KR101040597B1 - Method of estimating a atmospheric boundary layer height using a automatic weather system and terra/modis data - Google Patents

Abstract

The present invention relates to a method for calculating the mixed layer altitude, and more particularly, to a method for calculating the mixed layer altitude by an indirect method.

Mixed layer altitude calculation method according to the present invention, the first step of collecting the longitudinal observation data and the vertical temperature profile data provided by the satellite weather observation equipment measured in the automatic weather observation equipment of the observation point; Calculating a feeling heat flux in an indirect manner using synoptic observation data; And a third step of calculating the mixed layer altitude by an indirect method using the vertical temperature profile data and the feeling heat flux calculated in the second step.

According to the present invention, it is possible to calculate the mixed layer altitude at a low cost and manpower by calculating the mixed layer altitude of the whole country using only the synoptic observation data and the satellite observed temperature profile data. In addition, by using a simple method to calculate the altitude of the mixed layer throughout the country, there is an excellent effect that can be used as input data to improve and cope with various environmental problems.

Mixed Layer Altitude, Integral Method, Vertical Temperature Profile, Temperature Profile, Terra / MODIS

Description

METHODS OF ESTIMATING A ATMOSPHERIC BOUNDARY LAYER HEIGHT USING A AUTOMATIC WEATHER SYSTEM AND TERRA / MODIS DATA}

The present invention relates to a method for calculating the mixed layer altitude, and more particularly, to a method for calculating the mixed layer altitude by an indirect method.

In general, a mixed layer is a part of an atmospheric boundary layer, which is an atmospheric layer influenced by the ground, and is mixed by convection generated by heating of lower layer atmosphere by solar radiation and turbulence by vertical shear of wind, that is, thermal A layer in which the atmosphere is vertically mixed due to mixing and mechanical mixing. In such a mixed layer, heat, momentum, pollutants, etc. are uniformly distributed regardless of the altitude, and thus the mixed layer altitude, together with atmospheric stability, is a value that greatly influences the diffusion and transport of pollutants. Therefore, the study on the mixed bed altitude is essential to investigate the effects of air pollutants.

In the atmospheric boundary layer, the mixed layer altitude repeats the fluctuations of growth and disappearance by the buoyancy term by solar radiation and the sear term by wind. Therefore, in order to measure the mixed layer altitude of the atmospheric boundary layer to date, the sonde sensor has to be raised from the ground observation point and estimated from the vertical distribution of meteorological elements such as temperature, temperature, wind, and mixing ratio observed at 5 second intervals from the sonde. did. At this time, in the case of temperature, the inflection point at which the vertical change rate changes from positive to negative or zero, or the altitude where the temperature does not change with the altitude is determined as the mixed layer altitude.

However, the method of measuring the mixed layer altitude using the sonde has a disadvantage that the measurement point is narrow, so that a lot of investment is required in terms of time, cost, and manpower in measuring the mixed layer altitude over a wide range.

Therefore, efforts are being made to develop methods for quantitatively calculating mixed layer altitudes in large areas at low cost and manpower.

The present invention has been invented to solve the above problems, an object of the present invention is to provide a method for calculating the mixed layer altitude of the entire region using a low cost and manpower.

Mixed layer altitude calculation method according to the present invention to achieve the above object, the first step of collecting the vertical weather observation data measured by the automatic weather observation equipment of the weather observation point and the vertical temperature profile data provided from the satellite; Calculating a feeling heat flux in an indirect manner using synoptic observation data; And a third step of calculating the mixed layer altitude by an indirect method using the vertical temperature profile data and the feeling heat flux calculated in the second step.

In this case, the vertical temperature profile data collected in the first step may be vertical temperature profile data provided from Terra / MODIS.

In addition, the indirect method for calculating the feeling heat flux in the second step may be the Penman Monteith Method (PMM), and the indirect method for calculating the mixed layer altitude in the third step may be an integration method.

According to the present invention, it is possible to calculate the mixed layer altitude at a low cost and manpower by calculating the mixed layer altitude of the whole country using only the synoptic observation data and the satellite observed temperature profile data.

In addition, by using a simple method to calculate the altitude of the mixed layer throughout the country, there is an excellent effect that can be used as input data to improve and cope with various environmental problems.

The present invention will now be described in detail with reference to the accompanying drawings.

In the first step, the method for calculating the mixed layer altitude using the automatic meteorological observation equipment and the Terra / MODIS data is collected in the first stage. 68 ASOS (automatic synoptic observation stations) operated by the Korea Meteorological Administration (KMA) are networked with the local meteorological main computational system, providing a database of the local meteorological data collected in real time. The average spatial resolution of these synoptic observation points is about 60 km, and the data related to the present invention are shown in Table 1.

TABLE 1

Measurement data (unit) Measurement altitude Measuring interval Temperature (℃) 1.5m

1 hours Relative Humidity (%) 1.5m Wind speed and direction 10 m Amount of clouds - Solar radiation (Wm ^-1 ) 2 m Underground temperature (℃) 0m

In order to calculate the mixed layer altitude, observation data on the upper part of the mixed layer is generally required in addition to the data of the ground surface. However, there is a problem that observation data on the top of the mixed layer is generally difficult to obtain.

On the other hand, the satellite can provide the temperature profile data by scanning the earth atmosphere using the attached sensor. In particular, in case of Terra / MODIS, when scanning the Korean peninsula about twice a day, the atmospheric state is provided as temperature profile data of 20 layers, and the measured data are temperature, pressure, and altitude. Thus, the temperature profile provided from the satellite can be used in various modifications. FIG. 1 is a graph showing temperature profile data provided from satellites as warm weather data. For comparison, the temperature data measured using the Sonde sensor are also shown. Through this, it can be seen that the temperature data using the vertical temperature profile data show a similar daily change to the actual measured value. In the present invention, the temperature data of 1000, 950, 920 and 850 hPa belonging to the atmospheric boundary layer is used in the vertical temperature profile data. Especially, between 920 hPa and 850 hPa corresponds to the inflow zone of the mixed layer, the temperature gradient between these altitudes is Use as a reduction rate.

The method of calculating the mixed layer altitude of the present invention uses synoptic observation data collected every hour throughout Korea, and uses the temperature profile data provided by the satellite instead of the observation data on the upper layer meteorology with low cost and manpower. It is possible to calculate mixed altitudes across Korea.

In the second step of the present invention, the ground heat data is used to calculate the feeling heat flux in an indirect manner. In order to understand the state of heat and momentum due to turbulent motion in the surface layer below the atmospheric boundary layer, the feeling heat flux should be considered. The sensation heat flux can be measured not only directly by using a scintillometer using the properties of light and by using an ultrasonic wavemeter using a statistical method through sound waves, but also by an indirect method.

In the present invention indirectly calculate the feeling heat flux, in particular using the Penman-Monteith Method (PMM). PMM has the advantage of describing turbulent motion of the ground layer with only one temperature, humidity, and wind speed data, which indicates that it is possible to use synoptic observation data used as data in the present invention.

Hereinafter, a brief description will be made of a method of calculating the feeling heat flux through PMM.

와

를 구한다. To calculate the feeling heat flux in PMM, first use the following equation.

Wow

.

[Equation 1]

[Equation 2]

는 마찰속도이며,

는 공기역학저항으로, 운동량, 열 등의 전달에 대한 저항을 의미하는 값이다.

는 데이터를 측정한 고도이고,

는 마찰길이(m)로 0.03m 이며,

는

고도에서의 풍속자료로, 일반적으로 10m 높이에서 측정된 풍속자료를 이용한다.

는 폰카르만(von karman)상수로 0.4의 값을 사용하고,

은 오브코프(Obukhov)길이이며,

과

는 각각 운동량플럭스와 느낌열플럭스에 대한 안정도 보정함수이다.

Is the friction rate,

Is aerodynamic resistance, which means resistance to the transfer of momentum and heat.

Is the altitude of the data measured,

Is the friction length (m) of 0.03m,

Is

For wind speed data at altitude, wind speed data usually measured at a height of 10 m are used.

Uses a value of 0.4 for the von karman constant,

Is the length of Obukhov,

and

Are stability correction functions for momentum flux and feeling heat flux, respectively.

은 임의의 고도에서의 모닌-오브코프(Monin-Obukhov) 안정도 매개변수로서, 시어(shear)생성에 대한 부력생성의 상대적 중요성을 나타내는 열적 안정도이다.

이면 부력에 의해 난류가 생성되어 대기경계층이 불안정한 상태이고,

이면 난류에 의한 부력이 소멸되어 대기경계층이 안정한 상태이다. 그리고

이면 부력효과가 대기구조와 역학에 거의 영향을 미치지 않은 중립상태를 나타낸다. Meanwhile,

Is the thermal stability of the Monin-Obukhov stability parameter at any altitude, indicating the relative importance of buoyancy for shear generation.

If the turbulence is generated by buoyancy, the atmospheric boundary layer is unstable.

In this case, the buoyancy caused by turbulence disappears and the atmospheric boundary layer is stable. And

The buoyancy effect is neutral, with little effect on atmospheric structure and dynamics.

이 무한대의 값을 갖게 되고, 따라서

과

을 포함하는 성분은 각각 0으로 취급된다. 또한,

고도에서의 풍속을 0으로 가정하고

고도에서의 풍속자료인

를 대입한다. 이러한 값을 수식1과 수식2에 대입하여

와

를 산출한다.In order to find the values of Equations 1 and 2, first, a neutral condition is assumed. In neutral conditions

Will have this infinity, so

and

Each component containing is treated as zero. Also,

Assume that the wind speed at altitude is zero

Wind speed data at altitude

Replace with. Substituting these values into Equation 1 and Equation 2

Wow

Calculate

와

를 일반화된 PMM인 다음의 수식에 대입하여 중립조건의 느낌열플럭스(

)를 산출한다.Thus, assuming neutral conditions

Wow

Is substituted for the generalized PMM by the following equation.

) Is calculated.

[Equation 3]

이며,

는 공기의 정압비열로 1004JKkg^-1이고,

는 대기중의 기압이고,

는 물의 증발잠열로 2.5x10⁶Jkg^-1이다. At this time,

Is,

Is 1004JKkg ^-1 as the constant pressure of air

Is the atmospheric pressure,

Is the latent heat of evaporation of water at 2.5x10 ⁶ Jkg ^-1 .

는 잎의 기공에 관한 저항값으로, 토양의 습윤상태와 계절변화에 따라 식생의 기공상태를 경험식으로 적용한다.

는 공기역학저항을 의미하며,

는 기후적인 저항을 의미한다.

는 온도곡선에 대한 포화수증기압 기울기를 나타내는 경험식이며,

는 태양복사에너지로 기인하는 가용에너지이다.

Is the resistance value of the pore of the leaf, and the pore state of vegetation is applied empirically according to the wet state of the soil and the change of season.

Means aerodynamic resistance,

Means climatic resistance.

Is an empirical equation representing the gradient of saturated steam pressure over a temperature curve.

Is available energy due to solar radiation.

Substitute each term into Eq. 3 to calculate the feeling heat flux. The length of the obcorp is calculated by substituting the frictional velocity and the feeling heat flux calculated in the neutral condition as follows.

[Equation 4]

는 중력가속도이고,

는 지면온도와 1.5m 높이에서 측정된 기온을 평균한 온도이다.In Equation 4

Is the acceleration of gravity,

Is the average of the ground temperature and the temperature measured at a height of 1.5 m.

Next, the stability correction function is applied to consider the stability of the previously obtained values.

인 경우, 즉,

이 0보다 크거나 같은 경우에, 안정도 보정함수는 다음과 같다.

, That is,

If this is greater than or equal to 0, the stability correction function is

[Equation 5]

인 경우, 즉,

이 0보다 작은 경우에, 안정도 보정함수는 다음과 같다.And

, That is,

If this is less than zero, the stability correction function is

[Equation 6]

이다. In Equation 6

to be.

By using the correction functions for the momentum flux and the heat flux thus obtained, it is possible to calculate the frictional speed, the feeling heat flux, and the ofcope length in consideration of stability by repeating Equations 1 to 8 again.

In the third step of the present invention, the mixed layer altitude is indirectly calculated using the feeling heat flux calculated in the second step.

The mixed layer altitude in the atmospheric boundary layer depends on the atmospheric stability and the surface flux. The mixing in the atmospheric boundary layer actively promotes the transport of turbulence and convection by the sensational heat flux upwards to the surface heating by solar radiation at midday. It is common to ignore the role of dynamic turbulence when based on thermal methods, which can also be used to simulate mixed bed altitudes. In the case of unstable atmospheres, the mixed bed elevation simulated by thermodynamic methods can account for 80-90% of the observations. In this way, the daily change of the mixed layer altitude over time can be calculated by the following equation.

[Equation 7]

는 혼합층상부의 온위경도 또는 기온감율로, Terra/MODIS의 연직온도프로파일로 구할 수 있다.

는 종관기상관측 자료를 PMM으로 산출한 느낌열플럭스, 즉 지표면의 느낌열플럭스이고,

는 혼합층고도에서의 느낌열플럭스 이다.

Is the temperature gradient or temperature gradient of the upper layer, which can be obtained from the vertical temperature profile of Terra / MODIS.

Is the heat-excitation heat flux calculated from the PMM as PMM.

Is the felt heat flux at the mixed layer altitude.

와 같이 매개변수화 할 수 있으며, 이를 대입하고 수식7을 적분하면 다음과 같이 표현할 수 있다.If we assume that the exothermic heat flux emitted from the surface decreases linearly with altitude in the case of convective wind speeds, the exothermic heat flux at the top of the mixed bed

It can be parameterized as follows. Substituting it and integrating Equation 7 can be expressed as follows.

[Equation 8]

는 혼합층 상부의 온위경도로서, Terra/MODIS 위성으로부터 제공받은 연직온도프로파일 자료로부터 구할 수 있다.

는 존데센서로 측정한 혼합층고도이고,

는 느낌열플럭스를 산출하는 초 기 시간이며,

는 느낌열플럭스를 산출하는 종료시간이다. In Equation 8, the inflow coefficient C is 0.2.

Is the temperature gradient above the mixed bed and can be obtained from the vertical temperature profile data provided by Terra / MODIS satellite.

Is the mixed bed altitude measured by the sonde sensor,

Is the initial time to produce the feeling heat flux,

Is the end time for calculating the feeling heat flux.

Since the integrator of Equation 8 is the sum of the observation start time and the end time, the mixed layer altitude according to the time change and stability can be expressed by the following equation by substituting the feeling heat flux of the surface layer calculated by PMM in the second step.

[Equation 9]

The method of calculating the mixed layer altitude described above is called an integral method, and the mixed layer altitude of the hour can be calculated in any place in Korea using only the heat flux profile and the sensed temperature profile data provided through the satellite observation data. Hereinafter, the effect of the mixed layer height calculation method of the present invention.

2 is a graph showing the variation of the mixed layer altitude calculated by the mixed layer altitude calculation method of the present invention. The mixed layer altitude was calculated using the data of May 24, 2005 and October 26, 2005, and the value calculated by the integrating method using the upper layer observation data together with the value (□) calculated by the present invention (△). And the value (+) measured using the Sonde sensor is displayed together. According to this, it can be seen that the mixed layer altitude calculated by the present invention shows a similar change in the mixed layer altitude measured by the Sonde sensor.

Figure 3 is a graph comparing the two values in order to show the correlation between the mixed layer altitude calculated by the present invention and the value observed with sonde. The data were mainly selected on a clear day to calculate mixed layer altitudes. The data were expressed as winter (+), spring (□), summer (◇) and autumn (*) to distinguish the data by season. As a result of analyzing this data, the mixed layer altitude calculated by the present invention and the mixed layer altitude observed by Sonde showed a correlation of 0.85 or more, indicating that the mixed layer altitude calculation method of the present invention can be actually applied. have.

4 is a diagram illustrating a mixed layer altitude calculated for all regions of Korea using the mixed layer altitude calculation method of the present invention. The results were calculated using the randomly extracted measurement data at 12 pm and 3 pm on September 7, 2008 (a), 8 (b) and 9 (c).

As described above, when the mixed layer elevation calculation method of the present invention is used, it is understood that the mixed layer elevation is calculated as the input data for improving and coping with various environmental problems.

In the above, the present invention has been shown and described with respect to certain preferred embodiments. However, the present invention is not limited only to the above-described embodiment, and those skilled in the art to which the present invention pertains can make various changes without departing from the technical spirit of the present invention. Therefore, the scope of the present invention should not be limited to the specific embodiments, but should be construed as defined by the appended claims.

FIG. 1 is a graph showing temperature profile data provided from satellites as warm weather data.

2 is a graph showing the variation of the mixed layer altitude calculated by the mixed layer altitude calculation method of the present invention.

Figure 3 is a graph comparing the two values in order to show the correlation between the mixed layer altitude calculated by the present invention and the value observed with sonde.

4 is a diagram illustrating a mixed layer altitude calculated for all regions of Korea using the mixed layer altitude calculation method of the present invention.

Claims (4)

A first step of collecting longitudinal observation data and vertical temperature profile data provided from satellites measured by automatic weather observation equipment at the observation point; A second step of calculating the feeling heat flux using the synoptic observation data; And a third step of calculating a mixed layer altitude using the vertical temperature profile data and the feeling heat flux calculated in the second step. The method of claim 1, And a vertical temperature profile data collected in the first step is a vertical temperature profile data provided from Terra / MODIS. The method of claim 1, In the second step, the method for calculating the feeling heat flux is a PMN (Penman Monteith Method), The PMM collects the synoptic observation data collected in the first step. Equation

Wow Equation

Apply to,

Is the altitude of the data measured,

Is the friction length (m) of 0.03m,

Is

Wind speed data measured at a height of 10m at altitude.

Uses a value of 0.4 for the von karman constant,

Is the length of Obukhov,

and

Are stability correction functions for momentum flux and feeling heat flux, respectively.

By applying the conditions of

) And aerodynamic resistance

Step 2-1; Aerodynamic resistance obtained in step 2-1

)of Equation

Apply to,

Is,

Is 1004JKkg ^-1 as the constant pressure of air

Is the atmospheric pressure,

Is the latent heat of evaporation of water 2.5x10 ⁶ Jkg ^-1

Is the resistance value of the pore of leaves, and the pore state of vegetation is applied empirically according to the wet state of the soil and the change of season.

Means climatic resistance,

Is an empirical equation representing the gradient of saturated steam pressure over a temperature curve.

Is applied to the available heat from the solar radiation energy

Calculating step 2-2; And Friction velocity obtained in step 2-1

) And the feeling heat flux obtained in step 2-2

) Equation

Apply to,

Is the acceleration of gravity,

Is the average of the ground temperature and the temperature measured at a height of 1.5 m.

2-3) calculating; Obkov length obtained in steps 2-3

) Is greater than or equal to 0

Is selected as the stability correction function, and the

) Is less than 0

Wow

As the stability correction function,

Applying 2-4 steps; And By applying the stability correction function selected in step 2-4 and the values obtained in steps 2-1 to 2-4 to the equation of step 2-1,

) And aerodynamic resistance

), And repeating the steps 2-2 to 2-3 to calculate the feeling heat flux 2-5 step; mixed layer elevation calculation method comprising a. The method of claim 2, In the third step, the method of calculating the mixed layer altitude is an integral method, The integration method is Equation

Is obtained by

Is obtained from the vertical temperature profile data provided from the Terra / MODIS satellite as the temperature gradient or temperature gradient of the upper part of the mixed layer,

Is the mixed bed altitude measured by the sonde sensor,

Is the initial time to calculate the feeling heat flux,

Is the end time for calculating the feeling heat flux, inflow coefficient C is 0.2,

Mixed layer height calculation method, characterized in that the calculated heat flux calculated in step 2.

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