Wheat Green-up Date Variation and its Diverse Response on the Hydrothermal Conditions over the North China Plain, Using MODIS Time-Series Data

Vegetation phenology plays a critical role in the dynamic response of terrestrial ecosystems to climate change. However, the relationship between the phenology of winter wheat and hydrothermal factors is inadequate, especially in typical agricultural areas. In this study, the possible effects of preseason climate changes on the green-up date (GUD) of winter wheat over the North China Plain (NCP) was investigated, using the MODIS EVI 8-day time-series data from 2000 to 2015, as well as the concurrent monthly mean temperature (Tm), mean maximum (Tmax) and minimum temperature (Tmin) and total precipitation (TP) data. Firstly, we quantitatively identified the time lag effects of winter wheat GUD responses to different climatic factors; then, the major driving factors for winter wheat GUD were further explored by applying multiple linear regression models. The results showed that the time lag effects of winter wheat GUD response to climatic factors were site- and climatic parameters-dependent. Negative temperature effects with about a 3-month time lag dominated in most of the NCP, whereas positive temperature effects with a zero-month lag were most common in some of the southern parts. In comparison, total precipitation had a negative zero-month lag effect in the northern region, but two lagged months occurred in the south. Regarding the time lag effects, the explanation power of climatic factors improved relatively by up to 77%, and the explanation area increased by 41.20%. Additionally, change in winter wheat GUD was primarily determined by temperature rather than by TP, with a marked spatial heterogeneity of the Tmax and Tmin effect. Our results confirmed different time lag effects from different climatic factors on phenological processes in spring, and further suggested that both Tmax and Tmin should be considered to improve the performance of spring phenology models.

Weather variables and the El Niño Southern Oscillation may drive the epidemics of dengue in Guangdong Province, China

ObjectiveTo investigate the periodicity of dengue and the relationship between weather variables, El Niño Southern Oscillation (ENSO) and dengue incidence in Guangdong Province, China. MethodsGuangdong monthly dengue incidence and weather data and El Niño index information for 1988 to 2015 were collected. Wavelet analysis was used to investigate the periodicity of dengue, and the coherence and time-lag phases between dengue and weather variables and ENSO. The Generalized Additive Model (GAM) approach was further employed to explore the dose-response relationship of those variables on dengue. Finally, random forest analysis was applied to measure the relative importance of the climate predictors. ResultsDengue in Guangdong has a dominant annual periodicity over the period 1988–2015. Mean minimum temperature, total precipitation, and mean relative humidity are positively related to dengue incidence for 2, 3, and 4months lag, respectively. ENSO in the previous 12months may have driven the dengue epidemics in 1995, 2002, 2006 and 2010 in Guangdong. GAM analysis indicates an approximate linear association for the temperature-dengue relationship, approximate logarithm curve for the humidity-dengue relationship, and an inverted U-shape association for the precipitation-dengue (the threshold of precipitation is 348mm per month) and ENSO-dengue relationships (the threshold of ENSO index is 0.6°C). The monthly mean minimum temperature in the previous two months was identified as the most important climate variable associated with dengue epidemics in Guangdong Province. ConclusionOur study suggests weather factors and ENSO are important predictors of dengue incidence. These findings provide useful evidence for early warning systems to help to respond to the global expansion of dengue fever.

Assessing the social and environmental determinants of pertussis epidemics in Queensland, Australia: a Bayesian spatio-temporal analysis.

Pertussis epidemics have displayed substantial spatial heterogeneity in countries with high socioeconomic conditions and high vaccine coverage. This study aims to investigate the relationship between pertussis risk and socio-environmental factors on the spatio-temporal variation underlying pertussis infection. We obtained daily case numbers of pertussis notifications from Queensland Health, Australia by postal area, for the period January 2006 to December 2012. A Bayesian spatio-temporal model was used to quantify the relationship between monthly pertussis incidence and socio-environmental factors. The socio-environmental factors included monthly mean minimum temperature (MIT), monthly mean vapour pressure (VAP), Queensland school calendar pattern (SCP), and socioeconomic index for area (SEIFA). An increase in pertussis incidence was observed from 2006 to 2010 and a slight decrease from 2011 to 2012. Spatial analyses showed pertussis incidence across Queensland postal area to be low and more spatially homogeneous during 2006-2008; incidence was higher and more spatially heterogeneous after 2009. The results also showed that the average decrease in monthly pertussis incidence was 3·1% [95% credible interval (CrI) 1·3-4·8] for each 1 °C increase in monthly MIT, while average increase in monthly pertussis incidences were 6·2% (95% CrI 0·4-12·4) and 2% (95% CrI 1-3) for SCP periods and for each 10-unit increase in SEIFA, respectively. This study demonstrated that pertussis transmission is significantly associated with MIT, SEIFA, and SCP. Mapping derived from this work highlights the potential for future investigation and areas for focusing future control strategies.

Responses of radial growth to fire disturbance in alpine pine (Pinus densata) of different age classes in Nang County, Xizang, China

Aims Forest fire plays a complex and important role in affecting forest regeneration, tree growth, and stand development. Despite the importance of forest fire in modulating forest dynamics, researches on the response patterns of trees of different age-classes to fire disturbances are scarce. This study was conducted to determine the growth patterns of surviving trees of different age-classes in an alpine pine (Pinus densata) forest in the southeastern Xizang Plateau, where a moderate surface fire occurred in 2005. Methods We collected tree-ring samples of P. densata in the Gong-Zi-Nong valley in Nang County, Xizang Autonomous Region, in western China. Based on the diameter at breast height (DBH), the sampling trees were divided into saplings (DBH < 10 cm) and mature trees (DBH ≥10 cm). The tree-ring samples were subsequently polished, measured, cross-dated, and detrended to produce sequences of tree-ring width indices. The detrended tree-ring sequences were averaged using bi-weight robust method to develop chronologies for saplings and mature trees separately. Pearson correlation coefficients and response coefficients between the sequences of tree-ring width indices and climate factors (air temperature and precipitation) were calculated for examination of the responses of tree-ring sequences to monthly mean air temperature and monthly total precipitation both before and after the fire event. Indices of growth resistance and growth recovery were calculated based on the relative changes of trees’ raw ring width before and after the fire event, for trees in different age-classes. These indices were then compared between the trees in different age classes to assess the impacts of fire on trees. Important findings Before the fire event, the radial growth of saplings showed a significantly negative response to the monthly mean minimum temperature of the preceding November, whereas the radial growth of mature trees ©植物生态学报 Chinese Journal of Plant Ecology 李宝等: 西藏朗县地区不同龄级高山松林木径向生长对火干扰的响应 437 doi: 10.17521/cjpe.2015.0440 showed a significantly positive response to monthly mean minimum temperature and monthly mean temperature of current September; following the fire event, radial growth of both the saplings and the mature trees showed a significantly negative response to monthly mean temperature and monthly mean maximum temperature of January of the tree-ring formation year. Based on the ratios of mean tree-ring widths of 5 post-fire years to those of 5 pre-fire years, the mature trees were significantly more fire resistant than the saplings. Moreover, the mature trees also showed greater ability in post-fire recoveries than the burnt saplings. Our results demonstrated that moderate surface fire stimulated the radial growth of both saplings and mature trees, and that the mature trees better recovered from the fire event than the saplings. The changes in growth-climate relationships following the fire event may attribute to changes in understory vegetation and microenvironments.

近44年藏东南低纬山地降水和气温的气候变化分析

选取1971~2014年藏东南4个气象站逐日气象资料，采用线性趋势、Mann-Kendall非参数检验等方法，分析了藏东南年、季降水量和气温的年际和年代际变化、气候突变。结果表明：近44 a年降水量呈现为减少趋势，平均每10 a减少1.24 mm，春季降水呈增加趋势，其他季节趋于减少，以秋季减少最为明显。年平均气温以0.28℃/10 a的速率显著升高，最高气温和最低气温都出现了升高的趋势。在10 a年际变化尺度上，年平均气温表现为逐年代升高趋势；年降水量在20世纪90年代偏多，其他3个年代均偏少。在时间突变点上，年平均气温出现在1994年；年、季降水量未出现突变。 Based on homogeneity-adjusted monthly mean temperature, maximum and minimum temperature and precipitation data of 4 stations in Southeastern Tibet from 1971 to 2014, the climatic variations and climate abrupt characteristics of air temperature and precipitation are analyzed by using the methods of linear regression and Mann-Kendall test, etc. The results show that during the past 44 years the annual precipitation decreases with a rate of 1.24 mm/10 a, while that in spring increases, but decreases in other season, especially in autumn. The annual mean temperature has increased in Southeastern Tibet with a rate of 0.28℃/10 a, the trends of mean maximum and minimum temperatures are increasing. On the decadal scale, the annual mean temperature shows increase trend, and the annual precipitation is more in the 1990s and less in the other three decades. According to the Mann-Kendall test, the abrupt change of annual mean temperature occurred in 1994, but no abrupt change appeared for annual and seasonal precipitation.

长白山红松(Pinus koraiensis)不同树高处径向生长特征及其对气候响应研究

PDF HTML阅读 XML下载 导出引用 引用提醒 长白山红松不同树高处径向生长特征及其对气候的响应 DOI: 10.5846/stxb201308262159 作者: 作者单位: 北京林业大学 作者简介: 通讯作者: 中图分类号: 基金项目: 北京林业大学青年科技启动基金(blx2011004); 国家"十二五"科技支撑计划(2012BAC01B03) Characteristics of Korean pine (Pinus koraiensis) radial growth at different heights and its response to climate change on Changbai Mountain Author: Affiliation: Beijing Forestry Unviersity Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:利用长白山红松不同树高(0.3、1.3、4、10、15、20、25 m)处的径向生长资料,分析各树高处径向生长特征,建立红松生长与气候因子的相关关系,以期完善红松种群对气候变化的响应机制。结果表明:(1)红松不同树高处年径向生长量变化趋势基本一致,除在1980年前后,20 m处径向生长量出现异常增加外,其他各高度径向生长均出现下降趋势,红松基部和顶端(0.3、1.3 m和20 m)处径向生长年际变化更明显。随着树高增加,各处年径向生长率有所降低,0.3m处生长速率最大,且与10 m和15 m处径向生长差异显著(P < 0.05)。(2)不同树高处径向生长对气候因子的响应存在明显差异,10 m树高是红松径向生长对温度和降水响应差异的分界线。10 m以下红松径向生长主要受到生长季温度的负作用,尤其是4 m处,与当年生长季初期(4月和5月)温度显著负相关(P < 0.05)。0.3 m和1.3 m处径向生长分别与上年9月平均温度显著正相关(P < 0.05),当年6月平均和最高温度显著负相关(P < 0.05)。随着树高上升,降水对径向生长的促进作用增强,而温度对径向生长的作用也发生改变。10 m(含)以上则受到温度和降水的共同作用。10 m处径向生长对气候因子响应最敏感,受到当年生长季高温的抑制作用,还与上年和当年生长季末(9月)降水显著正相关(P < 0.05)。15 m处径向生长与上年9月最低温度和降水显著正相关(P < 0.05),而与当年5月月平均温度显著负相关(P < 0.05)。20 m处径向生长与当年3月月平均、最低和最高温度,当年7月月平均温度以及当年5月降水显著正相关(P < 0.05),而与当年1月降水显著负相关(P < 0.05)。 Abstract:Understanding the relationship between climate and growth at different heights gives insight into the mechanisms by which trees respond to climate change. In this paper, tree-ring data at different heights (0.3, 1.3, 4, 10, 15, 20, and 25 m,) on the north side of Korean pine (Pinus koraiensis) trees on Changbai Mountain were collected from 155 cores, taken from 25 Korean pine trees. Dendrochronology and a multiple comparison method (LSD) were used to analyze the radial growth characteristic and the climate-growth relationship. The results show that the trends in annual radial growth of Korean pine at different heights were essentially identical. Apart from an abnormal increase in the annual radial growth at a height of 20 m around 1980, the annual radial growths at other heights showed a downward trend. The most obvious variations were found at the base (0.3 m and 1.3 m) and crown (20 m) of Korean pines. With increasing tree height, the annual growth rates at different heights were all reduced. The maximum growth rate was observed at a height of 0.3 m, which was significantly different from the annual growth rates at 10 m and 15 m (P < 0.05). We identified a differential response of radial growth to temperature and precipitation at different heights, depending on whether the height was above or below 10 m. Radial growth at heights below 10 m was mainly controlled by temperature, particularly at a height of 4 m. The radial growth at 0.3 m and 1.3 m was significantly positively correlated with monthly mean temperature in September of the previous growing season (P < 0.05) and significantly negatively correlated with the monthly mean and maximum temperatures in June of the current growing season (P < 0.05), respectively. At a height of 4 m, the radial growth was significantly negatively correlated with the temperature at the beginning of current growing season (May and June) (P < 0.05). The positive influences of precipitation on radial growth became stronger and the impact of temperature on growth also changed with increasing tree height. Radial growth at heights above 10 m was strongly affected by both temperature and precipitation. The radial growth of Korean pine at a height of 10 m was much more sensitive to the climate than that at other heights. Radial growth at a height of 10 m was significantly negatively correlated with the temperature in the current growing season, and significantly positively correlated with precipitation at end of the previous and current growing seasons (September) (P < 0.05). The radial growth at a height of 15 m was significantly positively correlated with the monthly minimum temperature and precipitation in September of the previous season (P < 0.05), but negatively correlated with the monthly mean temperature in May of the current season (P < 0.05). At a height of 20 m, radial growth was significantly positively correlated with the monthly mean and maximum and minimum temperatures in March of the current season, and with the monthly mean temperature in July of the current season (P < 0.05). 参考文献 相似文献 引证文献

Japanese encephalitis risk and contextual risk factors in southwest China: a Bayesian hierarchical spatial and spatiotemporal analysis.

It is valuable to study the spatiotemporal pattern of Japanese encephalitis (JE) and its association with the contextual risk factors in southwest China, which is the most endemic area in China. Using data from 2004 to 2009, we applied GISmapping and spatial autocorrelation analysis to analyze reported incidence data of JE in 438 counties in southwest China, finding that JE cases were not randomly distributed, and a Bayesian hierarchical spatiotemporal model identified the east part of southwest China as a high risk area. Meanwhile, the Bayesian hierarchical spatial model in 2006 demonstrated a statistically significant association between JE and the agricultural and climatic variables, including the proportion of rural population, the pig-to-human ratio, the monthly precipitation and the monthly mean minimum and maximum temperatures. Particular emphasis was placed on the time-lagged effect for climatic factors. The regression method and the Spearman correlation analysis both identified a two-month lag for the precipitation, while the regression method found a one-month lag for temperature. The results show that the high risk area in the east part of southwest China may be connected to the agricultural and climatic factors. The routine surveillance and the allocation of health resources should be given more attention in this area. Moreover, the meteorological variables might be considered as possible predictors of JE in southwest China.

Statistical analysis of temperature changes in israel: an application of change point detection and estimation techniques

The main goal of this study is to present and apply recently developed nonparametric change point&#x0D; detection and estimation techniques for confirming patterns of regional changes in temperature.&#x0D; Utilizing these methods, monthly temperatures (mean, mean maximum, mean minimum) and diurnal&#x0D; temperature ranges in different regions of Israel have been investigated over a period of 37-years,&#x0D; (1967-2003). The results were supported also by traditional statistical methods. The temperature&#x0D; and the diurnal temperature range analyses reveal a complex pattern of change. In particular, we&#x0D; found an increase in the monthly mean temperatures in the warm season in all areas of Israel&#x0D; approximately from the mid-1980s to the mid-1990s, namely, the summers have become warmer.&#x0D; Also detected was a significant increase in the monthly mean minimum temperature in Israel's&#x0D; coastal plain area for all months of the year. Whereas, in mountainous and desert areas a significant&#x0D; increase in the monthly mean minimum temperature was detected only in months of the warm&#x0D; season. The winters have become warmer in the Israeli coastal plain and have not significantly&#x0D; changed in its mountainous and desert areas. In addition, in Israel's coastal plain the monthly mean&#x0D; DTRs are decreasing, while in mountainous and desert areas the situation is reversed, that is,&#x0D; monthly mean DTRs are increasing.

Multiple linear regression model for forecasting Bluetongue disease outbreak in sheep of North-west agroclimatic zone of Tamil Nadu, India

Aim: A study was undertaken to develop a forecasting model for predicting bluetongue outbreaks in North-west agroclimatic zone of Tamil Nadu, India. Materials and Methods: Eleven bluetongue outbreaks were characterised by active and passive surveillances for a period of twelve years and used in this study. Meteorological data comprising of maximum and minimum temperatures, relative humidity, rainfall and wind speed were collected and used as the multiple predictor variables in the multiple liner regression model. Results: A multiple liner regression model was developed for the North-west zone of Tamil Nadu. Values of the dependant variables were less than or greater than one, and indicated remote or greater chances of bluetongue outbreaks respectively. The monthly mean maximum and minimum temperatures, relative humidity at 8.30 h and at 17.00 h IST, wind speed, and monthly total rainfall of 29.1 - 31.0°C, 20.1 - 22.0°C, 80.1 - 85.0%, 65.1 - 70.0%, 3.1 - 5.0 km/h and < 200 mm respectively, were identified as the ideal climatic conditions for increased numbers of bluetongue outbreaks in this zone. Conclusion: Based on the values obtained from the prediction model, stake holders can be warned timely through the media to institute suitable prophylactic measures against bluetongue, to avoid economic losses due to disease.

Estimation of the monthly and annual mean maximum and mean minimum air temperature values in Greece

In this study, regression equations to estimate the monthly and annual values of the mean maximum and mean minimum air temperatures in Greece are derived. For this purpose, data from 87 meteorological stations distributed all over Greece are used. Geographical parameters, i.e., altitude, latitude, longitude, minimum distance from the sea and an index of terrain morphology, are used as independent variables. These equations explain 79–97% of the variance of the temperature values and have standard error of estimate between 0.59 and 1.20°C. Data from 37 other meteorological stations are used to validate the accuracy of the equations. Topographic or climatic factors, which could not be introduced into the equations, are responsible for most temperature residuals >0.5°C or <−0.5°C. Moreover, some particular emphasis has been given to the values of the regression coefficient for the altitude, since it is the estimator for the mean lapse rate of air temperature.