Date (Creation)

2021-06-24

Date (Revision)

2021-06-24

Date (Publication)

2021-06-24

Date (released)

2021-06-24

Edition

1.0

Unique resource identifier

https://doi.org/10.5285/c5cc491e-7119-4500-b05a-e5e34274438f

Codespace

doi

Unique resource identifier

GB/NERC/BAS/PDC/01513

Codespace

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

Unique resource identifier

NE/G014124/1

Codespace

award

Other citation details

Please cite this item as: Orr, A., & Phillips, T. (2021). Kilometre and sub-kilometre scale atmosphere-only model simulations using the Met Office Unified Model of a foehn wind event over the Larsen C Ice Shelf, Antarctic Peninsula on 27 January 2011 (Version 1.0) [Data set]. NERC EDS UK Polar Data Centre. https://doi.org/10.5285/c5cc491e-7119-4500-b05a-e5e34274438f

Credit

No credit.

Status

Completed

Point of contact

Organisation name	Individual name	Electronic mail address	Role
British Antarctic Survey	Orr, Andrew		Author
British Antarctic Survey	Phillips, Tony		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 > Atmosphere > Atmospheric Winds

Theme

• Antarctic Peninsula

• Foehn winds/jets

• Kilometre and sub-kilometre grid scales

• Larsen C Ice Shelf

• MetUM

• Regional atmospheric model

Place

• Larsen C Ice Shelf, Antarctic Peninsula Antarctica

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

Cross reference

Spatial representation type

Text, table

Language

English

Character set

UTF8

Topic category

• Climatology, meteorology, atmosphere

Begin date

2011-01-08

End date

2011-02-09

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:

We carried out a high-resolution atmosphere-only model simulation of the Larsen C Ice Shelf and surrounding area from 8 January 2011 to 8 February 2011, using the nested configuration of version 11.1 of the UK Met Office Unified Model (MetUM). Three nested model domains at horizontal resolutions of 4, 1.5 and 0.5 km are used. The outer 4 km model domain covers the Antarctic Peninsula and the Larsen C Ice Shelf (domain size of 220 × 220 grid points), while the two additional (one way nested) 1.5 and 0.5 km model domains cover the northern Antarctic Peninsula and Larsen C Ice Shelf (domain size of 450 × 450 and 1000 × 1000 grid points, respectively). Boundary conditions for the 1.5 km (0.5 km) model are derived from the 4 km (1.5 km) model. All three models employ 70 vertical levels (going up to 40 km), which are terrain-following near the surface, with 16 levels below 1000 m and a lowest model level at ~5 m above the surface.

The orography used by the 4, 1.5 and 0.5 km models is derived from the high-resolution (200 m) Radarsat Antarctic Modelling Project (RAMP) digital elevation model. Due to the very steep terrain, the 4 and 1.5 km (0.5 km) orography was smoothed by convolution with a normalised 2-d Gaussian kernel with standard deviation of 0.6 grid points (0.8485 grid points). The coastline and ice shelf extent are taken from the Scientific Committee on Antarctic Research (SCAR) Antarctic Digital Database. The science configuration of the dynamics and physics schemes used by the nested models was the mid-latitude regional atmosphere configuration (RA1-M).

The 4 km model is nested within a 12 km version of the model (domain size of 150 × 150 grid points), which has a much larger limited area domain encompassing the whole of the Antarctic Peninsula and the surrounding ocean (not shown). The required start data and boundary conditions for the 12 km model are provided by the global model configuration of the MetUM at N320 resolution (domain size of 640 × 480 grid points, equivalent to a horizontal resolution of ~40 km), which is initialised by ERA-Interim reanalysis.

The MetUM 4 km model was run twice daily at 00 UTC and 12 UTC from 8 January 2011 to 8 February 2011 for 24 h, with output saved at T+15, T+18, T+21 and T+24 h. Earlier output was discarded as spin-up, with the remaining part of the forecasts concatenated together to form a continuous time-series from 15 UTC 8 January 2011 to 24 UTC 8 February 2011. The computationally expensive MetUM 1.5 km and 0.5 km models were only run to obtain output for 27 January 2011, i.e., coinciding with the foehn event that occurred at this time. A further sensitivity experiment was conducted for 27 January using the MetUM 4 km model but replacing the 'sharp' stability function with the 'long-tail' stability function for the boundary layer scheme, i.e., to examine the impact of stronger turbulent mixing for statically stable conditions.

Data collection:

The model used was version 11.1 of the Met Office Unified Model.

Data quality:

Examination of the model output showed that: i) the features commonly associated with foehn winds, such a leeside hydraulic jump, and enhanced leeside warming, were comparatively insensitive to resolution in the 4 to 0.5 km range, although the 0.5 km simulation shows a slightly sharper and larger hydraulic jump, ii) during the foehn wind event, the simulated near-surface air temperature over the Larsen C Ice Shelf was characterised by a both a large nocturnal cold bias of around 10°C and a much too strong low-level temperature inversion, with neither representation improving with increased resolution, and iii) the simulation of fine-scale foehn jets over the Larsen C Ice Shelf during the foehn event showed considerable dependence on grid spacing, although no evidence of convergence at higher resolution.

Metadata

File identifier

c5cc491e-7119-4500-b05a-e5e34274438f XML

Metadata language

English

Character set

UTF8

Hierarchy level

Dataset

Hierarchy level name

dataset

Date stamp

2021-06-24

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