The Science of Sea2Cloud
See the general overview of Sea2Cloud science or choose a specific research topic to learn how we’re answering important questions about the Earth’s oceans and atmosphere.
What we want to know?
Our experimental approach
To understand the connections between the oceans and atmosphere we collect data of both sea water and atmospheric properties in varying environments. We conduct measurements during two ship campaigns in the Pacific Ocean and field measurements at field station in New Zealand.
Ship campaigns enable sampling different types of water masses far from human pollution. The first ship campaign that Sea2Cloud participated was the TONGA campaign in November 2019. It departed from Noumea in New Caledonia and travelled east to the Tonga volcanic arc. Find out more about the TONGA campaign here http://tonga-project.org/.
The second campaign will be on board Tangaroa in March-April 2020. The voyage on Tangaroa will depart from Wellington and travel through both sub antarctic waters in southeast and sub tropical waters in northeast. Different water types are populated by different plankton communities and can thus have different climatic impacts.
As the ship campaigns only last up to a month, we collect longer data sets at field stations in New Zealand. Our main station is at Baring Head https://niwa.co.nz/atmosphere/facilities/baring-head.
How we study the gas phase processes?
In order to study what happens in the gas phase we use Air-Sea-Interaction Tanks (ASIT). The tanks contain seawater and the atmosphere above the water is enclosed. The water contains different biological species (1) which can emit different chemical vapours to the atmosphere (2). In the atmosphere these chemical species can form aerosol particles (3).
By constantly feeding the headspace of ASIT with clean air and sampling the air that has been in the headspace we can directly see what chemical vapours the biological species are producing without interference from other sources.
We will use seawater collected from different environments and monitor its biological species and chemical composition.
The sea surface contains many different biological species such as plankton and bacteria that can emit vapours into the atmosphere. These vapours can then form new aerosol particles through gas to particle conversion. To measure the particles, we use Particle Size Magnifier (PSM) which is able to detect particles as small as 1 nm. Additionally, we use a state of the art mass spectrometer (Atmospheric Pressure Interface Time-of-Flight Mass Spectrometer, APi-TOF) to measure the composition of chemical clusters. By combining the information from these two instruments, we can find out which chemical species are responsible for new particle formation. By further connecting this to the information on prevailing biological species and sea water properties we can also find out which marine sources are responsible for particle formation.
Sea Spray Aerosols
A state-of-the-art aquarium system allows for production of sea spray aerosol particles in controlled laboratory settings. Aerosols are then monitored to learn how changing ocean biology alters their climate-relevant properties, including their chemical composition and ability to serve as cloud droplet and ice nuclei.
Ice droplets are critical to the precipitation characteristics of clouds. Some aerosol particles are better than others at serving as surfaces upon which these ice particles can form. LINDA (LED based Ice Nucleation Detection Apparatus) allows for detection of which aerosols are best at serving as ice nuclei in clouds.
From Measurements to Global Impact by Modelling
After acquiring measurement data we can use our results as model parameters. This way we can study the effect of marine biology on climate on regional and global level.