An investigation of long-term variability of ozone 3-dimensional fields in the tropics connected with the 11-year solar cycle and peculiarities of the general atmospheric circulation

In this study, the long-term features of 3-dimensional ozone fields in the tropics (30° S– 30° N) over the 25-year period (1979–2003) based on the solar backscatter ultraviolet (SBUV) version 8 satellite observations were analysed. The application of the Empirical Orthogonal Function (EOF) decomposition allows characteristic spatial and temporal patterns to be identified in fields of partial ozone pressure anomalies, which are closely related to the natural causes such as the 11-year solar cycle, the Quasi Biennial Oscillation (QBO) and the Quasi Biennial Oscillation and an Annual Beat (QBO-AB). Also the vertical structure of the ozone QBO at the equator was investigated in comparison with the vertical structure of the zonal wind QBO. The analysis of the SBUV ozone data showed that the phase of the ozone QBO at the equator remains constant within the layer 10–50 hPa.     

基于GEE云平台的黄河源区河流径流量遥感反演研究

河流径流量是陆地上最重要的水文要素之一,准确获取径流信息对于区域的水资源评价和生态修复方面都具有重要作用.研究基于Google Earth Engine(GEE)云平台提供的Sentinel-1、Sentinel-2影像数据,结合数字高程模型(DEM)对河长、河宽、糙率、比降、河深和流速等水力学参数进行遥感估算,进而采...     

Effect of data length on rainfall–runoff modelling

A 64-year data set of daily rainfall and runoff, and average monthly potential evapotranspiration (PET) was split into subsets of 2, 5, 10, 20 and 30 years. Each subset was used to calibrate the AWBM daily rainfall–runoff model. Each subset calibration was then used to estimate runoff from the 64 years of rainfall and PET data. The ratios of calculated to actual total runoff were used to determine the ranges of error from the different lengths of data used for calibration. There was little difference in results from the 2- and 5-year subsets with 90% of estimates of long term runoff in the range of −21% to +31% of the recorded value. Overestimation of long term runoff reduced with length of calibration data of 10 or more years; however, the chances of underestimating were only slightly reduced even with 30 years of calibration data. Some limited repetition of the calculations with the Curve Number rainfall–runoff model indicated that the error characteristics were inherent in the data set and not an artifact of the model used. The ramifications for applications of rainfall–runoff modelling are briefly discussed.     

超声波时差法在平原渠道流量监测中的应用

针对我国华北平原常态化引调水工程监控对水文监测数据的时效性、准确性越来越高的要求,不断提高自动化监测能力和水平是解决问题的有效途径,因此在华北平原引调水工程水量监测站安装超声波时差法流量监测系统,分析工作流程,开展研发实践应用.在分析测量原理的基础上,运用数理统计法建立时差法流量多元线性回归模型,通过与同步实测流量比测...     

Cover: Detection of oil spills near offshore installations using synthetic aperture radar (SAR)

The number of sunspots is characterized by a long-term temporal variation, reaching its maximum or its minimum approximately every 11 years (the solar cycle). This variation, in turn, has an effect in terms of variation in the global climate. Since 1979, the use of satellite-borne radiometers has enabled accurate measurements of total solar irradiance (TSI). For instance, the sunspot numbers that are scaled to correspond to Nimbus-7 TSI observations for 1979–1993 show little long-term trend. However, while the observations of different extremes of the solar cycle, which are available from 1749, seem irregular in time and magnitude and difficult to quantify, they appear to have a strong correlation between them when they are sorted pairwise according to their size rather than sequentially in time. A similar relation holds among the solar cycle lengths (periods) and the solar cycle extremes, which, in parallel, obey a linear relation that is reminiscent of the Gutenberg–Richter seismic law. This can be used for a probabilistic approach to forecast solar parameters that are connected to global climate.

Based on the reasonable assumption that the basic parameters like extremes and length of the 11-year solar cycle are associated with the energy oscillating between the dipolar and quadrupolar phases of the cycle, it is concluded that these parameters obey a power-law distribution similar to that of the Gutenberg–Richter seismic law.

The question of whether solar activity is deterministically chaotic is also investigated by exploring the behaviour of the main characteristics of the 11-year solar cycle. This is done by constructing return maps of solar cycle strength and duration, which seem to take the familiar up–down U shape, implying both non-linearity and re-injection. The results suggest that there might exist a coupling between two or three different non-linear deterministic dynamical systems on the Sun, depending on which variable of the solar cycle is being considered.     

Co-constructing with stakeholders a role-playing game to initiate collective management of erosive runoff risks at the watershed scale

Erosive runoff is a recurring problem and is a source of sometimes deadly muddy floods in the Pays de Caux (France). The risk results from a conjunction of natural factors and human activity. Efficient actions against runoff in agricultural watersheds are well known. However they are still difficult to implement as they require co-operation between stakeholders. Local actors thus need tools to help them understand the collective consequences of their individual decisions and help to initiate a process of negotiation between them. We decided to use a participatory approach called companion modelling (ComMod), and, in close collaboration with one of the first group of local stakeholders, to create a role-playing game (RPG) to facilitate negotiations on the future management of erosive runoff. This paper describes and discusses the development of the RPG and its use with other groups of local stakeholders within the framework of two game sessions organized by two different watershed management committees. During the joint construction step, stakeholders shared their viewpoints about the environment, agents, rules, and how to model runoff in preparation for the creation of the RPG. During the RPG sessions, two groups of eight players, including farmers, mayors and watershed advisors, were confronted with disastrous runoff in a fictive agricultural watershed. Results showed that they managed to reduce runoff by 20–50% by engaging a dialogue about grass strips, storage ponds and management of the intercrop period. However, further progress is still needed to better control runoff through the implementation of better agricultural practices because, during the RPG sessions, the watershed advisors did not encourage farmers to do so. Because of the complexity of management problems, results of jointly constructing the game and the RPG sessions showed that modelling and simulation can be a very useful way of accompanying the collective learning process. This new way of working was welcomed by the participants who expressed their interest in organizing further RPG sessions.     

基于流水线模式的河系径流预报并发计算研究

在河系径流预报计算中,一方面受单站水文过程计算复杂性影响,另一方面下游站点依赖上游关联节点,现有洪水预报系统在河系预报计算时多采用串联模式进行计算。这在河流系预报节点较多、模型方法略为复杂时,计算效率较低。为突破河系径流预报计算效率瓶颈,本研究引入流水线并行模式,对河系径流预报站点初始化、单元产汇流计算、河道洪水演算、校正分析等模块进行拆解,构建流水线式工作站,将径流预报站点按水力联系连续入站,实现河系节点集径流过程的平行并发计算。选取淮河正阳关以上流域50余断面进行了模拟试验,结果表明：研究构建的并发计算方法计算结果可靠,较串行结构效率提升超3倍,可满足洪水预报实时性要求、尤其适用于B/S模式对系统响应效率的需求。     

Watershed model parameter estimation and uncertainty in data-limited environments

Parameter uncertainty and sensitivity for a watershed-scale simulation model in Portugal were explored to identify the most critical model parameters in terms of model calibration and prediction. The research is intended to help provide guidance regarding allocation of limited data collection and model parameterization resources for modelers working in any data and resource limited environment. The watershed-scale hydrology and water quality simulation model, Hydrologic Simulation Program – FORTRAN (HSPF), was used to predict the hydrology of Lis River basin in Portugal. The model was calibrated for a 5-year period 1985–1989 and validated for a 4-year period 2003–2006. Agreement between simulated and observed streamflow data was satisfactory considering the performance measures such as Nash–Sutcliffe efficiency (E), deviation runoff (Dv) and coefficient of determination (R²). The Generalized Likelihood Uncertainty Estimation (GLUE) method was used to establish uncertainty bounds for the simulated flow using the Nash–Sutcliffe coefficient as a performance likelihood measure. Sensitivity analysis results indicate that runoff estimations are most sensitive to parameters related to climate conditions, soil and land use. These results state that even though climate conditions are generally most significant in water balance modeling, attention should also focus on land use characteristics as well. Specifically with respect to HSPF, the two most sensitive parameters, INFILT and LZSN, are both directly dependent on soil and land use characteristics.     

Radar remote sensing of the spring thaw transition across a boreal landscape

The seasonal transition of the boreal forest between frozen and non-frozen conditions affects a number of ecosystem processes that cycle between winter dormant and summer active states. The relatively short K_u-band wavelength (2.14 cm) of the space-borne NASA scatterometer (NSCAT) is sensitive to changes in dielectric properties, associated with large-scale changes in the relative abundance and phase (frozen or thawed) of canopy and surface water. We used a temporal change detection analysis of NSCAT daily radar backscatter measurements to characterize the 1997 seasonal spring thaw transition period across the 10⁶ km² BOREAS study region of central Canada. In the spring, air temperature transitions from frozen to non-frozen conditions and surface observations of seasonal snow cover depletion were generally coincident with decreases in radar backscatter of more than 2.9 dB, regardless of regional landcover characteristics. We used a temporal classification of NSCAT daily differences from 5-day smoothed backscatter values to derive three simple indices describing the initiation, primary event and completion of the spring thaw transition period. Several factors had a negative impact on the relative accuracy of NSCAT-based results, including periodic gaps in NSCAT daily time-series information and a large (i.e., >2 cm day⁻¹) spring rainfall event. However, these results were generally successful in capturing the seasonal transition of the region from frozen to non-frozen conditions, based on comparisons with regional weather station network information. These results illustrate the potential for improved assessment of springtime phenology and associated ecosystem dynamics across high latitude regions, where field based and optical remote-sensing methods are substantially degraded by frequent cloud cover, low solar illumination and sparse surface weather station networks.     

Statistical and geostatistical analysis of rainfall in central Japan

Precipitation data have been analyzed statistically and geostatistically in order to obtain fundamental information for assessing water resources and predicting natural hazards caused by heavy rains. The study area is the mountainous Chubu and plain Kanto districts, central Japan. For the statistical distribution of hourly, daily and annual precipitations, lognormal distributions were fitted well in both districts, but exponential distribution was more suited for monthly precipitations. Weibull distribution illustrates also hourly and monthly precipitations well. Spatial variograms of annual precipitations show clearly nuggets and sills as well as ranges. The range is about 130 km in both districts. This range value, which is about seven times of the average station distance, indicates that the station density is sufficient for assessing water resource. Temporal variograms of hourly precipitations through a year have ranges of 8 h. In the analysis of heavy rain on August 14, 1999, when severe floods attacked some areas in Kanto, variograms of hourly precipitations show clear ranges (50–70 km), if it rains heavy in a wide area on a series of rainfall. Ranges of variograms increase with increasing accumulation time, and become constant as 120–150 km over 3–5 h. This range value is two or three times of the average station distance, and the accumulation time is three to five times of the measuring intervals. It concluded, accordingly, that the station density and the measuring interval of AMeDAS are insufficient for predicting natural hazards.     

The next 10,0002 years. I

Forecasts technological breakdowns and breakthroughs for the next 16 (10,000 to the base 2) years. Change has always been a part of recent history. Indeed, Earth-shaking change occurs about every 150-200 years. It takes about 50 years to make the transition from the old to the new, and we are nearing the end of just such a 50-year period. Change is caused by both technological breakthroughs and technological breakdowns. In the current 50-year transition, the breakthrough is in networking and software development, and the breakdown is in processor (VLSI) technology. Both forces will propel the high-tech world into a new model of computing by the year 2012. The new model will be based on a networked, global megacomputer that obeys the Gustafson-Barsis speedup law instead of the Amdahl law of parallelism. The next century's information superhighway will actually be a network of cable TV operators, not telephone companies. A new era of programming that eliminates traditional programming languages (and scolds the software engineering community for failure) will arise and lead to a software economy-an electronic commerce dominated by software artisans     

Inferring hemispherical reflectance of the earth's surface for global energy budgets from remotely sensed nadir or directional radiance values

The importance of the hemispherical reflectance (albedo) of terrestrial surfaces to biospheric and atmospheric processes is briefly reviewed. It is proposed that satellite-borne instruments represent the only practical means of obtaining global estimates of surface albedo data at reasonable time resolution, the problem being how to relate the nadir or directional reflectance observations obtained from such sensors to the integrated hemispherical reflectance. This paper discusses results measured at ground level in which NOAA satellite 7/8 AVHRR data, Bands 1 (0.58–0.68 μm) and 2 (0.73–1.1 μm), were used to investigate 1) the relationships between directional reflectances (spanning the entire reflecting hemisphere) and hemispherical reflectance (albedo) and 2) the effect of solar zenith angle and cover type on these relationships. Eleven natural vegetation surfaces ranging from bare soils to dense vegetation canopies were considered in the study. The results show that errors in inferring hemispherical reflectance from nadir reflectance can be as high as 45% for all cover types and solar zenith angles. By choosing a time of observation such that the solar zenith angle is between 30 and 40° the same error is reduced to less than 20% in both bands. For both bands a view angle of 60° off-nadir and ±90° from the solar azimuth reduces this error to less than 11% for all sun angles and cover types. A technique using two specific view angles reduces this error to less than 6% for both bands and for all sun angles and cover types. These techniques may yield considerable dividends in terms of more reliable estimation of hemispherical reflectance of natural surfaces.     

Investigation of the Periodic Systematic Error in Determining the Centers of Star Images on the CCD Matrix of the BOKZ-M60 Star Sensor

We investigate the periodic systematic error found in ground-based measurements of the BOKZ-M60 star sensor. This error can be explained by the periodic pixel structure of the sensor CCD matrix. Our conclusion is based on processing a sufficiently long series of measurement data. The measurements are processed in a few stages. First, we approximate the stellar sky motion on the matrix plane using an appropriate mathematical model. Then, we trace the motion of some particular stars relative to the model sky motion. Using spectral analysis, we then find the periodic components of their motion. The period of those components allow us to make the conclusion given above.     

小波方法在澜沧江降水量周期变化分析中的应用

采用Morlet复小波对澜沧江下游段降水量进行分析,揭示了澜沧江下游地区年度降水量的多尺度振荡特性和周期性变化,确定了主周期。分析结果表明,澜沧江下游河段在24a时间尺度上存在明显的周期性丰、枯变化,其它在12a和36a尺度上的周期性振荡能量较弱,周期变化不明显。根据主周期预测,2004年～2010年该地区处于降水量偏多期的末段,逐步趋于下一个枯水期的到来。     

Long-term trends and decadal solar variability in ozone near the tropopause over the Indian region

To investigate the long-term trends and effects of decadal solar variability in the upper tropospheric ozone, data obtained from the Stratospheric Aerosol and Gas Experiment II (SAGE II) aboard the Earth Radiation Budget Satellite (ERBS) during the period 1985–2005 were analysed using a multifunctional regression model over the Indian region (8–40° N; 65–100° E). Analysis of time series spanning these years shows statistically insignificant trends (at the two-sigma level (95% confidence level)) at upper tropospheric pressure levels (10?16 km). This period covers two solar cycles, one lasting from 1985 to 1995 and the other from 1996 to 2005; these are referred to as decade I and decade II, respectively. Since temporal variation in ozone number density indicates 11 year periodicity, trends are statistically significant when calculated separately during each solar cycle. Trend analysis indicates statistically significant positive trends (0.7 ± 1.7% to 3.9 ± 2.9% year^?1 during decade I, and 2.2 ± 1.6% to 4.5 ± 3.0% year^?1 during decade II). In general, higher ozone trends are observed during decade II. Seasonal variation in trends during decade II shows increasing trends during the pre-monsoon (0.8?3.8% year^?1), monsoon (0.8?7.1% year^?1), and post-monsoon (2.8?8.0% year^?1) seasons. The annually averaged solar signal in ozone is found to be of the order of around??5 ± 4.3% to??13.8 ± 6.7%/(100 sfu). Results obtained in the present study are also compared with those obtained by other researchers.     

Artificial neural network–genetic algorithm for estimation of crop evapotranspiration in a semi-arid region of Iran

This study compares the daily potato crop evapotranspiration (ET_C) estimated by artificial neural network (ANN), neural network–genetic algorithm (NNGA) and multivariate nonlinear regression (MNLR) methods. Using a 6-year (2000–2005) daily meteorological data recorded at Tabriz synoptic station and the Penman–Monteith FAO 56 standard approach (PMF-56), the daily ET_C was determined during the growing season (April–September). Air temperature, wind speed at 2 m height, net solar radiation, air pressure, relative humidity and crop coefficient for every day of the growing season were selected as the input of ANN models. In this study, the genetic algorithm was applied for optimization of the parameters used in ANN approach. It was found that the optimization of the ANN parameters did not improve the performance of ANN method. The results indicated that MNLR, ANN and NNGA methods were able to predict potato ET_C at desirable level of accuracy. However, the MNLR method with highest coefficient of determination (R ² > 0.96, P value < 0.05) and minimum errors provided superior performance among the other methods.     

基于尺度能量参数的子波变换及其应用

提出基于尺度能量参数的子波变换方法。首先给出了尺度能量参数的概念，讨论基于这一参数的子波变换的时频特性，然后推导基于尺度能量参数的子波变换的逆变换，给出并证明其容许性条件成立的充分条件。文中给出基于尺度能量参数的子波变换中尺度与波长的关系，并且分析了一组黄河上游年径流量数据。研究结果表明，基于尺度能量参数的子波变换能够放大、突出不同尺度下的信号特征。     

The Changing Capabilities of Cohorts of the Elderly in Russia during 1990–2020: Measurement using a Quantitative Index

Russia has had a high elderly share of its population like the OECD countries, but has had a more turbulent history over the past 100 years, which has caused fluctuations in the capabilities of those turning 60 (measured by education and training, income, enabling environment, medical care, and health status). This article analyses the life experiences and capabilities of five Russian birth cohorts turning 60 over the period 1990–2020. It presents relevant concepts, reviews past research, and evaluates the importance of health factors (health environment, health-related behaviours, medical care, health status) in determining the activities and contributions of older people in Russia. A Human Capabilities of the Elderly in Russia Index (HCERI) with 22 indicators is developed. Russian data are used in the calculation of the HCERI for the cohorts turning 60 in 1990, 1995, 2000, 2010 and 2020. The article then presents evaluations of the experiences and changes in capabilities for each of the five selected cohorts of the elderly in four periods of life: Childhood (1–15 years), Young Adult (16–49), Mature Adult (50–59), and Early Elderly (60–69). The implications of changes in the characteristics of the elderly for Russian government policies are discussed.     

南水北调西线一期工程调水区生态环境质量遥感分析与综合评价

南水北调西线工程,是从长江上游干支流调水入黄河上游的跨流域调水重大工程,对解决黄河水资源短缺有着重大意义,但是在调水工程实施前,对调水区生态环境质量进行客观评价是很有必要的。在大量的野外调查和室内综合分析的基础上,对南水北调西线调水区域的生态环境进行了评价。主要利用现代遥感技术和地理信息系统分析方法,在地学综合思想和生态系统理论的指导下,提取了研究区影响环境质量的6个因子图层数据,叠加形成一个综合环境指数图层数据,对其等间距划分成4个环境分区。各综合自然环境指数的空间分析结果表明,综合自然环境指数一级和二级区具有较好的自然环境条件, 集中分布在研究区的东部,约占研究区面积的50％;三级区是自然环境比较敏感的地区,主要分布在调水区域的西部高原丘陵上; 四级区是自然环境比较脆弱、恶劣的区域,主要分布在调水区域的高寒山原地带。所以,一级和二级区的自然环境具有一定的抗干扰能力,在适当的环境保护措施下,可以进行一定规模的工程建设;三级区进行工程建设时, 必须特别注意对自然环境的各项保护措施,加大环境保护的力度及投入;四级区上进行工程建设会造成较大的环境破坏,不宜进行工程建设。     

Long-term trends of total ozone content over mid-latitudes of the Northern Hemisphere

Dynamic climatic normals and long-term trends of total ozone in the mid-latitudes of the Northern hemisphere (30°N–60°N) have been determined using data from satellite observations for the period of 1978–2017. The annual course of total ozone is shown as changing over the various regions during the period of observations. The specific features of alteration in the state of the ozone layer are discussed depending on latitude and longitude. Thus, a general increase in total ozone in winter, an increase in spring (with the exception of the northern latitudes of Europe, Asia, and Pacific), and a continuing decrease in summer (with the exception of the northern latitudes of America) during the last 17 years is revealed. The long-term trends of total ozone for different regions and latitude zones (30°N–40°N, 40°N–50°N, and 50°N–60°N) are given depending on season.