Possible Sources of Forecast Errors Generated by the Global/Regional Assimilation and Prediction System for Landfalling Tropical Cyclones. Part Ⅱ: Model Uncertainty

This paper investigates the possible sources of errors associated with tropical cyclone (TC) tracks forecasted using the Global/Regional Assimilation and Prediction System (GRAPES). In Part I, it is shown that the model error of GRAPES may be the main cause of poor forecasts of landfalling TCs. Thus, a further examination of the model error is the focus of Part II. Considering model error as a type of forcing, the model error can be represented by the combination of good forecasts and bad forecasts. Results show that there are systematic model errors. The model error of the geopotential height component has periodic features, with a period of 24 h and a global pattern of wavenumber 2 from west to east located between 60°S and 60°N. This periodic model error presents similar features as the atmospheric semidiurnal tide, which reflect signals from tropical diabatic heating, indicating that the parameter errors related to the tropical diabatic heating may be the source of the periodic model error. The above model errors are subtracted from the forecast equation and a series of new forecasts are made. The average forecasting capability using the rectified model is improved compared to simply improving the initial conditions of the original GRAPES model. This confirms the strong impact of the periodic model error on landfalling TC track forecasts. Besides, if the model error used to rectify the model is obtained from an examination of additional TCs, the forecasting capabilities of the corresponding rectified model will be improved.     

Studying the Deep Structure of Elbrus Volcano by Microseismic Sounding

This paper presents results from a study of the deep structure of the Elbrus edifice and adjacent areas using geophysical techniques. We confirmed the existence of a shallow magma chamber, derived a more accurate location of the chamber in the host rocks and its characteristic dimensions, and compared new results with known studies. More accurate estimates have been obtained for the temperature at the top of the magma chamber and new evidence is adduced concerning the deep structure of the fluid magmatic systems in the Elbrus volcanic area.     

考虑土-结构相互作用的振动台实时子结构试验仿真分析

本文基于状态空间方程进行了实时子结构试验的初步探索,提出了一种新的实时子结构试验方法。通过simulink仿真发现,这种方法能很好地再现整体分析的结构反应。最后,对考虑土-结构相互作用的振动台实时子结构试验进行了仿真分析。     

南海夏季风爆发日期和强度的短期气候预测方法研究

利用合成及相关统计方法，研究冬季南海季风指数与850hPa风场、500hPa高度、海表温度、OLR等环境场的相互关系及其影响南海夏季风活动的可能机制。指出冬季南海季风指数及环境场的异常特征可以作为预测南海夏季风活动的前兆信号。在此基础上建立了预测南海夏季风爆发日期和强度的概念模型，1998－2001年的预测试验取得了较好成绩。     

上高县紫皮大蒜种植气候适宜性区划

基于紫皮大蒜生长周期和当地农业气象条件,得到上高县紫皮大蒜气候适宜性指标：10—11月的最低气温、10月至次年4月的平均气温和平均降水量以及2—4月的累计日照时数。利用1970—2020年宜春市和新余市辖区内共12个地面观测站的气象资料,采用GIS建立上高县紫皮大蒜种植区划因子地理空间分析模型。依据分区等级指标,将上高县划分为最适宜、一般适宜和不适宜3个紫皮大蒜气候种植区。     

一种可能的短期前震

分析大地震前小地震时、空分布发现,1973年2月6日炉霍7.9级地震1974年4月22日溧阳5.5级地震及1976年5月29日龙陵7.3级地震前约3个月内,2级以上小地震有沿一定方向(顺时或逆时)逐个发生,从而形成环的现象。溧阳和龙陵地震发生在环内一侧或其附近,而炉霍大地震则离环较远,但处于同一构造带。根据蠕变曲线有非线性增加段及其时间特征,它可定为短期前震,並且可能表现了震前固体潮触发蠕滑的过程。     

桶形基础沉贯室内模型试验研究

桶形基础采用负压沉贯法施工,其贯入阻力与压桩,打桩等施工方法显著不同。本文介绍了在粉土和粉质粘土地层中的一组模型试验情况,认为负压法施工可显著降低粉土的抗贯阻力,但在粉质粘土中减阻效果不明显。     

The impact of rural land management changes on soil hydraulic properties and runoff processes: results from experimental plots in upland UK

To develop an evidence base to help predict the impacts of land management change on flood generation, four experimental sites were established on improved grassland used for sheep grazing at the Pontbren catchment in upland Wales, UK. At each site, three plots were established where surface runoff was measured, supplemented by measurements of soil infiltration rates and soil and vegetation physical properties. Following baseline monitoring, treatments were applied to two of the plots: exclusion of sheep (ungrazed) and exclusion of sheep and planting with native broadleaf tree species (tree planted), with the third plot acting as a control (grazed pasture). Due to a particularly dry summer that occurred pre‐treatment, the soil hydrological responses were initially impacted by the effects of the climate on soil structure. Nevertheless, treatments did have a clear influence on soil hydrological response. On average, post‐treatment runoff volumes were reduced by 48% and 78% in ungrazed and tree‐planted plots relative to the control, although all results varied greatly over the sites. Five years following treatment application, near‐surface soil bulk density was reduced and median soil infiltration rates were 67 times greater in plots planted with trees compared to grazed pasture. The results illustrate the potential use of upland land management for ameliorating local‐scale flood generation but emphasise the need for long‐term monitoring to more clearly separate the effects of land management from those of climatic variability. Copyright © 2013 John Wiley & Sons, Ltd.     

用地震危险性分析方法预测山东地区震害

依据地震危险性分析的思路，提出一种场地震害预测的方法。依此方法，给出山东地区５０ａ超越概率为１０％的震害预测略图     

Cosmic‐ray rejection for single spectroscopic CCD images by means of template matching

This article describes a novel algorithm for cosmic‐ray rejection in single spectroscopic CCD images. This algorithm is based on a variation of template matching. It focuses on identifying those pixels belong to spectra, while other conventional algorithms tried to locate the cosmic‐ray hits directly. The main principle is applying template matching to find suspicious blocks, which is followed by surface patching to locate the legitimate pixels accurately. Therefore, the rest pixels are the ones corrupted by cosmic‐ray hits. Meanwhile, almost all the parameters are automatically extracted from the images. Examples of its performance are given for both simulated and observed images. It shows an advantage of significantly low false alarm rate with relatively high detection rate (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)