水稻观测应注意的几个问题

水稻观测应注意的几个问题匡昭敏（玉林地区气象局５３７０００）１９９４年下半年开始实施执行的新的《农业气象观测规范》与原来的规范有一定差别，其中有一些技术要求作了改变，另外还增加了一部分新的观测项目，由于对以前观测的习惯性和对新增内容的生疏，故在观测过...     

水稻物候观测中易出现的错情及解决方法

通过审核广西1994—2007年早、晚稻物候观测记录,以及早晚稻物候观测记录年报表,统计出现的各种错情,发现错情主要表现在:发育期观测,产量结构分析,农业气象灾害、病虫害的观测和调查,观测记录簿表填写,以及水稻物候期观测记录错误分析。各种错情出现的主要原因是没有深刻理解、熟记《农业气象观测规范》中的规定,没有熟练掌握补充规定和有关技术规定,文章提出了减少和消除错情的技术方法,旨在进一步提高水稻物候期观测业务的质量。     

水稻拔节观测方法对比试验

由国家气象局编定、气象出版社1993年6月出版的《农业气象观测规范》^[1]中没有明确规定水稻拔节（茎基部茎节开始生长,形成有显著茎杆的茎节为拔节）的观测方法,造成观测标准不统一^[2],农气人员在实际操作中惯常用手触摸水稻茎基部,通过手感觉水稻的第一个节是否形成以及拔节的高度,来判断水稻是否进入拔节期。     

对《农业气象观测规范》(上卷)中若干技术问题的商榷

由原国家气象局编定,气象出版社出版的《农业气象观测规范》（以下简称《规范》已在全国各地农业气象（候）试验站正式执行。这套《规范》对指导基层农气（试）站的农业气象观测、统一观测程序和方法等方面发挥了重要作用。笔者在实际工作中,发现这套规范还存在着一些错漏或不甚严密的地方。由于业务范围所限,笔者仅就《规范》(上卷)中的棉、稻、麦、物候和土壤湿度等内容予以讨论。     

正确理解新版《地面气象观测规范》风观测规定

新版《地面气象观测规范》(以下简称《规范》)已从2004年1月开始执行。与1979年版旧《规范》相比，对风要素的观测，从概念、记录方法到数据处理都作了修改。这是为适应气象观测现代化和自动气象站业务需要而作的调整。只有准确理解风要素的相关概念和观测、记录、处理规定，才能在工作中自觉执行，从而获得具有代表性、准确性和比较性的风观测记录。     

作物观测经验一得

作物观测是农业气象的重要业务工作。各级业务部门要求观测员努力认真学习《农业气象观测规范》各种业务技术规定,掌握熟记各项业务技术规定,做好作物观测工作,按时完成编发工作,坚决不出或少出错情。但是,《农业气象观测规范》各种业务技术规定,对作物观测的标准、项目、内容、方法的规定千头万绪,繁杂多变。     

浅谈新《地面气象观测规范》学习和使用体会

对新《地面气象观测规范》中关于观测项目及数据记录应注意的问题进行了介绍,并对新规范中异常记录的处理进行了分析。     

对农作物高度测量的几点建议

对农作物高度测量的几点建议植株高度是衡量作物生长速度的标志之一，是农作物生长状况测定的一个主要方面，农业气象条件对其影响极其显著；新的《农业气象观测规范》对原《农业气象观测方法》中高度观测作了较大修订，减少了观测次数，使之更科学。通过一年多的实际观测...     

一般站最小能见度的记法

为了适应沙尘天气预报服务的需要，新版《地面气象观测规范》新增了地面状态、最小能见度以及草面(雪面)温度观测等项目。根据新规定，最小能见度观测是我省所有台站均需观测的项目，但并未明确一般站的记录方法，因此一般站如何按照新版《地面气象观测规范》的要求作好观测记录，就成为广大测报人员在学习新版《地面气象观测规范》时的一个重点。     

一般站最小能见度的记法

为了适应沙尘天气预报服务的需要,新版《地面气象观测规范》新增了地面状态、最小能见度以及草面(雪面)温度观测等项目。根据新规定,最小能见度观测是我省所有台站均需观测的项目,但并未明确一般站的记录方法,因此一般站如何按照新版《地面气象观测规范》的要求作好观测记录,就成为广大测报人员在学习新版《地面气象观测规范》时的一个重点。

     

CHARACTERISTICS AND TRENDS OF CLIMATIC EXTREMES IN CHINA DURING 1959–2014

The spatial and temporal variations of daily maximum temperature(Tmax), daily minimum temperature(Tmin), daily maximum precipitation(Pmax) and daily maximum wind speed(WSmax) were examined in China using Mann-Kendall test and linear regression method. The results indicated that for China as a whole, Tmax, Tmin and Pmax had significant increasing trends at rates of 0.15℃ per decade, 0.45℃ per decade and 0.58 mm per decade,respectively, while WSmax had decreased significantly at 1.18 m·s~(-1) per decade during 1959—2014. In all regions of China, Tmin increased and WSmax decreased significantly. Spatially, Tmax increased significantly at most of the stations in South China(SC), northwestern North China(NC), northeastern Northeast China(NEC), eastern Northwest China(NWC) and eastern Southwest China(SWC), and the increasing trends were significant in NC, SC, NWC and SWC on the regional average. Tmin increased significantly at most of the stations in China, with notable increase in NEC, northern and southeastern NC and northwestern and eastern NWC. Pmax showed no significant trend at most of the stations in China, and on the regional average it decreased significantly in NC but increased in SC, NWC and the mid-lower Yangtze River valley(YR). WSmax decreased significantly at the vast majority of stations in China, with remarkable decrease in northern NC, northern and central YR, central and southern SC and in parts of central NEC and western NWC. With global climate change and rapidly economic development, China has become more vulnerable to climatic extremes and meteorological disasters, so more strategies of mitigation and/or adaptation of climatic extremes,such as environmentally-friendly and low-cost energy production systems and the enhancement of engineering defense measures are necessary for government and social publics.     

ANALYSIS OF “BIMODAL PATTERN” STORM ACTIVITY CHARACTERISTICS OF THE BAY OF BENGAL

Storms that occur at the Bay of Bengal (BoB) are of a bimodal pattern, which is different from that of the other sea areas. By using the NCEP, SST and JTWC data, the causes of the bimodal pattern storm activity of the BoB are diagnosed and analyzed in this paper. The result shows that the seasonal variation of general atmosphere circulation in East Asia has a regulating and controlling impact on the BoB storm activity, and the “bimodal period” of the storm activity corresponds exactly to the seasonal conversion period of atmospheric circulation. The minor wind speed of shear spring and autumn contributed to the storm, which was a crucial factor for the generation and occurrence of the “bimodal pattern” storm activity in the BoB. The analysis on sea surface temperature (SST) shows that the SSTs of all the year around in the BoB area meet the conditions required for the generation of tropical cyclones (TCs). However, the SSTs in the central area of the bay are higher than that of the surrounding areas in spring and autumn, which facilitates the occurrence of a “two-peak” storm activity pattern. The genesis potential index (GPI) quantifies and reflects the environmental conditions for the generation of the BoB storms. For GPI, the intense low-level vortex disturbance in the troposphere and high-humidity atmosphere are the sufficient conditions for storms, while large maximum wind velocity of the ground vortex radius and small vertical wind shear are the necessary conditions of storms.     

LOW-FREQUENCY CIRCULATION AND EXTENDED-RANGE FORECAST IN CONNECTION WITH AUTUMN EXTREME HEAVY RAINFALL PROCESS IN HAINAN

Observed daily precipitation data from the National Meteorological Observatory in Hainan province and daily data from the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis-2 dataset from 1981 to 2014 are used to analyze the relationship between Hainan extreme heavy rainfall processes in autumn (referred to as EHRPs) and 10–30 d low-frequency circulation. Based on the key low-frequency signals and the NCEP Climate Forecast System Version 2 (CFSv2) model forecasting products, a dynamical-statistical method is established for the extended-range forecast of EHRPs. The results suggest that EHRPs have a close relationship with the 10–30 d low-frequency oscillation of 850 hPa zonal wind over Hainan Island and to its north, and that they basically occur during the trough phase of the low-frequency oscillation of zonal wind. The latitudinal propagation of the low-frequency wave train in the middle-high latitudes and the meridional propagation of the low-frequency wave train along the coast of East Asia contribute to the ‘north high (cold), south low (warm)’ pattern near Hainan Island, which results in the zonal wind over Hainan Island and to its north reaching its trough, consequently leading to EHRPs. Considering the link between low-frequency circulation and EHRPs, a low-frequency wave train index (LWTI) is defined and adopted to forecast EHRPs by using NCEP CFSv2 forecasting products. EHRPs are predicted to occur during peak phases of LWTI with value larger than 1 for three or more consecutive forecast days. Hindcast experiments for EHRPs in 2015–2016 indicate that EHRPs can be predicted 8–24 d in advance, with an average period of validity of 16.7 d.     

AN ATTRIBUTION ANALYSIS OF CHANGES IN POTENTIAL EVAPOTRANSPIRATION IN THE BEIJING–TIANJIN–HEBEI REGION UNDER CLIMATE CHANGE

Based on the measurements obtained at 64 national meteorological stations in the Beijing–Tianjin–Hebei (BTH) region between 1970 and 2013, the potential evapotranspiration (ET0) in this region was estimated using the Penman–Monteith equation and its sensitivity to maximum temperature (Tmax), minimum temperature (Tmin), wind speed (Vw), net radiation (Rn) and water vapor pressure (Pwv) was analyzed, respectively. The results are shown as follows. (1) The climatic elements in the BTH region underwent significant changes in the study period. Vw and Rn decreased significantly, whereas Tmin, Tmax and Pwv increased considerably. (2) In the BTH region, ET0 also exhibited a significant decreasing trend, and the sensitivity of ET0 to the climatic elements exhibited seasonal characteristics. Of all the climatic elements, ET0 was most sensitive to Pwv in the fall and winter and Rn in the spring and summer. On the annual scale, ET0 was most sensitive to Pwv, followed by Rn, Vw, Tmax and Tmin. In addition, the sensitivity coefficient of ET0 with respect to Pwv had a negative value for all the areas, indicating that increases in Pwv can prevent ET0 from increasing. (3) The sensitivity of ET0 to Tmin and Tmax was significantly lower than its sensitivity to other climatic elements. However, increases in temperature can lead to changes in Pwv and Rn. The temperature should be considered the key intrinsic climatic element that has caused the "evaporation paradox" phenomenon in the BTH region.     

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.     

Revisiting the Concentration Observations and Source Apportionment of Atmospheric Ammonia

正While China’s Air Pollution Prevention and Control Action Plan on particulate matter since 2013 has reduced sulfate significantly, aerosol ammonium nitrate remains high in East China. As the high nitrate abundances are strongly linked with ammonia, reducing ammonia emissions is becoming increasingly important to improve the air quality of China. Although satellite data provide evidence of substantial increases in atmospheric ammonia concentrations over major agricultural regions, long-term surface observation of ammonia concentrations are sparse. In addition, there is still no consensus on     

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.     

Information for Authors

正AIMS AND SCOPE Atmospheric and Oceanic Science Letters (AOSL) publishes short research letters on all disciplines of the atmosphere sciences and physical oceanography. Contributions from all over the world are welcome.SUBMISSIONAll submitted     

Information for Authors

AIMS AND SCOPE Atmospheric and Oceanic Science Letters （AOSL） pub- lishes short research letters on all disciplines of the atmos- phere sciences and physical oceanography. Contributions from all over the world are welcome.