IceCast (version 2.1.0)

create_mapping: Map a set of observations and predictions

Description

Finds all the mappings for a set of observations and predictions often over multiple years

Usage

create_mapping(start_year, end_year, obs_start_year, pred_start_year,
  observed, predicted, reg_info, month, level, dat_type_obs, dat_type_pred,
  plotting = FALSE, obs_only = FALSE, pred_only = FALSE, nX = 304,
  nY = 448, xmn = -3850, xmx = 3750, ymn = -5350, ymx = 5850)

Arguments

start_year

first year to be mapped

end_year

last year to be mapped

obs_start_year

year in which observation array starts

pred_start_year

year in which prediction array starts

observed

array of observed values of dimension year x longitude x latitude

predicted

array of predicted values of dimension year x longitude x latitude

reg_info

a reg_info list (see documentation for reg_info)

month

month under consideration

level

concentration level for which to build contour

dat_type_obs

string of either "bootstrap" or "simple" indicating the file type of the observation (see details)

dat_type_pred

string of either "gfdl" or "simple" indicating the file type of the prediction (see details)

plotting

boolean indicatng whether maps should be plotted (defaults to false)

obs_only

indicator to run mapping only for observations

pred_only

indicator to run mapping only for predictions

nX

dimension in the x (defaults to value for Northern Polar stereographic grid: 304)

nY

dimension in the y (defaults to value for Northern Polar stereographic grid: 448)

xmn

min x value (defaults to value for Northern Polar stereographic grid: -3850)

xmx

max x value (defaults to value for Northern Polar stereographic grid: 3750)

ymn

min y value (defaults to value for Northern Polar stereographic grid: -5350)

ymx

max y value (defaults to value for Northern Polar stereographic grid: 5850)

Value

map object (see details)

Details

The object maps is obtained from running the create_mapping function. It is a list of four objects. The first two items in the list, start_year and end_year, give the first and last year that were mapped. The second two items, obs_list and pred_list, are lists of arrays with one 3-dimensional array for each region. The first dimension is for the year. The other two dimensions are for the fixed points' y-coordinates, the mapped points' x-coordinates, the mapped points' y-coordinates, the length of the mapping vectors in the x-direction, the length of the vectors in the y-direction, and the angles of the mapping vectors.

For dat_type_obs = "simple" and dat_type_pred = "simple" the values in the observed and predicted arrays are indicators of whether the grid box contains ice (1: ice-covered, 0: no ice, NA: land). If datTypePred = "gfdl" or dat_type_obs = "bootstrap", the values in the observed and predicted arrays correspond to the raw ice concentrations values observed or predicted (including indicators for missing data, land etc.). If datTypePred = "gfdl", the predictions are formatted as in the CM2.5 Forecast-oriented Low-Ocean Resolution (FLOR) model produced by the National Oceanic and Atmospheric Administration<U+2019>s Geophysical Fluid Dynamics Laboratory and converted to a Polar Stereographic grid (Vecchi et al. 2014; Msadek et al. 2014). If datTypeObs = "bootstrap" the array values are assumed to be from the monthly sea ice concentration obtained from the National Aeronautics and Space Administration (NASA) satellites Nimbus-7 SMMR and DMSP SSM/I-SSMIS and processed by the bootstrap algorithm. Weights for converting to a polar stereograhic grid were obtained from the spherical coordinate remapping and interpolation package (SCRIP) (Jones 1997).

References

Comiso, J., 2017: Bootstrap sea ice concentrations from Nimbus-7 SMMR and DMSP SSM/I-SSMIS. version 3. Boulder, Colorado USA: NASA National Snow and Ice Data Center Distributed Active Archive Center. doi: https://doi.org/10.5067/7Q8HCCWS4I0R

CM2.5 Forecast-oriented Low-Ocean Resolution (FLOR) model: Vecchi, Gabriel A., et al. "On the seasonal forecasting of regional tropical cyclone activity." Journal of Climate 27.21 (2014): 7994-8016.

Msadek, R., et al. "Importance of initial conditions in seasonal predictions of Arctic sea ice extent." Geophysical Research Letters 41.14 (2014): 5208-5215.

National Center for Atmospheric Research, 2017: Earth system grid at NCAR. https://www.earthsystemgrid.org/home.html.

Jones, P.W. "A user<U+2019>s guide for SCRIP: A spherical coordinate remapping and interpolation package." Los Alamos National Laboratory, Los Alamos, NM (1997).

Examples

# NOT RUN {
create_mapping(start_year = 1981, end_year = 1981, obs_start_year = 1981,
               pred_start_year = 1980, observed = obsFeb19811982,
               predicted = emFeb19811982, reg_info = reg_info, month = 2,
               level = 15, dat_type_obs = "bootstrap", dat_type_pred = "gfdl",
               plotting = TRUE) 
# }