The Iceland Greenland Seas Project

Ian A Renfrew ,M E Brooks,A Mitchell,G W K Moore,R Ladkin,D Smith,K D Williams,Denis E Sergeev ,M Dolores Pérez‐Hernández ,Marius O Jonassen ,Barbara Brooks ,Erik Magnus Bruvik ,Andrew D Elvidge ,Silje Skjelsvik ,Alexandra Touzeau ,Heidi Midtgarden Golid ,Harald Sodemann ,Matilda Hallerstig ,George H Tupper ,Chris Barrell ,Henrik Søiland ,Chris Payne ,Frank Bahr ,Lukas Papritz ,Astrid Pacini ,Kjersti Konstali ,Ian M Brooks ,Robert S Pickart ,Karsten Kvalsund ,Peigen Lin ,Héðinn Valdimarsson ,Ilker Fer ,Leah Mcraven ,Karen Roberts Jackson ,Xiangwei Yang ,Thomas Spengler ,Thomas J Bracegirdle ,Maria N Pisareva ,Michael A Spall ,Steingrímur Jónsson ,Ailin Brakstad ,Erik W Kolstad ,Annecke Macrander ,Alexandra Weiss ,Tom Lachlan-Cope ,Stefanie Semper ,Leah A Houghton ,Mattia Almansi ,Joachim Reuder ,Idar Hessevik ,Andrew Seidl ,Annick Terpstra ,Jørn Kristiansen ,Haraldur Ólafsson ,Bolli Pálmason ,James O Pope ,Ying Weng ,Guðrún Nína Petersen ,Algot Kristoffer Peterson ,Jennifer Brooke ,Christiane Duscha ,Emil Jeansson ,Stephanie Waterman ,Jin‐Ding Huang ,Kjetil Våge ,Shenjie Zhou

doi:10.1175/bams-d-18-0217.1

Abstract

AbstractThe Iceland Greenland Seas Project (IGP) is a coordinated atmosphere–ocean research program investigating climate processes in the source region of the densest waters of the Atlantic meridional overturning circulation. During February and March 2018, a field campaign was executed over the Iceland and southern Greenland Seas that utilized a range of observing platforms to investigate critical processes in the region, including a research vessel, a research aircraft, moorings, sea gliders, floats, and a meteorological buoy. A remarkable feature of the field campaign was the highly coordinated deployment of the observing platforms, whereby the research vessel and aircraft tracks were planned in concert to allow simultaneous sampling of the atmosphere, the ocean, and their interactions. This joint planning was supported by tailor-made convection-permitting weather forecasts and novel diagnostics from an ensemble prediction system. The scientific aims of the IGP are to characterize the atmospheric forcing and the ocean response of coupled processes; in particular, cold-air outbreaks in the vicinity of the marginal ice zone and their triggering of oceanic heat loss, and the role of freshwater in the generation of dense water masses. The campaign observed the life cycle of a long-lasting cold-air outbreak over the Iceland Sea and the development of a cold-air outbreak over the Greenland Sea. Repeated profiling revealed the immediate impact on the ocean, while a comprehensive hydrographic survey provided a rare picture of these subpolar seas in winter. A joint atmosphere–ocean approach is also being used in the analysis phase, with coupled observational analysis and coordinated numerical modeling activities underway.

Highlights

A coordinated atmosphere–ocean research project, centered on a rare wintertime field campaign to the Iceland and Greenland Seas, seeks to determine the location and causes of dense water formation by cold-air outbreaks
Previous studies suggest that the dominant contribution to the Atlantic meridional overturning circulation (AMOC) and its variability comes from the subpolar seas to the east of Greenland (Pickart and Spall 2007; Holte and Straneo 2017; Lozier et al 2019)
The dense water formed in the Nordic Seas enters the North Atlantic through gaps in the submarine ridge between Greenland and Scotland (Østerhus et al 2019)

Summary

Introduction

A coordinated atmosphere–ocean research project, centered on a rare wintertime field campaign to the Iceland and Greenland Seas, seeks to determine the location and causes of dense water formation by cold-air outbreaks. We coordinated research flights in the vicinity of the ship on three separate days (shaded in Table 2) during the development and evolution of the long-lived CAO over the Iceland Sea. This enabled the first simultaneous and coordinated water vapor isotope measurements from aircraft and ship.

Results

Conclusion