


Vol 43, No 8 (2018)
- Year: 2018
- Articles: 10
- URL: https://journal-vniispk.ru/1068-3739/issue/view/14280
Article
Operative Scheme for the Short-range Complex Forecasting of Surface Air Temperature and Humidity
Abstract
The statistical scheme is proposed for the forecast of surface air temperature and humidity using operative weather forecasts with 3–5-day lead time from the best forecasting hydrodynamic models as well as the archives of forecasts of these models and observational data from 2800 weather stations of Russia, Eastern Europe, and Central Asia. The output of the scheme includes the forecasts of air temperature for the standard observation moments with the period of 6 hours and extreme temperatures with the lead times of 12–120 hours. The accuracy of temperature and humidity forecasts for the period from July 2014 till June 2017 is much higher than that for the forecasts of original hydrodynamic models. The skill scores for extreme temperature forecasts based on the proposed method are compared with the similar results of the Weather Element Computation (WEC) forecasting scheme and forecasts by weathermen.



Changes in Cu Characteristics and Precipitation during Cu Merging
Abstract
The results of investigation of convective cloud merging observed near Saint Petersburg are presented. Data obtained with a set of remote sensing instruments (radar, radiometer, and lightning location system) were analyzed. Rain gage network data are used. Clouds simulation is performed using a 1.5-dimensional nonstationary model. A method to calibrate the radar measurements to obtain precipitation characteristics using rain gage network data is developed. According to radar data, a 2-km increase in the cloud top height was observed after Cu merging, the maximum reflectivity of clouds increased at 10 dBZ, maximum rain intensity and rain flux increased by about two times. The increase in rainfall intensity is also corroborated by rain gage observations and numerical simulations. An increase in the intensity of lightning discharges during the merging is registered.



Peculiarities of Generation of Infragravity Waves
Abstract
The peculiarities of the generation of infragravity sea waves with the periods from 30 s to 5 minutes are identified by the processing and analysis of experimental data obtained with the laser meter of hydrosphere pressure variations in the Vityaz’ Bay (the Sea of Japan).



Calculation of Precipitation Layer as a Water Balance Component of the Sea of Azov
Abstract
A statistical model of the spatial coupling of precipitation over the Sea of Azov is constructed using SEVIRI radiometer data. The set of four locations of precipitation field was identified to retrieve integral precipitation layer over the sea. It was found that the model can be applied for the water-balance studies of the Sea of Azov based on data from coastal weather stations.



Long-term Changes in the Main Components of Lake Khanka Water Regime
Abstract
Changes in annual total precipitation and annual pan evaporation for the Lake Khanka water area during the period of 1949–2015 are analyzed based on observational data of weather stations within the lake basin. The reliability of the calculated values of characteristics affecting evaporation changes was confirmed by their comparison with observations at the 20-m2 evaporation pan installed at Astrakhanka lake station. It is shown that against a background of significant interannual fluctuations of annual precipitation during the whole period under study, its trends are almost absent. However, a rather stable increase in annual precipitation value caused by the summer precipitation rise has been noted since the early 2000s. The value of annual pan evaporation decreased from 1949 to 2015, and the rate of its decrease till 1980 was higher than in the next period. Moreover, some evaporation increase has been observed in the recent decade. The main contribution to the evaporation change is made by wind speed changes which cause about 50% of evaporation variance. Air humidity deficit is the second affecting factor that determines a little over 20% of annual evaporation variance. It is demonstrated that the increase in annual precipitation is possible by the middle of the 21st century, while the change in annual evaporation from the Lake Khanka water area would be minimal. Under such changes in the main components of the lake water regime, no reduction of its level due to natural climate processes should be expected.



To the Problem of Verification of Methods for Short-range Forecasting of Hydrological Parameters
Abstract
The main principles of the existing methodology for the verification of forecasting techniques in the absence of the sample volume impact on the accuracy of determination of statistical parameters are considered. A method is proposed for the verification, comparison, and selection of forecasting methods. The method is based on the persistence of the predicted phenomenon and allows creating optimum forecast schemes with account of priority of expected parameters of accuracy. It is anticipated that the obtained results will find application in the practice of hydrological forecasting.



The Climate Change Effect on the Water Regime. The Case Study: the Karun Catchment, Iran
Abstract
One of the most important effects of climate change is changes in the water regime and the frequency of flood occurrence. The Karun catchment is one of the most important Iran catchments, but it has never been studied specifically. This study considers the effect of climate change on the annual and the maximum runoff of the Karun catchment in the Shalu bridge area. First, temperature and monthly precipitation of the HadCM3 model were downscaled based on three scenarios, AlB, A2, and B1, ustng the LARS-WG model. Then data were spatially downscaled based on the change factor model, and the SRM model was used to simulate runoff. The results show that the climate change affects the water regime of this catchment.



Reviews and Consultations
Ozone Content over the Russian Federation in the Second Quarter of 2018
Abstract
The review is compiled on the basis of the results of the operation of the total ozone (TO) monitoring in Russia and adjoining territories that functions in the operational mode at the Central Aerological Observatory (CAO). The monitoring system uses data from the national network equipped with M-124 filter ozonometers being under the methodological supervision of the Main Geophysical Observatory. The quality of the functioning of the entire system is operationally controlled based on the OMI satellite equipment observations (NASA, USA). Basic TO observation data are generalized for each month of the second quarter of 2018 and for the second quarter. The data of routine observations of surface ozone values in the Moscow region and Crimea are also considered.



Erratum





