Date (Creation)

2021-03-01

Date (Revision)

2021-03-01

Date (Publication)

2021-03-01

Date (released)

2021-03-01

Edition

1.0

Unique resource identifier

https://doi.org/10.5285/f4245a21-dee9-46cf-85b2-114798cb7ebc

Codespace

doi

Unique resource identifier

GB/NERC/BAS/PDC/01473

Codespace

https://data.bas.ac.uk/

Unique resource identifier

NE/N01099X/1

Codespace

award

Other citation details

Please cite this item as: Shore, R., Freeman, M., & Chisham, G. (2021). Dominant spatial and temporal patterns of horizontal ionospheric plasma velocity variation covering the northern polar region, for the month of February 2001 (Version 1.0) [Data set]. UK Polar Data Centre, Natural Environment Research Council, UK Research & Innovation. https://doi.org/10.5285/f4245a21-dee9-46cf-85b2-114798cb7ebc

Credit

No credit.

Status

Completed

Point of contact

Organisation name	Individual name	Electronic mail address	Role
British Antarctic Survey	Shore, Robert		Author
British Antarctic Survey	Freeman, Mervyn		Author
British Antarctic Survey	Chisham, Gareth		Author
NERC EDS UK Polar Data Centre		PDCServiceDesk@bas.ac.uk	Point of contact

Maintenance and update frequency

As needed

Maintenance note

Completed

Global Change Master Directory (GCMD) Science Keywords

• EARTH SCIENCE > Sun-earth Interactions > Ionosphere/Magnetosphere Dynamics

Theme

• Data Interpolating Empirical Orthogonal Functions

• Ionospheric electrodynamics

• Plasma velocity

• SuperDARN reanalysis

• Upper atmosphere dynamics

Place

• F-region Ionosphere

GEMET - INSPIRE themes, version 1.0

• Atmospheric conditions

Access constraints

Other restrictions

Other constraints

no limitations to public access

Access constraints

Other restrictions

Other constraints

no limitations

Use constraints

License

Other constraints

Open Government Licence v3.0

Use constraints

Other restrictions

Other constraints

This data is governed by the NERC Data Policy: https://www.ukri.org/who-we-are/nerc/our-policies-and-standards/nerc-data-policy/

Use constraints

Other restrictions

Other constraints

This data is governed by the NERC data policy and supplied under Open Government Licence v.3

Unique resource identifier

url

Codespace

url

Association Type

Cross reference

Unique resource identifier

url

Codespace

url

Association Type

Larger work citation

Unique resource identifier

doi

Codespace

doi

Association Type

Cross reference

Spatial representation type

Text, table

Language

English

Character set

UTF8

Topic category

• Climatology, meteorology, atmosphere

Begin date

2001-02-01

End date

2001-02-28

Supplemental Information

It is recommended that careful attention be paid to the contents of any data, and that the author be contacted with any questions regarding appropriate use. If you find any errors or omissions, please report them to polardatacentre@bas.ac.uk.

Title

European Petroleum Survey Group (EPSG) Geodetic Parameter Registry

Date (Publication)

2008-11-12

Cited responsible party

Organisation name	Individual name	Electronic mail address	Role
European Petroleum Survey Group		EPSGadministrator@iogp.org	Publisher

Unique resource identifier

urn:ogc:def:crs:EPSG::3031

Version

6.18.3

Hierarchy level

Dataset

Statement

Methodology:

Following the data binning into an equal-area grid and 5-min medians as described in the abstract, the data gaps are infilled as follows. We initially infill the data gaps in the sparse binned data with zeros, and then we apply the method of data-interpolating Empirical Orthogonal Functions (EOFs). This allows global (i.e. the full extent of the binned data set) spatial and temporal basis vector patterns to be obtained. These basis vectors collectively describe the full variability of the dataset. The form (i.e. morphology/shape) of the basis vectors is controlled by the cross-correlations within the dataset. Since the ionospheric plasma velocity is strongly correlated in space and time, the spatial and temporal behaviour of the basis vectors with the largest eigenvalues (i.e. those which describe the majority of the variability in the dataset) are defined by the underlying physics of the ionospheric plasma. In contrast, since the missing data are relatively uncorrelated in space and time, the missing data contributes to lower-eigenvalue basis vectors. This provides us with a method to infill the missing values with the largest-eigenvalue basis vector, which is a better guess for the underlying plasma velocity field than the initial infill of zeros. Moreover, we have done this without any a priori specification of source geometry. The EOF-solution-and-infill process is repeated iteratively, until the amplitude of the infill converges with that of the data measurements, where both overlap. This infill only converges when it reinforces patterns present in the original data, thus providing a self-consistent description of the plasma velocity at the original temporal resolution of the SuperDARN data set. This gives complete spatial and temporal coverage without resorting to climatological averages, spatially smoothed models, or a priori relationships determined from solar wind drivers. Following this retrieval of the un-measured variability of the data, we fit a sinusoid model to translate the basis vectors from their line-of-sight (i.e. radar look direction) basis to a basis of cardinal north and east plasma velocity vector components. This method is described in full in a paper ('Data-Driven Basis Functions for SuperDARN Ionospheric Plasma Flow Characterisation and Prediction'), presently under review in JGR Space Physics (2021).

Data collection:

The data were gathered using the northern hemisphere radars of the SuperDARN global array, and the fitted Doppler velocities were processed from the original autocorrelation functions using version 4.0 of the radar software toolkit (RSTv4.0) and within that toolkit, fitting routine 'fitacfv2.5'.

Data quality:

The SuperDARN data were processed to remove ground scatter, and to eliminate measurements with too low power (lower than 3dB), or which had a poor-quality flag (identified in RSTv4.0). When binning the data, range gates below 11 and above 150 (where those values correspond to multiple of 45 km range distance from the radar array location) were not used, since these gave inaccurate locational estimates.

Metadata

File identifier

f4245a21-dee9-46cf-85b2-114798cb7ebc XML

Metadata language

English

Character set

UTF8

Hierarchy level

Dataset

Hierarchy level name

dataset

Date stamp

2021-03-01

Metadata standard name

ISO 19115 Geographic Information - Metadata

Metadata standard version

ISO 19115:2003(E)

Metadata author

Organisation name	Individual name	Electronic mail address	Role
NERC EDS UK Polar Data Centre		polardatacentre@bas.ac.uk	Point of contact