YetAnotherCoupler  2.4.2
Source to Target mapping

Table of Contents

Description

This method supports source fields that are defined on points at the grid corners, cells, or edges.

For each source point this method searches for the nearest target point. Around the target point a bounding circle is then generated. The field value of the source point will then be distributed among all non-masked target points within this circle. Weights for each source point are computed such that their sum is 1.0. The user can select the method that is being used for the computation of these weight. If multiple source point contribute to a target point, their contributions are summed up. Target points not associated with any source point will not get any value.

This method has been implemented in particular to cover the mapping of the hydrological discharge. This quantity is provided on selected cells at the coastline. In ICON, the discharge is assembled at coastal land cells and then stored on the nearest ocean cells on the donor grid. The goal of all other interpolation schemes is to generate an interpolation for target cells. In contrast to that, this method aims to be mass conserving and not to loose any water from the donor cells.

Source field from atmosphere on ocean coast cells

Options

  • Radius of bounding circle in degree (default: spread_distance="0.0")

    Valid range: 0.0 <= spread_distance < 90.0

    A radius of 0.0 results in the source field values being assigned to the single closest target point.

  • Weighting type (default weighted="ARITHMETIC_AVERAGE")
    • ARITHMETIC_AVERAGE

      Simple average

      Target field on ocean
      spread_distance = 0.0 spread_distance = 0.5 spread_distance = 1.0 spread_distance = 2.0
    • DISTANCE_WEIGHTED

      Inverse distance weighted

      Target field on ocean
      spread_distance = 0.0 spread_distance = 0.5 spread_distance = 1.0 spread_distance = 2.0

XML example

<interpolation method="source_to_target_map"
weighted="ARITHMETIC_AVERAGE"
spread_distance="0.5"/>