Grid names

[pbett]

We'll need some way of naming/describing the different grids we're using.

• Unique shorthand name
• Longer descriptive name
• Some mnemonic name that describes the length scale in mid-latitudes (e.g. "60 km")
• Global or regional?
• Rotated pole or not?
• (Approximately) equal area or not?
• number of cells in an x-direction
• number of cells in a y-direction

There's the added complication of winds (and what else?) being on a shifted grid compared to things like temperature and precip.

I think we're generating data on these grids:

• GCM grid (N216, ~60 km global)
• 25km PDFs (rotated pole regional)
• 12km RCM (rotated pole regional)
• 2.2km CPM (rotated pole regional)

There's also the:

• 5 km NCIC obs grid-point data (OSGB projection = transverse Mercator, approx equal-area)
• Other grids on OSGB projections, for serving data to the public?

[pbett]

I think we can make very quick-and-easy decisions on the naming - I'm just a bit fuzzy on the definitions at the moment, which is just a matter of ignorance rather than difficulty.

[pbett]

GCM Grids:

1. Grid for winds and things on pressure levels:

• Nametag: N216wind
• Mid-latitude km scale: 60km
• Long name: N216 grid for winds etc
• Grid cells: 432 × 325
• Global
• Not rotated pole
• Not equal area

2. Grid for non-wind surface/other variables

• Nametag: N216temperature
• Mid-latitude km scale: 60km
• Long name: N216 grid for temperatures etc.
• Grid cells: 432 × 324
• Global
• Not rotated pole
• Not equal area

There might be better choices of names for these of course, but this gives us something to play with.

[pbett]

RCM grids

1. Grid for Land Strand 1 (PDFs):

• Nametag: 25km
• Mid-latitude km scale: 25 km
• Long name: 25 km grid for PDF data
• Grid cells: xxx × xxx
• Regional
• Rotated pole at xx°E xx°N
• Not equal area

2. Grid for intermediate RCM (12km)

• Nametag: RCM12grid
• Mid-latitude km scale: 25 km
• Long name: RCM 12 km grid
• Grid cells: xxx × xxx
• Regional
• Rotated pole at xx°E xx°N
• Not equal area

3. Grid for CPM (2.2 km)

Note that this is harder to specify as it has a lower-resolution rim.

• Nametag: CPM2.2grid
• Mid-latitude km scale: 2.2 km
• Long name: CPM 2.2 km grid
• Grid cells: 294 × 354
• Regional
• Rotated North Pole at 175.5°E, 35.5°N
• Not equal area

[agstephens]

This information should be documented on the UKCP18 site somewhere.