The researchers also use this method. Either method frequently used to measure the diameter of the point rainfall is to use flour that is put on a place and left open under the rain, and can be counted diameter of a grain rain. Results from several measurement with the flour using this method the most accurate data is measurements made by Laws & Parsons. They do measurements in Washington DC for some type of rain.
Along with the development of increasingly sophisticated technology the measurement is done using the latest modern equipment. Equipment including the other: electromechanical sensor that is known by the name "Disdrometer" change the dots fall on the rain into a cavity pulse electrics, besides there is also called the electrostatic sensor measure the diameter size of the rain that point depends on the electric point charge on the rain, have also called the optical detector 2 fruits emit parallel light beam that can measure the size of the diameter and speed of the rain through the beam.
After finding a way to make measurements on diameter that point the rain is very small. This method on a which are given a pot of oil and placed under rain. Then dots of light rain in the top of the oil with the relatively small size can be measured. Thickness of oil can be make a point without oil penetrate rain damaged (broken). Point rain smallest diameter that can be measured is 0.025 mm.
Form and Size of Rainfall
Form of measurement of rainfall has been made by the researchers. This measurement indicates that the point rainfall has a diameter > 1 mm have a spheroidal shape (such as the ball) with a flat base. At the point where the process of rain fall and be on air will pro late spheroid shape, and after fall over the land surface will oblate spheroid shape. Measuring the depth of rainfall from one of the refers to Beard & Pruppacher. They use design vent with very carefully to minimize the turbulence in the flow of air so that they can reach the point of rain the ideal.
Form of the rain in the final speed can be calculated if the theoretical equation describing the settlement of stability internal and external pressure on the surface point rain. This is difficult done to complete the analytical equation. With assumption that the point is that rains oblate spheroid, Sphilhaus calculate the axial ratio of rainfall with a large introduction of some measurements by using the coefficient formula:
Axial ratio=a/b
a=high radius of rainfall
b=width radius of rainfall
Jones measure the shape of each of the two speckle camera the optically axis mutually orthogonal and are on the field horizontal axial ratio to find out the truth. Results shows that the forms Lighted from oblate to pro late spheroid. Example to drop ball equivolumetric with radius A0 1.5 mm axial ratio a / b is from 0.6 to 1.2, where 2a and 2b is the width of the spotty. Speck can be seen in the picture below
Differences in measurements of the two axial ratio appears to widen even consider the conditions and methods of measurement different. The form of droplets of water fall on the speed of the terminal can be calculated theoretically if the settlement of a describing equation balance of internal and external pressure on the speckled surface.
Imai calculate form of low rainfall (patter-patter) with the assumption of potential flow around the point and find the rain that point to a more rain to form oblate spheroid. Look at the picture below. (a) oblate spheroid (b) prolate speheroid.
Pruppacher and Pitter found that the measurement of pressure aerodinamic around the surface of a rigid sphere is very close to the pressure that is permitted (without internal pressure in the internal circulation) from the calculation of the water droplets form of point rainfall measurements. Look at the picture below. Thirteen forms which measured by Pruppacher and Pitter.
By using this invention they solve numerical equality of pressure balance and the shape of point rainfall in various sizes. Comparison between calculation and point measurements of rainfall show that the agreement is very good.
Along with the development of increasingly sophisticated technology the measurement is done using the latest modern equipment. Equipment including the other: electromechanical sensor that is known by the name "Disdrometer" change the dots fall on the rain into a cavity pulse electrics, besides there is also called the electrostatic sensor measure the diameter size of the rain that point depends on the electric point charge on the rain, have also called the optical detector 2 fruits emit parallel light beam that can measure the size of the diameter and speed of the rain through the beam.
After finding a way to make measurements on diameter that point the rain is very small. This method on a which are given a pot of oil and placed under rain. Then dots of light rain in the top of the oil with the relatively small size can be measured. Thickness of oil can be make a point without oil penetrate rain damaged (broken). Point rain smallest diameter that can be measured is 0.025 mm.
Form and Size of Rainfall
Form of measurement of rainfall has been made by the researchers. This measurement indicates that the point rainfall has a diameter > 1 mm have a spheroidal shape (such as the ball) with a flat base. At the point where the process of rain fall and be on air will pro late spheroid shape, and after fall over the land surface will oblate spheroid shape. Measuring the depth of rainfall from one of the refers to Beard & Pruppacher. They use design vent with very carefully to minimize the turbulence in the flow of air so that they can reach the point of rain the ideal.
Form of the rain in the final speed can be calculated if the theoretical equation describing the settlement of stability internal and external pressure on the surface point rain. This is difficult done to complete the analytical equation. With assumption that the point is that rains oblate spheroid, Sphilhaus calculate the axial ratio of rainfall with a large introduction of some measurements by using the coefficient formula:Axial ratio=a/b
a=high radius of rainfall
b=width radius of rainfall
Jones measure the shape of each of the two speckle camera the optically axis mutually orthogonal and are on the field horizontal axial ratio to find out the truth. Results shows that the forms Lighted from oblate to pro late spheroid. Example to drop ball equivolumetric with radius A0 1.5 mm axial ratio a / b is from 0.6 to 1.2, where 2a and 2b is the width of the spotty. Speck can be seen in the picture below
Differences in measurements of the two axial ratio appears to widen even consider the conditions and methods of measurement different. The form of droplets of water fall on the speed of the terminal can be calculated theoretically if the settlement of a describing equation balance of internal and external pressure on the speckled surface.Imai calculate form of low rainfall (patter-patter) with the assumption of potential flow around the point and find the rain that point to a more rain to form oblate spheroid. Look at the picture below. (a) oblate spheroid (b) prolate speheroid.
Pruppacher and Pitter found that the measurement of pressure aerodinamic around the surface of a rigid sphere is very close to the pressure that is permitted (without internal pressure in the internal circulation) from the calculation of the water droplets form of point rainfall measurements. Look at the picture below. Thirteen forms which measured by Pruppacher and Pitter.
By using this invention they solve numerical equality of pressure balance and the shape of point rainfall in various sizes. Comparison between calculation and point measurements of rainfall show that the agreement is very good.
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