With a lot of debate this week on how models simulate permafrost thaw & climate impacts, I want to explain how we actually MEASURE permafrost change. Follow this thread for the pretty scenes or the weird science. Here is me caught in a surprise squall w/ permafrost gear. 1/

The traditional method of monitoring permafrost change is through the trusty frost probe. In this quick video I explain our work on -permafrost interactions while taking a frost probe measurement. 2/

Below check out a time lapse video of frost probing along one of our transects in the Northwest Territories . I share these field sites with an array of incredible students & the fabulous @forestecogrp. 3/ https://twitter.com/queenofpeat/status/1179007462327947264?lang=en

Frost probing tells us whether the top active layer is thickening & thus thawing surface permafrost. But what about carbon? Well one approach is to frost probe near collars where we measure CO2 & CH4 emissions. Here @fen_fatale probes our @BNZ_LTER flux collars near Fairbanks. 4/

Another challenge for us is to quantify how much carbon is contained in the permafrost & how this varies w/ depth. We can drill into the frozen soils w/ some elbow grease & mechanical help. We can collect a few meters of core this way, bigger drill rigs can go much deeper! 5/

Images of permafrost cores! Notice the variation in color & patterns. Permafrost can be frozen peat or mineral soil. Frozen peat tends to be very carbon-rich! We collect & analyze these cores before & after . Another measure of permafrost change! 6/

After thaw of ice-rich permafrost, soils are so wet that we use limnology methods to collect them. The frozen finger technique uses dry ice to freeze thawed material to the outside of our corer. This is weird science for sure! @CarolynG_22 @subarcticmonkee 7/