Fine-scale atmosphere-only model simulation of near-surface temperature and wind from a reanalysis-driven Met Office Unified Model simulation of the Brunt Ice Shelf for the year 2015

• Main Authors: Orr, Andrew, Phillips, Tony
• Format: Dataset
• Language: English
• Published: UK Polar Data Centre, Natural Environment Research Council, UK Research & Innovation 2021
• Subjects: "EARTH SCIENCE","ATMOSPHERE","ATMOSPHERIC TEMPERATURE","SURFACE AIR TEMPERATURE"; "EARTH SCIENCE","ATMOSPHERE","ATMOSPHERIC WINDS"; Antarctica; Brunt Ice shelf; Halley; high-resolution regional climate modelling; temperature; Antarctic; The Antarctic; Brunt Ice Shelf; Antarc*; British Antarctic Survey; Ice Shelf
• Online Access: https://dx.doi.org/10.5285/20f3bf27-bf33-4c21-8164-005667b2ddb8; https://data.bas.ac.uk/full-record.php?id=GB/NERC/BAS/PDC/01454

High-resolution simulations of near-surface (1.5 m) temperature and (10 m) zonal and meridional winds over the Brunt Ice Shelf in the Antarctic for the year 2015 were conducted using the atmosphere-only Met Office Unified Model by the British Antarctic Survey, Cambridge, UK. The datasets produced were necessary to place point meteorological measurements from the various automatic weather stations on the Brunt Ice Shelf into a wider spatial context by identifying spatial temperature gradients and investigating how such gradients may have affected the homogeneity of the composite Halley temperature record. : We carried out a high-resolution atmosphere-only model simulation of the Brunt Ice Shelf and surrounding area for 2015, using the nested configuration of version 11.1 of the UK Met Office Unified Model (MetUM). The inner model domain had a horizontal resolution of 1.5 km (consisting of 250 × 250 grid points), covering the Brunt Ice Shelf and surrounding area. This domain was nested within a larger outer domain with a horizontal resolution of 4 km (consisting of 200 × 200 grid points), covering a much larger part of the area surrounding the Brunt Ice Shelf. Both domains had 70 vertical levels up to an altitude of 40 km and used a rotated latitude-longitude grid. In order to construct a broadly reasonable coastline of the Brunt Ice Shelf in the innermost domain for the 2015 period, the model coastline and orography was revised using an up-to-date digital elevation model based on the TanDEM-X (TerraSAR-X Add-On for Digital Elevation Measurement) 90-m digital elevation model. The science configuration of the dynamics and physics schemes used by the nested models was the mid-latitude regional atmosphere configuration (RA1-M). The required start data and lateral boundary conditions for the nested domains were supplied by a global version run of the MetUM at N512 resolution (1024 × 768 grid points, equivalent to a horizontal resolution of ~25 km at mid-latitudes), which was itself initialised by the ERA-Interim reanalysis. The model was used to produce a series of 24 hour forecasts, initialised every 12 hours, for the period 01 January 2015, 0000UTC to 31 December 2015, 1200UTC. The initial 12 hours of each forecast was discarded as spin-up, with the remaining part of the forecasts concatenated together to form a continuous time-series for 2015. : The model used was version 11.1 of the Met Office Unified Model. : Comparison of the model output with the automatic weather station data on Brunt Ice Shelf demonstrated that: i) the model accurately captured the temporal variability of both temperature and wind speed, ii) model temperatures were biased cold, and iii) wind speed and direction were simulated accurately.