Assimilating FY-4A AGRI Radiances with a Channel-Sensitive Cloud Detection Scheme for the Analysis and Forecasting of Multiple Typhoons

This paper presents an attempt at assimilating clear-sky FY-4A Advanced Geosynchronous Radiation Imager(AGRI)radiances from two water vapor channels for the prediction of three landfalling typhoon events over the West Pacific Ocean using the 3DVar data assimilation(DA)method along with the WRF model.A channel-sensitive cloud detection scheme based on the particle filter(PF)algorithm is developed and examined against a cloud detection scheme using the multivariate and minimum residual(MMR)algorithm and another traditional cloud mask–dependent cloud detection scheme.Results show that both channel-sensitive cloud detection schemes are effective,while the PF scheme is able to reserve more pixels than the MMR scheme for the same channel.In general,the added value of AGRI radiances is confirmed when comparing with the control experiment without AGRI radiances.Moreover,it is found that the analysis fields of the PF experiment are mostly improved in terms of better depicting the typhoon,including the temperature,moisture,and dynamical conditions.The typhoon track forecast skill is improved with AGRI radiance DA,which could be explained by better simulating the upper trough.The impact of assimilating AGRI radiances on typhoon intensity forecasts is small.On the other hand,improved rainfall forecasts from AGRI DA experiments are found along with reduced errors for both the thermodynamic and moisture fields,albeit the improvements are limited.

AGRIS

AGRIS(The Agricultural Sciences and Technology)is a booklist-style international agricultural database which is established by the international agricultural technology information system subordinate to FAO.It embodies continued publications,documents,corpuses,books,technology reports,patents,maps,meeting papers,and other literatures,which are collected by 135 countries and regions,146 branches of AGRIS,and 22 international organizations.Its content comprises all the agricultural fields in the world,as well as forestry,economy,aquatic sciences,fishery,human dietetics,and so on.This database is an international intelligence communication system maintained by FAO,which updates quarterly and increases by 0.13 million records annually,with large data amount.

AGRIS

AGRIS(The Agricultural Sciences and Technology)is a booklist-style international agricultural database which is established by the international agricultural technology information system subordinate to FAO.It embodies continued publications,documents,corpuses,books,technology reports,patents,maps,meeting papers,and other literatures,which are collected by 135 countries and regions,146 branches of AGRIS,and 22 international organizations.

FY-4A/AGRI海表温度产品和质量检验

风云四号气象卫星A星(FY-4A)是我国第2代静止气象卫星首发星,搭载的先进静止轨道辐射成像仪AGRI是迄今为止我国静止轨道最先进的辐射成像仪。海表温度产品是FY-4A/AGRI基础定量产品之一,采用非线性海表温度算法在业务系统实时反演得到。以现场实测海表温度数据为参考,选择观测时间为30 min、观测空间距离为4 km的时空匹配窗口,对FY-4A/AGRI海表温度产品进行质量检验,评估结果表明:质量为优的像元平均偏差为-0.45~-0.42℃,标准差为0.81~0.88℃,相关系数在0.985以上。以Himawari-8/AHI海表温度数据为参考,按观测时间为1 h、空间距离为4 km的时空匹配窗口,对FY-4A/AGRI海表温度进行质量检验,质量为优的像元平均偏差为-0.26~-0.07℃,标准差为0.68~0.82℃,两者相关系数在0.985以上,达到0.001显著性水平。

AGRIS

AGRIS(The Agricultural Sciences and Technology)is a booklist-style international agricultural database which is established by the international agricultural technology information system subordinate to FAO.It embodies continued publications,documents,corpuses,books,technology reports,patents,maps,meeting papers,and other literatures,which are collected by 135 countries and regions,146 branches of AGRIS。

基于朴素贝叶斯的FY-4A/AGRI云检测方法

光学遥感云检测是定量遥感和遥感应用的基础,尝试将朴素贝叶斯的机器学习方法应用于风云四号气象卫星A星(FY-4A)搭载的先进静止轨道辐射成像仪(AGRI)红外通道数据云检测。因辐射物理方法的云检测采用可见光通道导致存在日夜不连续现象,仅选取FY-4A/AGRI载荷7个红外通道的光谱数据,构建10种特征分类,利用正交偏振云-气溶胶激光雷达(CALIOP)与FY-4A/AGRI时空匹配数据,对不同地表类型和不同季节的数据集进行分类训练和验证。与CALIOP数据交叉验证显示除积雪上空云识别准确率约为81%,深海、浅水、陆地和荒漠上空的云识别准确率均高于92%,误判率基本低于10%,总体云识别精度达到90%;与2021年10月和2022年1,4,7月MODIS 2级云检测产品比对,深海、浅水云识别准确率均在88%以上,误判率分别低于3%和10%,夏季云识别效果最佳,总体云识别准确率高达90%。云检测结果不仅得到云、可能云、可能晴空和晴空4种分类结果,还得到每种特征和综合特征云检测分类器的不确定性概率值,这为云和地表相关检测产品提供重要参考。

Assimilation of the FY-4A AGRI Clear-Sky Radiance Data in a Regional Numerical Model and Its Impact on the Forecast of the“21·7”Henan Extremely Persistent Heavy Rainfall

Assimilation of the Advanced Geostationary Radiance Imager(AGRI)clear-sky radiance in a regional model is performed.The forecasting effectiveness of the assimilation of two water vapor(WV)channels with conventional observations for the“21·7”Henan extremely heavy rainfall is analyzed and compared with a baseline test that assimilates only conventional observations in this study.The results show that the 24-h cumulative precipitation forecast by the assimilation experiment with the addition of the AGRI exceeds 500 mm,compared to a maximum value of 532.6 mm measured by the national meteorological stations,and that the location of the maximum precipitation is consistent with the observations.The results for the short periods of intense precipitation processes are that the simulation of the location and intensity of the 3-h cumulative precipitation is also relatively accurate.The analysis increment shows that the main difference between the two sets of assimilation experiments is over the ocean due to the additional ocean observations provided by FY-4A,which compensates for the lack of ocean observations.The assimilation of satellite data adjusts the vertical and horizontal wind fields over the ocean by adjusting the atmospheric temperature and humidity,which ultimately results in a narrower and stronger WV transport path to the center of heavy precipitation in Zhengzhou in the lower troposphere.Conversely,the WV convergence and upward motion in the control experiment are more dispersed;therefore,the precipitation centers are also correspondingly more dispersed.

基于FY-4A AGRI数据研究2023-02-06土耳其地震水汽异常变化

首先利用探空数据对风云四号气象卫星A星(FY-4A)先进的静止轨道辐射成像仪(AGRI)提供的水汽产品进行精度验证;然后利用AGRI获取2023-02-06土耳其地震震中区域水汽、陆表温度和降水估计的时间序列,并对水汽异常变化特征进行分析。结果表明:1) AGRI水汽和探空水汽的相关系数为0.90,RMSE和平均bias分别为2.51 mm和-0.06 mm;2)临震时,AGRI水汽方差上升至0.029-0.156 mm,波动加剧;震后,AGRI水汽出现一个明显的陡升-陡降过程;3)基于AGRI陆表温度和降水估计,推断出现水汽异常变化的原因可能是地震后地面热作用增加使得水汽上升,在峰值时形成降水,导致水汽急剧下降。

AGRIS

AGRIS(The Agricultural Sciences and Technology)is a booklist-style international agricultural database which is established by the international agricultural technology information system subordinate to FAO.It embodies continued publications,documents,corpuses,books,technology reports,patents,maps,meeting papers,and other literatures,which are collected by 135 countries and regions,146 branches of AGRIS,and 22 international organizations.Its content comprises all the agricultural fields in the world,as well as forestry,economy,aquatic sciences,fishery,human dietetics,and so on.This database is an international intelligence communication system maintained by FAO,which updates quarterly and increases by 0.13 million records annually,with large data amount.

AGRIS

AGRIS(The Agricultural Sciences and Technology)is a booklist-style international agricultural database which is established by the international agricultural technology information system subordinate to FAO.It embodies continued publications,documents,corpuses,books,technology reports,patents,maps,meeting papers,and other literatures,which are collected by 135 countries and regions,146 branches of AGRIS,and 22 international organizations.Its content comprises all the agricultural fields in the world,as well as forestry,economy,aquatic sciences,fishery,human dietetics,and so on.This database is an international intelligence communication system maintained by FAO,which updates quarterly and increases by 0.13 million records annually,with large data amount.

AGRIS

AGRIS(The Agricultural Sciences and Technology)is a booklist-style international agricultural database which is established by the international agricultural technology information system subordinate to FAO.It embodies continued publications,documents,corpuses,books,technology reports,patents,maps,meeting papers,and other literatures,which are collected by 135 countries and regions,146 branches of AGRIS,and 22 international organizations.Its content comprises all the agricultural fields in the world,as well as forestry,economy,aquatic sciences,fishery,human dietetics,and so on.This database is an international intelligence communication system maintained by FAO,which updates quarterly and increases by 0.13 million records annually,with large data amount.

CABI、AGRICOLA和AGRIS数据库比较研究

本文对美国银盘公司检索系统webspirs下的CABI、AGRICOLA和AGRIS三个数据库从文献收录数量、质量、语种和重复情况等方面进行比较研究,对选择订购和文献检索有一定的参考价值。

CABI、AGRICOLA和AGRIS数据库比较研究

对美国银盘公司检索系统webspirs下的三大农业数据库 ,CABI、AGRICOLA和AGRIS进行比较研究发现 :三个数据库在文献收录数量 ,收录内容和语种等方面存在显著差异。对植物、动物、饲料、肥料和灌溉五大类代表文献的检索结果显示 :AGRIS在文献总量上占优势 ,但从近 10年检索结果来看 ,CABI则在文献收录量上领先。从收录文献的语种来看 ,AGRICOLA以英语为主 ,其次是法语、俄语 ,CABI和AGRIS除英语外 ,还收录较多的汉语和法语文献。从收录文献的类型来看 ,三个数据库均以期刊文献为主 ,但各具特色 ,如CABI以收录会议论文、图书、技术报告见长 ,A GRIS除会议文献外 ,还收录较多的单行本、学位论文、书目和数据库文献 ,AGRICOLA除单行本和书目外 ,还收录一定量的参考工具书。比较结果显示 3个数据库都存在不同程度的重复 ,重复率在2 0 %～ 6 0 %。对数据库收录文献的质量、数量综合比较显示 :CABI最优 ,其次是AGRIS和AGRI COLA。

2%Agri-Terra颗粒剂防治番茄根结线虫

用2%Agri-Terra颗粒剂(有效成分:海藻酸丙二酯)温室处理土壤防治番茄根结线虫试验表明:2%Agri-Terra颗粒剂可较好地控制番茄根结线虫危害。2%Agri-Terra颗粒剂22.5、30.0、37.5kg/hm2三个处理,药后90d土壤中2龄幼虫数量减退率分别为75.67%、77.13%、84.42%,而对照药剂1.8%阿维菌素乳油15.0L/hm2处理的线虫减退率为75.88%。药后90d,2%Agri-Terra颗粒剂各处理防治效果分别为58.63%、66.91%、80.75%,而对照药剂为61.79%。2%Agri-Terra颗粒剂可有效地控制番茄根结线虫的危害,有较高的推广应用价值。

Agri-star松土促根剂对烤烟生长发育及经济性状的影响

采用大田对比试验,以中烟100为材料,研究了Agri-star松土促根剂对烤烟生长发育、主要病害及经济性状的影响。结果表明,与不施松土促根剂相比,施用Agri-star松土促根剂处理烟株的农艺性状均有提高,移栽后45 d,株高增加4.4 cm,茎围增加0.26 cm,叶片数增加0.8片,叶面积增加184.1 cm2,其中叶面积提高最明显;降低了烟草花叶病和气候斑点病的发病率,二者分别下降14.3、7.5个百分点,提高了烟株的抗病能力;增加了烟株根、茎、叶干物质质量和根系体积,促进了根系发育;使得烟叶的经济性状有了明显提高。

Agri-50E对温室白粉虱防治效果

采用茎叶喷雾法,测试了Agri-50E对温室番茄白粉虱的作用。结果表明,间隔14d两次施药,第一次药后3、28d,2.5、3.33、5L/hm2处理对白粉虱的防效在55%～68.9%、71%～85.7%、80%～91.3%;对照药剂10%吡虫啉90ga.i./hm2,防效54%～63.3%。Agri-50E防效和速效性都好于吡虫啉。

新型杀线虫剂Agri-Terra防治黄瓜根结线虫(Meloidogyne incognita)的效果

Agri-Terra是由美国加州农产品有限公司(CAL AGRI PRODUCTS LLC)研制开发的无机环保型杀线虫剂。通过温室小区试验研究测定了Agri-Terra对黄瓜根结线虫病的防治作用。结果表明,Agri-Terra能减少南方根结线虫(Meloidogyne incognita)对黄瓜的侵染,显著地降低黄瓜根结指数和土壤中二龄幼虫的数量。药后90 d,二龄幼虫虫口相对减退率最高达81.8%,相对防效为72.1%(病指由94.0%降低到26.2%),二者均显著高于对照药剂阿维菌素(虫口减退率23.7%、相对防效9.5%)。此外,试验中还发现Agri-Terra具有促进植株生长效果,处理区植株产量比对照增加46.2%;而对照药剂阿维菌素增产率仅为9.2%。Agri-Terra可有效地控制黄瓜根结线虫的危害,有较高的推广应用价值。

世界农业文献数据库AGRIS中云南农业大学科技论文分析

对云南农业大学科技论文被录入国外农业文献数据库ＡＧＲＩＳ的情况进行统计，并分析所录用论文的学科、作者、期刊的分布等。

利用Internet网络免费使用AGRIS数据库的方法

AGRIS数据库是世界上农业文献检索的三大农业数据库之一 。

AGRIS

AGRIS (The Agricultural Sciences and Technology) is a booklist-style international agricultural database which is established by the international agricultural technology information system subordinate to FAO. It embodies continued publications, documents, corpuses, books, technology reports, patents, maps, meeting papers, and other literatures, which are collected by 135 countries and regions, 146 branches of AGRIS, and 22 international organizations.