Dataset: Dinitrogen fixation rates and nifH community structure

Name: Dinitrogen fixation (N2fix) rates and nifH community structure from in situ 15N2 Gas Array from R/V Kilo Moana KM1016, KM1110 in the North Pacific Subtropical Gyre near Station ALOHA from 2010-2011 (DIAZOTROPHS-CO2 project)
Published: 2013-08-22
Keywords: oceans

Cite This Dataset

Spatial Extent: N:25.4193 E:-157.9648 S:22.7485 W:-160.7528

Project:

Oceanic diazotroph community structure and activities in a high carbon dioxide world (DIAZOTROPHS-CO2)

Program:

Ocean Carbon and Biogeochemistry (OCB)

Principal Investigator:

Matthew J. Church (University of Hawai'i, UH)

Co-Principal Investigator:

Ricardo Letelier (Oregon State University, OSU-CEOAS)

Version:

22 August 2013

Version Date:

2013-08-22

Validated:

Current State:

Final no updates expected

Dinitrogen fixation (N2fix) rates and nifH community structure from in situ 15N2 Gas Array from R/V Kilo Moana KM1016, KM1110 in the North Pacific Subtropical Gyre near Station ALOHA from 2010-2011 (DIAZOTROPHS-CO2 project)

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Description

Assessments of fixation rates of Rates of ¹⁵N₂ and cyanobacterial nifH gene dynamics from In situ
¹⁵N₂ Gas Array near station ALOHA deployed during KM1016 and KM1110.

Methods & Sampling

Rates of ¹⁵N₂ fixation were assessed using the ¹⁵N isotopic tracer technique. Whole seawater samples from six discrete depths (5, 25, 45, 75, 100, and 125 m) were withdrawn into acid-washed duplicate 4.3 L polycarbonate bottles and sealed with caps fitted with a silicone septa. Three mL of ¹⁵N₂ gas (98 %; Isotech Laboratories ©) was injected into each polycarbonate bottle through the silicone septum using a gas-tight syringe fitted with a stainless steel needle. The bottles were attached to a free drifting array, deployed before dawn and incubated at in situ light and temperature for ~24 hours. After recovery of the array, the entire volume of each bottle was filtered onto pre-combusted glass microfiber (GF/F) filters (25 mm diameter) for whole seawater N₂-fixation estimates. All GF/F filters were placed on combusted foil pieces in Petri dishes and stored frozen at -20 °C for transport.

Data Processing Description

See: Dinitrogen fixation and nifH analysis methods.

Data Files

File
N2fix_array.csv (Comma Separated Values (.csv), 4.05 KB) MD5:b30082649dc182d9908e99e3d1c10839 Primary data file for dataset ID 4017

More Information about this dataset

Funding Sources

Funding Source	Award Number
NSF Division of Ocean Sciences	OCE-0850827

Deployments

Deployment	Synonyms	Start Date	Platform	Investigator
KM1016		2010-08-20	R/V Kilo Moana	Matthew J. Church (Chief Scientist)	data info
KM1110		2011-03-12	R/V Kilo Moana	Matthew J. Church (Chief Scientist)	data info

Instruments

Mass Spectrometer

Supplied Description:

Instrument Type

Generic Name: Mass Spectrometer

Acronym: Mass Spec

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/LAB16/

Generic Description:

General term for instruments used to measure the mass-to-charge ratio of ions; generally used to find the composition of a sample by generating a mass spectrum representing the masses of sample components.

Parameters

Date and time formats are described in python strftime() syntax.

Supplied Name	Supplied description	Supplied Units	Standard Name
cruise_id	Cruise Id	text	cruiseid
sta	Station Id	integer	sta
date	date sampling began	YYYYMMDD	date
time	time sampling began	hhmm	time
lon	longitude; negative denotes West	decimal degrees	lon
lat	latitude; negative denotes South	decimal degrees	lat
depth	depth of measurement	meters	depth
year	Year of sample	YYYY	year
month	month of sample	MM	month
day	day of sample	DD	day
N2fix_mean	Mean dinitrogen fixation rate (mean from num_obs.) bd = below detection	nanomol N/liter/day	no_bcodmo_term
N2fix_diff	Difference in dinitrogen fixation rate using N2fix_num_obs samples.	nanomol N/liter/day	no_bcodmo_term
PP_mean	Primary production mean derived from num_obs samples. bd = below detection	micrograms/liter/day	no_bcodmo_term
PP_std_dev	Standard deviation between Primary Production samples using PP_num_obs samples.	micrograms/liter/day	no_bcodmo_term
N2fix_num_obs	number of samples used in calculation of dinitrogen fixation rate mean (N2fix_mean) and difference (N2fix_std_dev.)	integer	no_bcodmo_term
PP_num_obs	number of samples used in calculation of Primary Production mean (PP_mean) and standard deviation (PP_std_dev.)	integer	no_bcodmo_term
leuc_3H_light_incorp_mean	3H-leucine (Light) incorporations rates in picomoles Leucine(Light) per liter per hour	picomole/liter/hour	no_bcodmo_term
leuc_3H_dark_incorp_mean	Mean 3H-Leucine (Dark) incorporation rates in picomoles Leucine (Dark) per liter hour using Leucine_3H_Dark_num_obs samples.	picomole/liter/hour	no_bcodmo_term
leuc_3H_light_incorp_diff	Standard deviation between leuc_3H_num_obs samples of 3H-Leucine (light) incorporation rate.	picomole/liter/hour	no_bcodmo_term
leuc_3H_dark_incorp_diff	Standard deviation between leuc_3H_num_obs samples of 3H-Leucine (dark) incorporation rate.	picomole/liter/hour	no_bcodmo_term
leuc_3H_light_num_obs	Number of observations used in calculation of leuc_3H_light_incorp mean and standard deviation.	integer	no_bcodmo_term
leuc_3H_dark_num_obs	Number of observations used in calculation of leuc_3H_dark_incorp mean and standard deviation.	integer	no_bcodmo_term

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Dataset: Dinitrogen fixation rates and nifH community structure