Optical instruments displace Tretyakov’s bucket

    Despite the crazy pace of technology development on the planet, there are such conservative areas of knowledge where any novation can appear only after decades of close comparative experiments. One such area is meteorology. The pros and cons of this situation on the example of a specific measuring device - precipitation meter - I propose to discuss under the cut.



    What are we measuring?


    Meteorological measurements are based on measurements of basic physical quantities - temperature, pressure, relative humidity, wind direction and speed. These are the main characteristics, from which, with the help of various transformations and sometimes not simple formulas, additional (but no less important) meteorological parameters are restored

    - the average values ​​of relative humidity;
    - the elasticity of water vapor;
    - moisture deficit;
    - dew point temperature;
    - intensity of fluctuations in temperature and wind speed;
    - vertical flows of heat and momentum;
    - characteristic scales of turbulent fluctuations in temperature and wind speed
    , etc.


    All these parameters are necessary for building forecast maps and keeping trends of long-term meteorological observations. Data collection has been going on for more than 150 years and the main principle that operates in this conservative area is not to rush to change measuring instruments.

    What's the problem?


    According to the principle of correctness of metrological measurements, all measurements should be clearly regulated and carried out by one type of measured sensor. For example, you need to measure the temperature. We measure it in a special box, at a certain height, at the same time every day, with the same thermometer. The thermometer is out of order - we replace it with a metrological attorney of the same brand or type. What if we want to automate the process? Put a digital sensor! More accurate and not wrong, unlike the meteorologist at the station. It is impossible. It is necessary to ensure data convergence and not disrupt the trend of long-term observations. Thus, in order to replace the sensor with a new one, it is necessary to take readings from the old and at the same time from the new one, watch data convergence and measurement gaps, do special comparative tests and,

    Precipitation measurement


    The most troublesome, perhaps, is the measurement of precipitation. Nothing better has been invented here than a simple bucket of a construction by V. D. Tretyakov. It consists of a vessel with a receiving area of ​​200 cm² and a height of 40 cm, where precipitation is collected, as well as special protection (these petals are in the photo above), which prevents wind blowing away of precipitation. The precipitation gauge is installed so that the receiving surface of the bucket is at a height of 2 meters above the soil. The amount of precipitation in mm of the water layer is measured with a measuring cup with the divisions applied on it, and the amount of solid precipitation is measured after it melts in room conditions. Here is a method. I foresee various malicious comments, but I write as it is. But despite the conservatism of the industry, there are brave developers and companies who are ready to offer new approaches to measurements in meteorology.

    Optical precipitation meter


    The development of IMCES SB RAS turned out to be the most successful design of a fully automated precipitation meter. The device implements the optical principle with the processing of images of drops and snowflakes in a certain measuring volume.


    The principle of operation is extremely simple. Drops or snowflakes fly in the center and literally cast shadows on the optical radiation receiver from the source. Measurements are taken in mutually orthogonal areas, which reduces the effect of overlap. The device (RF patent No. 119898) showed amazing characteristics. The maximum sensitivity for the amount of measured precipitation is 2 • 10-5 mm. The device eliminated the influence of wind undercounting characteristic of the Tretyakov bucket. The meter can work offline with the issuance of information to a remote server. An interesting feature of the device is the ability to measure precipitation strength, gusts, droplet velocities and type of precipitation. The device is able to distinguish between rain, snow and hail.

    Summary


    The developers of the device will use its next modification in a major project of IMCES SB RAS to create a large-scale system for monitoring and forecasting the state of the atmosphere. This project has an industrial partner, Sibanalitpribor LLC, and from the state side the project is supported by the Ministry of Education and Science (agreement No. 14.607.21.0030).

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    Can science solve the problem of correct weather forecasting?

    • 13.1% Yes, perhaps in the near future we will see a breakthrough in weather forecasting methods. 77
    • 46.6% Short-term forecasts (up to a week) at least make accurate! 274
    • 25.2% Perhaps this task is too complicated. Breakthroughs are not worth the wait ... 148
    • 13.9% Yes, normally they give forecasts in general. It works for me! 82
    • 1% I have my own opinion and I will write a comment now! 6

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