BCReader

BCFileInfo

Stores information specific to each boundary condition from a file and each variable.

Inputs:

• bcfile_dir::b # directory of the BC file
• comms_ctx::X # communication context used for MPI
• hdoutfileroot::S # filename root for regridded data
• varname::V # name of the variable
• all_dates::D # vector of all dates contained in the original data file
• monthly_fields::C # tuple of the two monthly fields, that will be used for the daily interpolation
• scaling_function::O # function that scales, offsets or transforms the raw variable
• land_fraction::M # fraction with 1 = 100% land, 0 = 100% ocean and/or sea-ice
• segment_idx::Vector{Int} # index of the monthly data in the file
• segmentidx0::Vector{Int} # `segmentidx` of the file data that is closest to date0
• segment_length::Vector{Int} # length of each month segment (used in the daily interpolation)
• interpolate_daily::Bool # switch to trigger daily interpolation
• mono::Bool # flag for monotone remapping of input data

bcfile_info_init(
    FT,
    bcfile_dir,
    datafile_rll,
    varname,
    boundary_space,
    comms_ctx;
    interpolate_daily = false,
    segment_idx0 = nothing,
    scaling_function = no_scaling,
    land_fraction = nothing,
    date0 = nothing,
    mono = true,
)

Regrids from lat-lon grid to cgll grid, saving the output in a new file, and returns the info packaged in a single struct.

Arguments

• FT: [DataType] Float type.
• bcfile_dir: [String] directory the BC file is stored in.
• datafile_rll: [String] file containing data to regrid.
• varname: [String] name of the variable to be regridded.
• boundary_space: [Spaces.AbstractSpace] the space to which we are mapping.
• comms_ctx: [ClimaComms.AbstractCommsContext] context used for this operation.
• interpolate_daily: [Bool] switch to trigger daily interpolation.
• segment_idx0: [Vector{Int}] reference date which, after initialization, refers to the the first file date index used minus 1 (segment_idx[1] - 1)
• scaling function: [Function] scales, offsets or transforms varname.
• land_fraction: [CC.Fields.field] fraction with 1 = land, 0 = ocean / sea-ice.
• date0: [Dates.DateTime] start date of the file data.
• mono: [Bool] flag for monotone remapping of datafile_rll.

Returns

• BCFileInfo

update_midmonth_data!(date, bcf_info::BCFileInfo{FT}) where {FT}

Extracts boundary condition data from regridded (to model grid) NetCDF files. The times for which data is extracted depends on the specifications in the bcf_info struct).

Arguments

• date: [Dates.DateTime] start date for data.
• bcf_info: [BCFileInfo] containing boundary condition data.

next_date_in_file(bcf_info)

Returns the next date stored in the file bcfile_info struct after the current date index given by segment_idx. Note: this function does not update segment_idx, so repeated calls will return the same value unless segment_idx is modified elsewhere in between.

Arguments

• bcf_info: [BCFileInfo] containing the date information.

Returns

• Dates.DateTime

interpolate_midmonth_to_daily(date, bcf_info::BCFileInfo{FT}) where {FT}

Interpolates linearly between two Fields in the bcf_info struct, or returns the first Field if interpolation is switched off.

Arguments

• date: [Dates.DateTime] start date for data.
• bcf_info: [BCFileInfo] contains fields to be interpolated.

Returns

• CC.Fields.field

no_scaling(field, bcf_info)

Remap the values of a field onto the space of the bcf_info's land_fraction without scaling.

Arguments

• field: [CC.Fields.Field] contains the values to be remapped.
• bcf_info: [BCFileInfo] contains a land_fraction to remap onto the space of.

interpol(f1::FT, f2::FT, Δt_tt1::FT, Δt_t2t1::FT)

Performs linear interpolation of f at time t within a segment Δt_t2t1 = (t2 - t1), of fields f1 and f2, with t2 > t1.

Arguments

• f1: [FT] first value to be interpolated (f(t1) = f1).
• f2: [FT] second value to be interpolated.
• Δt_tt1: [FT] time between t1 and some t (Δt_tt1 = (t - t1)).
• Δt_t2t1: [FT] time between t1 and t2.

Returns

• FT