A warm cloud sub-divisional broadcast catalytic system based on four-dimensional multi-source meteorological data assimilation numerical weather model

Abstract

The application discloses a warm cloud grading broadcast catalysis system based on four-dimensional multi-source meteorological data assimilation numerical weather model, and the system comprises a four-dimensional data assimilation coupling module, a discharge source generation and reading module, an aerosol initial and boundary condition generation module, a sand and sea salt coupling module, a vertical mixing coupling module, an aerosol dry deposition module, an aerosol grading setting module, an aerosol grading broadcast module and a catalysis effect calculation module; the application is based on the WRF-FDDA framework, and the WRF-SBM model is reformed and optimized to build a perfect warm cloud grading broadcast catalysis system, realize simulation of different warm cloud catalyst broadcast processes and evaluation and analysis of catalysis effects, and provide scientific basis and technical support for optimizing warm cloud catalysis operation.

Description

Technical Field

[0001] This invention relates to a warm cloud tiered seeding catalytic system, and more particularly to a warm cloud tiered seeding catalytic system based on a numerical weather model assimilated from four-dimensional multi-source meteorological data. Background Technology

[0002] Against the backdrop of current global climate change and water scarcity, weather modification technology has become a key measure for preventing and mitigating meteorological disasters and improving water resource utilization. Particularly in tropical, subtropical, and mid-latitude regions, warm clouds, due to their widespread distribution and significant precipitation processes, play a crucial role in local water resource balance and climate regulation. Warm cloud processes focus on small- to medium-scale events, differing significantly from convective processes at traditional numerical weather scales. The development of warm clouds is highly dependent on surface environmental conditions, such as near-surface water vapor supply, aerosol concentration distribution, and topography, emphasizing the interaction between the surface environment and weather processes. This makes accurately simulating and capturing the subtle changes in warm cloud formation, development, and precipitation extremely challenging, and also places higher demands on the accuracy of atmospheric cloud water resource simulation and forecasting.

[0003] Traditional numerical weather models typically employ a bulk scheme to handle cloud microphysical processes. This scheme treats condensates of different sizes as a mixed whole and describes them with a few parameters. While this method is simple to implement, it struggles to accurately reflect the specific quantitative variations of condensates of different sizes and their crucial impact on precipitation formation. In this context, bin schemes are particularly important because they can more finely describe variations in cloud droplet spectra. By dividing cloud droplets according to their size, bin schemes more realistically simulate the evolution of cloud droplets, contributing to a more accurate understanding of the complex interactions between aerosols, clouds, and precipitation.

[0004] Existing spatiotemporal distribution data for aerosols in the natural environment are largely based on assumptions, lacking an accurate characterization of the dynamic changes of aerosols in the real atmosphere. As the primary source of cloud condensation nuclei (CCNs), the spectral and concentration distributions of aerosols directly influence the macroscopic and microscopic properties of clouds. For example, aerosols from different sources have different chemical compositions and particle size distributions. Under the same meteorological conditions, the activation characteristics of CCNs will differ significantly, leading to marked differences in cloud droplet number concentration, cloud droplet spectral width, and cloud development and evolution processes. However, the spatiotemporal distribution of aerosols assumed in existing tiered microphysics schemes cannot accurately reflect these differences. This results in significant errors in both the simulation of natural clouds and the representation of warm cloud catalytic processes, making it difficult to accurately assess the actual effects of warm cloud catalysts and severely limiting the accuracy and effectiveness of weather modification operations. Summary of the Invention

[0005] Purpose of the invention: The purpose of this invention is to provide a warm cloud tiered seeding catalytic system based on a four-dimensional multi-source meteorological data assimilation numerical weather model to improve the accuracy of warm cloud process simulation, deepen the understanding of aerosol-cloud-precipitation interaction, and realize the simulation of different warm cloud catalyst seeding processes and the evaluation and analysis of catalytic effects.

[0006] Technical solution: The warm cloud tiered seeding catalytic system of the present invention includes:

[0007] The four-dimensional data assimilation and coupling module is used to fuse multi-source observation data through four-dimensional data assimilation technology to obtain the initial state information of warm clouds;

[0008] The emission source generation and reading module is used to convert the emission source inventory into a gridded pollutant emission inventory of the target study area, forming atmospheric aerosols;

[0009] The aerosol initial and boundary condition generation module is used to generate the aerosol initial and boundary conditions of the target study area within a given time, and convert them into the CCN number concentration required for the graded microphysical processes.

[0010] The dust and sea salt coupling module is used to calculate the emissions of dust and sea salt aerosols and integrates them into the overall simulation;

[0011] The vertical mixing coupling module is used to calculate the time-varying effects of vertical mixing and dry sedimentation on the species mixing ratio;

[0012] The aerosol dry sedimentation module is used to simulate the gravity sedimentation process of aerosol particles of different grades.

[0013] The aerosol grading module is used to divide aerosols into different grades to simulate the behavior of aerosols with different particle sizes.

[0014] The aerosol graded dispersal module is used to simulate the dispersal process of different grades of aerosols;

[0015] The catalytic effect calculation module is used to calculate the catalytic effect for catalytic processes involving aerosols.

[0016] Preferably, the multi-source observation data in the four-dimensional data assimilation and coupling module includes ALL WTO / GTS standard stations, automatic wind weather stations, wind profiler radar, satellite observations, weather radar, microwave radiometers, flight weather reports, and meteorological observation data; the initial state information of warm clouds includes the macroscopic structure, microscopic physical properties, and aerosol distribution of the clouds.

[0017] Preferably, the emission source generation and reading module calculates the aerosol concentration release value of each grid point through density conversion, emission calculation and time accumulation function to form atmospheric aerosols.

[0018] Preferably, the aerosol initial and boundary condition generation module obtains online forecast results of CCN number concentration through emission source input, atmospheric chemical processes, transport and diffusion, vertical mixing, and dry deposition processes, and further simulates them.

[0019] Preferably, the dust and sea salt coupling module includes a GOCART overall dust scheme, a GOCART 5-level dust coupling scheme, a GOCART overall sea salt scheme, and a GOCART 4-level sea salt scheme;

[0020] The GOCART overall dust scheme calculates dust aerosol emissions and equates them to PM2.5. 2.5 and PM 10 The portion is further refined into 43 or 33 aerosols, with the overall spectral distribution defined by the aerosol grading module.

[0021] The GOCART 5-level sand and dust coupling scheme calculates the vertical sand lifting flux in 5 particle size segments and calculates the corresponding aerosol emissions.

[0022] The GOCART overall sea salt scheme calculates sea salt aerosol emissions based on a parameterized method of the sea salt aerosol source function using a semi-empirical formula.

[0023] The GOCART 4-level sea salt scheme is based on a semi-empirical formula to obtain a sea salt source function parameterization method applicable to submicron and ultramicron particles to calculate the number and particle size distribution of sea salt aerosols, and further refines the 4-level sea salt aerosols into 43 or 33 levels of aerosols.

[0024] Preferably, the vertical mixing coupling module uses a diffusion equation to calculate the time variation of the species mixing ratio due to vertical mixing and dry deposition, the diffusion equation being as follows:

[0025] ;

[0026] in, t is the mixing ratio of species, z is the vertical coordinate, D is the diffusion coefficient, and Vd is the dry sedimentation velocity.

[0027] Preferably, the Stokes law is applied in the aerosol dry sedimentation module to calculate the sedimentation velocity of CCN particles larger than 1µm, as shown in the following formula:

[0028] ;

[0029] in, is the settling rate, and r is the particle radius. It is the density of the particles. Where is the density of air, and g is the acceleration due to gravity. It is the dynamic viscosity of air.

[0030] Preferably, the aerosol grading module divides the aerosol into Eigen nucleus mode, accumulation mode and coarse mode according to the aerodynamic diameter.

[0031] Preferably, the aerosol graded dispensing module includes: considering the influence of different chemical components, adding 8 grades of warm cloud catalyst aerosol, adjusting the three properties of the catalyst (molar molecular mass MAERO, aerosol density RHO, and ion number IONS) according to the chemical composition of the catalyst, and adjusting the particle size of the catalyst according to the spectral distribution.

[0032] Preferably, the catalytic effect calculation module includes: simulating atmospheric aerosol and warm cloud processes using natural and anthropogenic aerosol profiles as a control experiment; adding aerosols of the catalyst profile for dispersal as a dispersal experiment; and comparing the two experiments with and without dispersal to obtain the warm cloud catalytic effect.

[0033] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages:

[0034] 1. Based on the WRF-SBM tiered microphysics scheme, this system improves emission sources, CCN initial boundary conditions, and aerosol transport and diffusion processes. It constructs a warm cloud tiered seeding catalytic system (WRF-FDDA-CABIN or WRF-CABIN) based on a four-dimensional multi-source meteorological data assimilation numerical weather model. The system supports flexible data source strategies for CCN initial boundary condition settings. In the replacement mode, high-precision data from global atmospheric chemistry models (such as WACCM and CHEM-CAM) are used as initial and boundary conditions to replace the original initialization method, obtaining more realistic aerosol distribution information. In the overlay mode, when global atmospheric chemistry numerical model data is lacking, the system will activate the model's original initialization function to calculate aerosol initial boundary conditions and supplement and correct them by combining regional observation data or a simplified emission inventory, ensuring the simulation process can still proceed smoothly.

[0035] 2. By coupling WRF-FDDA technology and utilizing data from multi-source meteorological observation platforms, combined with four-dimensional data assimilation technology, the initial atmospheric state can be finely calibrated in both temporal and spatial dimensions. This can effectively improve the simulation accuracy of cloud water resources and provide more precise initial field conditions for warm cloud catalysis processes. Simultaneously, WRF-CABIN possesses large eddy simulation capabilities, enabling high-resolution simulation studies of warm cloud catalyst seeding and aerosol-cloud interactions on a small scale (such as in specific environments like local mountainous areas and urban heat islands). This captures key features that traditional models struggle to resolve, such as turbulent motion and changes in the fine structure of cloud microphysics, thus providing a scientific basis for optimizing warm cloud catalysis strategies and evaluating the effectiveness of weather modification.

[0036] 3. By integrating natural aerosols, anthropogenic aerosols, and warm cloud catalyst seeding sources, an additional 8 warm cloud catalyst aerosol categories are added to the existing 43 or 33 aerosol / CCN categories. Based on the chemical composition of the catalyst, its molar molecular mass, aerosol density, and ion quantity are precisely adjusted, and the particle size is adapted according to the spectral distribution, thereby refining the characteristic description of CCNs with different chemical compositions. The dry sedimentation process of CCNs of different categories is introduced, and the influence of turbulence is simulated by subgrid vertical mixing to improve the aerosol transport and diffusion mechanism. Aerosol activation is calculated by a microphysical scheme, abandoning chemical processes to reduce resource consumption, and also has the function of customized human shadowing operations such as catalyst seeding and specified spectral distribution.

[0037] 4. Through flexible initial and boundary condition settings, high-precision data assimilation, and high-resolution simulation capabilities, meteorological fields are generated online via WRF. Multi-level aerosol / CCN and newly added catalysts are integrated, and the microphysical scheme of environmental aerosols is considered through SBM (fast, full and liquid) to realize the simulation of aerosol-cloud interactions and artificial weather modification operations. This improves the realism of warm cloud catalysis and cloud microphysical processes, and supports research on artificial weather modification. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the system configuration of the present invention;

[0039] Figure 2 A schematic diagram of the microphysical scheme for classifying environmental aerosols in this invention;

[0040] Figure 3 This is a schematic diagram of the aerosol concentration and water vapor mixing ratio profile after 24 hours of integration in a single-column experiment according to the present invention; wherein, Figure 3 (a) in the diagram is a schematic of the vertical mixing ratio profile being enabled. Figure 3 (b) in the diagram is a schematic of the vertical mixing ratio profile being turned off. Figure 3 (c) in the diagram is a schematic diagram of the water vapor profile;

[0041] Figure 4 This is a schematic diagram of the time series of ground aerosol concentration and water vapor mixing ratio from 0 to 24 hours in the single-column test of the present invention.

[0042] Figure 5 This is a schematic diagram showing the horizontal and cross-sectional concentration distribution of aerosols when the vertical mixing switch is turned on and off according to the present invention.

[0043] Figure 6 This is a schematic diagram showing the change of the vertical profile of the aerosol in this invention over time. Detailed Implementation

[0044] The technical solution of the present invention will be further described below with reference to the accompanying drawings.

[0045] The Weather Research and Forecasting (WRF) model is a next-generation mesoscale numerical weather prediction system designed to meet the needs of atmospheric research and operational forecasting. WRF provides the foundational framework and meteorological field simulation capabilities for CABIN. Its widespread global application and large user base and research foundation provide rich experience, data, and model component references for CABIN technology development. WRF's dynamic core and physical process parameterization schemes provide the underlying support for CABIN's simulation of complex processes such as aerosol-cloud-precipitation.

[0046] WRF-FDDA is a four-dimensional data assimilation (FDDA) technique based on the WRF model. By combining multi-source observation data (such as satellite, radar, and ground observations) with the WRF model, it continuously adjusts the model's initial field in both temporal and spatial dimensions, enabling the model to more accurately reflect actual atmospheric conditions and improve the accuracy of numerical weather prediction. CABIN technology focuses on warm cloud seeding catalytic schemes, requiring precise initial field conditions to accurately simulate aerosol distribution, cloud microphysical processes, and catalyst seeding and catalytic effects. WRF-FDDA can provide WRF-CABIN with more realistic atmospheric initial states, including aerosol concentration, macroscopic and microscopic cloud characteristics, compensating for WRF-CABIN's own shortcomings in initial field construction and playing a crucial role in improving its simulation accuracy.

[0047] This invention uses WRF and WRF-FDDA as the basic framework, with CABIN technology serving as a supplementary function to WRF-FDDA and also a modification of WRF itself. Its operation requires the operation of WRF or WRF-FDDA. In summary, CABIN technology and WRF, as well as WRF-FDDA, are deeply coupled; therefore, it is named WRF-CABIN, WRF-FDDA-CABIN, or a segmented microphysics scheme considering environmental aerosols.

[0048] like Figures 1-2 As shown, the warm cloud tiered seeding catalytic system based on a four-dimensional multi-source meteorological data assimilation numerical weather model, namely WRF-FDDA-CABIN, consists of nine modules: a four-dimensional data assimilation coupling module, an emission source generation and reading module, an aerosol initial and boundary condition generation module, a dust and sea salt coupling module, a vertical mixing coupling module, an aerosol dry deposition module, an aerosol tiered setting module, an aerosol tiered seeding module, and a catalytic effect calculation module.

[0049] The specific functions of each module are as follows:

[0050] The four-dimensional data assimilation and coupling module is used to fuse atmospheric observation data from different times and multiple dimensions to obtain the initial state information of warm clouds, optimize the initial field of the simulation, and improve the accuracy of the simulation. Specifically:

[0051] The accuracy of numerical weather prediction heavily relies on a precise description of the initial atmospheric state. Four-dimensional data assimilation technology can fully integrate multi-source observation data, more accurately depicting the initial atmospheric state in both temporal and spatial dimensions. This provides high-quality initial conditions for numerical weather models, significantly improving the accuracy and reliability of numerical simulation results. For simulations focusing on small- to medium-scale warm cloud processes, four-dimensional data assimilation technology can effectively integrate multi-source observation data from satellite remote sensing, radar detection, and ground observations. It allows for the acquisition of initial state information of warm clouds with refined spatiotemporal resolution, including the macroscopic structure, microscopic physical properties, and aerosol distribution. This solves the problem of accuracy in cloud water resource simulation and lays the foundation for subsequent simulations of warm cloud catalytic processes.

[0052] The four-dimensional data assimilation coupling module integrates four-dimensional data assimilation technology (WRF-FDDA) into the basic functions of WRF-CABIN. Through a coupler, it enables calculations of aerosol-cloud interactions, aerosol-diffusion, aerosol-dynamic transport, and graded catalytic effects within a more accurate cloud-water resource and meteorological condition forecast field. Simultaneously, it employs a separation scheme for assimilation and catalysis, isolating the assimilation and catalysis stages in terms of time integration to prevent the assimilation effect from overriding the catalytic effect.

[0053] The emission source generation and reading module is used to process aerosol emission source data and provide various aerosol emission inputs for the simulation, as follows:

[0054] In atmospheric chemistry models, primary aerosols and gases are mainly generated through release, while emission sources describe the rate, temporal, and spatial distribution of this release. Therefore, using appropriate emission source data is a crucial prerequisite for the accurate simulation of aerosols or CCNs. In WRF-SBM, an emission source scheme is not employed; instead, only initial values ​​and fixed boundary conditions are set to idealize aerosol concentrations within the simulation region. Commonly used bulk microphysics schemes typically do not consider the mixing and transport effects of CCNs in three-dimensional space, thus simplifying the calculation process. However, in the WRF-SBM scheme, aerosol concentrations are divided into 33 or 43 levels, and transport, diffusion, and activation processes are integrated and calculated at each integration step using an online calculation method. This is highly beneficial for a detailed description of aerosol-cloud-precipitation microphysics processes. Therefore, using overly idealized aerosol distributions in WRF-SBM would severely waste these online calculations, potentially leading to suboptimal simulation results, even worse than the bulk scheme. Therefore, to address these issues, the emission source generation and reading module of WRF-CABIN has ported and adjusted the emission source reading function in WRF-CHEM atmospheric chemistry, and is compatible with multi-scale emission inventory models (Multi-resolution Emission Inventory for China, MEIC) and the EDGAR (Emissions Database for Global Atmospheric Research) global atmospheric emission database, enabling the calculation of "emission source-aerosol" emission processes applicable to WRF-SBM.

[0055] Using algorithms such as interpolation, concentration conversion, and vertical stratification, the original MEIC emission source inventory is transformed into a gridded pollutant emission inventory (mainly for aerosols) for the target study area. Then, through density conversion, emission calculation, and time accumulation functions, the aerosol concentration release value of each grid point in the model is calculated, ultimately forming atmospheric aerosols, such as PM2.5. 2.5 PM 10 Mass concentration of chemical substances, such as PM. 2.5 and PM 10 The aerosol concentration of chemical substances will provide basic data for calculating aerosol number concentration at levels 43 or 33.

[0056] The aerosol initial and boundary condition generation module is used to set the state parameters of aerosols at the start of the simulation and at the boundary of the region, such as concentration and particle size, as follows:

[0057] For online CCN forecasting, in addition to emission sources, initial and boundary conditions are crucial. Initial values ​​provide the CCN concentration distribution at the initial time, while boundary conditions provide information about external inputs to the target area. After passing through emission source inputs, atmospheric chemical processes, transport and diffusion, vertical mixing, and dry deposition, the final online forecast of CCN concentration is obtained, which is then further simulated using microphysics schemes.

[0058] In the WRF-SBM model, the initial and boundary conditions for CCN concentrations are preset concentrations, not actual online simulations of CCN in the atmosphere. Therefore, the simulation results are overly idealized, failing to account for regional distribution characteristics, new particle generation and chemical evolution, diurnal and seasonal variations, and the idealization of vertical and horizontal concentration distributions. The WRF-CABIN technology, through external input embedding, processes the simulation results of two global atmospheric chemistry models to generate initial and boundary conditions for aerosols in a target region over a given time period, converting them into CCN number concentrations at 43 and 33 levels required for microphysical processes. Readable global atmospheric chemistry models include CHEM-CAM and WACCM.

[0059] The dust and sea salt coupling module is used to consider the generation and transport processes of dust (terrestrial source) and sea salt (marine source) aerosols, integrating them into the overall simulation, as detailed below:

[0060] The GOCART overall dust scheme mainly involves adjusting and coupling the bulk dust module in aerosol-aware thompson to calculate the emission of dust aerosols. It calculates the emission of dust particles based on different parameters (such as soil moisture, wind speed, soil type, etc.) and adds them to the e_pm_dust array.

[0061] First, the mass of dust particles (dustmas) is calculated based on their density and diameter. Then, the threshold wind speed (u_ts0) is calculated based on the mass, wind speed, and several constants. Next, the soil moisture (gwet) is used to determine if the soil is sufficiently dry to allow for dust particle emission. If the soil is sufficiently dry, the threshold wind speed (u_ts) is adjusted accordingly. Then, the emission area (srce) is calculated based on the erodibility (erodin), wind speed, and several constants. Finally, the emission rate (dsrc) is calculated based on the emission area, wind speed, and several constants. This calculation process considers factors such as dust particle density, diameter, wind speed, soil moisture, and erodibility to determine the emission rate. This is then equated to PM2.5. 2.5 and PM 10The aerosols are further subdivided into 43 or 33 aerosols, and the overall spectrum distribution is defined by the aerosol subdivision setting module.

[0062] The GOCART 5-stage dust coupling scheme, also known as the Goddard Chemistry Aerosol Radiation and Transport scheme, is based on a 10m wind speed and soil moisture. It calculates the vertical dust-lifting flux across five particle size ranges: 0–1 μm, 1–1.8 μm, 1.8–3 μm, 3–6 μm, and 6–10 μm. The formula for calculating the vertical dust-lifting flux is as follows:

[0063] ;

[0064] In the formula, G represents the vertical sand-lifting flux, and C is a constant of 0.8 μg·s. -2 ·m 5 S is the wind erosion index, representing the influence of surface features such as snow and ice cover and vegetation coverage on the distribution of potential dust sources. The mass ratios of dust particles in each size range are: 0.1 for particles of 0-1 μm and 0.25 for all other particle sizes. The horizontal wind speed at 10m above the ground. The critical friction speed is affected by the size of the sand and dust particles and the soil moisture.

[0065] In WRF-CABIN, the GOCART bulk scheme can calculate and generate dust particle emissions. It calculates the amount of dust particles emitted based on different parameters (such as soil moisture, wind speed, soil type, etc.), adds them to the e_pm_dust array, and calculates the corresponding aerosol emissions. The dust spectrum distribution is refined by the aerosol grading setting module.

[0066] The GOCART overall sea salt scheme is a parameterization method for the sea salt aerosol source function based on semi-empirical formulas from existing technologies (Monahan, EC, Spiel, DE, & Davidson, KL (1986). A model of marine aerosol generation via whitecaps and wave disruption. In Oceanic whitecaps (pp. 167-174). Springer, Dordrecht.) and existing technologies (Gong, SL (2003). A parameterization of sea-saltaerosol source function for sub- and super-micron particles. Global biogeochemical cycles, 17(4).). It mainly considers submicron and supermicron particles formed by wave breakup and whitecaps, and the overall spectrum distribution is defined by the aerosol banding module. When waves break up on the ocean surface, small water droplets are generated, which contain salt particles from the seawater. At the same time, wind also carries salt particles from the seawater into the air. These salt particles are suspended in the atmosphere as water droplets or aerosols, and then dispersed and propagated with atmospheric motion.

[0067] The GOCART 4-level sea salt scheme is based on a semi-empirical formula from existing technology (Monahan, EC, Spiel, DE, & Davidson, KL (1986). A model of marine aerosol generation via whitecaps and wave disruption. In Oceanic whitecaps (pp. 167-174). Springer, Dordrecht.). It develops a parameterization method for sea salt source functions applicable to submicron and ultramicron particles, extending the applicability of the Monahan formula to a particle size range of 0.05 μm while maintaining good simulation results for sea salt aerosols with radii greater than 0.2 μm. This is of great significance for accurately predicting the number and size distribution of sea salt aerosols and assessing their indirect impacts on climate, especially when submicron particles may play a major role in aerosol-cloud interactions.

[0068] The dust and sea salt coupling module couples with GOCART's 4-level sea salt scheme, and then further refines the 4-level sea salt aerosols into 43 or 33 levels of aerosols. The refinement rules of the spectral distribution are defined by the aerosol classification setting module.

[0069] The vertical mixing coupling module is used to characterize the mixing and diffusion of aerosols in the vertical direction (at different height levels), reflecting their vertical distribution changes, as detailed below:

[0070] The transport and mixing processes of the catalyst are crucial to the effectiveness of mulching operations, determining whether the dispersed catalyst can be reasonably transported and diffused to the target location in three-dimensional space. The transport process mainly relies on grid-scale atmospheric flow calculations, which are implemented within the WRF dynamic framework. The sub-grid mixing process of the catalyst, however, requires consideration of atmospheric boundary layer processes.

[0071] Vertical mixing within the atmospheric boundary layer is driven by vortices ranging from 100 to 3000 meters in diameter, which also determines the atmospheric state within the boundary layer (ROLAND B. STULL). However, most mainstream scales in NWP cannot resolve this part of the turbulence. In WRF models, the primary responsibility of boundary layer parameterization schemes is to parameterize the turbulent exchange processes at the "subgrid scale" and describe them at the "grid scale." In ordinary WRF models, various boundary layer schemes are only responsible for parameterizing the vertical mixing of a specified atmospheric scalar field (such as T, Q, etc.) and do not handle additional introduced variables, such as aerosols and chemical gases. In the current version of WRF-Chem, the turbulent diffusion coefficient is diagnosed by a subset of boundary layer parameterization schemes, including YSU, MYJ, MYNN2, BL, QNSE, and UW schemes, and is handled by a separate subroutine using a first-order closed scheme to process the vertical mixing process of chemical substances. Therefore, in WRF-Chem, the diffusion of chemical substances is only affected by local mixing processes in the boundary layer scheme, while meteorological variables are affected by local mixing, non-local mixing, and entrainment processes, depending on the selected boundary layer scheme.

[0072] The WRF-CHEM scheme, employing an independent local subgrid vertical mixing scheme, was coupled with the WRF-CABIN scheme. This scheme used a diffusion equation to calculate the time-varying effects of vertical mixing and dry deposition on the species mixing ratio. The general form of the diffusion equation can be expressed as:

[0073] ;

[0074] in, Here, is the species mixing ratio, t is time, z is the vertical coordinate, D is the diffusion coefficient, and Vd is the dry deposition velocity. The diffusion coefficient and dry deposition velocity are given by the input parameters kt_turb and vd. By calculating the coefficients a_coeff and b_coeff, the diffusion equation is discretized into a tridiagonal matrix form. Then, the discretized diffusion equation is solved to obtain the time variation of the species mixing ratio.

[0075] This scheme can handle vertical mixing processes of aerosol subgrids with 33 or 43 subgrids independently, is compatible with various boundary layer schemes, and has a significantly higher operating efficiency than high-resolution LES. The vertical mixing switch in the module only affects the aerosol diffusion process.

[0076] The aerosol dry deposition module is used to simulate the dry deposition process of aerosols to the ground surface due to gravity, turbulence, and other factors. This is related to aerosol removal, as detailed below:

[0077] Gravity dry settling refers to the slow descent of aerosol particles towards the ground under the influence of gravity due to their larger mass. The settling velocity of the particles is related to factors such as their size, density, and air viscosity. Larger aerosol particles settle to the ground more quickly due to gravity, while smaller particles settle more slowly. Gravity settling primarily utilizes Stokes' law to calculate the settling velocity of CCN aerosol particles larger than 1 μm.

[0078] ;

[0079] in, is the settling velocity (in m / s), and r is the particle radius (in m). It is the density of the particles (unit: kg / m³). 3 ), It is the density of air (unit: kg / m³). 3 g is the acceleration due to gravity, approximately 9.81 m / s². 2 , It is the dynamic viscosity of air.

[0080] Generally, only aerosol particles with a diameter greater than 1 micrometer need to be considered for gravitational sedimentation, especially PM2.5. 10 and PM 2.5 For particles smaller than 1 micrometer, the gravitational settling effect is weak, and they mainly propagate in the atmosphere through other mechanisms (such as diffusion and convection). Gravitational settling is more pronounced for particles larger than 10 micrometers. In the case of dry gravitational settling, large-particle aerosols will lose the effect of falling gravity.

[0081] The aerosol grading module is used to classify aerosols into different grades (categories) based on properties such as particle size, enabling refined simulation of the behavior of aerosols with different particle sizes, as detailed below:

[0082] Atmospheric aerosols can be classified into Eigen nucleus mode (0.001–0.1 μm), accumulation mode (0.1–1 μm), and coarse mode (>1 μm) according to their aerodynamic diameter. From a physical perspective, Eigen nucleus mode originates from gas-particle conversion processes, accumulation mode from collision and heterogeneous condensation, while coarse mode is mainly generated by mechanical processes. Aerosol particles that act as condensation nuclei for water vapor condensation into cloud particles are called cloud condensation nuclei (CCNs), and these are typically particles smaller than 1 μm. Generally, aerosols of different sizes have different effects on cloud droplet nucleation and growth processes. Accurately describing the aerosol particle size distribution helps to better simulate cloud microphysical processes. Therefore, considering aerosol particle size stratification in stratified cloud models is essential.

[0083] The aerosol tiered dispersal module is used to simulate the dispersal process of different tiers of aerosols (such as dispersal operations in weather modification scenarios), as detailed below:

[0084] Both warm cloud catalyst seeding and aerosol emission sources essentially involve injecting atmospheric chemicals into the three-dimensional space of a model and allowing them to move with the atmosphere, calculating their transport, diffusion, and deposition processes based on atmospheric conditions. This module, based on silver iodide seeding technology in cold cloud catalysis, develops a scheme suitable for graded aerosol seeding. This module not only retains various injection methods from all silver iodide seeding technologies but also adds aerosol grading functionality. This allows a certain mass concentration of injected aerosols to be resolved into 43 or 33 CCN concentration levels based on atmospheric conditions and a customized aerosol spectrum distribution. This enables point source, line source, and area source seeding modules to achieve different seeding schemes for aircraft, rockets, anti-aircraft guns, and ground-based smoke generators.

[0085] Namelist injection, through editing the namelist file during WRF runtime, sets the dissemination location, dissemination time, and dissemination rate (mass concentration / area / time), and injects a specified aerosol type. This technology requires no data preparation or processing, is highly flexible and adaptable. It can set up to 6 point sources and 1 volume source, where the volume source can be adjusted to point, line, or area sources via x, y, and z range settings. Only stationary emission sources can be considered. It is suitable for a small number of ground point sources and catalytic dissemination testing.

[0086] Grid-based emission source injection, similar to emission source injection in WRF-CHEM, reads specific emission substances from a 3D NC emission source data file at fixed time points through a special data channel. This technique is suitable for large-scale fixed emission sources and mobile point sources with long time intervals, such as point sources moving more than once an hour.

[0087] External sequence file injection: Of the two injection methods mentioned above, namelist injection can only describe fixed-point sources, while grid-based emission source injection has a limited time interval and cannot describe rapid changes in a short period of time (such as minutes or seconds). Therefore, neither is suitable for rapidly moving or instantaneously spreading two processes.

[0088] Therefore, by using a special file channel and injecting external sequence files, it is possible to describe the time, geographical location, altitude, and dispersal volume of point sources at intervals of up to the integration step size. This scheme can compensate for the limitation of namelist emission sources, which can only set up to 6 point sources, by setting up multiple point source dispersals at fixed times. At the same time, it can describe aircraft dispersal and instantaneous fixed point source dispersal, as well as dispersal methods such as anti-aircraft guns and rockets, by using rapidly changing time and location information.

[0089] In addition to the WRF-CABIN technology mentioned above, which can consider the nucleation process of aerosol particles from both natural and anthropogenic emissions in SBM-based cloud microphysics, and can achieve numerical simulation of warm cloud seeding and catalysis through a seeding scheme, there are certain problems with this process: the seeding aerosol fixation and CCN homogeneity (e.g., sodium chloride or ammonium sulfate) cannot meet the current requirements for evaluating novel warm cloud catalysts, and the influence of different chemical components needs to be considered. Therefore, this technical solution adds 8 additional warm cloud catalyst aerosols to WRF-CABIN, which can adjust the three properties of the catalyst—molar molecular weight (MAERO), aerosol density (RHO), and ion quantity (IONS)—according to the chemical composition of the catalyst, and adjust the particle size of the catalyst according to the spectral distribution.

[0090] The catalytic effect calculation module is used to calculate the effect of aerosol-involved catalytic processes (such as the catalysis of cloud precipitation), as detailed below:

[0091] Previous studies have shown that tiered cloud microphysics schemes can simulate aerosol-cloud-precipitation processes under different scenarios by setting different CCN concentrations and particle size distributions. Based on custom aerosol spectra technology and suitable warm cloud catalyst seeding simulation technology in WRF-CABIN, a warm cloud catalysis scheme was designed. The specific catalysis scheme is as follows: first, atmospheric aerosol and warm cloud processes are simulated using natural and anthropogenic aerosol spectra as control experiments; then, catalyst spectra aerosols are added and seeded as a seeding experiment; finally, the warm cloud catalysis effect is obtained by comparing the two experiments with and without seeding.

[0092] In terms of spatial distribution, the PM of artificial CABIN 2.5 The emission sources are mainly on land and sea routes, which can better reflect the spatial distribution of CCN aerosols released by human activities, which is a huge improvement for WRF-SBM.

[0093] like Figure 3 As shown, the mixing ratio profiles of aerosol concentration and water vapor after 24 hours of integration in a single-column experiment are presented. To demonstrate the importance of vertical mixing and diffusion of aerosols, an ideal single-column experiment (WRF_SCM) of chemically neutral aerosol diffusion was conducted, with an emission source continuously emitting aerosol catalyst placed on the ground.

[0094] like Figure 4 As shown, the time series of ground aerosol concentration and water vapor mixing ratio from 0 to 24 hours of a single-column experiment are presented. The results indicate that without vertical mixing, aerosols will continuously accumulate at the ground level, causing the ground concentration to rise continuously. However, with vertical mixing enabled, aerosols diffuse vertically, and the ground concentration exhibits diurnal variation characteristics. The aerosol profile and diurnal variation characteristics are quite similar to those of water vapor, which is reasonable.

[0095] A ground-based seeding point source was placed in the test area to investigate the impact of vertical mixing of aerosols in the real atmosphere during ground-based seeding diffusion. The comparison revealed that vertical mixing allows seeded aerosols to diffuse significantly higher vertically, especially during the day. If vertical mixing is disabled, silver iodide struggles to leave the seeding layer and is transported more horizontally, a crucial factor for ground-based smoke generator seeding. Because ground-based seeding is a bottom-up diffusion and transport process, if the boundary layer is well-developed and turbulent activity within the mixing layer is appropriate, ground-seeded pollutants will be carried higher by turbulent activity, making them more likely to reach the critical seeding area.

[0096] like Figure 5 As shown, the horizontal and vertical (profile) concentration distribution of aerosols in the test case is illustrated with the vertical mixing switch on and off; Figure 6 As shown, the vertical profile of aerosols changes over time, with the horizontal axis representing the time series (15-minute intervals). When the model resolution is insufficient to resolve the turbulence scale, the vertical mixing scheme can reflect the sub-grid mixing process of the catalyst in the vertical direction under the influence of turbulent mixing. Furthermore, this invention is faster, more effective, and more stable than high-resolution large eddy simulations, thus making it more suitable for operational use. On the other hand, besides seeded aerosols, natural / anthropogenic aerosols also require vertical mixing to reflect the impact of boundary layer turbulent transport on the distribution of ground pollutants. Without vertical mixing, ground pollutants will continuously accumulate, leading to a continuous accumulation of aerosol concentrations near the pollution source and producing unrealistically high values. Therefore, vertical mixing plays a crucial role in the online simulation of CCN and the diffusion of warm cloud catalysts.

[0097] By comparing the initial concentration distributions of SBM FAST and CABIN, WRF-CABIN can employ more realistic initial and boundary conditions compared to WRF-SBM.

[0098] The module has been upgraded with tiered options for all the above-mentioned seeding technologies. Users can customize the aerosol spectrum scheme, and this module can directly seed 33 or 43 bins of aerosol CCN bin by bin. The specific seeding amount (number concentration) of each bin is calculated from the aerosol spectrum and the total amount of seeded aerosol catalyst.

[0099] A warm cloud catalytic simulation experiment was conducted on a convective process in Fujian Province on November 11, 2023. First, a control experiment was conducted, designating both natural and anthropogenic sources as p1. Then, a seeding experiment was conducted, seeding the 10th layer of the model with a p101 spectral catalyst, also designated as p1. Thirty minutes after seeding, the changes in qrain and cloud_rain (seeding experiment minus control experiment) were observed in both experiments. Analysis of the warm cloud catalytic effect showed that a broadening of the cloud-rain droplet particle spectrum and an increase in QRAIN occurred within the convective cloud region. This demonstrates that CABIN possesses the capability to simulate warm cloud bin seeding catalytic processes, providing a fundamental tool for simulating and evaluating warm cloud catalytic effects in the weather modification industry, thereby generating economic value.

Claims

1. A warm cloud tiered seeding catalytic system based on a four-dimensional multi-source meteorological data assimilation numerical weather model, characterized in that, include: The four-dimensional data assimilation and coupling module is used to fuse multi-source observation data through four-dimensional data assimilation technology to obtain the initial state information of warm clouds; The emission source generation and reading module is used to convert the emission source inventory into a gridded pollutant emission inventory of the target study area, forming atmospheric aerosols; The aerosol initial and boundary condition generation module is used to generate the aerosol initial and boundary conditions of the target study area within a given time, and convert them into the CCN number concentration required for the graded microphysical processes. The dust and sea salt coupling module is used to calculate the emissions of dust and sea salt aerosols and integrates them into the overall simulation; The vertical mixing coupling module is used to calculate the time-varying effects of vertical mixing and dry sedimentation on the species mixing ratio; The aerosol dry sedimentation module is used to simulate the gravity sedimentation process of aerosol particles of different grades. The aerosol grading module is used to divide aerosols into different grades to simulate the behavior of aerosols with different particle sizes. The aerosol graded dispersal module is used to simulate the dispersal process of different grades of aerosols; The catalytic effect calculation module is used to calculate the catalytic effect for catalytic processes involving aerosols.

2. The warm cloud tiered seeding catalytic system according to claim 1, characterized in that, The multi-source observation data in the four-dimensional data assimilation and coupling module includes ALL WTO / GTS standard stations, automatic wind weather stations, wind profiler radar, satellite observations, weather radar, microwave radiometers, flight weather reports, and meteorological observation data; the initial state information of warm clouds includes the macroscopic structure, microscopic physical properties, and aerosol distribution of the clouds.

3. The warm cloud tiered seeding catalytic system according to claim 1, characterized in that, The emission source generation and reading module calculates the aerosol concentration release value of each grid point through density conversion, emission calculation, and time accumulation function to form atmospheric aerosols.

4. The warm cloud tiered seeding catalytic system according to claim 1, characterized in that, The aerosol initial and boundary condition generation module obtains online forecast results of CCN number concentration through emission source input, atmospheric chemical processes, transport and diffusion, vertical mixing, and dry deposition processes, and further simulates them.

5. The warm cloud tiered seeding catalytic system according to claim 1, characterized in that, The dust and sea salt coupling module includes the GOCART overall dust scheme, the GOCART 5-level dust coupling scheme, the GOCART overall sea salt scheme, and the GOCART 4-level sea salt scheme. The GOCART overall dust scheme calculates dust aerosol emissions and equates them to PM2.

5. 2.5 and PM 10 The portion is further refined into 43 or 33 aerosols, with the overall spectral distribution defined by the aerosol grading module. The GOCART 5-level sand and dust coupling scheme calculates the vertical sand lifting flux in 5 particle size segments and calculates the corresponding aerosol emissions. The GOCART overall sea salt scheme calculates sea salt aerosol emissions based on a parameterized method of the sea salt aerosol source function using a semi-empirical formula. The GOCART 4-level sea salt scheme is based on a semi-empirical formula to obtain a sea salt source function parameterization method applicable to submicron and ultramicron particles to calculate the number and particle size distribution of sea salt aerosols, and further refines the 4-level sea salt aerosols into 43 or 33 levels of aerosols.

6. The warm cloud tiered seeding catalytic system according to claim 1, characterized in that, The vertical mixing coupling module uses a diffusion equation to calculate the time-dependent changes in the species mixing ratio caused by vertical mixing and dry deposition. The diffusion equation is as follows: ； in, t is the mixing ratio of species, z is the vertical coordinate, D is the diffusion coefficient, and Vd is the dry sedimentation velocity.

7. The warm cloud tiered seeding catalytic system according to claim 1, characterized in that, The aerosol dry sedimentation module applies Stokes' law to calculate the sedimentation velocity of CCN particles larger than 1µm, as shown in the following formula: ； in, is the settling rate, and r is the particle radius. It is the density of the particles. Where is the density of air, and g is the acceleration due to gravity. It is the dynamic viscosity of air.

8. The warm cloud tiered seeding catalytic system according to claim 1, characterized in that, The aerosol grading module divides aerosols into Eigen nucleus mode, accumulation mode, and coarse mode according to their aerodynamic diameter.

9. The warm cloud tiered seeding catalytic system according to claim 1, characterized in that, The aerosol graded dispersal module includes: considering the influence of different chemical components, adding 8 grades of warm cloud catalyst aerosols, adjusting the three properties of the catalyst (molar molecular mass MAERO, aerosol density RHO, and ion number IONS) according to the chemical composition of the catalyst, and adjusting the particle size of the catalyst according to the spectral distribution.

10. The warm cloud tiered seeding catalytic system according to claim 1, characterized in that, The catalytic effect calculation module includes: simulating atmospheric aerosol and warm cloud processes using natural and anthropogenic aerosol spectra as a control experiment; adding aerosols of the catalyst spectra for dispersal as a dispersal experiment; and comparing the two experiments with and without dispersal to obtain the warm cloud catalytic effect.

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