# Data-Interpolating Variational Analysis (Diva)

## Diva

Spatial interpolation of observations on a regular grid is a common task in many oceanographic disciplines (and geosciences in general). It is often used to create climatological maps for physical, biological or chemical parameters representing e.g. monthly or seasonally averaged fields. Since instantaneous observations can not be directly related to a field representing an average, simple spatial interpolation of observations is in general not acceptable. Diva (Data-Interpolating Variational Analysis) is an analysis tool which takes the error in the observations and the typical spatial scale of the underlying field into account. Barriers due to the coastline and the topography in general and also currents estimates (if available) are used to propagate the information of a given observation spatially.

Access the web-interface of Diva

## Diva Four-Dimensional Analysis

Diva 4D Climatology Building software, based on Diva analysis system, allows creating climatologies as four dimensional analysis netcdf files. It uses input data from ODV4 spread-sheets for a given set of variables and climatology time information.
A climatology netcdf files for a variable contains the diva analysis of the variable and a set of variable related information fields: relative error and error standard deviation fields, variable masked (using two relative error thresholds) fields, deepest values of the variable field and the related masked fields. It contains also fields of information about data distribution and outliers as well as fields of correlation length and signal to noise ratio parameters.

Access the web-visualisation of climatologies