Water Temperature Measurements Research Articles

The relationship between thermal spatial variability and mean temperature alters movement and population dynamics

AbstractThe importance of spatial and temporal environmental variation in shaping ecosystem dynamics is well appreciated, yet the ecological consequences of dynamic spatial variability, that is, the temporal patterning of spatial variation, remain unresolved. Here, we experimentally generate temporally fluctuating thermal environments that have either a negative, positive, or neutral relationship between the mean spatial environmental temperature and the degree of thermal spatial heterogeneity. We test the hypothesis that the timing of spatial variation relative to diel temperature cycles can meaningfully alter movement patterns and population dynamics, using the motile green algae Chlamydomonas reinhardtii. Our results indicate that C. reinhardtii individuals growing in environments with positive relationships between spatial variability and mean temperature show reduced population growth rates, more directed movement as indicated by a reduced turning angle, and decreased negative thermotaxis over time, relative to those growing in environments with a negative relationship between spatial variability and mean temperature. We additionally document substantial regional variation in the dynamics of natural spatial variability by collecting summer water temperature measurements from five ponds in the Mount Saint Helens watershed, WA, USA. Our results collectively suggest that the dynamics of spatial variation are an underappreciated but salient feature within the broader interwoven fabric of spatiotemporal variation.

Temperature Monitoring System and pH Control of Catfish Breeding Pond Water Based on NodeMCU 8266 with Telegram Bot Notification

This research presents the design of a temperature monitoring and pH control device for catfish nurseries. The pH range of 6.5 to 8.5 with a temperature of 27℃ to 31℃ is the optimal condition for catfish farming. However, water quality can decrease due to unstable pH conditions and temperature changes. In this case, periodic monitoring is necessary to maintain stable pH and temperature conditions. This tool is constructed to monitor temperature and control water pH using DS18B20 temperature sensors, pH sensors, water pumps, Node MCU 8266, and a telegram application. This device is applied to maintain the stability of the pH of the water; pH control is carried out with a new water replacement method when the pH value is over the normal limit or is in acid and alkaline state. The new water replacement method is carried out by utilizing a water pump for the circulation process. When all components are well integrated into a system, including the whole program, then testing is carried out. Testing on this tool begins with turning on and running the system and observing the system's performance, dipping the temperature sensor and pH sensor probe into the water, and then observing the temperature and pH data displayed on the LCD. Furthermore, if the pH is in an acid or alkaline state, the pump will be active to carry out the process of circulating water replacement. The output of water temperature and pH measurements is displayed on the LCD and with Telegram notifications by sending messages or statuses on Telegram.

Sistem Pengendalian Salinitas Air Pada Budidaya Cacing Nipah Namalycastis rhodochorde Berbasis Internet of Things (IoT)

Nypa palm worm (Namalycastis rhodochorde) is a new species of Polychaeta class found in Sei Kakap area. Apart from being obtained from the river coast, cultivation is one way to get worms, but the cultivation of nypa palm worm is still within the scope of the lab and is done manually. Manual cultivation has a problems, especially in controlling water salinity which affects the survival or survival rate of worm. Therefore, this requires an Internet of Things in installation of worm cultivation. This system aims to control the salinity of the water and then monitor the salinity and temperature of the water as well as the temperature and humidity of the air. Another goal is to control water salinity which affects the survival rate of worms. The results of monitoring and controlling the water salinity will be displayed on a website-based application. Arduino Uno is used as hardware that controls the system, NodeMCU ESP32 is used as a tool to connect to the server, water salinity sensor is used to measure water salinity, DS18B20 sensor is used to measure water temperature, as well as DHT11 sensor is used to measure air temperature and humidity. The results of testing the reading system of each sensor obtained an error value 0,017% and 0,032% water salinity sensors, 0,015% DS18B20 sensor, as well as 0.011% and 0.003% DHT11 sensor. Application of the system can reduce water salinity by 1-3 ppt and resulted in the survival rate of worms by 41%.

Regional estimation of river water temperature at ungauged locations

River water temperature measurement networks suffer from an inadequate spatial coverage and a lack of data. No methods exist for the regional estimation of river water temperature at ungauged sites based on data series from gauged sites. The development of such methods is hence of significant importance. It is proposed in this study to develop a Temperature-Duration-Curve (TDC) based method to estimate river water temperature at ungauged sites on a real-time basis. A Generalised Additive Model (GAM) based method is used to estimate TDCs at ungauged sites. The estimated TDCs are then used in combination with a spatial interpolation method to obtain daily temperature estimates at ungauged sites. Results are compared with a simple method based on the geographical distance weighted average of neighboring stations. The approaches are applied to 126 river thermal stations located on Atlantic salmon rivers in eastern Canada. Leave-one-out cross validation results indicate that the TDC based methods are robust and outperform the geographical distance weighted method.

High frequency flow and temperature measurements of domestic water in two office and education buildings

For a long period, the energy use for domestic hot water (DHW) in non-residential buildings has been neglected. As energy use for space heating, ventilation, and lightning has been reduced through the years, the energy share for DHW production has increased. With today’s focus on energy efficient buildings, the DHW systems must not be left behind the other fields to obtain a holistic approach to energy efficient buildings. To develop more energy efficient DHW systems for non-residential buildings, more knowledge is needed regarding draw-off durations, flow rates, and water temperatures from different draw-off types.This paper presents high frequency measurement results in two Danish office and educational buildings, which show that three DHW systems only utilize between 3.4 and 7.5 % of the total energy used for DHW production. Above 85 % of the total energy use is lost from the recirculation circuit to secure a high hot water temperature at the draw-off point. However, temperature measurements at the draw-off points show that a significant share of the heat is lost from pipes not covered by recirculation. One reason is draw-off durations are approximately 50 % of the time below 10 s at washbasins and kitchen sinks. Another reason is actual maximum flow rates are far from the calculated design flow.The high frequency measurements at multiple draw-off points give essential knowledge of use patterns for washbasins, kitchen sinks, and service sinks in non-residential buildings. This knowledge can contribute to developing energy efficient DHW systems and new types of DHW production.

Self-Temperature Compensated Water Level and Velocity Sensor Based on Fiber Bragg Gratings

This work proposes a fiber Bragg gratings (FBG) sensor for simultaneous measurements of water level, velocity, and temperature in open channels. The optical fibers are placed on a rectangular aluminum rod attached to the bottom of the channel. The water flow causes a distributed load and a characteristic bend in the rod, depending on the water level and velocity. A set of four FBGs are used to monitor the rod’s bending profile. Taking the wavelength difference of two FBGs makes it possible to eliminate the temperature effect and obtain a system of nonlinear equations dependent on velocity and water level. Velocities from 0.1 ms to 0.9 m/s and water levels from 0.4 m to 0.7 m were experimentally evaluated. A semi-empirical model was obtained to describe the wavelength shift, and finally the water level and velocity are calculated. The results show that the proposed system can determine the water level, mean velocity and temperature with satisfactory accuracy. Artificial neural networks are used as a second and more straightforward approach to determine the water level and velocity from the measured wavelengths, considering mean values and standard deviation. With this method, the maximum absolute deviations were 0.02 m/s and 3.1 cm, for the mean velocity and water level, respectively.

Remotely Monitored Buoys for Observing the Growth and Development of Sea Ice In Situ

Abstract This paper describes a remotely monitored buoy that, when deployed in open water prior to freeze up, permits scientists to monitor not only temperature with depth, and hence freeze up and sea ice thickness, but also the progression of sea ice development—e.g., the extent of cover at a given depth as it grows (solid fraction), the brine volume of the ice, and the salinity of the water just below, which is driven by brine expulsion. Microstructure and In situ Salinity and Temperature (MIST) buoys use sensor “ladders” that, in our prototypes, extend to 88 cm below the surface. We collected hourly measurements of surface air temperature and water temperature and electrical impedance every 3 cm to track the seasonal progression of sea ice growth in Elson Lagoon (Utqiaġvik, Alaska) over the 2017/18 ice growth season. The MIST buoy has the potential to collect detailed sea ice microstructural information over time and help scientists monitor all parts of the growth/melt cycle, including not only the freezing process but the effects of meteorological changes, changing snow cover, the interaction of meltwater, and drainage. Significance Statement There is a need to better understand how an increasing influx of freshwater, one part of a changing Arctic climate, will affect the development of sea ice. Current instruments can provide information on the growth rate, extent, and thickness of sea ice, but not direct observations of the structure of the ice during freeze up, something that is tied to salinity and local air and water temperature. A first deployment in Elson Lagoon in Utqiaġvik, Alaska, showed promising results; we observed fluctuations in ice temperatures in response to brief warmings in air temperature that resulted in changes in the conductivity, liquid fraction, and brine volume fraction within the ice.

A novel method for measuring latent heat of low-temperature PCM phase transition by oxygen bomb calorimeter

The method for the determination on the latent heat of phase change by oxygen bomb calorimetry of low-temperature phase change materials (PCMs) was feasible and validated. Experiments on the solidification of the variable boundary temperature of OP24 (the ratio was 57.5% caprylic acid + 42.5% myristic acid) low-temperature organic PCM, an energy storage medium, were carried out in a modified oxygen bomb calorimeter. In addition, a one-dimensional model of the solid–liquid two-phase cylindrical PCM solidification process was constructed by numerical simulation. Using the measured time-varying data of the PCM axial temperature, the oxygen bomb surface temperature, and the water temperature of the inner cylinder, the model was applied to approximate the latent heat of phase change of OP24 PCM using a cubic polynomial heat balance integration method. The calculated results were accurate for engineering applications when compared to the values obtained by differential scanning calorimetry. Moreover, the invisible phase interface moving with time could be obtained. The calculation process was relatively simple and convenient for engineering applications. Improving the accuracy of water temperature measurements in the inner cylinder could be the way forward to reduce experimental errors in the determination of the latent heat of phase change in low-temperature PCMs using oxygen bomb calorimetry.

How Heat Transfer Indirectly Affects Performance of Algae-Bacteria Raceways

Oxygenation in wastewater treatment leads to a high energy demand. High-rate algal-bacterial ponds (HRABP) have often been considered an interesting solution to reduce this energy cost, as the oxygen is provided by microalgae during photosynthesis. These complex dynamic processes are subject to solar fluxes and consequently permanent fluctuations in light and temperature. The process efficiency therefore highly depends on the location and the period of the year. In addition, the temperature response can be strongly affected by the process configuration (set-up, water depth). Raised pilot-scale raceways are typically used in experimental campaigns, while raceways lying on the ground are the standard reactor configuration for industrial-scale applications. It is therefore important to assess what the consequences are for the temperature patterns of the different reactor configurations and the water levels. The long-term validated algae-bacteria (ALBA) model was used to represent algae-bacteria dynamics in HRABPs. The model was previously validated over 600 days of outdoor measurements, at two different locations and for the four seasons. However, the first version of the model, like all the existing algae-bacteria models, was not fully predictive, since, to be run, it required the measurement of water temperature. The ALBA model was therefore updated, coupling it with a physical model that predicts the temperature evolution in the HRABP. A heat transfer model was developed, and it was able to accurately predict the temperature during the year (with a standard error of 1.5 C). The full predictive model, using the temperature predictions, degraded the model’s predictive performances by less than 3%. NO predictions were affected by %, highlighting the sensitivity of nitrification to temperature The temperature response for two different process configurations were then compared. The biological process can be subjected to different temperature dynamics, with more extreme temperature events when the raceway does not lie on the ground and for thinner depths. Such a situation is more likely to lead to culture crashes.

Comparison of the accuracy of two UAV‐mounted uncooled thermal infrared sensors in predicting river water temperature

AbstractMeasurement by a unmanned aerial vehicles (UAV) equipped with thermal infrared sensors has great potential as a new technique for understanding the spatial heterogeneity of river water temperature; however, the measurement technique has not been established yet. Therefore, this study measured surface and water temperatures using two uncooled thermal infrared sensors, which are commercially available, for 7 months, to obtain knowledge to establish a method for predicting the river water temperature using uncooled thermal infrared sensors mounted on UAVs. The survey covered a 500 m section upstream from the confluence of the Inukai River in the Katsura River of the Yodo River system, in Japan. DJI Zenmuse XT2 and MicaSense Altum were mounted on a DJI Matrice 300 at the same time and took images seven times at intervals of approximately 1 month between June 2021 and January 2022. The water temperature and depth were measured at several locations within the study area within 1.5 hr after the UAV acquisition. Then, the relationship between the measured water temperature and the surface temperature extracted from the thermal infrared orthorectified mosaic image was analyzed. Altum was more suitable than XT2 for obtaining thermal infrared orthorectified mosaic images with less inconsistencies among courses in the surface temperature range, and the difference in water temperature was also smaller, making it suitable for understanding the river water temperature. To predict water temperature from surface temperature, actual measured data of water temperature is necessary, but I demonstrated that it is possible to measure the river water temperature in a spatially continuous manner.

Time-Averaged And Time-Resolved Laser Optical Temperature Measurements In Water With Filtered Brillouin Scattering Combined With LDV

A laser measuring system was developed and built that allows to optically measure temperature in water using the method of Filtered Brillouin Scattering (FBS). First time-resolved optical temperature measurements were demonstrated. Furthermore, the FBS-system was combined with an LDV to enable simultaneous measurement of flow velocity and therefore the system is also capable to measure the heat flow. Time-averaged temperature values were determined with good accuracy and, as a special highlight, also time-resolved temperature measurements have been demonstrated with temporal resolution in the order of approximately 10 ms, validated by comparison with fast thermocouple measurements. The overarching goal of the research project was to prepare the market introduction of a laser-optical measuring system for spatially point-based and time-resolved measurement of the heat flow in liquids, especially in water. In order to realize this, it was necessary to measure the local velocity and the local temperature in a liquid. The optical measurement of the local velocity has long been possible using the established method of laser Doppler velocimetry (LDV). Therefore, the heat flow measurement method to be developed should be based on this technology. Until now, there was no suitable optical method for measuring the temperature. In recent years, however, the physical phenomenon of Brillouin scattering has become one focus of measurement technology development. If a small volume of liquid is irradiated with light, the molecules in the liquid scatter back part of the light, which is known as Brillouin scattering. The spectrum of the scattered light depends on the local temperature in the liquid; and it turns out that this physical relationship can be exploited to develop a highly accurate, fast, and non-contact method for measuring temperature. In this paper, we explain the Filtered Brillouin Scattering (FBS) method, show a setup for measuring temperature and velocity in water flows and thus a method for determining the heat flow, and demonstrate the measurement accuracy using a calibration test bench. The temperature measurement accuracy achieved is in the order of 1 K.

Simultaneous Measurement of Water Pressure and Temperature Based on a Simple Fabry-Pérot Sensor

We proposed a simple and compact Fabry-Perot (FP) sensor for simultaneous measurement of water pressure and temperature, composed of a standard fiber ferrule connector/flat contact (FC/FC) connector and aluminum foil attached to a thin metal plate. Two dips in the interference spectrum are selected to illustrate the response of the FP sensor to the water pressure and temperature, we can obtain the simultaneous measurement via a method of sensitivity coefficient matrix. Experimental results show the maximum sensitivity of −2.948 nm/kPa for water pressure sensing in 0~9 kPa and 1.119nm/°C for temperature sensing in 33~45 °C. In addition, the dual-parameter sensor has the advantages of compactness, stability, simple production, small size, and high sensitivity, making it suitable for a wide range of practical applications.

Characterization of marine heatwaves in the Cantabrian Sea, SW Bay of Biscay

The trend towards an increased incidence of marine heatwaves (MHWs) due to climate change poses a serious threat to the health of coastal ecosystems. Here, we characterized MHWs based on daily in situ water temperature measurements collected from 1998 to 2019 in two intertidal coves, Oleiros and La Franca, located in the central Cantabrian Sea coast, N Spain. The two study locations cover the transition zone between cold- and warm-temperate benthic communities that characterizes the biogeography of intertidal assemblages along the SW Bay of Biscay. We examined the incidence, duration and magnitude of MHWs, and assessed the emergence of trends towards more frequent, prolonged and intense MHWs during the study period. We further assessed mechanistic links with modes of climate variability by examining the association between MHW occurrence and the East Atlantic pattern (EA). We detected 78 MHW events between Jan. 1998 and Mar. 2019 (40 in Oleiros, 38 in La Franca) and more than half were synchronous among study locations. The incidence, duration, and intensity of MHWs were higher during the positive phase of the EA, which is associated with air pressures above normal and southwesterly winds during summer. The recorded MHWs also coincided with documented shifts in the abundance and distribution of dominant macroalgae species that triggered abrupt changes in the structure of intertidal communities of the region. Our findings and the present scenario of climate change emphasize the need to enhance research around the trends in the occurrence of MHWs in the coast of northern Spain, and the NE Atlantic Ocean coast in general.

Cave monitoring in Hungary: An overview

AbstractIn this study, already published and new monitoring data are compiled from the Baradla and Béke caves in the Aggtelek Karst, from the Vacska Cave in the Pilis Mountains as well as from the Szemlőhegy and Pálvölgy caves in the Buda Hills. Recent investigations (2019–2020) include monitoring of climatological parameters (e.g., temperature, CO2) measured inside and outside the caves, and the chemical, trace element and stable isotopic compositions of drip waters. In the Baradla Cave, the main focus of the investigation was on the stable isotope composition and the temperature measurements of drip water. In the Vacska Cave, which belongs to the Ajándék-Ariadne cave system, CO2measurements and drip water collection were conducted in order to perform chemical and stable isotope measurements. In the Szemlőhegy and Pálvölgy caves, the chemical and stable isotope compositions of drip waters at six sites were determined. These datasets were used to characterize the studied caves and the hydrological processes taking place in the karst, and to trace anthropogenic influences. Climatological investigation revealed seasonality in CO2concentration related to outside temperature variation, indicating a variable ventilation regime in the caves. In addition, the contributions of the winter and summer precipitation to the drip water were also estimated, in order to evaluate the main infiltration period. The knowledge of these parameters plays a crucial role in constraining the carbonate precipitation within the cave. Thus, the dataset compiled in this study can provide a basis for the interpretation of speleothem-based proxies.

Water Temperature Measurement Method Based on Square-Wave Signal Generator

Water temperature measurement is widely used and plays an important role in fishery breeding, agricultural irrigation, temperature control of household water heater and other aspects. People have a huge demand for water temperature measurement devices. The performance of the existing device is greatly affected by the environment and often requires manual intervention. The square-wave signal generator has simple structure, stable output, low energy consumption, easy operation and low price. The water temperature measurement method based on the square-wave signal generator can expand the application range of the square-wave signal generator, promote the convenience of measurement work and then improve the measurement sensitivity. Based on operational amplifier, Schmitt-Trigger Inverter and 555 Timer, the output frequency of the circuit changes according to the change of the overall resistance value of the circuit. A waterproof thermistor is added to the circuit and placed in water. The water temperature would change the resistance value of the overall circuit by changing the resistance value of the thermistor. Therefore, different output frequencies of the measuring circuit reflect different water temperatures. The working principles of the above three measuring circuits are specifically described, and their measuring characteristics are compared. It can be seen that the circuit based on 555 Timer has stable measuring performance and high sensitivity, which can be widely applied to the needs of water temperature measurement in production and life. What’s more, it provides a new idea for water temperature measurement.

Analysis of E. coli trends in the Wheeling Creek watershed

Escherichia coli (E. coli) is a gut bacterium found in intestinal tracts of warm-blooded animals and pollutes water bodies through fecal contamination. At high concentrations some strains can cause serious illnesses if ingested by individuals. High concentrations of E. coli can also indicate the presence of other potentially harmful pathogens. Surface waters can become contaminated via nonpoint sources of runoff from agricultural lands and resident waterfowl population and point sources including leaking sewage infrastructure and combined sewer overflows (CSOs). In freshwaters E. coli can live free floating throughout the water column or attached to streambed sediments, and when these sediments are resuspended due to precipitation E. coli concentrations increase in the water column. The USEPA has set a maximum safe limit for recreational waters at 235 CFU/100 mL of water for a single sample and a 30-day five-sample mean of 126 CFU/100 mL. We chose seventeen sampling sites to monitor and identify trends and predictors of E. coli in Wheeling Creek watershed, in the northern panhandle of West Virginia. We measured water temperature, pH, dissolved oxygen, conductivity, chloride, and turbidity in the field and used an IDEXX system for E. coli quantification. Our results indicate that 51% of samples (125 out of 245) have exceeded that single sample safe limit (235 CFU/100ml). Escherichia coli concentrations are increasing with increasing urban development and show a positive correlation with turbidity, this could suggest that humans are the primary source of E. coli in Wheeling Creek.

Analysis of the structural characteristics and spatial organization of macrobenthic fauna in Oualidia lagoon, Morocco

Morocco is a very rich country in terms of wetlands, including bays, estuaries, lagoons, lakes, and rivers, among others. However, many of them need to be well managed and better exploited, thus requiring baseline descriptive studies to assess faunal patterns and trends. Oualidia lagoon is not an exception. In fact, the studies conducted to date in the lagoon mainly focused on its oceanographic features and aquaculture capacities. The present paper presents the first study on the whole macrofaunal assemblages of Oualidia lagoon, having as main objectives analyze the composition and structure of the assemblages, as well as their relationships with the main environmental variables explaining their spatial distribution variability in the enclosed ecosystem of the Oualidia coastal lagoon. The benthic macroinvertebrates of Oualidia lagoon were studied in summer 2013 based on 43 stations spread over the whole lagoon by using a Van Veen grab. Two replicate samples were collected for macrobenthos and one additional replicate for sediment analyses at each station. Also, single water salinity and temperature measurements were recorded at each station. Fifty-one species from seven different taxa were recorded, among which mollusks (37%), polychaetes (25%) and crustaceans (25%) dominated in terms of species number. Peringia ulvae, Abra alba, Sphaeroma serratum, Cerastoderma edule and Corophium sp. accounted for 88% of total abundance. The benthos was structured along a downstream–upstream gradient, showing three assemblages, named according to the IndVal index: (1) Diopatra cf. marocensis, (2) Peringia ulvae, and (3) Cerastoderma edule, while the main factors driving their distribution were granulometry and salinity. The Biotic and Environmental analysis showed that the combination of granulometry and salinity was the major factors controlling the spatial distribution of the macrozoobenthos in the Oualidia Lagoon.

Passive acoustic monitoring during the construction of the Coastal Virginia Offshore Wind project

A suite of hydrophone arrays was deployed to monitor pile driving sound and seafloor particle motion during construction of two wind turbine towers in the Coastal Virginia Offshore Wind (CVOW) project in May 2020. The primary objective of this passive acoustic monitoring (PAM) work was to assess the effectiveness of bubble curtains for underwater noise mitigation. The arrangement of the PAM tracks also enabled studies of azimuthal and range dependencies of pile driving sound propagation. Measurements of water temperature, salinity and surface heights were made during the monitoring period to assess underwater sound propagation conditions. PAM data showed that the bubble curtain effectively reduced the pile driving noise above 200 Hz, and a significant azimuthal dependency was observed. Statistical analyses of pile driving noise will be presented, along with recommendations for future wind farm construction monitoring, especially on marine mammal acoustic monitoring during construction. [Work supported by the Bureau of Ocean Energy Management]

Система прогноза ветровых апвеллингов для российского побережья Черного моря

The paper presents a forecast system for wind Ekman upwelling for the Black Sea coast. The system is based on the calculation of the upwelling criterion, which depends on the wind speed and wind direction and the thickness of the upper mixed layer. The archived wind forecast was extracted from the COSMO-Ru07 model. The upwelling forecast with a lead time of 24–72 hours was calculated for three points off the Crimean coast for the period from May to November 2019. The quality of upwelling forecasts was assessed using in situ water temperature measurements in Balaklava, Foros, and Partenit. The comparison showed that 50% of the cases of a significant temperature drop for Foros and Balaklava are successfully predicted with a lead time of 48–72 hours. The cases of the significant temperature drop are rare in the study region, so the result is unsatisfactory. A part of cases that were not predicted by the system are probably downsurge upwellings or the horizontal advection of cold water. Keywords: upwelling, Black Sea, upwelling forecast, COSMO-Ru07, sea temperature

The paper presents a forecast system for wind Ekman upwelling for the Black Sea coast. The system is based on the calculation of the upwelling criterion, which depends on the wind speed and wind direction and the thickness of the upper mixed layer. The archived wind forecast was extracted from the COSMO-Ru07 model. The upwelling forecast with a lead time

Criteria of cumulative temperatures for the calculation of optimal sowing periods for winter grain crops (wheat, triticale, rye) were specified on the basis of monitoring data from the hydrometeorological observation network, results of tilling capacity studies, and literary sources. The optimal sowing periods and average air temperature for these periods were determined, which provide the highest correlation between the beginning and end of the sowing periods for winter crops. The equations of the relationship between the dates of the beginning and end of winter grain crop sowing at the observation stations are derived depending on average air temperature. Optimal periods for sowing winter grain crops were determined for the period from 2000 to 2020. A distribution of cumulative active temperatures (zoning) on the territory of Belarus for the autumn period was obtained. Аn algorithm for specifying optimal sowing periods for winter grain crops in a particular year оn the basis of forecasted temperature for September was developed. Keywords: climate change, cumulative temperatures, nongrowing season dates, optimal sowing periods for winter grain crops