CN105067534A - Pollutant transport flux measurement and calculation method based on ground-based MAX-DOAS - Google Patents

Abstract

The invention discloses a pollutant transport flux measurement and calculation method based on ground-based MAX-DOAS. The method comprises the steps: observing by using the ground-based MAX-DOAS to obtain the slant column density of polluted gas, and transforming into the vertical column density; obtaining a high-resolution two-dimensional distribution result of the polluted gas on an observation interface by using a satellite data result; using wind direction, wind speed information and an MAX-DOAS site location, determining a transport interface passing through an MAX-DOAS site, combining with a satellite data gridding result, and fitting to obtain a distribution curve of the polluted gas density along the interface; correcting satellite data by using the MAX-DOAS measurement result, to obtain a density distribution curve based on the ground-based MAX-DOAS vertical column density result; and finally, using a flux calculation formula, combining with relevant parameters, and calculating to obtain the transport flux of the polluted gas. The observation and measurement method is simple, apparatuses are easy to implement, the cost is low and the algorithm is mature.

Description

Based on the pollutant transportation flux measuring method of ground MAX-DOAS

Technical field

The present invention relates to measurement and the flux measuring and calculating field of dusty gas vertical column concentration in ambient atmosphere, be specially a kind of pollutant transportation flux measuring method based on ground MAX-DOAS.

Background technology

Since the eighties in 20th century, Chinese society economy enters the high speed development stage, and short 20 years are just walked to be over migration path century-old in developed country.Due to socioeconomic fast development, air environmental pollution problem is increasingly serious, cause the environmental problem that should occur in different phase embody a concentrated reflection of in a short time and break out out, various pollutant intercouples superposition, and presents the new feature of regionality and compound pollution gradually.

Current China has established the air quality monitoring station centered by city, and establish part of the foundation remote sensing website, as Chinese Academy of Sciences's Anhui ray machine laser radar, the passive super station of DOAS etc., the area observation of atmospheric environment that simultaneously utilized external satellite data also to carry out, tentatively achieve the stereoscopic monitoring of air combined pollution, define the steric environment monitoring net that " point, line, surface " combine with ", empty, sky ".But the regionality of at present atmospheric pollution needs effective support of respective algorithms, how assessment area level of pollution, and the influence degree that estimation area pollutes becomes the focus of scientific research personnel, environmental administration and public attention.Ground single at present, remote sensing equipment can't answer the influence degree of regional pollution completely, also do not have clear and definite quantization method for the conveying of regional pollution thing.Although and air quality model can obtain the distribution of regional pollution thing and situation of change by the method for analog simulation, lack the combination with measured data, often accurately can not reflect the formation development law of pollutant.Therefore, need to study a kind of effective ways in conjunction with pollutant transportation between existing observation technology assessment area, carry out the research of air pollution Forming Mechanism, differentiation and course of conveying, quantitative test is carried out to atmospheric pollution object area transport fluxes.

Summary of the invention

The object of this invention is to provide a kind of pollutant transportation flux measuring method based on ground MAX-DOAS, interactional problem between region transport fluxes, assessment area cannot be obtained to solve prior art.

In order to achieve the above object, the technical solution adopted in the present invention is:

Based on the pollutant transportation flux measuring method of ground MAX-DOAS, it is characterized in that: comprise the following steps:

(1) utilize ground MAX-DOAS to measure the atmospheric scattering spectrum of different angles, utilize the inverting of DOAS algorithm to obtain dusty gas (NO ₂, SO ₂deng) along the slant column intensity SCD (SlantColumnDensity) of light path integration; Utilize atmospheric radiation transmission SCIATRAN to calculate air quality factors A MF (AirMassFactor), slant column intensity is converted into troposphere vertical column concentration VCD (VerticalColumnDensity);

(2) the Lv2 data of OMI satellite and overlapping pixel coordinate data is utilized, the NO obtained by satellite ₂post concentration profile rebuilds, and is dispensed to high precision (0.1 × 0.1 degree) grid, obtains the dusty gas vertical column concentration Two dimensional Distribution VCD of specific region high spatial resolution _i(lon, lat);

(3) pollution transportation height H and pollution layer thickness h is determined: utilize MAX-DOAS slant column intensity result, inverting dusty gas vertical distribution profiles c=c (z _i), height H and the pollution layer thickness h of pollutant transportation is judged in conjunction with profile distribution;

(4) delivery interface x is determined _i: utilize the borderline wind direction in wind field information acquisition specific region, wind speed information determine the throughput direction θ (with the angle of direct north) of this period internal contamination thing, obtain the curvilinear equation through ground MAX-DOAS website in delivery interface

(5) according to the curvilinear equation that step (4) obtains, the dusty gas troposphere vertical column concentration utilizing step (2) to obtain and the high-resolution satellite dusty gas distribution results rebuild, obtain along concentration distribution of pollutants V=V (y, the VCD on curve _i);

(6) flux computing formula is utilized in conjunction with wind field information, pollutant levels vertical distribution information, pollutant along the distributed intelligence of delivery interface, calculate the operational throughput F of pollutant.

In described step (1), the storage of optics import system, light signal transmission system, spectrum investigating system and spectrum and resolution system are made up of focusing telescope system, optical fiber, spectrometer and computing machine respectively; The slant column intensity of dusty gas is utilize DOAS algorithm to obtain in conjunction with the measure spectrum inverting of different angles, reflection be the integration of concentration along light path; Dusty gas vertical column concentration then reflects local level of pollution;

In described step (2), Lv2 data and the overlapping pixel coordinate data of OMI satellite are downloaded from NASA official website, what post concentration construction method adopted is gridding disposal route, the grid of low spatial resolution data acquisition high spatial resolution is processed, obtains high-resolution CONCENTRATION DISTRIBUTION result;

The slant column intensity inverting that in described step (3), profile is obtained by the measurement of MAX-DOAS different angles obtains, and according to profile vertical distribution information determination delivery head and pollution layer thickness;

Wind field data in described step (4), adopt wind profile radar result or sounding balloon result, the curvilinear equation utilizing wind direction to determine is through MAX-DOAS website;

The troposphere vertical column concentration correction OMI satellite result utilizing ground MAX-DOAS measurement to obtain in described step (5) is also brought curvilinear equation into and is obtained concentration profile in delivery interface;

In described step (6), the transport fluxes calculated is input on vertical transport interface, output quantity.

The present invention has the following advantages:

(1) observed pattern is simple, and apparatus easily realizes, cost low (relatively airborne and spaceborne instrument);

(2) algorithm is ripe, dusty gas inversion method based on DOAS is successfully applied to atmosphere environment supervision field, measuring accuracy higher (error is less than 2%), the flux computing formula used in calculating is widely used in a lot of field;

(3) compared with vehicle-mounted, airborne measurement equipment, the method is more conducive to long-term observation, can obtain the pollution transportation rule that a region is long-term.

Accompanying drawing explanation

Fig. 1 is the pollutant region transport fluxes computational algorithm process flow diagram based on MAX-DOAS and OMI satellite data.

Fig. 2 is the principle schematic measuring pollutant transportation flux based on MAX-DOAS.

Fig. 3 is the OMI satellite NO after gridding process ₂regional distribution chart.

Fig. 4 is delivery interface concentration distribution of pollutants figure.

Fig. 5 is MAX-DOAS gasoloid and trace gas inversion method process flow diagram.

Embodiment

Pollution transportation mainly refers to peripheral pollution source under specific Wind, continues the pollutant input process brought monitored area.To the monitoring of pollution transportation process, be conducive to source, the approach of studying pollutant, effective Data support can be provided for the appearance of pollution prevention measure.

MAX-DOAS result is utilized to calculate the algorithm flow of pollutant transportation flux as Fig. 1, utilize DOAS algorithm can obtain troposphere pollutant vertical column concentration in conjunction with measure spectrum, again in conjunction with wind field information, utilize flux computing formula, pollutant transportation intensity can be calculated, the pollutant transportation amount in a period of time can be estimated in conjunction with information such as wind frequencies.

The basis of DOAS observational network measurement pollutant Regional Distribution Characteristics is studied the computing method of pollutant region transport fluxes.The vertical column concentration information of MAX-DOAS, can not only reflect the local distributed intelligence of pollutant, can also by wind field data-evaluation pollutant transportation amount.Wind field and wind frequency analysis pollution transportation rule is dominated in conjunction with observation area.Be illustrated in figure 2 the principle schematic utilizing MAX-DOAS to study emission source pollution transportation.

The first step: based on the dusty gas vertical column retrieving concentration of MAX-DOAS

MAX-DOAS take diffusion light of the sun as light source, is called passive DOAS technology, and because light there occurs Multiple Scattering in an atmosphere, its light path is unknown, so MAX-DOAS measurement obtains is the integration of dusty gas concentration along light path, i.e. post concentration.So utilize Lambert-Beer theorem to obtain

$I\left(\mathrm{\λ}\right)=I_0\left(\mathrm{\λ}\right)\exp \{-\∫\[\underset{j=1}{\overset{n}{\Σ}}\left({\mathrm{\σ}}_j^b\right(\mathrm{\λ})+{\mathrm{\σ}}_j^{\′}(\mathrm{\λ}\left)\right)c_j+{\mathrm{\ϵ}}_R\left(\mathrm{\λ}\right)+{\mathrm{\ϵ}}_M\left(\mathrm{\λ}\right)\]ds\}---\left(1\right)$

In formula, I (λ) is the incident intensity that detector receives, I ₀(λ) be detector receive not through dusty gas absorb intensity of solar radiation.By all in above formula " changing slowly " part ε _r(λ) and ε _m(λ) writing I is merged ₀' (λ), then have:

$I\left(\mathrm{\λ}\right)=I_0^{\′}\left(\mathrm{\λ}\right)\exp \{-\∫\[\underset{j=1}{\overset{n}{\Σ}}{\mathrm{\σ}}_j^{\′}\left(\mathrm{\λ}\right)c_{j}ds\]\}---\left(2\right)$

Make SCD _j=∫ c _j(s) ds, then above formula can be written as:

$\frac{I\left(\mathrm{\λ}\right)}{I_0^{\′}\left(\mathrm{\λ}\right)}=\exp (-{\mathrm{\Σ\σ}}_j^{\′}(\mathrm{\λ}\left){\mathrm{SCD}}_j\right)---\left(3\right)$

Wherein SCD (SlantColumnDensity) is the slant column intensity of measurement gas.Utilize radiative transfer model, calculate the air quality factors A MF in corresponding moment, just slant column intensity can be converted to the vertical column concentration VCD reflecting local contamination gas scapus concentration information, namely

Second step: the OMI satellite data based on GRIDDING WITH WEIGHTED AVERAGE reconstructs

Ground space resolution due to OMI is 13km × 24km, and corresponding ground space resolution is less, and limited compared with the resolution characteristic of the pollutant distribution situation in zonule or city for one, the satellite data therefore obtaining high spatial resolution is very necessary.Here we adopt gridding disposal route, utilize the Overlapping data between the measurement result of each pixel of OMI satellite and pixel, set up high precision (as 0.1 °, longitude 0.1 ° × latitude) ground space grid, satellite data utilized the method for interpolation to be distributed in corresponding grid to go, obtain the OMI satellite result of high spatial resolution.Utilizing the OMI satellite result of high spatial resolution, just can obtain the CONCENTRATION DISTRIBUTION regional change rule in delivery interface, providing important Data support for utilizing MAX-DOAS result zoning flux further.

3rd step: based on the Vertical Profile inverting of optimization algorithm

Pollution transportation height H and pollution layer thickness h are 2 important parameters calculating pollution transportation flux, and wherein the determination of pollution transportation height is very necessary for choosing of wind field information, and pollution layer thickness is then the major parameter determining pollution transportation amount., utilize the Vertical Profile information of optimization algorithm inverting dusty gas here, thus the solid distribution obtaining pollutant directly perceived, determine the thickness of delivery head and pollution layer.

The measurement at MAX-DOAS many elevations angle has different sensitivity for the air of differing heights, so can by the difference slant column intensity Δ SCD at many elevations angle measured _nO2(zenith spectrum is as FRS reference spectrum in same measurement circulation) its vertical distribution of inverting.Because aerocolloidal state is the key factor (Sinreichetal, 2005) affecting trace gas inverting, therefore have employed a kind of two step refutation processes (as Fig. 5).First utilize multiaxis DOAS at the Δ SCD of the same band Simultaneous Inversion _o4, RTM and the Aerosol Extinction vertical distribution inversion algorithm (APRM) based on optimal estimation obtain gasoloid profile; Then by gasoloid profile input RTM, and input gasoloid single scattering albedo and the asymmetric factor of this area's feature, utilize trace gas concentration vertical distribution inversion algorithm (GPRM) to obtain troposphere (0-4km) dusty gas volumetric mixture ratio (VMR) vertical distribution profiles.

Adopt the maximum a posteriori probability method (MAP, Maximumaposteriori) that Rodgers proposed in 2000, inverting profile expression formula as follows

$\hat{x}={(K^T{S_{\mathrm{\ϵ}}}^{\mathrm{-1}}K+{S_a}^{-1})}^{-1}(K^T{S_{\mathrm{\ϵ}}}^{-1}y+{S_a}^{-1}{x}_a)---\left(5\right)$

Wherein, K is weighting function matrix, S _εfor the covariance matrix of measuring error, S _afor the covariance matrix of prior uncertainty, y is calculation matrix, x _afor priori profile information.

The dusty gas profile result utilizing inverting to obtain, intuitively can obtain pollutant transportation height and pollution layer thickness information (H, h), for the calculating of pollution transportation flux lays the first stone.

4th step: based on the determination of the concentration profile of wind field information and satellite data

Utilize the wind field information (wind profile radar or sounding data) of observation station obtain pollutant transportation direction, in conjunction with high-resolution satellite pollutant levels areal distribution result, determine the pollutant transportation interface length l through MAX-DOAS observation station and curve y; Utilize MAX-DOAS observed result, revise satellite data result, and obtain the concentration distribution of pollutants along curve further.

5th step: the calculating of pollutant transportation flux

Utilize flux computing formula the above parameter determined of input, calculates the operational throughput of pollutant.

Claims (6)

1., based on the pollutant transportation flux measuring method of ground MAX-DOAS, it is characterized in that: comprise the following steps:

(1) utilize ground MAX-DOAS to observe the diffusion light of the sun spectrum of different angles, utilize DOAS algorithm to obtain the slant column intensity of different angles dusty gas, slant column intensity is converted into vertical column concentration by recycling radiative transfer model;

(2) the vertical column concentration that obtains of integrating step (1), the change curve of dusty gas concentration minimum value during utilizing minimum value linear fit to obtain observation, thus determine the background values of measured zone dusty gas;

(3) utilize the high-resolution satellite data result after gridding process, obtain the Two dimensional Distribution result at observation area dusty gas;

(4) in conjunction with MAX-DOAS slant column intensity result, utilize optimization algorithm inverting dusty gas vertical distribution information, determine delivery head and the thickness of dusty gas, and highly choose wind field information based on this;

(5) utilize wind direction, wind speed information and MAX-DOAS site location, determine a delivery interface through MAX-DOAS website, and the satellite data result that integrating step (3) obtains, extract the vertical column concentration results of dusty gas in delivery interface;

(6) according to the dusty gas vertical column concentration along interface that step (5) obtains, matching obtains the distribution curve of dusty gas along interface;

(7) according to the distribution curve that step (6) obtains, revise in conjunction with MAX-DOAS measurement result, obtain the concentration profile based on ground MAX-DOAS vertical column concentration results;

(8) delivery head, thickness and the wind field information determined of the concentration profile that obtains of integrating step (6) and step (4), utilizes flux computing formula to obtain the operational throughput of dusty gas.

2. according to claim 1 based on the pollutant transportation flux measuring method of ground MAX-DOAS, it is characterized in that: in described step (1), ground MAX-DOAS is by telescopic system, multi-angle scanning system, light signal transmission system, spectrum investigating system and spectrum store and resolution system composition, by the atmospheric scattering light of multi-angle scanning system detection different angles, measure spectrum is utilized to parse contamination gas scapus concentration information, described dusty gas vertical column concentration is that ground MAX-DOAS inverting obtains, vertical column concentration reflects the dusty gas molecular number along height integration in the local unit area of measurement point.

3. according to claim 1 based on the pollutant transportation flux measuring method of ground MAX-DOAS, it is characterized in that: described step (3) Satellite data adopt high precision gridding interpolation to obtain by closing on pel data, and ground space resolution can bring up to longitude and latitude 0.1 ° × 0.1 °.

4., according to claim 1 based on the pollutant transportation flux measuring method of ground MAX-DOAS, it is characterized in that: in described step (5) conveying cross section be one through MAX-DOAS website and the straight line vertical with wind direction.

5. according to claim 1 based on the pollutant transportation flux measuring method of ground MAX-DOAS, it is characterized in that: the correction of result to satellite data utilizing ground MAX-DOAS in described step (7), be that the measurement result that utilizes ground MAX-DOAS under identical meteorological condition and satellite data carry out correlativity contrast, utilize the correction that related coefficient is carried out.

6. according to claim 1 based on the pollutant transportation flux measuring method of ground MAX-DOAS, it is characterized in that: MAX-DOAS profile result in described step (4), be the slant column intensity in conjunction with different angles and the dusty gas profile result utilizing optimization algorithm inverting to obtain, dusty gas profile result reflects the distributed intelligence of dusty gas in differing heights, in conjunction with delivery head and the thickness of dusty gas profile determination pollutant.