Estimating Asian terrestrial carbon fluxes from CONTRAIL aircraft and surface CO&lt;sub&gt;2&lt;/sub&gt; observations for the period 2006 to 2010

Abstract. Current estimates of the terrestrial carbon fluxes in Asia ("Asia" refers to lands as far west as the Urals and is divided into Boreal Eurasia, Temperate Eurasia and tropical Asia based on TransCom regions) show large uncertainties particularly in the boreal and mid-latitudes and in China. In this paper, we present an updated carbon flux estimate for Asia by introducing aircraft CO2 measurements from the CONTRAIL (Comprehensive Observation Network for Trace gases by Airline) program into an inversion modeling system based on the CarbonTracker framework. We estimated the averaged annual total Asian terrestrial land CO2 sink was about −1.56 Pg C yr−1 over the period 2006–2010, which offsets about one-third of the fossil fuel emission from Asia (+4.15 Pg C yr−1). The uncertainty of the terrestrial uptake estimate was derived from a set of sensitivity tests and ranged from −1.07 to −1.80 Pg C yr−1, comparable to the formal Gaussian error of ±1.18 Pg C yr−1 (1-sigma). The largest sink was found in forests, predominantly in coniferous forests (−0.64 Pg C yr−1) and mixed forests (−0.14 Pg C yr−1); and the second and third large carbon sinks were found in grass/shrub lands and crop lands, accounting for −0.44 Pg C yr−1 and −0.20 Pg C yr−1, respectively. The peak-to-peak amplitude of inter-annual variability (IAV) was 0.57 Pg C yr−1 ranging from −1.71 Pg C yr−1 to −2.28 Pg C yr−1. The IAV analysis reveals that the Asian CO2 sink was sensitive to climate variations, with the lowest uptake in 2010 concurrent with summer flood/autumn drought and the largest CO2 sink in 2009 owing to favorable temperature and plentiful precipitation conditions. We also found the inclusion of the CONTRAIL data in the inversion modeling system reduced the uncertainty by 11% over the whole Asian region, with a large reduction in the southeast of Boreal Eurasia, southeast of Temperate Eurasia and most Tropical Asian areas.

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Estimating Asian terrestrial carbon fluxes from CONTRAIL aircraft and surface CO2 observations for the period 2006–2010

Atmospheric Chemistry and Physics ◽

10.5194/acp-14-5807-2014 ◽

2014 ◽

Vol 14 (11) ◽

pp. 5807-5824 ◽

Cited By ~ 30

Author(s):

H. F. Zhang ◽

B. Z. Chen ◽

I. T. van der Laan-Luijk ◽

T. Machida ◽

H. Matsueda ◽

...

Keyword(s):

A Priori ◽

Carbon Fluxes ◽

Terrestrial Carbon ◽

Tropical Asia ◽

Observation Network ◽

Fossil Fuel Emission ◽

Annual Total ◽

Co2 Sink ◽

Summer Flood ◽

Ecosystem Flux

Abstract. Current estimates of the terrestrial carbon fluxes in Asia show large uncertainties particularly in the boreal and mid-latitudes and in China. In this paper, we present an updated carbon flux estimate for Asia ("Asia" refers to lands as far west as the Urals and is divided into boreal Eurasia, temperate Eurasia and tropical Asia based on TransCom regions) by introducing aircraft CO2 measurements from the CONTRAIL (Comprehensive Observation Network for Trace gases by Airline) program into an inversion modeling system based on the CarbonTracker framework. We estimated the averaged annual total Asian terrestrial land CO2 sink was about −1.56 Pg C yr−1 over the period 2006–2010, which offsets about one-third of the fossil fuel emission from Asia (+4.15 Pg C yr−1). The uncertainty of the terrestrial uptake estimate was derived from a set of sensitivity tests and ranged from −1.07 to −1.80 Pg C yr−1, comparable to the formal Gaussian error of ±1.18 Pg C yr−1 (1-sigma). The largest sink was found in forests, predominantly in coniferous forests (−0.64 ± 0.70 Pg C yr−1) and mixed forests (−0.14 ± 0.27 Pg C yr−1); and the second and third large carbon sinks were found in grass/shrub lands and croplands, accounting for −0.44 ± 0.48 Pg C yr−1 and −0.20 ± 0.48 Pg C yr−1, respectively. The carbon fluxes per ecosystem type have large a priori Gaussian uncertainties, and the reduction of uncertainty based on assimilation of sparse observations over Asia is modest (8.7–25.5%) for most individual ecosystems. The ecosystem flux adjustments follow the detailed a priori spatial patterns by design, which further increases the reliance on the a priori biosphere exchange model. The peak-to-peak amplitude of inter-annual variability (IAV) was 0.57 Pg C yr−1 ranging from −1.71 Pg C yr−1 to −2.28 Pg C yr−1. The IAV analysis reveals that the Asian CO2 sink was sensitive to climate variations, with the lowest uptake in 2010 concurrent with a summer flood and autumn drought and the largest CO2 sink in 2009 owing to favorable temperature and plentiful precipitation conditions. We also found the inclusion of the CONTRAIL data in the inversion modeling system reduced the uncertainty by 11% over the whole Asian region, with a large reduction in the southeast of boreal Eurasia, southeast of temperate Eurasia and most tropical Asian areas.

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Site-level model–data synthesis of terrestrial carbon fluxes in the CarboEastAsia eddy-covariance observation network: toward future modeling efforts

Journal of Forest Research ◽

10.1007/s10310-012-0367-9 ◽

2013 ◽

Vol 18 (1) ◽

pp. 13-20 ◽

Cited By ~ 28

Author(s):

Kazuhito Ichii ◽

Masayuki Kondo ◽

Young-Hee Lee ◽

Shao-Qiang Wang ◽

Joon Kim ◽

...

Keyword(s):

Eddy Covariance ◽

Carbon Fluxes ◽

Model Data ◽

Terrestrial Carbon ◽

Data Synthesis ◽

Observation Network ◽

Level Model

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Inverse analysis of fire-induced carbon emission from Equatorial Asia in 2015 with CONTRAIL and NIES-VOS data

10.5194/egusphere-egu21-7005 ◽

2021 ◽

Author(s):

Yosuke Niwa ◽

Yousuke Sawa ◽

Hideki Nara ◽

Toshinobu Machida ◽

Hidekazu Matsueda ◽

...

Keyword(s):

Carbon Flux ◽

Inverse Analysis ◽

Carbon Emission ◽

Carbon Fluxes ◽

Commercial Aircraft ◽

Aircraft Observation ◽

Inverse Simulation ◽

Observation Network ◽

Reliable Monitoring ◽

Annual Total

The fire-induced carbon emission in Equatorial Asia was estimated using the inverse system named NICAM-based Inverse Simulation for Monitoring (NISMON) carbon dioxide (CO2). The analysis was performed with the four-dimensional variational method for 2015, when the big El Ni&#241;o was occurred. NISMON-CO2 extensively used high-precision atmospheric mole fraction data of CO2 from the commercial aircraft observation project of Comprehensive Observation Network for TRace gases by AIrLiner (CONTRAIL). Furthermore, independent atmospheric CO2 and carbon monoxide data from National Institute for Environmental Studies (NIES) Volunteer Observing Ship (VOS) Programme were used to elucidate the validity of the estimated fire-induced carbon emission. Finally, using both CONTRAIL and NIES-VOS CO2 data, the inverse analysis indicated 273 Tg C for fire emission during September - October 2015. This two-month-long emission accounts for 75% of the annual total fire emission and 45% of the annual total net carbon flux within the region, indicating that fire emission is a dominant driving force of interannual variations of carbon fluxes in Equatorial Asia. In the future warmer climate condition, Equatorial Asia would experience more severe droughts and have risks for releasing a large amount of carbon into the atmosphere. Therefore, the continuation of these aircraft and shipboard observations is fruitful for reliable monitoring of carbon fluxes in Equatorial Asia.

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Quantifying the benefit of A-SCOPE data for reducing uncertainties in terrestrial carbon fluxes in CCDAS

Tellus B ◽

10.3402/tellusb.v62i5.16634 ◽

2010 ◽

Vol 62 (5) ◽

Author(s):

T. Kaminski ◽

M. Scholze ◽

S. Houweling

Keyword(s):

Carbon Fluxes ◽

Terrestrial Carbon

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Improvement of Soil Respiration Parameterization in a Dynamic Global Vegetation Model and Its Impact on the Simulation of Terrestrial Carbon Fluxes

Journal of Climate ◽

10.1175/jcli-d-18-0018.1 ◽

2018 ◽

Vol 32 (1) ◽

pp. 127-143 ◽

Cited By ~ 2

Author(s):

Dongmin Kim ◽

Myong-In Lee ◽

Eunkyo Seo

Keyword(s):

Spatial Distribution ◽

Soil Respiration ◽

Soil Temperature ◽

Vegetation Type ◽

Carbon Fluxes ◽

Decomposition Process ◽

Spatial And Temporal Variation ◽

In Situ Observation ◽

Terrestrial Carbon ◽

Soil Temperature And Moisture

Abstract The Q10 value represents the soil respiration sensitivity to temperature often used for the parameterization of the soil decomposition process has been assumed to be a constant in conventional numerical models, whereas it exhibits significant spatial and temporal variation in the observations. This study develops a new parameterization method for determining Q10 by considering the soil respiration dependence on soil temperature and moisture obtained by multiple regression for each vegetation type. This study further investigates the impacts of the new parameterization on the global terrestrial carbon flux. Our results show that a nonuniform spatial distribution of Q10 tends to better represent the dependence of the soil respiration process on heterogeneous surface vegetation type compared with the control simulation using a uniform Q10. Moreover, it tends to improve the simulation of the relationship between soil respiration and soil temperature and moisture, particularly over cold and dry regions. The modification has an impact on the soil respiration and carbon decomposition process, which changes gross primary production (GPP) through controlling nutrient assimilation from soil to vegetation. It leads to a realistic spatial distribution of GPP, particularly over high latitudes where the original model has a significant underestimation bias. Improvement in the spatial distribution of GPP leads to a substantial reduction of global mean GPP bias compared with the in situ observation-based reference data. The results highlight that the enhanced sensitivity of soil respiration to the subsurface soil temperature and moisture introduced by the nonuniform spatial distribution of Q10 has contributed to improving the simulation of the terrestrial carbon fluxes and the global carbon cycle.

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