RCMexample              package:fields              R Documentation

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_D_e_s_c_r_i_p_t_i_o_n:

     Transformed surface precipitation fields simulated by the WRFP
     regional climate model (RCM) over North Amreica forced by
     observation data. The fields are 3 hour precipitation for 8 time
     periods in January 1, 1979. The grid is unequally spaced in
     longitude and latitude but near equally in a more appropriate
     projection centered on the model domain. Precipitation is in a log
     10 scale where values smaller than 4.39e-5 ( the .87 quantile)
     have been been set to this value.

_U_s_a_g_e:

     data(RCMexample)

_F_o_r_m_a_t:

     The format is a list of three arrays:


        *  x: 123X101 matrix of the longitude locations 

        *  y: 123X101 matrix of the latitude locations 

        *  z: 123X101X8 transformed matrix of precipitation

     Units are degrees with longitude being 0-360 westward from the
     prime meridian. (See the shift argument in world for overlaying
     world map.) Precipitation is log 10 of cm / 3 hour period.

_D_e_t_a_i_l_s:

     This is primarily an example of a regular grid that is not equally
     spaced and is due to transforming an equally spaced grid from one
     map projection into longitude latitude coordinates. This model is
     one small part of an extension series of numerical experiments the
     North American Regional Climate Change and Assessment Program
     (NARCCAP). NARCCAP has used 4 global climate models and
     observational data to supply the atmospheric boundery conditions
     for 6 different regional climate models. In the current data the
     forcing is the observations derived from the NCEP reanalysis data
     and is for Janurary 1, 1979. The full simulation runs for 20 years
     from this starting date. See <URL: www.image.ucar.edu/Data> for
     more information about these data.

     To facilatate an animation of these fields the raw precipitation
     values  have been transformed to the log scale with all values
     below 4.39E-5 cm/3 hours set to this lower bound.

_E_x_a_m_p_l_e_s:

     data(RCMexample)
     # second time period

     image.plot( RCMexample$x, RCMexample$y, RCMexample$z[,,2])
     world( add=TRUE, shift=TRUE, lwd=2)

