Call for Soil Thermal Properties Data

Dear colleagues,

We are seeking your support in compiling a dataset of globally distributed soil thermal properties, ideally combined with hydraulic properties, if available.

This dataset would serve to support the development and verification of models simulating thermal properties, by both existing and novel approaches.

We are hopeful that there are data available in the community, including unpublished data, that you are willing to share with us. We welcome data obtained from laboratory and in-situ methods.

Those who provide data, and assist with the description/interpretation of these data, will be invited to co-author a journal article describing the new database.

What we would need from you is described in detail in the thermal data Excel template sheet, and consists broadly of:

Required data

• Metadata: Data describing the experimental location and its land use, nature of the data and procedures, as well as basic soil physical properties
• Thermal property data: Thermal conductivity (& thermal diffusivity, volumetric heat capacity, if available) vs. soil moisture (or relative saturation)

Optional data, but very much desirable if available for the same sample/site

• Hydraulic properties: Water retention curve and hydraulic conductivity curves, or parts thereof (e.g. soil moisture point at field capacity or wilting point, or saturated hydraulic conductivity)
• Soil mineralogical information: Mineralogical composition (types of minerals) of the sand, silt, and clay fractions, or any non-size-resolved information on the mineralogy, if available

A list of already available data is in the spreadsheet (please check this first before starting your contribution sheet, as your published data may already be contained in the current version of the database).

The global database to be constructed will be subjected to a preliminary analysis in the first instance, and the paper submitted to a data journal (e.g. Earth System Data Science, or Scientific Data).

With this database in place, we aim to test existing, and design/test improved equations of thermal soil properties (that can be used in land surface models, for example, at the field to global scales). Furthermore, we plan to link thermal theories with hydraulic theories to develop a unified underlying theory, which will yield both thermal and hydraulic parameters, in a more consistent fashion.