日气温数据缺测的插补方法试验与误差分析

对缺测气象观测记录进行插补是建立连续气象数据集的基础.将孤立1日或数日缺测资料进行插补的线性回归模型法应用于连续缺测数月的逐日最高、最低和平均气温的插补,并进行了一系列改进,包括:(1)用滑动选优法确定邻近参考气象站站数和数据样本时间窗的最佳值;(2)在记录缺测站与邻近参考站之间建立逐日气温的线性回归模型,并选取以最小绝对误差(Least Absolute Deviation,LAD)为目标函数求取模型参数的方法,取代以最小均方根误差为目标函数的最小二乘法(Least Squares Estimate,LAD)求解模型参数的方法,可提高计算效率和参数的稳定性;(3)进一步提出将LAD法与DeGaetano标准化序列法插补结果平均的综合插补方法,以减少极端误差.通过对湖北蔡甸气象站1961-2006年插补试验表明:(1)以4个邻近站和年数为8年、日数为15天时间窗的样本资料建模进行插补误差达到最小;(2)逐日最高、最低和平均气温的平均绝对误差分别为0.32℃、0.45℃、0.28℃,误差在±0.8℃以内的频次分别占总数的94.1%、84.8%、96.1%,观测值与插补值月相关系数在0.886以上.插补与观测资料平均值和相关系数分别通过了显著水平为0.05和0.01的检验.     

三种气温插补方法在中国西南地区的应用分析

观测数据的插补是提升气象数据完整性、恢复缺失数据真实性的重要手段。本文采用标准序列、空间回归和随机森林3种插补方法,对中国西南地区5个主要气候区地面气象观测站日平均气温序列数据以及犍为和北碚2个百年站月平均气温序列数据进行插补试验,并选用平均绝对误差、均方根误差以及插补值与观测值偏差分别在±0.8℃和±0.5℃区间的样本占比(P_0.8、P_0.5)等4项指标对插补结果进行评估。结果表明：3种方法对中国西南地区5个气候区站点气温日均值与2个百年站气温月均值插补效果较好,且空间回归方法的插补精度高、适用性最好,在5个气候区的插补精度都高于其他两种方法,在地形较为平坦的四川盆地P_0.8约0.90,在地形最为崎岖的川西南滇北山地P_0.8也在0.60以上,地形对气温插补精度影响明显。选取最优参考站数可有效降低插补误差,2个百年站95%以上的月平均气温样本插补误差可控制在±0.5℃以内。     

河北保定气象站长序列气温资料缺测记录插补和非均一性订正

基于多源的气温月值资料,在数据整合和初步质量控制基础上,同时采用标准化序列法和多元线性回归法对河北保定气象站1913-2014 年月平均气温、最高气温和最低气温资料进行了插补。通过交叉检验法分析发现,标准化序列法插补得到的气温序列效果较好,并且气候统计特征与同区域周边站的研究结果更具一致性。利用惩罚最大F 检验（PMF）对插补后序列的均一性进行了检验,结果表明：通过插补得到的保定站百年气温月值序列的均一性相对较好,仅月平均最低气温序列存在2 个显著间断点,分别由同类型仪器的更换和台站迁移导致,研究中采用分位数匹配（QM）对其进行了订正,建立了保定站百年气温月值序列。通过与邻近单站及我国中东部区域均一化百年气温序列的综合对比显示,本文建立的保定站百年气温月值序列与邻近单站的相关性基本达到0.8 以上;从增暖趋势来看,保定站与中东部区域平均序列分别达0.121 ℃/10a、0.204 ℃/10a,基本在同一量级内：这一定程度上说明建立的保定站百年气温序列相对合理。     

西安观测站长序列气温资料缺测记录插补和非均一性检验

以西安观测站1971—2013年日平均气温、最高气温和最低气温序列为研究对象,利用标准序列法和多元线性回归法进行插补实验,计算插补值与实测值的平均误差、平均绝对误差、均方根误差和插补值与实测值误差在0.5℃以内的样本比例,对比分析两种插值方法的相对优劣。结果表明：多元线性回归法插补得到的气温序列效果好于标准序列法,并且气候趋势特征与实际观测值序列更具一致性。采用t检验法、惩罚最大T检验（PMTT）、惩罚最大F检验（PMFT）对西安站1951—2020年平均气温序列的均一性进行检验。依据台站历史沿革数据进行的t检验,在6次台站历史沿革变化中,只有2次造成了年平均气温和年平均最高气温序列间断,分别由观测时次增加和仪器换型导致;年平均最低气温有4次出现间断,分别由台站站址迁移、观测时次增加、仪器换型、缺测值插补造成。PMTT和PMFT检测中发现的4次间断点因无元数据支持,认为属于合理间断点,这2种方法均未检测出因缺测值插补引起的间断点,一定程度上说明采用多元线性回归法对缺测值插补得到的西安站1951—2020年气温序列相对合理,气温序列的均一性较好。     

藏北高原气温资料插补及其变化的初步分析

通过定义最优配对分段插补法,以NewD66/D66、D105、Amdo和BJ为主站,D66/五道梁气象站(WDL)、D110、MS3478和MS3608为辅站,对主站缺失的地面气温资料进行插补,以获得完整的气温序列,并以此为基础分析主站近期气温变化。主站和辅站气温一致性分析结果表明,一年中每两个配对站的气温变化均有很好的一致性;温差表现为冬半年大、夏半年小。插补效果分析表明,插补效果夏季比冬季好;插补效果D66站最好,D105站相对较差;插补误差近似服从正态分布,时间尺度越大插补结果的可用性越强;大幅降温、降水、较大风速以及较大风向转变是影响插补效果的主要因素。对主站完整气温序列分析表明,NewD66站的气温年较差最大(26℃),Amdo站最小(19℃);BJ站多年平均气温最高(-0.3℃),D105站最低(-5℃);BJ站处于季节冻土区,其余三站处于多年冻土区;近十几年主站年平均气温均呈波动上升趋势,BJ站和NewD66站升温明显,D105站和Amdo站升温缓慢。     

20世纪全球表面温度场序列的插补试验

利用基于主分量典型相关分析的典型变量回归 (CVR)插补模式 ,在综合分析Jones等 5°× 5°格点温度资料覆盖率的演变情况、缺测场与基本场温度距平相关结构、稳定性的基础上 ,确定合理的插补方案 ,对其陆面格点温度场进行插补延长试验 ,得到了 1 90 0～ 1 998年连续、均一的全球月平均气温场序列。独立样本检验表明插补效果优良 ,总缺测场误差方差与原序列方差之比低于 0 .40。插补前后全球及纬向平均序列的演变特征基本一致 ,原 Jones序列的线性增温率较重建序列高0 .1 1℃ /(1 0 0年 ) ,可能与原 Jones场序列空间分布的不均一性有关     

日平均计算方法对气温统计值的影响

为了弄清不同日平均计算方法对气温统计值的影响,利用陕西6个基准站的定时气温资料分别进行24次观测与4次观测,以及4次与3次观测值计算所得日平均气温计算值的差异分析,并对1961-2010年的3次、4次、24次计算的年平均气温序列进行均一性的惩罚最大F检验(PMFT).结果表明:24次气温定时值计算的日平均气温均值高于4次值,平均差值为0.13℃,标准差为0.39℃,两者差值在秋季较大.4次比3次日平均气温值平均偏低0.14℃,标准差为0.85℃,一年中,夏季差值最大.不同次数的日平均气温计算方法可引起月、年平均气温值0.2℃甚至以上的升降.24次气温值的使用可以使单站的气温增暖速率提高0.03～0.04℃/10a.但日平均气温计算方法的改变不会造成气温序列的非均一.     

基于动态时间规整的气温日值数据二次插补

气温作为研究气候演变最基础的物理量,其日值序列的完整性和准确性对于气候分析与评估工作有着重要意义。近些年随着大量无人值守地面加密自动气象站的布设,不断出现随机站点和随机长度这种双随机特点的气象资料序列缺失,给气候分析和业务应用造成了不小的障碍。针对现有气象数据插补方案的不足,提出了一种全新的基于动态时间规整(dynamic time warping,DTW)的气温日值数据二次插补方法。该方法采用了一种实时的插补策略,主要技术内容包括:1)利用一元线性回归方程将原始气温观测时间序列分解出拟合直线和残差曲线,并将二者重构组成新的气温序列;2)给出了气温插补区的定义和插补条件;3)提出了利用动态时间规整方法计算站点间距离的新模式。利用山东省2021年的气温实况数据对该方法进行了双随机检验,检验结果表明:该方法可以满足日平均气温、日最高气温和日最低气温数据的插补需求;在插补流程中采用DTW距离测度和二次插补的组合方法,其插补效果优于目前常见的基于站点地理临近关系的组合方法;该方法对地形有一定的敏感性,平原或丘陵地区的插补效果要优于山地地区。     

气候要素栅格化技术方法研究

为便于气候资源分析和农作物、果树等农业气候区划,在分辨率为3″×3″栅格图上的每一点都对应相应的气候要素值,利用泰安市及周围19个气象台站1971—2000年的气象资料,采用三维二次趋势面分析与空间插值相结合等方法,在地理信息系统CityStar4·0平台上对泰安市年平均气温、积温等热量资源进行栅格化。结果显示,各项指标通过检验,复相关系数均在0·960以上,F检验值均大于F0·05。年平均气温、1月平均气温和7月平均气温的平均绝对误差均在0·5℃以内;日平均气温T-日≥0℃、T-日≥5℃、T-日≥10℃、T-日≥15℃的积温的相对误差均在5%以下。     

地面气温、湿度埸内插标准误差的分布特征——气象观测站网最佳密度的研究

本文用河北省54个站的日平均温度和日平均绝对湿度资料计算表明, 气温场和湿度场的结构函数和内插标准误差的特征值与两站间距离呈线性相关。 日平均气温的内插标准误差冬季大于夏季, 而日平均绝对湿度的内插标准误差则夏季大于冬季。     

COMPARATIVE ANALYSIS OF VARIOUS DATA OF AIR–SEA TEMPERATURE DIFFERENCE AND ITS VARIATION ACROSS SOUTH CHINA SEA IN THE PAST 35 YEARS

Using the International Comprehensive Ocean-Atmosphere Data Set(ICOADS) and ERA-Interim data, spatial distributions of air-sea temperature difference(ASTD) in the South China Sea(SCS) for the past 35 years are compared,and variations of spatial and temporal distributions of ASTD in this region are addressed using empirical orthogonal function decomposition and wavelet analysis methods. The results indicate that both ICOADS and ERA-Interim data can reflect actual distribution characteristics of ASTD in the SCS, but values of ASTD from the ERA-Interim data are smaller than those of the ICOADS data in the same region. In addition, the ASTD characteristics from the ERA-Interim data are not obvious inshore. A seesaw-type, north-south distribution of ASTD is dominant in the SCS; i.e., a positive peak in the south is associated with a negative peak in the north in November, and a negative peak in the south is accompanied by a positive peak in the north during April and May. Interannual ASTD variations in summer or autumn are decreasing. There is a seesaw-type distribution of ASTD between Beibu Bay and most of the SCS in summer, and the center of large values is in the Nansha Islands area in autumn. The ASTD in the SCS has a strong quasi-3a oscillation period in all seasons, and a quasi-11 a period in winter and spring. The ASTD is positively correlated with the Nio3.4 index in summer and autumn but negatively correlated in spring and winter.     

Could the Recent Taal Volcano Eruption Trigger an El Ni?o and Lead to Eurasian Warming?

正The Taal Volcano in Luzon is one of the most active and dangerous volcanoes of the Philippines. A recent eruption occurred on 12 January 2020(Fig. 1a), and this volcano is still active with the occurrence of volcanic earthquakes. The eruption has become a deep concern worldwide, not only for its damage on local society, but also for potential hazardous consequences on the Earth's climate and environment.     

VARIABILITY OF INTER-ANNUAL RELATIONSHIP BETWEEN INDIAN OCEAN DIPOLE AND HUAXI REGION’S AUTUMN PRECIPITATION

The moving-window correlation analysis was applied to investigate the relationship between autumn Indian Ocean Dipole (IOD) events and the synchronous autumn precipitation in Huaxi region, based on the daily precipitation, sea surface temperature (SST) and atmospheric circulation data from 1960 to 2012. The correlation curves of IOD and the early modulation of Huaxi region’s autumn precipitation indicated a mutational site appeared in the 1970s. During 1960 to 1979, when the IOD was in positive phase in autumn, the circulations changed from a “W” shape to an ”M” shape at 500 hPa in Asia middle-high latitude region. Cold flux got into the Sichuan province with Northwest flow, the positive anomaly of the water vapor flux transported from Western Pacific to Huaxi region strengthened, caused precipitation increase in east Huaxi region. During 1980 to 1999, when the IOD in autumn was positive phase, the atmospheric circulation presented a “W” shape at 500 hPa, the positive anomaly of the water vapor flux transported from Bay of Bengal to Huaxi region strengthened, caused precipitation ascend in west Huaxi region. In summary, the Indian Ocean changed from cold phase to warm phase since the 1970s, caused the instability of the inter-annual relationship between the IOD and the autumn rainfall in Huaxi region.     

A COMPARATIVE ANALYSIS OF ATMOSPHERIC AND OCEANIC CONDITIONS BEFORE THE OCCURRENCE OF TWO TYPES OF EL NIO EVENTS

The atmospheric and oceanic conditions before the onset of EP El Ni?o and CP El Ni?o in nearly 30 years are compared and analyzed by using 850 hPa wind, 20℃ isotherm depth, sea surface temperature and the Wheeler and Hendon index. The results are as follows: In the western equatorial Pacific, the occurrence of the anomalously strong westerly winds of the EP El Ni?o is earlier than that of the CP El Ni?o. Its intensity is far stronger than that of the CP El Ni?o. Two months before the El Ni?o, the anomaly westerly winds of the EP El Ni?o have extended to the eastern Pacific region, while the westerly wind anomaly of the CP El Ni?o can only extend to the west of the dateline three months before the El Ni?o and later stay there. Unlike the EP El Ni?o, the CP El Ni?o is always associated with easterly wind anomaly in the eastern equatorial Pacific before its onset. The thermocline depth anomaly of the EP El Ni?o can significantly move eastward and deepen. In addition, we also find that the evolution of thermocline is ahead of the development of the sea surface temperature for the EP El Ni?o. The strong MJO activity of the EP El Ni?o in the western and central Pacific is earlier than that of the CP El Ni?o. Measured by the standard deviation of the zonal wind square, the intensity of MJO activity of the EP El Ni?o is significantly greater than that of the CP El Ni?o before the onset of El Ni?o.     

IMPACT OF ATMOSPHERIC LOW-FREQUENCY OSCILLATION ON THE IMMIGRATION OF NILAPARVATA LUGENS(STL) IN HUNAN AND JIANGXI PROVINCES

Various features of the atmospheric environment affect the number of migratory insects, besides their initial population. However, little is known about the impact of atmospheric low-frequency oscillation(10 to 90 days) on insect migration. A case study was conducted to ascertain the influence of low-frequency atmospheric oscillation on the immigration of brown planthopper, Nilaparvata lugens(Stl), in Hunan and Jiangxi provinces. The results showed the following:(1) The number of immigrating N. lugens from April to June of 2007 through 2016 mainly exhibited a periodic oscillation of 10 to 20 days.(2) The 10-20 d low-frequency number of immigrating N. lugens was significantly correlated with a low-frequency wind field and a geopotential height field at 850 h Pa.(3) During the peak phase of immigration, southwest or south winds served as a driving force and carried N. lugens populations northward, and when in the back of the trough and the front of the ridge, the downward airflow created a favorable condition for N. lugens to land in the study area. In conclusion, the northward migration of N. lugens was influenced by a low-frequency atmospheric circulation based on the analysis of dynamics. This study was the first research connecting atmospheric low-frequency oscillation to insect migration.     

全球贸易隐含碳变化及其影响分析

基于最新的GTAP8 (Global Trade Analysis Project）数据库,使用投入产出法,分析了2004年到2007年全球贸易变化下南北集团贸易隐含碳变化及对全球碳排放的影响。结果显示,随着发展中国家进出口规模扩张,全球贸易隐含碳流向的重心逐渐向发展中国家转移。2004年到2007年,发达国家高端设备制造业和服务业出口以及发展中国家资源、能源密集型行业及中低端制造业出口的趋势加强,该过程的生产转移导致全球碳排放增长4.15亿t,占研究时段全球贸易隐含碳增量的63%。未来发展中国家的出口隐含碳比重还将进一步提高。贸易变化带来的南北集团隐含碳流动变化对全球应对气候变化行动的影响日益突出,发达国家对此负有重要责任。     

Analysis of Atmospheric Boundary Layer Height Characteristics over the Arctic Ocean Using the Aircraft and GPS Soundings

正ERRATUM to: Atmospheric and Oceanic Science Letters, 4(2011), 124-130 On page 126 of the printed edition (Issue 2, Volume 4), Fig. 2 was a wrong figure because the contact author made mistake giving the wrong one. The corrected edition has been updated on our website. The editorial office is sincerely sorry for any     

Index to Vol.31

正AN Junling;see LI Ying et al.;(5),1221—1232AN Junling;see QU Yu et al.;(4),787-800AN Junling;see WANG Feng et al.;(6),1331-1342Ania POLOMSKA-HARLICK;see Jieshun ZHU et al.;(4),743-754Baek-Min KIM;see Seong-Joong KIM et al.;(4),863-878BAI Tao;see LI Gang et al.;(1),66-84BAO Qing;see YANG Jing et al.;(5),1147—1156BEI Naifang;     

Information for Contributors

正Journal of Meteorological Research is an international academic journal in atmospheric sciences edited and published by Acta Meteorologica Sinica Press,sponsored by the Chinese Meteorological Society.It has been acting as a bridge of academic exchange between Chinese and foreign meteorologists and aiming at introduction of the current advancements in atmospheric sciences in China.The journal columns include Articles.Note and Correspondence,and research letters.Contributions from all over the world are welcome.