Calibration of an existing biogeochemical model of DMS production in the Antarctic Southern Ocean.
This project used computer-based modelling and existing field data to analyse the production and cycling of dimethylsulphide (DMS) and predicted its role in climate regulation in the Antarctic Southern Ocean.
From the Final Report:
Aims
(i) To calibrate an existing dimethylsulphide (DMS) production model in a section of the Antarctic Southern Ocean.
(ii) To use the calibrated model to investigate the effect of GCM-predicted climate change on the production and sea-to-air flux of DMS under current and enhanced greenhouse climatic conditions.
(iii) To provide regional assessments of the sign and strength of the DMS-climate feedback in the Southern Ocean. Characteristics of Study Region:
Our study region extends from 60-65 degrees S, 123-145 degrees E in the Antarctic Southern Ocean, and was the site of a major biological study in the austral summer of 1996 (Wright and van den Enden, 2000). Field observations show that a short-lived spring-summer bloom event is typical of these waters (El-Sayed, 1988, Skerratt et al. 1995); however there can be high interannual variability in the timing and magnitude of the bloom (Marchant and Murphy, 1994). The phytoplankton community structure has been described by Wright and van den Enden (2000), who report maximum chlorophyll (Chl) concentrations during January-March in the range (1.0-3.4) microgL-1. During this survey, macronutrients did not limit phytoplankton growth. Thermal stratification of the mixed layer was strongly correlated with high algal densities, with strong subsurface Chl maxima (at the pycnocline) observed. The mixed layer depth determined both phytoplankton community composition and maximum algal biomass. Coccolithophorids (noted DMS producers) were favoured by deep mixed layers, with diatoms dominating the more strongly stratified waters. Pycnocline depth varied from 20-50 m in open water. Algal abundance appeared to be controlled by salp and krill grazing.
Field data support the existence of seasonal DMS production in the Antarctic region. However, a large range in DMS concentrations has been reported in the open ocean , reflecting both seasonal and spatial variability (Gibson et al., 1990, Berresheim, 1987; Fogelqvist, 1991). Blooms of the coccolithophores, and prymnesiophytes such as Phaeocystis, form a significant fraction (~23%) of the algal biomass (Waters et al 2000). Concentrations of DMS in sea ice are reported to be very high (Turner et al. 1995) and may be responsible for elevated water concentrations during release from melt water (Inomata et al. 1997). Field measurements of dissolved DMS made in the study region have been summarised by Curran et al. (1998). DMS concentrations were variable in the open ocean during spring and summer (range: 0-22 nM), with the higher values recorded in the seasonal ice zone and close to the Antarctic continent. Zonal average monthly mean DMS in the study region have been estimated by Kettle et al. (1999).
(See downloadable full report for reference list).
A copy of the referenced publication is also available for download by AAD staff. It contains the modelling information.
Simple
Identification info
- Alternate title
- Calibration of an existing biogeochemical model of DMS production in the Antarctic Southern Ocean.
- Date (Publication)
- 2000-08-11
- Edition
- 1
Originator
Publisher
Principal investigator
Collaborator
- Name
- CAASM Metadata
- Status
- Completed
Custodian
- Topic category
-
- Geoscientific information
- Oceans
Extent
Extent
- Description
- Temporal Coverage
Temporal extent
- TimePeriod
- 2000-09-30 2001-03-31
- Title
- The sensitivity of dimethyl sulfide production to simulated climate change in the Eastern Antarctic Southern Ocean.
- Date (Publication)
- 2003
- Citation identifier
- 55B
Author
- Name
- Tellus
- Page
- 966-981
- NASA/GCMD Earth Science Keywords
-
- EARTH SCIENCE > OCEANS > OCEAN CHEMISTRY > BIOGEOCHEMICAL CYCLES
- Keywords
-
- BIOGEOCHEMICAL CYCLES
- CLIMATE CHANGE
- DIMETHYLSULPHIDE
- DMS
- MODEL
- SOUTHERN OCEAN
- NASA/GCMD Earth Science Keywords
-
- AMD/AU
- CEOS
- AMD
- NASA/GCMD Earth Science Keywords
-
- OCEAN > SOUTHERN OCEAN
- GEOGRAPHIC REGION > POLAR
Resource constraints
- Use limitation
- This metadata record is publicly available.
Resource constraints
- Access constraints
- licence
- Other constraints
- The report from the project can be accessed from the provided URL. A copy of a publication detailing the modelling results is available only to AAD staff from the provided URL.
Resource constraints
- File type
- Portable Network Graphic
- Title
- Attribution 4.0 International (CC BY 4.0)
- Website
-
https://creativecommons.org/licenses/by/4.0/legalcode
Legal code for Creative Commons by Attribution 4.0 International license
- Use constraints
- licence
- Other constraints
- This data set conforms to the CCBY Attribution License (http://creativecommons.org/licenses/by/4.0/). Please follow instructions listed in the citation reference provided at http://data.aad.gov.au/aadc/metadata/citation.cfm?entry_id=ASAC_1227 when using these data.
- Language
- English
- Character encoding
- UTF8
Distribution Information
Distributor
Distributor
Distributor
- Fees
- Free
- Planned available datetime
- 2000-08-11T00:00:00
Distributor
- Fees
- Free
- Planned available datetime
- 2000-08-11T00:00:00
- Units of distribution
- KB
- Transfer size
- 236
- Distribution format
-
- Units of distribution
- KB
- Transfer size
- 187
- Distribution format
-
- Word
- OnLine resource
-
GET DATA
Download point for the data
- OnLine resource
-
PROJECT HOME PAGE
Public information for ASAC project 1227
- OnLine resource
-
VIEW RELATED INFORMATION > PUBLICATIONS
Download point for the paper - AAD Staff Only
- OnLine resource
-
VIEW RELATED INFORMATION
Citation reference for this metadata record and dataset
Resource lineage
- Statement
- Values provided in temporal coverage are approximate only.
- Hierarchy level
- Dataset
- Maintenance and update frequency
- As needed
- Maintenance note
- 2014-07-23 - record updated by Dave Connell to add a publication provided by Al Gabric. 2015-05-01 - record updated by Dave Connell - basic updates.
Metadata
- Metadata identifier
- string/ASAC_1227
- Language
- English
- Character encoding
- UTF8
Author
Sponsor
Owner
Type of resource
- Resource scope
- Dataset
Alternative metadata reference
- Title
- gov.nasa.gsfc.gcmd
- Citation identifier
- 6cd7098b-e60f-46e0-a727-75012a68b9ee
Alternative metadata reference
- Title
- gov.nasa.gsfc.gcmd
- Date (Last Revision)
- 2015-11-30T04:49:01
Identifier
- Description
- metadata.extraction_date
Alternative metadata reference
- Title
- gov.nasa.gsfc.gcmd
- Citation identifier
- 8.6
- Metadata linkage
-
http://data.aad.gov.au/metadata/records/ASAC_1227
Point of truth for the metadata record
- Date info (Creation)
- 2000-08-11T00:00:00
- Date info (Last Update)
- 2017-04-26
Metadata standard
- Title
- ISO 19115-3
- Edition
- 2014
- Other citation details
- Version 1
- Title
- DIF to ISO 19115-1 Profile