Abstract:
This dataset contains two NetCDF files: Chorus_daa.nc (labelled from here as a) which contains the chorus pitch angle diffusion coefficients presented in Figure 1 of Reidy et al (2020) and Combined_daa.nc (labelled from here as b) containing the combined pitch angle diffusion coefficients which can be used to do the analysis presented in the remainder of the Reidy et al (2020) paper.
These data sets include:
a. A matrix containing the pitch angle diffusion coefficients for chorus waves at the angle of the loss cone for energies of 30, 100 and 300 keV between L*= 27.5, a full range of MLT sectors and for low (1 < Kp < 2), moderate (2 < Kp < 3) and high (4 < Kp < 7) geomagnetic activity levels. These were calculated from an average wave model presented in Meredith et al (2020) to capture the effect of waveparticle interactions in the BAS Radiation Belt Model (BASRBM). Also the arrays containing the energy, L*, MLT and Kp dependence are also included.
b, A matrix containing the combined pitch angle diffusion coefficients for chorus, hiss and EMIC waves and coulomb collisions between alpha = 0.5deg 9.45deg, Energy = 28.182511.89 keV , L* = 4.257.25, MLT = 024 and 6 different activity levels. The arrays containing the pitch angle, energy, L*, MLT and Kp dependence are also included.
Funding was provided by NERC Highlight Topic Grant NE/P01738X/1 and NERC National Capability grants NE/R016038/1 and NE/R016445/1
Keywords:
Pitch angle diffusion coefficients, radiation belt model, waveparticle interactions
Reidy, J. (2020). Pitch angle diffusion coefficients used to calculate electron precipitation from the Earth's radiation belts (Version 1.0) [Data set]. UK Polar Data Centre, Natural Environment Research Council, UK Research & Innovation. https://doi.org/10.5285/1ccb7d3848d84206be34b218fa763b5a
Use Constraints:  This data is governed by the NERC data policy http://www.nerc.ac.uk/research/sites/data/policy/ and supplied under Open Government Licence v.3 http://www.nationalarchives.gov.uk/doc/opengovernmentlicence/version/3/. 

Creation Date:  20200710 

Dataset Progress:  Complete 
Dataset Language:  English 
ISO Topic Categories: 

Parameters: 

Personnel:  
Name  UK PDC 
Role(s)  Metadata Author 
Organisation  British Antarctic Survey 
Name  Jade Reidy 
Role(s)  Technical Contact, Investigator 
Organisation  British Antarctic Survey 
Name  Dr Johnathan P J Ross 
Role(s)  Investigator 
Organisation  British Antarctic Survey 
Name  Dr Nigel Meredith 
Role(s)  Investigator 
Organisation  British Antarctic Survey 
Name  Dr Sarah Glauert 
Role(s)  Investigator 
Organisation  British Antarctic Survey 
Parent Dataset:  N/A 
Reference:  Abel, B., & Thorne, R. M. (1998). Electron scattering loss in earth's inner magnetosphere: 1. dominant physical processes. Journal of Geophysical Research: Space Physics, 103(A2), 2385 2396. doi: 10.1029/97JA02919 Glauert, S. A., & Horne, R. B. (2005). Calculation of pitch angle and energy diffusion coefficients with the PADIE code. Journal of Geophysical Research (Space Physics), 110(A4), A04206. doi: 10.1029/2004JA010851 Glauert, S. A., Horne, R. B., & Meredith, N. P. (2014). Threedimensional electron radiation belt simulations using the BAS Radiation Belt Model with new diffusion models for chorus, plasmaspheric hiss, and lightninggenerate whistlers. Journal of Geophysical Research (Space Physics), 119(1), 268289. doi: 10.1002/2013JA019281 Kersten, T., Horne, R. B., Glauert, S. A., Meredith, N. P., Fraser, B. J., and Grew, R. S. (2014), Electron losses from the radiation belts caused by EMIC waves, J. Geophys. Res. Space Physics, 119, 8820  8837, doi:10.1002/2014JA020366. Meredith, N. P., Horne, R. B., Shen X. C., Li, W., and Bortnik, J. (2020) Global Model of Whistler Mode Chorus in the NearEquatorial Region (λm < 18°). Geophysical Research Letters, 10.1029/2020GL087311 Reidy, J. A., Horne, R.B., Glauert, S. A., Clivered, M. A., Meredith, N. P., Woodfield, E. E., Ross, J. P., Allison, H. J. and Rodger, C. J. (2020) Comparing electron precipitation fluxes calculated from pitch angle diffusion coefficients to satellite observations, Submitted to Journal of Geophysical Research 


Quality:  Any places where there are no data are set to NaNs.  
Lineage:  The diffusion coefficients for the chorus waves were derived using combined observations from seven spacecraft; these observations are binned by L*, MLT, magnetic latitude and geomagnetic activity level as described in Meredith et al. (2012, 2020). In our study we use a chorus diffusion matrix which includes the wave dataset presented in Meredith et al. (2020). To create the data set presented here (a) we interpolated over the entire diffusion matrix in pitch angle to the loss cone angle (assuming a dipole) and in energy to 30, 100 and 300 keV for the aforementioned L*, MLT and activity levels. In the second data file (b), the pitch angle diffusion coefficients for chorus waves, hiss waves (derived as described in Glauert et al. (2014)), EMIC wave (Kerston et al., 2014) and coloumb collisions (calculated as outlined in Abel and Thorne (1998)) are combined. These diffusion coefficients are initially all interpolated to the same alpha, energy, L*, MLT and activity and then added together. We present a subset of this matrix that was used for the analysis presented in Reidy et al (2020). 
Location:  

Location  Van Allen Radiation Belts 
Detailed Location  L* between 2 and 7.5 in 0.5L* bins 
Data Collection:  These diffusion coefficients were initially calculated using the PADIE code (Glauert & Horne, 2005). 

Distribution:  

Distribution Media  Online Internet (HTTP) 
Distribution Size  1.2 MB 
Distribution Format  netCDF 
Fees  N/A 
Data Storage:  This file contains two NetCDF files, one containing chorus diffusion coefficients used in Figure 1 of Reidy et al (2020) and the other containing the combined diffusion coefficients which can be used to do the analysis presented in the remainder of the Reidy et al (2020) paper. Each file contains a matrix with the diffusion coefficients, labelled daa, and arrays detailing the matrix size. a. Chorus Daa [n_energy, n_lstar, n_mlt, n_act], where n_energy, n_lstar, n_mlt and n_act are the number of elements in the arrays for energy, lstar, MLT and activity level. These are all given as separate arrays. b. Combined Daa [n_alpha, n_energy, n_lstar, n_mlt, n_act], same as previous but now the diffusion coefficients also have pitch angle dependence and the pitch angle (alpha) are given as a separate matrix. 