Seasonal forecasting of air temperature anomalies using the time analog method

Proposed is a method of forecasting the monthly mean air temperature anomalies for three months of the moving season based on the statistical analysis of the array of analogous processes of temperature variations specially selected for the initial season using the operational forecast for the first ten-day period of prognostic period being available by the beginning of the forecast. The array of analogous processes is used for revealing the most frequently observed values of temperature anomalies in the future. The overall station-by-station analysis gives a field of anomaly forecast for the CIS territory for three forthcoming months and for a season. Presented is the assessment of forecasts issued from January 2007 to December 2010 using the real ten-day period forecasts. The estimates of forecasts based on the model using the normals for 1979?C2007 are also considered.     

Long-range forecasting of monthly and seasonal air temperatures considering periodical nonstationarity

A statistical method is proposed for prediction of monthly mean, seasonal mean, and annual mean temperatures with 12-month projection. The method is based upon revealing latent rhythms of the climate system which force sequences of interannual disturbances in air temperature. In selection of the rhythms with prognostic information, it is taken into account that season-to-season transition violates the time series stationarity. The forecast verification shows advantage of the proposed method as compared with climatologic forecasts.     

Long-range forecasting of forest fire danger based on the SLAV model seasonal ensemble forecasts

Developed is a scheme of the long-range forest fire danger (FD) forecasting based on the computation of the Nesterov??s index and on hydrodynamic forecasts of air temperature and precipitation of the SLAV model. The satellite information on the climatic distribution of the snow cover was taken into account for the forecast issuance. It is proposed to express the FD index not using traditional classes of fire danger but in ??above the norm,?? ??norm,?? and ??below the norm?? gradations. Presented are the results of author??s trials of the method based on the retrospective model data for six years. Discussed are the approaches to the improvement of the method of long-range fire danger forecasting.     

时间序列预报方法的推广

文中讨论了车贝雪夫多项式值计算误差对作者以前提出的一种新的时间序列预报方法的预报结果的影响,并在此基础上对原来的计算方案作了推广,推广后的算法有利于提高预报准确率。     

一个降水预报的时间序列线性平稳预测模型

本文利用兰州１９４４～１９９７年的月平均降水资料,建立了线性平稳序列的降水预测模型,该模型使用了功谱密度函数中的最大熵法（或叫全极模型）,并将特征多项式模大于１的根反射到单位圆内,再返回修正后的线性预测的系数。并对１９８６～１９９７年１１年的月降水做了预测试验,试验结果表明,该模型具有一定的预报能力,其中取１５阶预报效果较好。此方法在短期气候预测业务中,可作为台站月、季、年降水预测走向客观化、定量化方法的一种初步尝试     

Mean seasonal and spatial variability in global surface air temperature

Summary Using terrestrial observations of shelter-height air temperature and shipboard measurements, a global climatology of mean monthly surface air temperature has been compiled. Data were obtained from ten sources, screened for coding errors, and redundant station records were removed. The combined data base consists of 17 986 independent terrestrial station records and 6 955 oceanic grid-point records. These data were then interpolated to a 0.5° of latitude by 0.5° of longitude lattice using a spherically-based interpolation algorithm. Spatial distributions of the annual mean and intra-annual variance are presented along with a harmonic decomposition of the intra-annual variance.With 7 Figures     

An improved method for correction of air temperature measured using different radiation shields

The variation of air temperature measurement errors using two different radiation shields （DTR502B Vaisala,Finland,and HYTFZ01,Huayun Tongda Satcom,China） was studied.Datasets were collected in the field at the Daxing weather station in Beijing from June 2011 to May 2012.Most air temperature values obtained with these two commonly used radiation shields were lower than the reference records obtained with the new Fiber Reinforced Polymers （FRP） Stevenson screen.In most cases,the air temperature errors when using the two devices were smaller on overcast and rainy days than on sunny days; and smaller when using the imported rather than the Chinese shield.The measured errors changed sharply at sunrise and sunset,and reached maxima at noon.Their diurnal variation characteristics were,naturally,related to changes in solar radiation.The relationships between the record errors,global radiation,and wind speed were nonlinear.An improved correction method was proposed based on the approach described by Nakamura and Mahrt （2005） （NM05）,in which the impact of the solar zenith angle （SZA） on the temperature error is considered and extreme errors due to changes in SZA can be corrected effectively.Measurement errors were reduced significantly after correction by either method for both shields.The error reduction rate using the improved correction method for the Chinese and imported shields were 3.3％ and 40.4％ higher than those using the NM05 method,respectively.     

Estimation of surface air temperature trends over the Russian Federation territory using the quantile regression method

The results are presented of the estimation of surface air temperature variations in different climatically quasi-homogeneous regions of Russia using the nonparametric method of regression analysis (quantile regression). Daily observation records from 517 weather stations were used. The quantile regression technique used for analyzing the trends in long-term series allows obtaining information on trends for the whole range of quantile values from 0 to 1 of dependent variable distributions. Seasonal and regional features of daily minimum, mean, and maximum air temperature trends are considered in a wide range of quantile values. The proposed method that generalizes long-term trends obt ained for groups of stations by quantile regression, is applied to quasi-homogeneous climate regions identified on the territory of Russia.     

Characteristic seasonal variation of vertical air temperature profile in urban areas of Japan

The seasonality of the vertical air temperature profile in an urban area in the vicinity of the coast was studied. The vertical air temperature profile showed the characteristic seasonality. In the summer, the atmosphere was thermally stratified in the 60–100 m layer, while the 20–60 m layer was unstable or weakly stable throughout the day due to the strong solar radiation. On the other hand, no temperature inversion layer was observed in the winter presumably due to the heat supply from the sea as well as the strong wind speed in the vicinity of the coast. The vertical air temperature profiles at nighttime in the spring and autumn were transitional between the summer and the winter. In contrast, the vertical air temperature profile in the daytime in the spring was similar to that in the summer, while that in the autumn was comparable to that in the winter. Characteristic findings in the study due to the site location, i.e., in the vicinity of the coast, can be summarized as follows: (1) the elevated temperature inversion layer at noon was observed in the summer, and (2) no temperature inversion layer was observed in the winter.     

用时实资料结合数值产品做温度预报的尝试

通过在Micaps系统中建立一个按钮，实现自动读取当天的最低、最高（用14时值代）气温值以及T10608时和14时的温度预报值，多后自动求解△T，得出温度预告值。     

用时实资料结合数值产品做温度预报的尝试

通过在Micaps系统中建立一个按纽,实现自动读取当天的最低、最高(用14时值代)气温值以及T10608时和14时的温度预报值,然后自动求解△T,得出温度预告值.     

Complexity analysis of the air temperature and the precipitation time series in Serbia

Regional Atmospheric Modeling System (RAMS) was applied to the study of the effect of the topographical altitude of the Tibetan Plateau (TP) on a severe drought event which took place in eastern China from November 2008 to January 2009. Two simulations of this drought event were conducted: a control simulation (CNTRL run) using original model settings and a sensitive simulation (TOPO run), where no change other than to reduce the TP topography by 50 %. The results show that the CNTRL simulation validates RAMS by reproducing this drought event fairly accurately. However, as part of the TOPO simulation, the total heat flux showed a decrease over most parts of the TP, latent heat flux underwent a significant increase over the southeastern TP, contrary to sensible heat, and a universal decrease over eastern China; this led to an increase in precipitation over the southeastern TP and a decrease in precipitation over eastern China. The decrease of total heat flux over the TP is collocated with an anomalous anticyclonic circulation from the TP to the coasts of southeastern China. Changes in atmospheric circulation and low-level water vapor transport pathways were consistent with changes in precipitation. In general, reducing the topographical altitude of the TP worsens drought in eastern China and moreover causes a significant decrease in precipitation over southern China.     

Physiographic factors of seasonal distribution of linear trends in air temperature on the Azov-Black sea coast

The seasonal distribution of linear trends in air temperature on the coast of the Black and Azov seas in 1936-2010 is analyzed using the quantile regression method. Monthly mean and median values of temperature as well as 10% and 90% quantiles of average daily values of temperature are considered to describe changes in extreme positive and negative temperature anomalies. It is demonstrated that besides tendencies that are common for all meteorological stations, local features and physiographic location of the stations are of great importance for the distribution of temperature trends.     

用神经网络试报极端气温

用人工神经元技术,筛选出与气温相关性较大的１０个物理量,建立几组样本资料,经过学习和训练,建立预报专家网络,来试报哈尔滨市夏季最高和最低气温。     

The operational seasonal forecasting of the summer rainfall in China

The paper presents a review of the success and failure of the practical results from summer drought and flood forecasts and seasonal precipitation forecasts in the period from 1976 to 1985. An analysis is made on the anomaly of the general circulation winch gives rise to summer precipitation and drought-flood occurrences in the country. It is proposed that the subtropical high over the West Pacific, the South Asia high and middle-latitude westerlies are the major synoptical regimes producing summer weather in China. The analysis focuses on the features of low-frequency oscillation and abnormality of the West Pacific sub-tropical high in the monthly 500 hPa mean charts, and on their interactions with the sea temperature of the North Pacific and the Equatorial Pacific. The result shows that there exist quasi-cycles of 3－4 years, 11 years and 19 years or so in the subtropical high with the feature of strong persistence and seasonal changes. There is a rather good correlation between the behaviour of the subtropical high and changes in the cold current area in the East Pacific, and especially during the El Nino period, there is an ob-vious coupling with abnormal changes of the intensity of the subtropical high. Analysis is also made on the effect of the thermal condition of the Tibetan Plateau, the Northern Hemisphere westerly circulation and the astronomical factors on the West Pacific subtropical high, the South Asia high and precipitation in the rainy season in China.     

Multischeme ensemble forecasting of surface temperature using neural network over Turkey

The ensemble method has long been used to reduce the errors that are caused by initial conditions and/or parameterizations of models in forecasting problems. In this study, neural network (NN) simulations are applied to ensemble weather forecasting. Temperature forecasts averaged over 2 weeks from four different forecasts are used to develop the NN model. Additionally, an ensemble mean of bias-corrected data is used as the control experiment. Overall, ensemble forecasts weighted by NN with feed forward backpropagation algorithm gave better root mean square error, mean absolute error, and same sign percent skills compared to those of the control experiment in most stations and produced more accurate weather forecasts.     

A new multidimensional time series forecasting method based on the EOF iteration scheme

In this paper a new multidimensional time series forecasting scheme based on the empirical orthogonal func-tion (EOF) stepwise iteration process is introduced. The scheme is tested in a series of forecast experiments of Nino3 SST anomalies and Tahiti-Darwin SO index. The results show that the scheme is feasible and ENSO predictable.     

伊春市空气污染的气象因素及污染物浓度预报方法

对伊春市区二氧化硫、氮氧化物、空气悬浮颗粒物3种污染物浓度逐日资料及同期气象资料的分析,总结伊春市空气污染的一般规律,了解了影响伊春市区大气污染变化的天气形势及气象要素的特征,并运用这些要素特征采用多元回归方法建立污染物浓度的预报模式,为空气质量预报提供了定量依据。