Ultimately, the data collected by investigators will be used for input in or verification of General Circulation Models. In order to precisely fix the geographic position within the spatial framework of the models, it is important to indicate the location of the site and the degree of error associated with geopositioning. This part of the protocol addresses these issues.
In some cases, the site location may be a point, such as the position of a stationary data logger. In other cases, areal measurements across a region (CALM grid) are reported. In this event, the geographic coordinates of the southwest corner of the study area should be given. In all cases, geographic latitude and longitude should be reported in (degree, minute, and second) or (degree.decimal) format. Furthermore, the site elevation should be reported.
Level X: Positioning from map or similar sourceIndicate the geographic location of the site and approximate level of estimate accuracy (e.g., ± 30 seconds). Include the source, name, and scale of the base map. Report elevation (m), error estimate, and contour interval.
Level X ± 1: Positioning using GPS unitIndicate the geographic location, date of reading, and type of instrument (e.g., Garmin II). Report elevation.