Greenland Scientists Explore Arctic Marine Mysteries with ‘Neil Armstrong’ Published 15.11.2024

Researchers from the Greenland Climate Research Centre (GCRC) showcased the spirit of Greenland science during a one-month cruise aboard the American research vessel ‘Neil Armstrong’ in October 2024 . Senior scientist Thomas Juul-Pedersen, laboratory technician Else Osterman, and Alenya Merz, a master’s student at GCRC and Rijksuniversiteit Groningen in the Netherlands, joined forces in the challenging Arctic conditions to explore critical aspects of marine ecosystems in the Davis Strait.

Neil Armstrong in Nuuk Harbour.

Central to their mission was the CTD/Rosette, a device with 24 programmable bottles that capture samples from different water depths, while at the same time measuring many parameters, enabling a comprehensive snapshot of the water column. The team’s research focused on gathering ocean water data and analyzing microscopic photosynthetic algae called phytoplankton . These unseen organisms are an essential component of the marine food web, converting sunlight into food, just like plants on land, thus sustaining all marine life including fish and whales. Remarkably, they found living phytoplankton at depths of up to 40 meters below the ocean surface, thriving where very little sunlight is present, hundreds of kilometers away from the coasts.

CTD/Rosette sampling ocean water and phytoplankton during the RV ‘Neil Armstrong’ cruise (October 2024).

‘Typically, coastal areas in southwestern Greenland experience large phytoplankton blooms, coloring the waters green in spring, but finding high phytoplankton biomass far offshore and this deep in the water column in late October, is quite exciting and a largely undescribed chapter of marine ecosystem in Greenland!’ said Thomas Juul-Pedersen, senior scientist at GCRC. ‘Moreover, phytoplankton residing this deep in the water column, cannot be detected by modern remote sensing tools, such as satellites, underlining the need for direct sampling on research expeditions or other sampling tools’.

Else and Alenya processing samples on board of RV ‘Neil Armstrong’.

The research cruise on board of ‘Neil Armstrong’ was part of the Davis Strait Observing System program, which has been monitoring the physical and chemical oceanography of Canadian-Greenlandic waters for two decades. Since 2020, GCRC scientists have contributed a new biological oceanographic dimension to the project, focusing specifically on phytoplankton. This study area serves as one of four Arctic gateways for water mass exchanges between the Arctic Ocean and lower latitude seas, making long-term observations vital for understanding and modelling ecosystem changes in this sensitive region which has global implications.

Yet, for Alenya and Else, science wasn’t the only highlight of the October cruise. ‘Long hours on deck and in the lab often come with good conversations and friendships, lots of coffee, and chocolate’. Alenya shared. ‘Some people even bring their own coffee brewing kits!’. A favorite tradition on the cruise involves decorating Styrofoam cups with colorful messages and drawings, attaching them to water sampling equipment, and sending them to depths of up to 2500 meters. Upon retrieval, these cups shrink, becoming miniature versions of their former selves due to the immense pressure at such depths.

Decorated Styrofoam cups recovered from depths of the Davis Strait.

Throughout the extensive field campaign, the team managed the demanding tasks of sample collection on the deck and conducted detailed laboratory work, often enduring the harsh autumn conditions.

Contact: Thomas Juul-Pedersen (thpe@natur.gl)