Latest @Glacier_Albedo paper in @NatureComms available here https://rdcu.be/ceadp  Mineral phosphorus drives glacier algal blooms on the Greenland Ice Sheet. A quick thread about what we found 1/7

This study was a massive collaborative effort with @SteffiLutz C Williamson @tothepoles @andrew_tedstone A Vanderstraeten @_sashawilson_ A Stockdale S Bonneville @AlexAnesio M Yallop @jimmcquaid @MartynTranter1 & @LianeGBenning 2/7

We already knew glacier algae grow on the Greenland Ice Sheet and cause darkening and melting, but we don't have a great understanding of what controls the growth of these algae. We wanted to find out 3/7

Across the ‘Dark Zone’ (SW Greeland Ice Sheet), the algal community primarily contains Ancylonema nordenskioeldii & Mesotaenium sp. When we provided these algae with extra P, we found that their photosynthesis improved. We didn’t see this effect in response to extra N. 4/7

This result suggests that P is an important nutrient for glacier algae. There are low concentrations of dissolved P in the surface ice habitat. We wanted to know where it might be coming from. We wondered about the mineral dust. 5/7

We analyzed the mineral dust and found trace amounts of hydroxylapatite, which is a mineral that contains P. We wondered where the dust might be from, so we analyzed the rare Earth element content of the dust. The results indicate that the dust is from Greenland itself. 6/7

Takeaway: P availability may be a key second order control on glacier algal bloom development. P on the ice may be sourced from Greenlandic dust. This has implications for bloom formation, albedo reduction, and ice sheet melting. 7/7