Source and transformations of Chromophoric Dissolved Organic Matter and its role in surface ocean heating and carbon cycling in Nordic Seas and European Arctic (CDOM-Heat)

Increase of temperatures and loss of sea ice has have dramatically changed the Arctic’s physical system. One of the key factors driving the loss of sea-ice is the ice-albedo feedback resulting in more solar energy accumulated into the surface ocean. Colored dissolved organic matter (CDOM) is a key factor affecting the vertical entrapment of heat and light availability for primary production in the Arctic Ocean.

Recent studies in the western Arctic have shown that CDOM can result in over 30% more solar heat entrapment in the surface ocean compared to other open-ocean regions, contributing significantly to accelerated sea-ice melt. Very little is known about the distribution, sources and transformations and feedbacks related to increased CDOM oncentrations in the European Arctic.

In this project we propose to carry out an extensive study to understand the composition and sources of CDOM and the role of CDOM (and other optically active substances) in the fate of solar energy in the Nordic Seas and European Arctic, and how it contributes to the solar heating of the upper ocean and contributes to sea-ice melt, penetration of harmful ultraviolet (UV) light and light availability (UV and PAR) for primary production.

By combining forces from groups with complementing experience and expertise in geochemical tracers, physical oceanography, marine optics and sea-ice geophysics, in Arctic and sub-Arctic seas, and provided the access to the Arctic, and state-of-the-art instrumentation (both in the lab and field) we are set to meet this challenging task.

Expected results shall provide new information needed to understand on forcing and feedback mechanisms related with optical and chemical properties of CDOM on radiation budget, heat accumulation and carbon cycle in Nordic Seas and European Arctic sector. Results will provide baseline for sensitivity studies in climatic models testing different scenarios in changes of CDOM concentrations.

Increase of temperatures and loss of sea ice has have dramatically changed the Arctic’s physical system. One of the key factors driving the loss of sea-ice is the ice-albedo feedback resulting in more solar energy accumulated into the surface ocean. Colored dissolved organic matter (CDOM) is a key factor affecting the vertical entrapment of heat and light availability for primary production in the Arctic Ocean.

Recent studies in the western Arctic have shown that CDOM can result in over 30% more solar heat entrapment in the surface ocean compared to other open-ocean regions, contributing significantly to accelerated sea-ice melt. Very little is known about the distribution, sources and transformations and feedbacks related to increased CDOM oncentrations in the European Arctic.

In this project we propose to carry out an extensive study to understand the composition and sources of CDOM and the role of CDOM (and other optically active substances) in the fate of solar energy in the Nordic Seas and European Arctic, and how it contributes to the solar heating of the upper ocean and contributes to sea-ice melt, penetration of harmful ultraviolet (UV) light and light availability (UV and PAR) for primary production.

By combining forces from groups with complementing experience and expertise in geochemical tracers, physical oceanography, marine optics and sea-ice geophysics, in Arctic and sub-Arctic seas, and provided the access to the Arctic, and state-of-the-art instrumentation (both in the lab and field) we are set to meet this challenging task.

Expected results shall provide new information needed to understand on forcing and feedback mechanisms related with optical and chemical properties of CDOM on radiation budget, heat accumulation and carbon cycle in Nordic Seas and European Arctic sector. Results will provide baseline for sensitivity studies in climatic models testing different scenarios in changes of CDOM concentrations.