Skip to contents

Download meteorological and atmospheric data

Source: R/download.R
download_merra2.Rd

The download_merra2() function accesses and downloads various meteorological and atmospheric collections from NASA's Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2) model, and the daily corrected Global Fire Weather Index (FWI) product derived from MERRA-2 weather inputs.

Usage

download_merra2(
  collection = c("inst1_2d_asm_Nx", "inst1_2d_int_Nx", "inst1_2d_lfo_Nx",
    "inst3_3d_asm_Np", "inst3_3d_aer_Nv", "inst3_3d_asm_Nv", "inst3_3d_chm_Nv",
    "inst3_3d_gas_Nv", "inst3_2d_gas_Nx", "inst6_3d_ana_Np", "inst6_3d_ana_Nv",
    "statD_2d_slv_Nx", "tavg1_2d_adg_Nx", "tavg1_2d_aer_Nx", "tavg1_2d_chm_Nx",
    "tavg1_2d_csp_Nx", "tavg1_2d_flx_Nx", "tavg1_2d_int_Nx", "tavg1_2d_lfo_Nx",
    "tavg1_2d_lnd_Nx", "tavg1_2d_ocn_Nx", "tavg1_2d_rad_Nx", "tavg1_2d_slv_Nx",
    "tavg3_3d_mst_Ne", "tavg3_3d_trb_Ne", "tavg3_3d_nav_Ne", "tavg3_3d_cld_Np", 
    
    "tavg3_3d_mst_Np", "tavg3_3d_rad_Np", "tavg3_3d_tdt_Np", "tavg3_3d_trb_Np",
    "tavg3_3d_udt_Np", "tavg3_3d_odt_Np", "tavg3_3d_qdt_Np", "tavg3_3d_asm_Nv",
    "tavg3_3d_cld_Nv", "tavg3_3d_mst_Nv", "tavg3_3d_rad_Nv", "tavg3_2d_glc_Nx", "fwi"),
  nasa_earth_data_token = NULL,
  date = c("2018-01-01", "2018-01-01"),
  directory_to_save = NULL,
  acknowledgement = FALSE,
  download = TRUE,
  remove_command = FALSE,
  hash = FALSE,
  show_progress = TRUE,
  max_tries = 20,
  rate_limit = 2
)

Arguments

collection

character(1). MERRA-2 data collection file name, or "fwi" for the daily corrected Global Fire Weather Index product (MERRA2.CORRECTED).

nasa_earth_data_token

character(1) or NULL. NASA EarthData authentication token.

date

character(1 or 2). length of 10. Date or start/end dates for downloading data. Format "YYYY-MM-DD" (ex. January 1, 2018 = "2018-01-01").

directory_to_save

character(1). Directory to save data.

acknowledgement

logical(1). By setting TRUE the user acknowledges that the data downloaded using this function may be very large and use lots of machine storage and memory.

download

logical(1). DEPRECATED. Downloads happen automatically.

remove_command

logical(1). Deprecated, ignored.

hash

logical(1). By setting TRUE the function will return an rlang::hash_file() hash character corresponding to the downloaded files. Default is FALSE.

show_progress

logical(1). Show download progress (default TRUE)

max_tries

integer(1). Maximum retry attempts (default 20)

rate_limit

numeric(1). Minimum seconds between requests (default 2)

Value

invisible list with download results; or hash character if hash=TRUE

Note

Due to NASA data access policies, standard MERRA-2 GES DISC downloads require a valid NASA Earthdata token for authentication. Use setup_nasa_token() for setup. The "fwi" collection is hosted on the public GlobalFWI portal and does not require Earthdata authentication.

Author

Mitchell Manware, Insang Song, Kyle Messier

Examples

if (FALSE) { # \dontrun{
download_merra2(
  collection = "inst1_2d_int_Nx",
  date = "2024-01-01",
  directory_to_save = tempdir(),
  acknowledgement = TRUE
)
} # }