Influence of Hudson Bay on the carbon dynamics of a Hudson Bay Lowlands coastal site

Eddy covariance (EC) estimates of net ecosystem exchange (NEE) and the surface energy balance were gathered from an elevated peat plateau within the Hudson Bay Lowlands near Churchill, Manitoba, Canada (58°43′46″N, 93°49′57″W) during the growing season of 2007. Data were segregated into onshore and...

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Bibliographic Details
Published in:Arctic Science
Main Authors: Delidjakova, Kristina K., Bello, Richard L., Higuchi, Kaz, Pokharel, Bipin
Format: Article in Journal/Newspaper
Language:English
Published: Canadian Science Publishing 2016
Subjects:
General Earth and Planetary Sciences
General Agricultural and Biological Sciences
General Environmental Science
Canada
Hudson
Hudson Bay
Arctic
Churchill
Online Access:http://dx.doi.org/10.1139/as-2015-0026
https://cdnsciencepub.com/doi/full-xml/10.1139/as-2015-0026
https://cdnsciencepub.com/doi/pdf/10.1139/as-2015-0026
Description
Summary:Eddy covariance (EC) estimates of net ecosystem exchange (NEE) and the surface energy balance were gathered from an elevated peat plateau within the Hudson Bay Lowlands near Churchill, Manitoba, Canada (58°43′46″N, 93°49′57″W) during the growing season of 2007. Data were segregated into onshore and offshore wind regimes to assess the advective influence of the generally cold and moist Hudson Bay air masses compared to generally warm and dry air masses of nonmarine origin. Monthly average NEE ranged from an uptake of 0.2 µmol·m −2 ·s −1 in September to 5.6 µmol·m −2 ·s −1 in July. Over the growing season, onshore winds from Hudson Bay contributed to an average 4.2 °C reduction in air temperature and an NEE increase of 27%. When normalized with respect to sunlight receipt, the ratio of gross primary production to photosynthetically active radiation (GPP/PAR) was 26% stronger for offshore regimes than for onshore, while the ratio of ecosystem respiration to PAR (ER/PAR) was 71% stronger for offshore regimes. It was concluded that GPP maintains the same strength for both wind regimes, while ER is significantly stronger for offshore regimes, resulting in reduced NEE capacity during periods when winds originate from inland.

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