Take your permafrost metadata to the next level

by Nick Brown, NSERC PermafrostNet Data Scientist

Everyone’s been there. You are about to publish your dataset, but you’ve just spent the last half-hour trying to decide on the best formatting and naming conventions. Should that column be named “ground temperature”, “soil_temperature”, or just “Tg”? Maybe you should include units too; “ground_temperature_degree_C” has a ring to it. But how will other people know exactly what your dataset represents? Good metadata is the answer.

You may not realize it, but there are resources to help you in this situation. The CF Standard name table is a curated list of terms used to unambiguously identify the kinds of measurements in a dataset. For self-describing formats like netcdf, you can include these attributes directly in your data file, following the CF standards. Or, if you are publishing your data in a text file, like a CSV, you can include the information about each column in your dataset in a separate metadata file. This way, the name of your data column doesn’t have to do so much work describing itself.

Michel Paquette, Theme 1 Post-doctoral Fellow (Université de Montréal, NSERC PermafrostNet) and I have coordinated the inclusion of 12 additional permafrost-related terms (see table below) in the latest release of the Standard Names vocabulary (version 78). These terms will be particularly useful for field scientists wanting to make their published datasets more interoperable and for data publishers who host permafrost-related data. An additional 14 terms relevant to permafrost science have since been requested. The addition of permafrost-related terms contributes to improved data interoperability with the atmospheric science and modelling communities, where the CF terms are widely used.

For an up-to-date list of permafrost-related terms added to the CF names list by NSERC PermafrostNet, visit the Data Standard Recommendations page.

Common nameCF NameStatus
Ground temperaturetemperature_in_groundAdded (v78)
Excess iceice_volume_in_frozen_ground_
in_excess_of_pore_volume_in_unfrozen_ground_
expressed_as_fraction_of_frozen_ground_volume
Added (v78)
Ice saturation indexratio_of_ice_volume_in_frozen_ground_
to_pore_volume_in_unfrozen_ground
Added (v78)
Thaw depthdepth_at_base_of_unfrozen_groundAdded (v78)
Frozen thermal conductivitythermal_conductivity_of_frozen_groundAdded (v78)
Frozen heat capacityspecific_heat_capacity_of_frozen_groundAdded (v78)
Gravel content by massmass_fraction_of_gravel_in_soilAdded (v78)
Sand content by massmass_fraction_of_sand_in_soilAdded (v78)
Silt content by massmass_fraction_of_silt_in_soilAdded (v78)
Clay content by massmass_fraction_of_clay_in_soilAdded (v78)
Organic matter content by massmass_fraction_of_organic_matter_in_soilAdded (v78)
Soil water pHsoil_water_phAdded (v78)

Permafrost related terms added to v78 of the CF Standard Name vocabulary by NSERC PermafrostNet

Fieldwork report: Galina Jonat, Hannah Macdonell, Emilie Stewart-Jones and Stephan Gruber

Galina, Hannah, Emilie and Stephan spent a couple of weeks in Yellowknife, Northwest Territories (NWT), reading out data and exchanging ground and rock temperature loggers, soil moisture sensors and tilt loggers for measuring ground subsidence. A highlight was using a metal detector to find temperature loggers hiding just below the ground surface, installed nearly five years ago. In mid-August, we hopped on a floatplane heading to KDI, an exploration camp, approximately 300 km northeast of Yellowknife. Here, we read out and exchanged loggers for a network of around 80 soil and 10 rock near surface temperature loggers, and 12 thermistor strings installed in boreholes. We spent our days in the field and our evenings back at camp organizing the collected data, soldering new batteries into loggers and of course enjoying the camp cook’s wonderful food.

Going out in the field this summer and collecting data from a number of different locations offered us valuable learning opportunities. We experienced periglacial features in person; jumping across the wet troughs of ice-wedge polygons, enjoying the easy walking of an esker, and using the edge of a solifluction lobe as a seat. We became acquainted with the different types of tundra vegetation, learning to identify common northern plants like dwarf birch and to recognize Labrador tea by its earthy smell. We are now especially well versed in the identification of cloudberries and blueberries, yum yum! The fluffy mosses were a favourite stop for well-deserved naps whereas the thick willows teeming with black flies were an unpopular route choice. On our third day at KDI, we were met by a large muskox herd, roaming the vast rolling landscape, seemingly unbothered by our presence. It was a fascinating sight! A lone curious muskox did however follow us around at a distance, causing us to reschedule some of our maintenance work.

The data we collected in the field will support a number of research projects in NSERC PermafrostNet. Ground temperature data will be used to test permafrost models and give insight into permafrost changes in the Canadian North, supplementing the data that we have available from Lac de Gras, NWT. 

Successful fieldwork wouldn’t be possible without the amazing support of northern organizations such as the Northwest Territories Geological Survey (NTGS), Aurora Geosciences and Kennedy Diamonds Inc. (KDI). The NTGS was welcoming and allowed us to use their office as a home base for storage and essential equipment servicing, and gave us the chance to learn from local employees. The staff at the KDI camp was always accommodating and supportive of our work.

We would like to acknowledge our fieldwork activities took place in Chief Drygeese territory. From time immemorial, it has been the traditional land of the Yellowknives Dene First Nation, and more recently, the homeland of the North Slave Métis Alliance. We respect the histories, languages, and cultures of First Nations, Métis, Inuit, and all First Peoples of Canada, whose presence continues to enrich our vibrant community.

YKDFN: Chief Drygeese Territories (1900 & 1920, Treaty 8) (Link 1)