Some standard content:
ICS 07.060
Meteorological Industry Standard of the People's Republic of China
QX/T479—2019
Evaluation on meteorological condition index of PM25 pollution Issued on April 28, 2019
Implementation on August 1, 2019
Normative references
3 Terms and definitions
4EMI and sub-item calculation methods
Appendix A (Informative Appendix)
Appendix B (Normative Appendix)
Appendix C (Informative Appendix)
References
Physical meaning of each sub-item in EMI calculation formula
Application method of EMI in evaluation·
EMI numerical calculation method.
QX/T479—2019||tt| |Qx/T479—2019
This standard was drafted in accordance with the rules given in GB/T1.1—2009. This standard was proposed and coordinated by the National Technical Committee for Standardization of Meteorological Disaster Prevention and Mitigation (SAC/TC345). Drafting units of this standard: National Meteorological Center, China Meteorological Science Academy. Main drafters of this standard: Zhang Bihui, Liu Hongli, Zhang Di, Gong Shanling, He Jianjun, Zhang Hengde, Gui Hailin, Wang Jikang. 1 Scope
PM2.5 Meteorological Conditions Evaluation Index (EMI) This standard specifies the definition and calculation method of PM2.5 Meteorological Conditions Evaluation Index. This standard is applicable to the development of PM2.5 concentration changes in the Assessment of the contribution of meteorological conditions. 2 Normative referenced documents
QX/T479—2019
The following documents are indispensable for the application of this document. For any dated referenced document, only the dated version applies to this document. For any undated referenced document, the latest version (including all amendments) applies to this document. HJ633—2012 Technical Provisions on Ambient Air Quality Index (AQI) (Trial) 3 Terms and definitions
The following terms and definitions apply to this document. 3.1
Fine particulate matter
fineparticle
Aerodynamics Aerosol particles with a diameter less than or equal to 2.5um. [GB/T31159——2014. Definition 3.7]
PM2.5 meteorological condition evaluation index
evaluation on meteorological condition index of PM2.spollution; EMI is a dimensionless index that characterizes the contribution of meteorological conditions to the change of PM2.5 concentration. Note: EMI is expressed as the ratio of the average concentration of PM2.5 in the air column from the ground to 1500m to the reference concentration. The larger the value, the more unfavorable the meteorological conditions are for the dilution and diffusion of PM2.5 in the near-ground atmosphere.
4EMI and sub-item calculation method
EMI calculation method
The calculation formula is shown in formula (1):
[=I(to) -
Where:
EMI, dimensionless
1. ——Integral start time, in seconds (s); t)—Integral end time, in seconds (s); E—Emission deposition term, in seconds (s-1); T—Transmission term, in seconds (s\); D—Diffusion term, in seconds (s\); (E+T+D).d
QX/T479—2019
——Time, in seconds (s).
For the physical meaning of each sub-item, please refer to Appendix A, for the application method of EMI in the assessment, please refer to Appendix B, and for the numerical calculation method of EMI, please refer to Appendix C. 4.2 Calculation method for sub-items
4.2.1 Emission and deposition item
The calculation formula for emission and deposition item is shown in formula (2:
Wherein:
Emission and deposition item, unit is per second (s1); (sd).dh
-HJ633-2012 air quality index level 1, category is excellent PM2. concentration limit, C=35, unit is microgram per cubic meter (μg·m-\);
Air column height, H=1500, unit is meter (m);-PMz.s emission rate, unit is microgram per cubic meter second (μg·m-3·s\); PM2.s deposition rate, unit is microgram per cubic meter second (ug·m-3·s-1); height, unit is meter (m).
4.2.2 Transmission term
The transmission term calculation formula is shown in formula (3):
Where:
Transmission term, unit is per second (s-):
-Horizontal wind speed in the east-west direction, the westerly wind speed is positive, the easterly wind speed is negative, the unit is meter per second (m·s-1):C
-PM2.5 concentration, unit is microgram per cubic meter (μg·m-3); east-west distance, unit is meter (m); north-south horizontal wind speed, the south wind speed is positive, the north wind speed is negative, the unit is meter per second (m·s1): north-south distance, unit is meter (m); vertical wind speed, unit is meter per second (m·s); vertical distance, unit is meter (m). 4.2.3 Diffusion term
The diffusion term calculation formula is shown in formula (4) ：
“()+()+()
Wherein:
Diffusion term, unit is per second (s\);
Horizontal diffusion coefficient in the east-west direction, unit is square meter per second (m,\); Horizontal diffusion coefficient in the north-south direction, unit is square meter per second (m·s-\); Vertical diffusion coefficient, unit is square meter per second (m·s1). ...(3)
(Informative Appendix)
Physical meaning of each sub-item in the EMI calculation formula
QX/T479—2019
Formula (A.1) is the continuity equation of PM2.s concentration. 0+8++
++(k)+()+()++
Wherein:
.(A.1)||t t||Chemical reaction secondary generation rate, unit is microgram per cubic meter second (ug, m-·s-\). It can be seen from the continuity equation that the impact of meteorological conditions on PM2.5 concentration is reflected in the emission deposition term, transmission term and diffusion term, and its physical meaning is as follows:
Emission deposition term (E): The PM2s concentration variability per unit time in the air column caused by the difference between the PM2.5 emission rate and the deposition rate. It represents the net balance between the atmosphere and the surface in the region. A positive value indicates emission to the atmosphere, and a negative value indicates deposition. Transmission term (T): The PM2.5 concentration variability per unit time in the air column caused by the atmospheric transport in the horizontal and vertical directions. Positive values indicate input, and negative values indicate output. bzxz.net
Diffusion term (D): The PMz.5 concentration variability per unit time in the air column caused by the atmospheric flow. A positive value indicates PM.5 accumulation, which generally corresponds to a low mixing layer and stable atmospheric stratification; a negative value indicates PM2.5 dilution, which generally corresponds to an elevated mixing layer and unstable atmospheric stratification.
QX/T479—2019
Appendix B
(Normative Appendix)
Application of EMI in Assessment
Assuming that the annual emission rate (s) of PM2. remains unchanged, in order to reflect the inherent characteristics of seasonal changes in emissions, the monthly changes in emission rate are considered. Since the PM2. emission rates of different years have been set to remain unchanged, when the same months of different years are compared with each other, the difference in EMI is the rate of change of PM2. concentration caused by meteorological conditions under the condition of unchanged emissions. Assuming that the contribution of meteorological factors to the actual concentration is proportional, the contribution of emissions to the actual concentration is also proportional, and the meteorological factors and emission factors are separable variables, the PM2.s concentration of "Period 1\emissions under the meteorological conditions of "Period 0" is equal to the PM2.5 concentration of "Period 1" emissions under the meteorological conditions of "Period 1" divided by the ratio of the meteorological conditions of "Period 1" to the meteorological conditions of "Period 0". The specific calculation formula is shown in formula (B.1):
Where:
Co-—PMz.s concentration of "Period 1\emissions under the meteorological conditions of \Period 0\, in micrograms per cubic meter (μg·m-\); O, the measured PM2.5 concentration of "Period 1", that is, the PM2.5 concentration of "Period 1\" under the meteorological conditions of "Period 1", in micrograms per cubic meter (μg·m-3);
"Period 1\EMI, dimensionless;
"Period O" EMI. dimensionless.
According to the assumptions, under the meteorological conditions of "Period 0", the ratio of the PM2 concentration corresponding to the emissions of "Period 1" and the PM2.5 concentration corresponding to the emissions of "Period 0\" is equal to the ratio of the emissions of "Period 1" and \Period 0", see formula (B.2): Cro=E
Where:
is the measured PM concentration in "Period 0", that is, the PM concentration in "Period 0" under the meteorological conditions of "Period 0", in micrograms per cubic meter (μg·m-*);
"Period 1\emission rate, in micrograms per cubic meter second (ug·m-3·s-); E
"Period 0\emission rate, in micrograms per cubic meter second (ug·m-3,s-). Substituting formula (B.1) into formula (B.2), we get formula (B.3): x
The physical meaning of formula (B.3) is: the PM2.5 concentration ratio of two periods is equal to the product of the emission ratio and the EMI ratio. Therefore, when there is no obvious change in emissions, the change in PM2.s concentration is mainly determined by meteorological conditions. Definition of "emission change rate\ see formula (B.4): R=(EE)/E
Where:
The emission change rate of "Period 1" relative to "Period 0", dimensionless. Substituting formula (B.3) into formula (B.4), we can get formula (B.5) Re
Similarly, definition of "weather condition change rate" see formula (B.6): 0./0.
L/l.
Rw=(1,—10)/1
.(B.4)
Rw—The meteorological condition change rate of "Period 1" relative to "Period 0", dimensionless. Qx/T 479—2019
According to formula (B.5), the contribution rate of emission change to concentration change can be quantitatively calculated. Negative values indicate emission reduction effects, and positive values indicate increased emissions. According to formula (B.6), the contribution rate of meteorological condition changes to concentration changes can be quantitatively calculated. Negative values indicate that diffusion conditions are better, which has the effect of reducing PMz.5 concentration, and positive values indicate that diffusion conditions are worse, which has the effect of increasing PMz.s concentration. 5
QX/T479—2019
Appendix C
(Informative Appendix)
EMI numerical calculation method
EMI is difficult to obtain analytical solutions, and numerical solutions need to be obtained through numerical model systems. Based on the Chemical Weather Forecast System of the China Meteorological Administration (CUACE), the Chemical Weather Forecast System of the China Meteorological Administration-EMI Evaluation Model (CUACE-EMI) was developed to calculate the numerical solution of EMI.
CUACE-EMI calculation covers the whole country with a horizontal resolution of 15km; it uses the emission sources in 2015, assimilates meteorological analysis fields and ground and sounding observation data. The schematic diagram of the CUACE-EMI module structure is shown in Figure C.1, which includes regional meteorological module, CUACE, PM2.s tracer module and EMI analysis and evaluation module.
Meteorological analysis field
Meteorological observation data
(ground, sounding)
Total of n# in China
Basic emission sources
79*80°90°100° 110*120*130°140'Assimilation
Meteorological conditions and transport, diffusion parameters
Meteorological, radiation variables
Regional meteorological module
Radiation, cloud, fog
Puz, concentration
PM tracer module
(PM,, emission, diffusion, transmission, deposition)EMI analysis and evaluation module
EMI and sub-items
EMI change rate
and forecast products
CUACE-EMI module structure diagram
Meteorological conditions Item
Rate of change
Emission change rate
References
GB/T311592014 Terminology of atmospheric aerosol observation GB/T34299-2017
Grade of atmospheric self-purification capacity
QX/T269-2015
5 Aerosol pollution meteorological condition index (PLAM) Sheng Zhuangxuan, Mao Jietai, Li Jianguo, et al. Atmospheric Physics [M]. Beijing: Peking University Press, 2003 Tang Xiaoyan, Zhang Yuanhang, Shao Min. Atmospheric Environmental Chemistry [M. Beijing: Higher Education Press ，2006QX/T479—2019
People's Republic of China
Meteorological Industry Standard
PMs.Meteorological Conditions Evaluation Index (EMI)
QX/T479—2019
Published and distributed by Meteorological Press
No. 46, Zhongguancun South Street, Haidian District, Beijing Postal Code: 100081
Website: http://www.qxcbs.com Distribution Department: 010-68408042
Printed by Beijing Zhongke Printing Co., Ltd.|| tt||Distributed by Xinhua Bookstores in various places
Format: 880×1230
First edition in June 2019
Printing sheet: 0.75
Word count: 22.5 thousand words
First printing in June 2019
Book number: 135029-6053
Price: 15.00 yuan
Replaced by the publishing department of our company
If there is any printing error
Copyright reserved
Infringement will be investigated
Report phone number: (010)68406301, emission, diffusion, transmission, deposition) EMI analysis and evaluation module
EMI and sub-items
EMI change rate
and forecast products
CUACE-EMI module structure diagram
Meteorological conditions
Change rate
Emission change rate
References
GB/T311592014 Atmospheric aerosol observation terminology GB/T34299—2017
Big Air self-purification ability level
QX/T269-2015
5 Aerosol pollution meteorological condition index (PLAM) Sheng Zhuangxuan, Mao Jietai, Li Jianguo, et al. Atmospheric Physics [M]. Beijing: Peking University Press, 2003 Tang Xiaoyan, Zhang Yuanhang, Shao Min. Atmospheric Environmental Chemistry [M. Beijing: Higher Education Press, 2006 QX/T479—2019
People's Republic of China
Meteorological Industry Standard
PMs.Air Elephant Condition Evaluation Index (EMI)
QX/T479—2019
Published and distributed by Meteorological Press
No. 46, Zhongguancun South Street, Haidian District, Beijing Postal Code: 100081
Website: http://www.qxcbs.com Distribution Department: 010-68408042
Printed by Beijing Zhongke Printing Co., Ltd.
Distributed by Xinhua Bookstores in various places
Format: 880×12 30
First edition in June 2019
Printing sheet: 0.75
Word count: 22.5 thousand words
First printing in June 2019
Book number: 135029-6053
Price: 15.00 yuan
Replaced by the publishing department of our company
If there is any printing error
Copyright reserved
Infringement will be investigated
Report phone: (010)68406301, emission, diffusion, transmission, deposition) EMI analysis and evaluation module
EMI and sub-items
EMI change rate
and forecast products
CUACE-EMI module structure diagram
Meteorological conditions
Change rate
Emission change rate
References
GB/T311592014 Atmospheric aerosol observation terminology GB/T34299—2017
Big Air self-purification ability level
QX/T269-2015
5 Aerosol pollution meteorological condition index (PLAM) Sheng Zhuangxuan, Mao Jietai, Li Jianguo, et al. Atmospheric Physics [M]. Beijing: Peking University Press, 2003 Tang Xiaoyan, Zhang Yuanhang, Shao Min. Atmospheric Environmental Chemistry [M. Beijing: Higher Education Press, 2006 QX/T479—2019
People's Republic of China
Meteorological Industry Standard
PMs.Air Elephant Condition Evaluation Index (EMI)
QX/T479—2019
Published and distributed by Meteorological Press
No. 46, Zhongguancun South Street, Haidian District, Beijing Postal Code: 100081
Website: http://www.qxcbs.com Distribution Department: 010-68408042
Printed by Beijing Zhongke Printing Co., Ltd.
Distributed by Xinhua Bookstores in various places
Format: 880×12 30
First edition in June 2019
Printing sheet: 0.75
Word count: 22.5 thousand words
First printing in June 2019
Book number: 135029-6053
Price: 15.00 yuan
Replaced by the publishing department of our company
If there is any printing error
Copyright reserved
Infringement will be investigated
Report phone: (010)68406301
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