Effects of Serial Dependence and Large-Scale Tropospheric Circulation on Midlatitude North American Terrestrial Carbon Dioxide Exchange

Author:

Hember Robbie A.1,Lafleur Peter M.2

Affiliation:

1. Department of Forest Resources Management, University of British Columbia, Vancouver, British Columbia, Canada

2. Department of Geography, Trent University, Peterborough, Ontario, Canada

Abstract

Abstract Linear regression was used to relate modes of tropospheric circulation variability to estimates of gross ecosystem production (GEP) and ecosystem respiration (ER) measured at 14 midlatitude North American eddy covariance (EC) towers. The North Atlantic Oscillation (NAO) exhibited a north–south gradient in its effect on fluxes, with negative influence on fluxes at central and northeastern stations and positive influence on fluxes at southeastern stations. During spring, average values of GEP and ER within the northern “cold” sector decreased by 22 and 12 g C m−2 (18% and 11%), respectively, in response to a unit increase (+1 standard deviation) in the expansion coefficient of the NAO mode. Despite a northward advancement of the “warm” sector during summer, GEP and ER remained negatively correlated with the NAO at northern stations, decreasing on average by 48 and 30 g C m−2 (8% and 6%), respectively. During spring, the North Pacific Oscillation (NPO) reduced GEP and ER at central and northeastern stations on average by 20 and 7 g C m−2 (16% and 6%) and increased GEP and ER at southern and west coast stations on average by 53 and 49 g C m−2 (12% and 17%) in response to a unit increase in the NPO. This pattern persisted into summer, only shifted northward, with flux decreases of 19 and 24 g C m−2 (3% and 5%) at northern stations and increases of 72 and 82 g C m−2 (9% and 16%) at central stations. The direction of the flux response in each case was supported by synoptic conditions inferred from composite maps of North American circulation and gridded surface air temperature anomalies. The magnitude and timing of the relationships differed between stations and was attributed to differences in geographic location and plant functional type. Difficulty in the interpretation of significant correlations was attributed to the short sample length of typical EC records and unmodeled variability, including, for example, modulation by the NAO during high NPO. Despite these limitations, long-term monitoring EC stations show promise in characterizing the regional and ecosystem-specific carbon cycle response to low-frequency modes of tropospheric circulation variability and may play a critical role in validating ecosystem model responses to such phenomena.

Publisher

American Meteorological Society

Subject

Atmospheric Science

Cited by 2 articles. 订阅此论文施引文献 订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3