This DATASETreadme.txt file was generated on 2021-10-10 by Jinjin Hu & Xin Gao


GENERAL INFORMATION

1. Title of Dataset: 
    Data on streamer initiation from charged hydrometeors

2. Author Information
	A. Principal Investigator Contact Information
		Name: Jinjin Hu
		Institution: College of Physics, Guizhou University
		Address: Guiyang, Guizhou Province, China
		Email: 1257205625@qq.com

	B. Associate or Co-investigator Contact Information
		Name: Xin Gao
		Institution: College of Physics, Guizhou University
		Address: Guiyang, Guizhou Province, China
		Email: gaoxin0526@163.com

	C. Alternate Contact Information                               
		Name: 
		Institution: 
		Address: 
		Email: 

3. Date of data collection (single date, range, approximate date): 
    Data were obtained through a series of simulation studies. From 2020-12-01 to 2021-07-15.

4. Geographic location of data collection <latitude, longiute, or city/region, State, Country, as appropriate>: 
    The data is not measuered, but obtained through numerical simulation.  

5. Information about funding sources that supported the collection of the data: 
    This work is supported by National Natural Science Foundation of China(11965007).


SHARING/ACCESS INFORMATION

1. Licenses/restrictions placed on the data: 
   This work is licensed under a CC0 1.0 Universal (CC0 1.0) Public Domain Dedication license.

2. Links to publications that cite or use the data:
   https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2021JD034936

3. Links to other publicly accessible locations of the data: 
    No.

4. Links/relationships to ancillary data sets: 
    No.

5. Was data derived from another source? yes/no
    No.

6. Recommended citation for this dataset:
    https://doi.org/10.5061/dryad.prr4xgxn4


DATA & FILE OVERVIEW

1. File List: 
  <list all files (or folders, as appropriate for dataset organization) contained in the dataset, with a brief description>
  The dataset contains nine subfolders that generate the corresponding figures in the paper. 
  Subfolder Fig.1 contains data on electron density and electric field intensity(ne0, ne111 and field0, field111) in the simulation area and meshing and simulation area size(output.dat) used in the simulation process.
  Subfolder Fig.2 contains the data of the four corresponding curves in Fig.2.
  Subfolder Fig.3 contains two groups of simulated experimental data under different initial electron densities. Subfolders nb=1.0e9 and nb=10 contain simulation data with initial electron densities of 1.0e9 m^-3 and 10 m^-3, respectively.
  Subfolder Fig.4 contains the data of the five curves and the coordinates of each simulated data point in Fig.4. Five .TXT files correspond to the data of five curves. The first column of data corresponds to the abscissa and the second column corresponds to the ordinate. File simulation data.xlsx describes the coordinates of each data point in Fig.4.
  Subfolder Fig.5 contains the data of the four curves and the coordinates of each simulated data point in Fig.5. Four .TXT files correspond to the data of four curves. The first column of data corresponds to the abscissa and the second column corresponds to the ordinate. File simulation data.xlsx describes the coordinates of each data point in Fig.5.
  Subfolder Fig.6 contains two sets of simulated data Fig.6(a) and Fig.6(b), which contain data on electric field intensity and electron density in the simulated area.
  Subfolder Fig.7 contains data on electric field intensity(field) and electron density(ne) in the simulated area at different moments. File output.dat records the size of the simulated area and the meshing of the simulated area.
  Subfolder Fig.8 contains four .TXT files corresponding to the four curves in Fig.8.
  Subfolder Fig.9 contains four files, among which 3 .TXT files correspond to 3 curves in Fig.9 respectively, and the others 3 curves of the Sphere are generated by the formula in file sphere's data fomular.docx.
  Subfolder mymatlab contains five .m files, which are programs for drawing. You can run these programs with MATLAB.

2. Additional related data collected that was not included in the current data package: 
   No

3. Are there multiple versions of the dataset? yes/no
	A. If yes, name of file(s) that was updated: 
		i. Why was the file updated?
		ii. When was the file updated? 
    No


METHODOLOGICAL INFORMATION

1. Description of methods used for collection/generation of data: 
<Include links or references to publications or other documentation containing experimental design or protocols used in data collection>
   The simulation results are obtained through a series of numerical simulation.

2. Methods for processing the data: 
<describe how the submitted data were generated from the raw or collected data>
   Fig.1 and Fig.6 are generated by the corresponding electric field(field) and electron density(ne) distribution files.  
   Folder Fig.1 contains five files: ne0, ne111, field0, field111 and output.dat. 
   Files ne0 and ne111 represent the data of electron density in the simulated region at 0 ns and 11 ns, respectively, which can be opened with the MATLAB.
   Files ne0 and ne111 contain 2D data corresponding to the simulated area grid.
   The data in the first row and column of the ne0 and ne111 files are the simulation moments, and the other data are electron density values in the simulation area.
   The number of rows corresponds to the number of meshes on the Z-axis of the simulated region, and the number of columns corresponds to the number of meshes on the R-axis of the simulated region.
   Put folders Fig.1 and mymatlab into the computer software MATLAB and input the commands myplot('ne',0,5,22,1) and myplot('ne',111,5,22,1) in the command line window of the software to get Fig.1 (a)  in this paper.
   Similarly, Files field0 and field111 represent the data of electric field in the simulated region at 0 ns and 11 ns, respectively, which can be opened with the MATLAB.
   Files field0 and field111 contain 2D data corresponding to the simulated area grid.
   The data in the first row and column of the field0 and field111 files are the simulation moments, and the other data are electric field values in the simulation area.
   Put folders Fig.1 and mymatlab into the computer software MATLAB and input the commands myplot('field',0,0,1e7,0) and myplot('ne',111,0,1e7,0) in the command line window of the software to get Fig.1 (b)  in this paper.
   The file output.dat records the size and mesh of the simulated area, as well as the coordinates of grid points on the z and r axes. The function of this file is to provide data for the plotting program mymatlab.
   The folder Fig.6 is similar to the folder Fig.1, also containing the files ne, field, and output.dat, which have similar meanings and usage.
   Fig.1 is the simulation data of spherical hydrometeors, and Fig.6 is the simulation data of column hydrometeors.

   The data in Fig.2 are derived from streamer simulation. It contains four files: ne(nb=10).txt, ne(nb=1e9).txt and Emax(nb=10).txt, Emax(nb=1e9).txt. 
   Files ne(nb=10).txt, ne(nb=1e9).txt and Emax(nb=10).txt, Emax(nb=1e9).txt represent electron densities and maximum electric fields changing with simulation time for cases with background electron densities(nb) of 10 m^-3 and 10^9 m^-3, respectively.
   These files contains two columns, the first column corresponds to the abscissa and the second column corresponds to the ordinate of Fig.2. The abscissa represents time, and the ordinate represents electron density and electric field.
   Extract the first and second column data from these files to draw the four curves in Fig.2.

   Fig.3 and Fig.7 show the electric field and electron density distribution curves on the symmetry axis of the simulated region, which are generated by the data in the first column of fieldz and ne files in the corresponding folder.
   Folders Fig.3 contains two subfolders nb=10 and nb=1.0e9 representing the simulation results with background electron density of 10 m^-3 and 10^9 m^-3, respectively. They contain simulated data at different times within the simulated area.
   The files ne and fieldz are electron density and the components of electric field in the z direction, respectively. Files ne41 and ne51 represent simulated data of 4 ns and 5 ns respectively, and others are similar.
   Files ne(ne41, ne51...) and fieldz(fieldz41, fieldz51...) contain 2D data corresponding to the simulated area grid. Since we are using a cylindrical symmetric model, only half of the model needs to be simulated. 
   The first column of data is the simulated data of grid points on the symmetry axis of the simulated region, so extract the first column data from these files to draw the curves in Fig.3 and Fig.7.

   Folder Fig.4, Fig.5 and Fig.8 were obtained from Meek criterion by our program, where these .txt files contain the data to draw the curves in the corresponding figures.
   Folder Fig.4 is the data of spherical hydrometeors; folder Fig.5 is the data of column hydrometeors; folder Fig.8 contains the comparison of two groups of spherical hydrometeors and column hydrometeors.
   The first column of these.txt files is the radius of the hydrometeors, which corresponds to the abscissa; The second column is the background electric field satisfying the corresponding Meek number(M), corresponding to the ordinate of the curve.
   Extract the first and second column data from these files to draw the corresponding curves in Fig.4, Fig.5, and Fig.8.
   File simulation data.xlsx is the coordinates of the data points in the corresponding figure.

   Folder Fig.9 was obtained from the calculation of the electric field distribution of the Sphere and Column, including 3 .txt files and 1 .docx files. These .txt files record the electric field distribution on the symmetry axis of the column hydromteors with charge of 0pC,200pC and 300pC respectively.
   The three .txt files all contain two columns of data. The first column represents the horizontal coordinate (distance R(mm) from the lower surface of the hydrometeors), and the second column represents the vertical coordinate (electric field intensity R(mm) from the lower surface of the hydrometeors) in Fig.9.
   Extract the first and second column data from the three .txt files to draw the curves of column hydrometeors in Fig.9.
   The formula in file sphere's data fomular.docx is the electric field distribution function of spherical hydrometeors on the symmetry axis. Three curves of electric field distribution of spherical hydrometeors in Fig.9 can be drawn by this function.


3. Instrument- or software-specific information needed to interpret the data: 
<include full name and version of software, and any necessary packages or libraries needed to run scripts>
  Simulation program made by ourselves. 
  MATLAB 9.4 R2018a(or some other version)

4. Standards and calibration information, if appropriate: 

5. Environmental/experimental conditions: 

6. Describe any quality-assurance procedures performed on the data:
 All data are simulated results by the advanced simulation program based on the past researches. 

7. People involved with sample collection, processing, analysis and/or submission: 
  Jinjin Hu, Yikai Ma, Xin Gao, Ningyu Liu


DATA-SPECIFIC INFORMATION FOR: [FILENAME]
<repeat this section for each dataset, folder or file, as appropriate>

1. Number of variables: 
Fig.1: 4 variables.
Fig.2: 3 variables.
Fig.3: 3 variables.
Fig.4: 4 variables.
Fig.5: 4 variables.
Fig.6: 4 variables.
Fig.7: 3 variables.
Fig.8: 3 variables.
Fig.9: 3 variables.

2. Number of cases/rows: 
Fig.1: 4 cases.
Fig.2: 4 cases.
Fig.3: 32 cases. 
Fig.4: 16 cases.
Fig.5: 10 cases.
Fig.6: 4 cases.
Fig.7: 10 cases.
Fig.8: 4 cases.
Fig.9: 6 cases.

3. Variable List: 
<list variable name(s), description(s), unit(s)and value labels as appropriate for each>

Fig.1: (1)E(electric field), V/m
         (2)ne(electron density), m exp(-3)
         (3)abscissa(r), m 
         (4)ordinate(z), m
Fig.2: (1)Emax(maximum electric field), V/m
         (2)ne(maximum electron density), m exp(-3)
         (3)position(z), m 
Fig.3: (1)E(electric field), V/m
         (2)ne(electron density), m exp(-3)
         (3)position(z), m 
         (4)t(time), ns
Fig.4: (1)E0(ambient field), Ek
         (2)M(Meek number)
         (3)R(radius), m
         (4)Q(charge quantity), pC
Fig.5: (1)E0(ambient field), Ek
         (2)M(Meek number)
         (3)R(radius), m
         (4)Q(charge quantity), pC
Fig.6: (1)E(electric field), V/m
         (2)ne(electron density), m exp(-3)
         (3)abscissa(r), m 
         (4)ordinate(z), m
Fig.7: (1)E(electric field), V/m
         (2)ne(electron density), m exp(-3)
         (3)position(z), m 
         (4)t(time), ns
Fig.8: (1)E0(ambient field), Ek
         (2)R(radius), mm
         (3)Q(charge quantity), pC
Fig.9: (1)E(electric field), V/m
         (2)R(radius), mm
         (4)Q(charge quantity), pC
