摘要
为了探明褐飞虱灾变性迁入的大气动力学机制,根据2006年全国逐日褐飞虱灯诱资料和逐日北半球气象再分析资料,在Arc-GIS9.0中对2006年8月26-28日发生在中国东部稻区的一次褐飞虱重大迁入过程进行了空间分析。在此基础上,利用高时空分辨率的中尺度天气预报模式(WRF)对这次迁飞过程的大气背景进行了数值模拟,从模拟输出的大气背景中选取最能反映大气动力特征的4个物理量场:水平流场、K指数场、A指数场和涡度场进行分析。结果发现:(1)850hPa高度的水平流场能够准确地反映褐飞虱空中种群的主要迁飞方向。(2)在主要降虫时段内,K指数、A指数在表征大气不稳定程度的同时,也可以定性地反映出褐飞虱降虫的主要区域。当K≥35℃或A≥10℃,或者两个指标同时满足时,有利于区内大气垂直运动的发展,对褐飞虱的升降十分有利。(3)褐飞虱种群大量迁入前,降虫区850hPa等压面上或强或弱地表现为一致的负涡度区,表明有一定强度的下沉气流存在,这对降虫比较有利。
In order to reveal the atmospheric dynamic mechanisms of the catastrophic immigration of the Brown Plant Hopper （Nilaparvata lugens Stal） , a great migration event of the Brown Plant Hopper occurred on 26th to 28th Aug. , 2006 in the rice production areas of the Eastern China was taken as a case and the temporal-spatial migration pattern of the Brown Plant Hopper populations was analyzed by using AreGIS9.0, based on the data of the daily lighting trap catches of the Brown Plant Hopper in China and the daily re-analyzed meteorological data in the Northern Hemisphere. The atmospheric dynamical background of this process was simulated by the high temporal and spatial resolution model WRF V2.2 （ Weather Research and Forecasting Model, version 2.2）. Four physical fields, including the horizontal wind field, K index distribution, A index spatial pattern and vortieity field on 850 hPa isobaric surface, were chosen from the model output to represent the atmospheric dynamical characteristics. The results showed that： 1 ） The air streams of the horizontal wind field on the 850 hPa （approximately 1500m） could be used to describe the main migration directions of the Brown Plant Hopper populations. 2） During the cardinal landing periods of the Brown Plant Hopper migration populations, the spatial patterns of K index and A index on 850 hPa isobaric surface displayed the atmospheric instability and qualitatively indicated the distribution of the main landing regions of the Brown Plant Hopper populations. As K≥ 35℃ or A≥10℃ , or K≥35℃and A≥ 10℃ at same time, it was favorable for taking-off and landing of the Brown Plant Hopper populations due to favorable conditions for the development of the vertical atmospheric movement. 3） Before the massive migration of the Brown Plant Hopper population, the coherent negative vortieity either strong or weak on the 850 hPa isobaric surface in the landing areas of the Brown Plant Hopper populations appeared. It showed that there were the sinking airflows with certain strength in the regions. These sinking airflows were favorable for landing of the Brown Plant Hopper.
出处
《中国农业气象》
CSCD
2008年第3期347-352,共6页
Chinese Journal of Agrometeorology
基金
国家自然科学基金(30671340)
关键词
褐飞虱
迁入
WRF模式
大气动力背景
数值模拟
Brown Plant Hopper （Nilaparvata lugens Stal）
Migration
Weather Research and Forecasting Model （WRF）
Atmospheric dynamical background
Numerical simulation
