Atmospheric CO<sub>2</sub> observations and models suggest strong carbon uptake by forests in New Zealand

A regional atmospheric inversion method has been developed to determine the spatial and temporal distribution of CO<sub>2</sub> sinks and sources across New Zealand for 2011–2013. This approach infers net air–sea and air–land CO<sub>2</sub> fluxes from measurement records, us...

Full description

Bibliographic Details
Main Authors: K. Steinkamp, S. E. Mikaloff Fletcher, G. Brailsford, D. Smale, S. Moore, E. D. Keller, W. T. Baisden, H. Mukai, B. B. Stephens
Format: Article
Language:English
Published: Copernicus Publications 2017-01-01
Series:Atmospheric Chemistry and Physics
Online Access:http://www.atmos-chem-phys.net/17/47/2017/acp-17-47-2017.pdf
_version_ 1811238773526102016
author K. Steinkamp
S. E. Mikaloff Fletcher
G. Brailsford
D. Smale
S. Moore
E. D. Keller
W. T. Baisden
H. Mukai
B. B. Stephens
author_facet K. Steinkamp
S. E. Mikaloff Fletcher
G. Brailsford
D. Smale
S. Moore
E. D. Keller
W. T. Baisden
H. Mukai
B. B. Stephens
author_sort K. Steinkamp
collection DOAJ
description A regional atmospheric inversion method has been developed to determine the spatial and temporal distribution of CO<sub>2</sub> sinks and sources across New Zealand for 2011–2013. This approach infers net air–sea and air–land CO<sub>2</sub> fluxes from measurement records, using back-trajectory simulations from the Numerical Atmospheric dispersion Modelling Environment (NAME) Lagrangian dispersion model, driven by meteorology from the New Zealand Limited Area Model (NZLAM) weather prediction model. The inversion uses in situ measurements from two fixed sites, Baring Head on the southern tip of New Zealand's North Island (41.408° S, 174.871° E) and Lauder from the central South Island (45.038° S, 169.684° E), and ship board data from monthly cruises between Japan, New Zealand, and Australia. A range of scenarios is used to assess the sensitivity of the inversion method to underlying assumptions and to ensure robustness of the results. The results indicate a strong seasonal cycle in terrestrial land fluxes from the South Island of New Zealand, especially in western regions covered by indigenous forest, suggesting higher photosynthetic and respiratory activity than is evident in the current a priori land process model. On the annual scale, the terrestrial biosphere in New Zealand is estimated to be a net CO<sub>2</sub> sink, removing 98 (±37) Tg CO<sub>2</sub> yr<sup>−1</sup> from the atmosphere on average during 2011–2013. This sink is much larger than the reported 27 Tg CO<sub>2</sub> yr<sup>−1</sup> from the national inventory for the same time period. The difference can be partially reconciled when factors related to forest and agricultural management and exports, fossil fuel emission estimates, hydrologic fluxes, and soil carbon change are considered, but some differences are likely to remain. Baseline uncertainty, model transport uncertainty, and limited sensitivity to the northern half of the North Island are the main contributors to flux uncertainty.
first_indexed 2024-04-12T12:48:08Z
format Article
id doaj.art-43c255e6afa54273beda6cbebf1e53ca
institution Directory Open Access Journal
issn 1680-7316
1680-7324
language English
last_indexed 2024-04-12T12:48:08Z
publishDate 2017-01-01
publisher Copernicus Publications
record_format Article
series Atmospheric Chemistry and Physics
spelling doaj.art-43c255e6afa54273beda6cbebf1e53ca2022-12-22T03:32:33ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242017-01-01171477610.5194/acp-17-47-2017Atmospheric CO<sub>2</sub> observations and models suggest strong carbon uptake by forests in New ZealandK. Steinkamp0S. E. Mikaloff Fletcher1G. Brailsford2D. Smale3S. Moore4E. D. Keller5W. T. Baisden6H. Mukai7B. B. Stephens8National Institute of Water and Atmospheric Research, Wellington, New ZealandNational Institute of Water and Atmospheric Research, Wellington, New ZealandNational Institute of Water and Atmospheric Research, Wellington, New ZealandNational Institute of Water and Atmospheric Research, Wellington, New ZealandNational Institute of Water and Atmospheric Research, Wellington, New ZealandGNS Science, Lower Hutt, New ZealandGNS Science, Lower Hutt, New ZealandNational Institute for Environmental Studies, Tsukuba, Ibaraki, JapanNational Center for Atmospheric Research, Boulder, Colorado, USAA regional atmospheric inversion method has been developed to determine the spatial and temporal distribution of CO<sub>2</sub> sinks and sources across New Zealand for 2011–2013. This approach infers net air–sea and air–land CO<sub>2</sub> fluxes from measurement records, using back-trajectory simulations from the Numerical Atmospheric dispersion Modelling Environment (NAME) Lagrangian dispersion model, driven by meteorology from the New Zealand Limited Area Model (NZLAM) weather prediction model. The inversion uses in situ measurements from two fixed sites, Baring Head on the southern tip of New Zealand's North Island (41.408° S, 174.871° E) and Lauder from the central South Island (45.038° S, 169.684° E), and ship board data from monthly cruises between Japan, New Zealand, and Australia. A range of scenarios is used to assess the sensitivity of the inversion method to underlying assumptions and to ensure robustness of the results. The results indicate a strong seasonal cycle in terrestrial land fluxes from the South Island of New Zealand, especially in western regions covered by indigenous forest, suggesting higher photosynthetic and respiratory activity than is evident in the current a priori land process model. On the annual scale, the terrestrial biosphere in New Zealand is estimated to be a net CO<sub>2</sub> sink, removing 98 (±37) Tg CO<sub>2</sub> yr<sup>−1</sup> from the atmosphere on average during 2011–2013. This sink is much larger than the reported 27 Tg CO<sub>2</sub> yr<sup>−1</sup> from the national inventory for the same time period. The difference can be partially reconciled when factors related to forest and agricultural management and exports, fossil fuel emission estimates, hydrologic fluxes, and soil carbon change are considered, but some differences are likely to remain. Baseline uncertainty, model transport uncertainty, and limited sensitivity to the northern half of the North Island are the main contributors to flux uncertainty.http://www.atmos-chem-phys.net/17/47/2017/acp-17-47-2017.pdf
spellingShingle K. Steinkamp
S. E. Mikaloff Fletcher
G. Brailsford
D. Smale
S. Moore
E. D. Keller
W. T. Baisden
H. Mukai
B. B. Stephens
Atmospheric CO<sub>2</sub> observations and models suggest strong carbon uptake by forests in New Zealand
Atmospheric Chemistry and Physics
title Atmospheric CO<sub>2</sub> observations and models suggest strong carbon uptake by forests in New Zealand
title_full Atmospheric CO<sub>2</sub> observations and models suggest strong carbon uptake by forests in New Zealand
title_fullStr Atmospheric CO<sub>2</sub> observations and models suggest strong carbon uptake by forests in New Zealand
title_full_unstemmed Atmospheric CO<sub>2</sub> observations and models suggest strong carbon uptake by forests in New Zealand
title_short Atmospheric CO<sub>2</sub> observations and models suggest strong carbon uptake by forests in New Zealand
title_sort atmospheric co sub 2 sub observations and models suggest strong carbon uptake by forests in new zealand
url http://www.atmos-chem-phys.net/17/47/2017/acp-17-47-2017.pdf
work_keys_str_mv AT ksteinkamp atmosphericcosub2subobservationsandmodelssuggeststrongcarbonuptakebyforestsinnewzealand
AT semikalofffletcher atmosphericcosub2subobservationsandmodelssuggeststrongcarbonuptakebyforestsinnewzealand
AT gbrailsford atmosphericcosub2subobservationsandmodelssuggeststrongcarbonuptakebyforestsinnewzealand
AT dsmale atmosphericcosub2subobservationsandmodelssuggeststrongcarbonuptakebyforestsinnewzealand
AT smoore atmosphericcosub2subobservationsandmodelssuggeststrongcarbonuptakebyforestsinnewzealand
AT edkeller atmosphericcosub2subobservationsandmodelssuggeststrongcarbonuptakebyforestsinnewzealand
AT wtbaisden atmosphericcosub2subobservationsandmodelssuggeststrongcarbonuptakebyforestsinnewzealand
AT hmukai atmosphericcosub2subobservationsandmodelssuggeststrongcarbonuptakebyforestsinnewzealand
AT bbstephens atmosphericcosub2subobservationsandmodelssuggeststrongcarbonuptakebyforestsinnewzealand