Ocean Hypercapnia Data Challenge

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How does the leaderboard work?

Thinkable allows any scientist or team to host a competition with judging and/or member voting to award an unlimited set of prizes. The Thinkable leaderboard is only active during the voting/judging period where votes are automatically tallied either through the membership or through the organisers invited judges.

What is DIC?

DIC stands for Dissolved Inorganic Carbon concentration of seawater and can be thought of as the total carbon dioxide concentration of the ocean. Three forms of inorganic carbon make up DIC (see figure below) in the ocean including dissolved carbon dioxide (the molecule that exchanges with atmospheric CO2 and we worry about), carbonate ion (required for calcium carbonate production: CO3) and bicarbonate ion HCO3 (which makes up 90% of the DIC pool).

What is Alk?

Alk refers to the alkalinity concentration of seawater and can be thought of as the ability for a parcel of water to buffer an acid. It's defined by adding up all of the ionic properties of seawater (eg carbonate, bicarbonate, boron, hydrogen, siliceous acid etc). Alkalinity remains constant when CO2 enters the ocean from the atmosphere since it's a charge balance, however Alkalinity is a critical state variable along with DIC that defines the level of carbon dioxide in the ocean.

How do you calculate CO2 from DIC and ALK?

Carbon dioxide concentration can be calculated by knowledge of seawater temperature, salinity, DIC and ALK. Scott Denning's research team at Colorado State University has developed an online calculator to play with (CLICK HERE). Simply change the DIC and ALK concentrations to see how pCO2 concentrations, Revelle factors and pH change too.

Where has the data come from?

Over the 1990s until today a number of government funded measurement programs have given scientists an unprecedented snapshot into ocean physics, chemistry and biology. Thousands of oceanographers have invested decades of effort into sampling and measuring a range of ocean properties from coordinated multi-national programs. Below is a graphic illustrating the global data used for this challenge. Please see more at the Carbon Dioxide Information Analysis Center (CDIAC) and the Global Ocean Data Analysis Project.


We would like to thank all those who contributed to the collection, measurement and open disclosure of this valuable and important data-set. In particular, Bob Key from Princeton University and Alex Kozyr from the Oak Ridge National Laboratory for their leadership and dedication over decades in performing quality assurance and management of these bottle carbon data-sets.

Who to contact with questions?

Tristan Sasse at t.sasse@unsw.edu.au or click 'contact organisers'

Legals & Quorum

For the data challenge, there is no quorum required - however for the peer choice award, a minimum of 5 ideas will be needed before the competition and reward is activated.

 Funding Available