Pitch angle diffusion coefficients used in comparison of quasi-linear diffusion theory with in-situ measurements

These data include pitch angle diffusion coefficients for chorus waves which have been evaluated at the angle of loss cone calculated in multiple ways. We have predominately concentrated on the dawnside between 00-12 MLT (Magnetic Local Time), for 5<L*<5.5 as this is where we have Van Allen Radiation Belt Storm Probes (RBSP) measurements and scattering of electrons due to chorus waves is known to occur. We have used 7 years of RBSP wave and cold plasma measurements between November 2012 to October 2019 to calculate these diffusion coefficients. For the first two sets of data we provide chorus diffusion coefficients with fpe/fce times by 2 and divided by 2 respectively. The next four data sets have been calculated from RBSP data using two different methods, first using average values, as has previously been done (e.g. Horne et al [2013]) and used above, and secondly by using co-located measurements of the wave spectra and fpe/fce to calculate pitch angle diffusion coefficients (Daa), where fpe is the plasma frequency and fce is the proton gyro frequency, and then averaging, similar to that presented in Ross et al [2021] for Electromagnetic Ion Cyclotron (EMIC) waves and Wong et al [2022] for magnetosonic waves. Both methods use a modified version of the PADIE code Glauert et al [2005] which allows an arbitrary wave power spectral density input rather than Gaussian inputs. The RBSP chorus diffusion coefficient matrices are computed by combining RBSP data with a profile for how chorus wave power changes with latitude, derived from the VLF database in Meredith et al [2018]. The magnetic latitude profile enables us to map RBSP measurements to magnetic latitudes between 0<MLAT<60 and therefore include the effects of high latitude chorus in our results. The RBSP diffusion matrices also use a new chorus wave normal angle model derived from RBSP data composed of different wave normal angle distributions for different spatial location and fpe/fce bins. Lastly we include two data sets of RBSP-chorus diffusion coefficients combined with diffusion coefficients due to collisions with atmospheric particles to calculate the total diffusion of electrons near the loss cone between 00-12 MLT, for 5<L*<5.5. We have produced these different sets of chorus (and combined chorus and collision) diffusion coefficients to test our methods of calculating electron precipitation and find what variables these calculations are sensitive to.



Funding was provided by NERC Highlight Topic Grant NE/P01738X/1 (Rad-Sat) and NERC National Capability grants NE/R016038/1 and NE/R016445/1

Simple

Alternate title

Polar Data Centre (PDC) record GB/NERC/BAS/PDC/01762
Date (Publication)
2023-09-28
Citation identifier
http://www.antarctica.ac.uk/dms/metadata.php?id= / GB/NERC/BAS/PDC/01762
Point of contact
Organisation name Individual name Electronic mail address Role

British Antarctic Survey

pdc@bas.ac.uk

Custodian

NERC EDS UK Polar Data Centre

Reidy, J., Ross, J., & Wong, J.

pdc@bas.ac.uk

Originator
Maintenance and update frequency
Unknown
Keywords

  • NDGO0001

NERC OAI Harvesting

  • NERC_DDC

GCMD Parameter Valids

  • EARTH SCIENCE > Atmosphere > Atmospheric Radiation

BAS Free-text keywords

  • electron precipitation

  • pitch angle diffusion coefficients

  • radiation belt model

  • wave-particle interactions
Use limitation

Data released under the Open Government Licence V3.0 :



http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/

Access constraints
Other restrictions
Other constraints

Data released under the Open Government Licence V3.0 :



http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/

Language
English
Topic category
  • Geoscientific information
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Begin date
2012-11-01
End date
2019-10-31
Reference system identifier
OGP / urn:ogc:def:crs:EPSG::4326
Distribution format
    Distributor contact
    Organisation name Individual name Electronic mail address Role

    Polar Data Centre - British Antarctic Survey

    pdc@bas.ac.uk

    		Distributor
    OnLine resource
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    http

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    Hierarchy level
    Dataset

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    Measure identification
    INSPIRE / Conformity_001

    Conformance result

    Title

    INSPIRE Data Specification on unknown theme Guidelines
    Date
    Explanation

    See the referenced specification
    Pass
    No
    Statement

    Any places where there are no data are set to NaNs.

    Metadata

    File identifier
    GB_NERC_BAS_PDC_01762 XML
    Metadata language
    English
    Hierarchy level
    Dataset
    Date stamp
    2023-09-28
    Metadata standard name

    NERC profile of ISO19115:2003
    Metadata standard version

    1.0
    Metadata author
    Organisation name Individual name Electronic mail address Role

    British Antarctic Survey

    pdc@bas.ac.uk

    		Point of contact
    Dataset URI

    http://www.antarctica.ac.uk/dms/metadata.php?id=GB/NERC/BAS/PDC/01762

     
     

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