Journal Club: 04-07-2017

Article Title: Met Éireann high resolution reanalysis for Ireland

This article provided a description and initial data analysis of the high resolution reanalysis (MÉRA) produced by Met Éireann.  This reanalysis has been constructed with a configuration of the HARMONIE-AROME limited area NWP model at a 2.5km resolution, with ERA-Interim forcing at the boundaries.  MÉRA uses a combination of 3D-VAR and Optimal Interpolation to perform data assimilation within the model domain.

Model domain for MÉRA (left) with a plot of model orography. The right hand plot is the same but for ERA-Interim.

Skill scores were calculated for 2m temperature, 10m wind speed, mslp, radiosonde observations and rain-gauge observations for both MÉRA and ERA-Interim.  MÉRA offered improved performance compared to ERA-Interim both in terms of mean error and standard deviation of errors in the majority of cases.

Thoughts for research:

  • Should look to repeat our earlier analysis for MERRA2 and ERA-Interim with this dataset.  Also should be compared to Laura’s WRF-downscaled ERA-Interim data.
  • The dip in wind bias in the early nineties (fig.5(c) of paper) should be investigated to see if there are any issues with the wind observations we have been using.  Will contact Seamus Walsh at Met Éireann regarding this issue.
  • We have acquired MÉRA wind data but still need to get SW data.  Will contact Eoin Whelan regarding its availability.