1. Температура почвы

    • Summing up the results of the September Freeze in 2015/2016 academic year

      Dear Colleagues!

      In measuring the temperature of the soil participated Petrozavodsk and St. Petersburg, Moscow and Izhevsk, Republic of Tatarstan, Rostov region and the Astrakhan region.

      Of the participants with a high temperature in the day freeze frame start analysis profiles Cherkov-Grishensky school. When the air temperature 26 ° C, the surface of the air warmed to 29 ° C. Thus, when the air temperature measured at a depth of 10 cm, was quite significant difference - 18 ° C. At a depth of 20 cm has a total of 14 ° C.

      The group from the village Melikhovo Lazoriki initial data seems to be similar. High temperatures - 30 ° C, the surface temperature of the soil - 31 ° C. But then begin strangeness: at a depth of 10 cm - 31 ° C, and at a depth of 20 cm - 30 ° C. It seems to be intuitively clear that the soil warms up slowly and under a layer of earth is colder than on the ground. Man enjoyed this property, digging cellars. I think that in this case should be clarified how well the group Lazoriki complied with the study protocol.

      But the results of the participants from the village. Red Barricades can understand one of the reasons resulting in measuring errors. Look at the picture, which they placed in the questionnaire.

      When measuring only part of the "probe" sensor is immersed in the soil, it can be assumed that the participants did not pre-groove in the soil, as required by the protocol of the project and tried to plug the sensor directly into the soil. This gives rise to resistance, so it seems that you can not continue to stick to not to break the sensor. However, these temperature sensors have one unexpected property - is the measure of the entire length of the sensor. Therefore, half of the sensor measures the actual temperature of the soil at the desired depth, and half of the sensor is located in a warm outdoor air. As a result, there is a strong distortion of the measurement result.

      The same pattern can be seen from the other participants in the project, working with digital temperature sensors.

      I am very interested in the results of a member from St. Petersburg. This is the only form in which it is noted that the deeper the soil temperature is higher, although the difference is small. However, and in St. Petersburg temperature is lower than most of the other participants. The conclusion, which made the student with the nickname alice30701, coincides with the conclusions that have made my own students in stop-frame last year. In the autumn the soil cools rapidly from the surface, and at depths of more stores heat. In the spring, on the contrary, the deeper the cooler because the soil warms up gradually, starting from the surface. (This can be read in the article below, dedicated to the analysis of the March freeze-frame of the last school year).

      Maybe you can share with us their own findings and observations?

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    • Summing up the March Freeze

      Dear friends!

      The results of this project were quite diverse.

      So participants from Marx pointed out that they are having difficulty because of the area was covered with snow, in other places the snow has melted and the soil temperature at these points are different, so they decided to average values. I think that I would have chosen in their place a single point measurement is likely without snow and wrote about the conditions of the measurements in the text field of the questionnaire.

      Participants from Astrakhan observed typical spring picture that confirms many other profiles. The soil surface warmed by the sun is strong enough, and at a depth of 10 cm temperature drops sharply. The deeper the soil temperature is below. It is known, for example, that the potatoes can be planted when the soil warms up to 10 ° C, and in Astrakhan at a depth of 20 cm only 5 ° C, is obtained for gardening early.

      Participants from SHNOU "Vita" made in your profile detailed findings:

      1. The temperature on the surface of the soil is higher than the air temperature.
      2. When the wind blows the air temperature varies slightly, the soil temperature remains almost unchanged.
      3. When lowering the electrode to a depth in the soil, the temperature slightly decreases.

      Soil temperature have been significantly lower than in Astrakhan, which is not surprising, as more snow is preserved.

      In St. Petersburg, there was no snow, the soil is warmed better than in Rzhev, but the trend is similar, the deeper, the lower the temperature of the soil.

      Maybe you can share with us their own findings and observations?


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    • Scientific adviser GlobalLab asking questions ... discuss?

      For me there was always a mystery how plants manage to survive the winter, for example, in the mid-latitudes. Near Moscow visited the January cold, when the temperature dropped to -35 or even -39 degrees Celsius. I remember that once the new year, many cars that were on the street, not start from cold. Even antifreeze does not always help. But what about the underground parts of the plant? Roots, tubers? Well, the roots can go many meters deep. A tubers daffodils, for example, because they spend the winter at a shallow depth?


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