The emergence of mutant strains such as Omicron has increased the uncertainty of COVID-19, and all countries have taken strict measures to prevent the spread of the disease. The spread of the disease between countries is of particular concern. However, most COVID-19 research focuses mainly on the country or community, and there is less research on the border areas between two countries. In this study, we analyzed changes in the total nighttime light intensity (TNLI) and total nighttime lit area (TNLA) along the Sino-Burma border and used the data to construct an epidemic pressure input index (PII) model in reference to the Shen potential model. The results show that, as the epidemic became more severe, TNLI on both sides of the border at the Ruili border port increased, while that in areas far from the port decreased. At the same time, increases and decreases in TNLA occurred in areas far from the port, and PII can indicate the areas where imported cases are likely to occur. Along the Sino-Burma border, the PII model showed low PII in the north and south and high PII in the central region. The areas between Dehong and Lincang, especially the Ruili, Wanding, Nansan, and Qingshuihe border ports, had high PII. The results of this study offer a reference for public health officials and decision makers when determining resource allocation and the implementation of stricter quarantine rules. With updated epidemic statistics, PII can be recalculated to support timely monitoring of COVID-19 in border areas.

2013年10月6-7日台风"菲特"和台风"丹娜丝"影响中国东部,造成区域性大暴雨.利用客观分离方法及数值模拟两种方法辨别两个台风在不同阶段各自的作用.结果表明,对于10月6日区域性大暴雨,客观分离结果和数值模拟结果一致,被识别为主要由台风"菲特"造成的降水.对于10月7日江苏东南部、浙江东北部的区域性大暴雨,客观分离结果表明,两个台风都起到了关键性作用;模式模拟结果表明,强降水与台风"菲特"有直接关联,而与台风"丹娜丝"作用不大.锋生函数也表明,冷空气对强降水也起到了一定的作用.

A principal component stepwise regression prediction model of climatic field for the flood period rainfall in Fujian Province is established.The model predicts the precipitation of flood period in Fujian through predicting the principal component of the climatic field of that period.This study takes the 500hPa height and the sea surface temperature of Pacific Ocean and the sea-level pressure in the Northern Hemisphere and many principal component factors in various seasons and regions as predictors,calculating and analyzing the distribution and types of the principal components of the flood period rainfall in Fujian.Through correlation screening and double test stepwise regression,a prediction equation is developed for the principal component of the Fujian flood period rainfall.By applying this model to predicting the flood period precipitation in Fujian in 2012,it is found that the model is capable to predict the precipitation and its distribution in the flood period in Fujian.

Utilizing the NCEP/NCAR reanalysis data,the characteristics of annual south wind over East Asia are investigated.And it is discovered that a key area(22.5°—30°N,105°—110°E) where the south wind prevails all the year is over the southeast of the Tibetan Plateau.The south wind is strong in summer and weak in winter,showing a double peak.A peak occurs in the 15th pentad and the other peak occurs in the 37th pentad.Further research found that there is a good relationship between the south wind on the southeast of Tibetan Plateau and the spring precipitation in southern China.In the 15th pentad,the south wind on the southeast of Tibetan Plateau becomes stronger and expands eastwardly,and then the rainfall in the south of China becomes heavy.The occurring reason for the two peaks of the south wind is different. The south wind peak occurring in the 15th pentad is for a low-level cyclone caused by the Tibetan Plateau heating superimposed over the south wind.It causes the south wind stronger,and then South China comes into rainy period.The south wind peak occurring in the 37 th pentad is while the South China Sea monsoon broke out,the southwest wind in front of the Bay of Bengal trough intensifies the south wind. And then it brings about the rain over the Yangtze River.

该文利用厦门市1954-2010年共57年逐日地面气象观测资料,分析厦门市灰霾天气特征,找出影响因子;通过与金门气象资料的对比,分析厦门市热岛与干岛效应的变化规律.结果表明:厦门市灰霾日数总体呈上升趋势.20世纪90年代以前灰霾日数变化不大,90年代以后呈波动性上升.厦门市灰霾日数与气温、湿度有密切联系.气温越高,湿度越低,造成热岛和干岛效应越强,灰霾日越多.厦门热岛效应有逐年升高的趋势,春季热岛效应最强,秋季热岛效应最弱;干岛效应强度从2005年起都为负值,且逐年加强,夏季最显著,冬季最弱.

The landfalling tropical cyclone precipitation(TCP) during 3 d after its weakening is partitioned from the 101 landfalling TCs from 1965 to 2008 with the Objective Synoptic Analysis Technique and its improvement programs.The results show that,even if the landfalling TCs attenuate to a tropical depression or tend to be dead,high-intensity rainfall caused by the presence of the typhoon system is universal phenomenon.So it still requires a high degree of concern.The climate characteristics of TCP and TCs were analyzed with trend coefficient and power spectrum technique.The spatial distribution of TCs' weakening spots shows great regionalization,which is obviously consistent with terrain.The volume of landfalling weakened TCP does not monotonously decrease with time,and the distribution of TCP spreads westward and northward.Especially,more emphasis should be paid on precipitation from Jiang-Han to Jiang-Huai area in middle-latitude,which is the point to reduce and prevent disasters.The TC tracks of landfalling south and east China should be focused on,in order to limit the damage caused by landfalling weakened TCs.

Utilizing the NECP/NCAR reanalysis data,the annual atmospheric circulation over East Asia from 1981 to 2000 is investigated.It is discovered that a zonal positive vorticity belt maintains on the south side of Tibetan Plateau(TP),due to the interaction of the Plateau boundary layer and its neighboring free atmosphere.Particularly,there is an obvious topographic trough related to the positive vorticity near 90°E.In light of this,a Tibetan Plateau Topographic Trough Index(TPTTI) is defined in the paper over the key areas(80°~90°E,23°~26°N).The index is proved to be effective in distinguishing between the characteristic of the (TPTT) and that of the Bay of Bengal Trough(BBT).The annual variation of the TPTT is closely related to the Plateau heating source,and the former significant abrupt changes during April and June might be primarily induced by the seasonal sudden jump of the latter.In winter,the low-level anticyclone caused by the Tibetan Plateau cooling is strengthened and superimposes the westerly wind that should have been strengthened by dynamic effect,which weakens the TPTT.However,in summer,the low-level cyclone resulting from the TP heating strengthens the circumferential westerly and deepens the TPTT.Further investigations indicate that there is a considerable relationship between the South China Sea summer monsoon(SCSSM) onset and the evolution of the TPTT and the BBT.The TPTT propagates southward and the vortex near Sir Lanka moves northward continuously,till they meet and interact over the Bay of Bengal(BB).This is the direct process of the subtropical high belt splitting initially over BB and the establishment of the BBT.Subsequently,the southwesterly wind becomes stronger and promotes the eastward retreat of subtropical high,causing the SCSSM bursts over the whole South China Sea.

Utilizing the NECP/NCAR reanalysis data, the annual atmospheric circulation over East Asia from 1981 to 2000 is investigated. It is discovered that a zonal positive vorticity belt maintains to the south of Tibetan Plateau, due to the interaction of the plateau boundary layer and its neighboring free atmosphere. Particularly, there is an obvious topographic trough related to the positive vorticity near 90°E. According to this phenomenon, a Tibetan Plateau Topographic Trough Index (TPTTI) is defined in the paper over the key areas (80-90°E, 25°N). The index is proved to be effective in distinguishing between the characteristic of the Tibetan Plateau topographic trough (TPTT) and that of the Bay of Bengal Trough (BOBT). The annual variation of the TPTT is closely related to the plateau heating source, and the former's significant abrupt changes during April and June might be primarily induced by the seasonal sudden jump of the latter. In winter, the low-level anticyclone caused by the Tibetan plateau cooling is strengthened and superimposes the westerly wind that should have been strengthened by dynamic effect, which weakens the TPTT. However, in summer, the low-level cyclone resulting from the Tibetan plateau heating strengthens the circumferential westerly and deepens the TPTT. Further investigations indicate that there is a considerable relationship between the South China Sea summer monsoon onset and the evolution of the TPTT and the BOBT. The TPTT propagates southward and the vortex near Sir Lanka moves northward continuously, till they meet and interact over the Bay of Bengal. This is the direct process of the subtropical high belt splitting initially over Bay of Bengal and the establishment of the BOBT. Subsequently, the southwesterly wind becomes stronger and promotes the eastward retreat of subtropical high, causing the South China Sea summer monsoon bursts over the whole South China Sea.