El Niño-Southern Oscillation (ENSO): Impact on tomato spotted wilt intensity in peanut and the implication on yield

The impact of El Niño – Southern Oscillation (ENSO) on weather patterns could have cascading effects on several diseases of important crops in the southeastern United States. One such disease is spotted wilt of peanut caused by the Tomato spotted wilt virus (TSWV). Significant economic losses have been recorded by peanut growers in the southeastern United States since the disease was first reported in 1986. The virus is transmitted by western flower thrips Frankliniella occidentalis and tobacco thrips, Frankliniella fusca. The objective of this study was to examine the influence of El Niño – Southern Oscillation on spotted wilt intensity and peanut yield. Our analysis was based on field trials conducted between 1994 and 2005 at field locations in Georgia and Florida in the United States. The spotted wilt intensity (%) in two peanut genotypes and the corresponding yield were recorded and evaluated. Each season was categorized by ENSO (El Niño, Neutral or La Niña) based on the NOAA Climate Prediction Center classification scheme. Results showed that the interaction between ENSO and peanut genotypes significantly affected spotted wilt intensity. Spotted wilt intensity was significantly lower during La Niña when compared to El Niño or Neutral years. The results also showed a significant correlation between spotted wilt intensity and peanut yield. Incorporating findings from this study into the existing TWSV risk index could aid peanut producers in making management decisions for reducing spotted wilt.     

四川省汉源县大渡河干热河谷区清代洪涝灾害特征

[目的]分析四川省汉源县清代洪涝灾害特征及成因,为防灾减灾等工作提供科学支持。[方法]通过对大渡河干热河谷区汉源县清代洪灾等资料的搜集整理,运用数理统计分析等方法,探究了该地区清代洪灾的等级、频次、周期以及成因等问题。[结果]清代汉源县洪涝灾害共计发生55次,平均4.87a发生1次。轻度洪灾、中度洪灾、大洪灾和特大洪灾各占洪灾总数的14.55%,60.00%,21.82%和3.64%,以中度洪灾为主。从清代早期到晚期,洪灾呈波动增加的趋势且有明显的阶段性,1644—1739年和1770—1809年是洪灾少发期,1740—1769年和1810—1911年是洪灾高发期,并出现了5次重大洪灾事件。清代汉源县洪灾存在约5a,10a的震荡周期。[结论]在太阳黑子极值年、印度夏季风强盛期及南方涛动(ENSO)事件年前后出现洪灾的机率极大。清代中期以后的人口快速增长、农业垦殖、森林破坏等人为无序开发加剧了洪灾频次和严重程度。     

山东省干旱时空分布特征及其与ENSO的相关性

基于山东省15个气象台站1964—2010年的逐月降水和平均气温资料,采用标准化降水蒸散指数(SPEI)定量分析了山东省不同时间尺度干旱发生频率,利用Mann-Kendall非参数检验法和Arcgis软件,对近50年山东省干旱的时空变化趋势进行分析。为了研究厄尔尼诺/南方涛动(ENSO)对山东省干旱的影响,运用连续小波(CWT)、交叉小波变换(XWT)和小波相干谱(WTC)分析SPEI与ENSO指数(多变量ENSO指数,MEI)的相关关系和周期特征。结果表明:多时间尺度的SPEI值可以较好地反映山东省的干旱情况;不同时间尺度的SPEI值随时间变化的敏感性存在明显差异,时间尺度越小,变化幅度越大。近50年山东地区呈现明显的增暖趋势,其中东部增温最为显著,降水减少和温度升高使山东气候趋于"暖干化",加剧山东省干旱程度。空间变化趋势上,山东省年SPEI和山东省年降水的空间分布具有一致性,总体有西部变湿润、东部变干的趋势。在干旱发生时间尺度上,月尺度干旱发生频率高于年尺度干旱发生频率,四季中春、秋季干旱最为严重。春旱和秋旱以鲁西和鲁西北平原发生频率最高,各地区之间差异明显。ENSO暖事件时,山东易旱;ENSO冷事件时,干旱减少。SPEI存在1~2.5 a尺度的年际振荡周期特征,呈现了与MEI指数相似的变化特征。高能量区,SPEI和MEI存在5~6 a的共振周期,SPEI较MEI提前1~2个月;低能量区,SPEI与MEI存在3~3.8 a呈负相位的共振周期。     

毛乌素沙地1960—2018年气候变化特征及影响因子分析

为了解毛乌素沙地近年气候变化特征,以期为区域沙漠化防治和灾害预警提供参考,基于毛乌素沙地及其周围邻近地区10个气象站点1960—2018年的逐月气温和降水资料,采用线性倾向估计、Anusplin空间插值、Mann-Kendall突变检验、Morlet小波分析、R/S分析和Pearson相关分析等方法对毛乌素沙地近59 a的气候变化特征、未来气候变化趋势和主要影响因素进行了探究。结果表明:(1)毛乌素沙地近59 a的年平均气温呈显著上升趋势,增温速率达到0.35℃/10 a。其约在1996年发生突变,主要存在4 a左右的短变化周期,且增温速率随地区海拔的升高而加快。(2)毛乌素沙地近59 a的年降水变化速率为2.88 mm/10 a,夏季降水增速较快,但变化趋势均不显著且无明显的降水突变时间点和显著的振荡周期。(3)未来毛乌素沙地的年、季节平均气温和秋季降水均呈现持续性较强的上升趋势。总体而言,毛乌素沙地的气候呈现暖湿化趋向,厄尔尼诺—南方涛动(ENSO)事件对其冬季气温影响较大,北极涛动(AO)和北大西洋涛动(NAO)对其冬夏季节降水影响较显著。     

ENSO现象对中西太平洋鲣鱼围网渔场的影响分析

ENSO(El Nin^-o Southern Oscillation)是引起全球气候变化的最强烈的海-气相互作用现象,对世界渔业生产具有重要影响。本文研究表明：ENSO现象对中西太平洋鲣鱼围网渔场的空间分布有显著影响,厄尔尼诺发生时,单位捕捞努力量渔获量经度重心随着暖池的东扩而东移,拉尼娜发生时则随着暖池向西收缩而西移。同时,Nifio 3．4区海表温度与单位捕捞努力量渔获量经度重心有显著相关关系,可将Nifio 3．4区海表温度作为预报、预测中西太平洋鲣鱼围网渔场位置的一个重要指标。     

多类型厄尔尼诺和拉尼娜事件下秘鲁外海茎柔鱼栖息地的变动

茎柔鱼（）为短生命周期头足类,其栖息地易受气候及海洋环境的影响。本研究利用1950-2015年海表温度（SST）和海面高度距平（SSHA）数据,计算秘鲁外海茎柔鱼栖息地适宜性指数,分析不同强度厄尔尼诺和拉尼娜事件期间茎柔鱼栖息地适宜性的变动规律。结果表明,相较于弱厄尔尼诺和中强度厄尔尼诺事件,强厄尔尼诺事件期间,茎柔鱼渔场水温偏暖,海面高度偏高,适宜的SST和SSHA范围减小,适宜的栖息地面积减小,弱拉尼娜事件期间,水温偏暖,海面高度偏高;中强度拉尼娜和强拉尼娜事件期间,水温偏冷,海面高度偏低。相较之下,强拉尼娜事件期间较为适宜的栖息地面积明显多于中强度拉尼娜和弱拉尼娜事件。此外,随着厄尔尼诺强度的增加,适宜的栖息地纬度重心向南偏移;随着拉尼娜强度的增加,适宜的栖息地纬度重心向北偏移。结论认为,不同强度厄尔尼诺和拉尼娜事件期间茎柔鱼渔场环境存在明显差异,适宜的栖息地范围及空间分布不同。     

太阳活动与ENSO事件对汉江谷地旱涝灾害影响分析

为探究汉江谷地旱涝灾害发生机理,根据18个代表站点1960-2010年气象资料,运用Z指数法界定出旱涝灾害等级和年份后,分析太阳黑子活动和ENSO事件对汉江谷地旱涝灾害的关系。结果表明:1)研究时段内汉江谷地呈暖干化趋势,气温以0.136℃/10a的速度上升,降水以15.7mm/10a的速度减少,旱涝灾害的发生呈增加趋势。2)20世纪70-80年代旱涝灾害指数与太阳黑子数呈负相关,80年代后二者呈正相关,太阳黑子的减少趋势与研究区域干旱化趋势相同。3)厄尔尼诺强度增大时研究区域的涝灾增多,拉尼娜发生强度增大时旱灾增多。     

Local temperature and El Niño Southern Oscillation influence migration phenology of East Asian migratory waterbirds wintering in Poyang,China

Temperature is a critical factor influencing avian phenology, due to its direct impact on food and water availability. Most previous studies have focused on the timing of spring migration and the arrival of birds at breeding grounds along the European and American flyways; little is known about migration ecology at the wintering sites along the Asian flyways. Using linear regression models, this study investigates how local temperature variation and EI Niño Southern Oscillation (ENSO) influences the arrival and departure timing of 9 waterbird species breeding in Mongolia or Siberia and overwintering in Poyang, China from 2002 to 2013. Birds mainly arrive at Poyang in October and depart for their breeding sites in March. Out of the 9 species, 6 show a strong negative relationship between departure time and overwintering temperature in Poyang. Departure dates also show a negative association with overwintering ENSO and March ENSO for two species. Both local and large‐scale climate indices show no influence on the arrival timing of waterbirds. We suggest that birds react to the annual variation of overwintering temperature: an earlier departure of waterbirds is facilitated by a warmer overwintering period and vice versa. The long‐term accumulated temperature effect is more pronounced than ENSO and the short‐term local temperature effect. Our findings could help quantify the potential impact of global warming on waterbirds.     

A century and a half of change in the climate of the NE Pacific

Spectral analysis of twenty-one climate records indicates that NE Pacific temperatures and winter wind stress have fluctuated at four dominant time scales in this century: 2–3 years (quasi-biennial oscillation), 5–7 years (El Nio-Southern Oscillation, ENSO), 20–25 years (bidecadal oscillation, BDO), and a poorly resolved, very-low-frequency (VLF) oscillation with a 50–75 year period. Forty-four per cent of the low-frequency variability in British Columbia air temperatures is associated with the strength of the Aleutian Low pressure system in winter. Only 42% of the 'strong' and 25% of the 'moderate' ENSO events in this century have produced large warm anomalies off BC. Interactions between the ENSO, bidecadal and very-low-frequency oscillations produce a pattern of alternating warm and cool climate states, with major warnings every 50 to 75 years. Since 1850 there have been seven warm periods, lasting an average of 11.4 years, and six cool periods lasting an average of 10.8 years. Sharp transitions from cool to warm climate states (as in 1977/78) occur when warming phases of the BDO and VLF oscillations coincide. Recent evidence suggests that the BDO may originate in either the tropical or the subtropical North Pacific. The NE Pacific has experienced a major warming since 1978. A long-range forecast suggests that the BDO and VLF oscillations peaked in 1989 and are currently in a cooling phase. Consequently, coastal temperatures should moderate for the rest of this century. A transition to the next cool climate state could occur about the year 2001. The forecast for moderating temperatures could begin the first phase of the recovery of the southern BC coastal chinook and coho salmon and herring stocks, which are currently at low abundance levels.     

太阳活动与ENSO事件对云南省旱涝灾害的影响

根据云南省29个气象站点1958-2011年的逐月降水资料,运用Z指数法界定旱涝等级和年份,采用频次分析和Morlet小波技术分析了太阳活动与ENSO(厄尔尼诺和拉尼娜)事件对云南省旱涝灾害的影响。结果表明:(1) 近54 a云南省年均降水量总体呈下降趋势,下降速率为4.505 mm/10 a;旱涝灾害的发生呈增加趋势,进入21世纪之后旱灾发生频率明显高于涝灾发生频率。(2) 除了1967-1972年,20世纪60-90年代太阳黑子数和云南省旱涝指数呈明显的负相关关系。90年代中后期至今,二者则呈正相关关系。太阳黑子的减少趋势与研究区干旱化趋势相同。(3) ENSO事件与云南省旱涝灾害在14 a左右存在较好的周期对应关系;厄尔尼诺强度增大时研究区旱灾增多,拉尼娜强度增大时涝灾增多。