1

Collaborative Research: Global Ocean Repeat Hydrography, Carbon, and Tracer Measurements 2015-2020

Award Period: 

Thursday, January 1, 2015 to Sunday, February 28, 2021

Award Amount: 

$425 469

Agency Name: 

University of Miami

Award Number: 

S15-49

PI First Name: 

Craig

PI last name: 

Carlson

MSI Person: 

Area/s of Research: 

Abstract: 

Summary

 

DOM is one of the largest of the bioreactive pools of carbon in the ocean (680-700 Pg C; Williams and Druffel, 1987; Hansell and Carlson, 1998, Hansell et al., 2009), second only to TCO2.  The size of the reservoir (comparable to that of atmospheric CO2), as well as its role as a sink for autotrophically fixed carbon, as a substrate to heterotrophic microbes (Carlson, 2002; Carlson and Hansell 2014), and as a sink/source of carbon involved in climate variations over long time scales (Sexton et al. 2011), highlights the importance of DOM in the ocean carbon and nitrogen cycles. DOC exports 1.9 PgC yr-1 out of the epipelagic zone, contributing ~20% to the biological pump via meridional overturning circulation (Hansell et al. 2002; Carlson et al., 2010). Mechanisms that control DOM accumulation, allowing it to persist and be transported to the regions of overturn, are still poorly understood. Small perturbations in the production or sink terms of the oceanic DOC pool could strongly impact the balance between oceanic and atmospheric CO2. In this global ocean repeat hydrography, carbon and tracer program D. Hansell (University of Miami) and C. Carlson of UCSB will be responsible for at sea sampling and analyses of dissolved organic carbon (DOC) and nitrogen (DON) measurements.  The proposed program includes 14 legs over 11 cruises conducted in various ocean basins from 2015 – 2020.  The tentative break down of Carlson’s cruise coverage is as follows:

 

Year                                        Cruise                         At sea participation

2015                                        P16N Leg 2                             Yes     

2016                                        I08S, I09N, I01E                      Yes- all legs

2017                                        P06 leg 1                                 Yes     

2018                                        I05                                           Yes – all legs  

2019                                        I06S                                         Yes     

2020                                        S4P                                         No –sample analyses only     

 

Sample throughput will track that of the dissolved inorganic carbon and total alkalinity measurements.  DOC will be measured by high temperature combustion using a Shimadzu TOC-V or TOC –L systems with auto injection (CV of 1.5-2.5%). DON is calculated as the difference between total dissolved nitrogen concentrations this group will measure and dissolved inorganic nitrogen, measured by the hydrographic team. Oversight of project management for the UCSB component will be under the direction of C. Carlson.  Sample analyses for each cruise takes approximately 9 – 16 months from receipt of samples depending on the length of the cruise. The at sea sampling personnel will be covered through a combination of PI, senior technician and student participation.   

 

Sample analyses for each cruise takes approximately 9 – 16 months from receipt of samples depending on the length of the cruise.