Processing and Analysis Consortium (DPAC) (www.cosmos.esa.
int/web/gaia/dpac/consortium). Funding for DPAC has been
provided by national institutions, in particular the institutions
participating in the Gaia Multilateral Agreement. We acknowledge
the use of public TESS Alert data from pipelines at the TESS
Science Office and at the TESS Science Processing Operations
Center. This work was supported by the KESPRINT collaboration,
an international consortium devoted to the characterization and
research of exoplanets discovered with space-based missions.
Some of the observations were made at Gemini South using the
high-resolution imaging instrument Zorro, funded by the NASA
Exoplanet Exploration Program and built at the NASA Ames
Research Center by S. B. Howell, N. Scott, E. P. Horch, and
E. Quigley. Zorro was mounted on the Gemini South telescope of the
international Gemini Observatory, a program of NSF’s OIR Lab,
which is managed by the Association of Universities for Research in
Astronomy (AURA) under a cooperative agreement with the National
Science Foundation on behalf of the Gemini partnership: the
National Science Foundation (United States); the National Research
Council (Canada); Agencia Nacional de Investigacin y Desarrollo
(Chile); Ministerio de Ciencia, Tecnologa e Innovacin (Argentina);
Ministrio da Ciłncia, Tecnologia, Inovaes e Comunicaes (Brazil);
and the Korea Astronomy and Space Science Institute (Republic
of Korea). This is University of Texas Center for Planetary Systems
Habitability Contribution no. 0041.Funding:K.W.F.L., Sz.Cs.,
M.E., S.G., A.P.H., and H.R. were supported by Deutsche
Forschungsgemeinschaft grants PA525/18-1, PA525/19-1, PA525/
20-1, HA3279/12-1, and RA714/14-1 within the DFG Schwerpunkt
SPP 1992, Exploring the Diversity of Extrasolar Planets. Sz.Cs. is
supported by Deutsche Forschungsgemeinschaft Research Unit
2440, Matter Under Planetary Interior Conditions: High Pressure
Planetary and Plasma Physics. T.H. was supported by JSPS
KAKENHI grant no. JP19K14783, and N.N. was supported by JSPS
KAKENHI grant nos. JP18H01265 and JP18H05439 and JST PRESTO
grant no. JPMJPR1775. J.L. is supported by JSPS KAKENHI grant
no. JP20K14518. R.A.G. acknowledges support from PLATO and GOLF
CNES grants. P.K. acknowledges support from the MSMT grant
LTT20015. S.M. acknowledges support by the Spanish Ministry of
Science and Innovation with the Ramon y Cajal fellowship no.
RYC-2015-17697 and grant no. PID2019-107187GB-I00. N.C.S. was
supported by Fundaçao para a Ciência e a Tecnologia through national
funds and by FEDER through COMPETE2020 - Programa Operacional
Competitividade e Internacionalização grants UID/FIS/04434/2019,
UIDB/04434/2020, UIDP/04434/2020, PTDC/FIS-AST/32113/2017
and POCI-01-0145-FEDER-032113, and PTDC/FIS-AST/28953/2017
and POCI-01-0145-FEDER-028953. X.D. and G.G. acknowledge
funding in the framework of the Investissements d’Avenir program
(ANR-15-IDEX-02), Origin of Life project of the Université Grenoble-
Alpes. J.R.D.M. acknowledges grants from CNPq, CAPES, and FAPERN
Brazilian agencies. N.A.-D. acknowledges support from FONDECYT
project 3180063. Resources for the production of the SPOC data
products were provided by the NASA High-End Computing (HEC)
program through the NASA Advanced Supercomputing (NAS) Division
at Ames Research Center. S.A. is supported by the Danish National
Research Foundation (grant agreement no. DNRF106). D.G. and L.M.S.
acknowledge financial support from the Cassa di Risparmio di Torino
foundation under grant no. 2018.2323,“Gaseous or rocky? Unveiling the
nature of small worlds.”Author contributions:K.W.F.L. contributed to
the planet detection, transit light curve analysis, gyrochronology age
estimate, and tidal evolution calculations and led the writing of the
paper. Sz.Cs. performed the joint light curve and RV analysis using the
Transit and Light Curve Modeller (TLCM). N.A.-D. and X.B. led the
HARPS RV follow-up program and reduced and analyzed the RV data.
D.G. performed the frequency analysis of the RV and activity indicators.
F.D., O.B., A.P.H., and R.L. analyzed the RV data. S.P. determined the
interior composition of the planet and modeled the precursor gaseous
planet. M.E. performed the Rapid Eye Mount (REM) robotic telescope
observations and analysis. M.E. and A.M.S.S. derived the light
curve dilution factor. C.H., K.W.F.L., S.M., and R.A.G. determined the
stellar rotation period using WASP data. S.B.H. analyzed the
speckle imaging data. T.H. and M.F. performed the spectral analysis
using SpecMatch-Emp, and T.H. derived the stellar parameters using
an MCMC simulation. J.L. performed stellar characterization
using isochrone fitting. F.M. performed the LCOGT and HARPS
observations. K.A.C. coordinated the TESS SG1 working group.
K.A.C. and P.L. analyzed the ground-based photometric observations.
N.C.S. performed spectral characterization using ODUSSEAS. M.C.J.
determined the Galactic space velocities of the star. K.W.F.L. and
S.R. calculated the emission spectroscopy metric. J.K. performed
transit-timing variation (TTV) analysis. J.C., P.E., and S.G. analyzed the
light curve for planet detection. E.Gu. analyzed the activity indicators.
G.R.R., R.V., D.W.L., S.S., J.N.W., and J.M.J. led and organized the TESS
mission, including the observations, processing of the data, working
groups coordination, target selection, and dissemination of the data
products. E.H.M., M.V., and J.E.S. are members of the TESS POC
who coordinated and scheduled the TESS science observations and
conducted instrument planning. R.M., J.C.S., and J.D.T. are
members of the SPOC who performed data calibration, light curve
production, and transit planet detection. D.C., J.C., and S.N.Q.
are members of the TSO who reviewed the data and performed
planet candidate vetting. J.M.A., E.A., F.B., D.C., J.R.D.M., X.D.,
R.F.D., R.D., P.F., T.F., G.G., C.L., C.M., F.P., D.S., and S.U. are
coinvestigators of the proposal, which provided the HARPS
observations of the target and supported the interpretation of
results. S.A., P.C., A.C., W.D.C., E.Go., I.G., P.K., E.K., J.J.L., N.N.,
H.L.M.O., E.P., C.M.P., H.R., L.M.S., J.Š., and V.V.E. are part of the
KESPRINT consortium and contributed to the interpretation of the
results. All authors contributed to the preparation of the paper.
Competing interests:The authors declare no competing interests.
Data and materials availability:The TESS photometric
observations are available at the Mikulski Archive for Space
Telescopes (MAST) at https://exo.mast.stsci.edu under target
name TOI 731.01. The raw HARPS spectroscopic data are available
on the ESO Science Archive Facility http://archive.eso.org/cms.
html under ESO program IDs 072.C-0488, 082.C-0718, 183.C-0437
(primary investigators: M. Mayor and X. Bonfils), and 1102.C-0339
(primary investigator: X. Bonfils). The ground-based photometry
obtained by the LCO telescope and REM as well as the Gemini
imaging data are available on the Exoplanet Follow-up Observing
Program (ExoFOP) website https://exofop.ipac.caltech.edu/tess/
under target name TOI 731.01. The raw Gemini data are available at
https://archive.gemini.edu/searchform under program ID GS-
2021A-LP-105. The archival WASP data are available on the NASA
Exoplanet Archive https://exoplanetarchive.ipac.caltech.edu/docs/
SuperWASPMission.html under object name GJ 367. Our reduced
RVs and activity indices are listed in tables S1 and S2 and in
machine-readable form in data S1 and S2. The TLCM is available at
http://www.transits.hu/.
SUPPLEMENTARY MATERIALS
science.org/doi/10.1126/science.aay3253
Materials and Methods
Supplementary Text
Figs. S1 to S10
Tables S1 to S3
References ( 33 – 127 )
Data S1 and S2
31 December 2020; accepted 12 October 2021
10.1126/science.aay3253
CARBON CYCLE
Strong Southern Ocean carbon uptake evident in
airborne observations
Matthew C. Long^1 *, Britton B. Stephens^1 , Kathryn McKain2,3, Colm Sweeney^3 , Ralph F. Keeling^4 ,
Eric A. Kort^5 , Eric J. Morgan^4 , Jonathan D. Bent1,4†, Naveen Chandra^6 ‡, Frederic Chevallier^7 ,
Róisín Commane^8 , Bruce C. Daube^9 , Paul B. Krummel^10 , Zoë Loh^10 , Ingrid T. Luijkx^11 , David Munro2,3,
Prabir Patra^12 , Wouter Peters11,13, Michel Ramonet^7 , Christian Rödenbeck^14 , Ann Stavert^10 ,
Pieter Tans^3 , Steven C. Wofsy9,15
The Southern Ocean plays an important role in determining atmospheric carbon dioxide (CO 2 ), yet
estimates of air-sea CO 2 flux for the region diverge widely. In this study, we constrained Southern Ocean
air-sea CO 2 exchange by relating fluxes to horizontal and vertical CO 2 gradients in atmospheric transport
models and applying atmospheric observations of these gradients to estimate fluxes. Aircraft-based
measurements of the vertical atmospheric CO 2 gradient provide robust flux constraints. We found
an annual mean flux of–0.53 ± 0.23 petagrams of carbon per year (net uptake) south of 45°S during
the period 2009–2018. This is consistent with the mean of atmospheric inversion estimates and
surface-ocean partial pressure of CO 2 (PCO 2 )–based products, but our data indicate stronger annual
mean uptake than suggested by recent interpretations of profiling float observations.
O
cean water-column carbon inventories
suggest that the Southern Ocean accounts
for more than 40% of the cumulative
global ocean uptake of anthropogenic
CO 2 ( 1 , 2 ). However, estimates of con-
temporary net Southern Ocean air-sea carbon
fluxes based on surface-ocean partial pressure
of CO 2 (PCO 2 ) observations or atmospheric in-
versions remain highly uncertain ( 3 – 8 ). Recent
interpretations of profiling float observations
have introduced further complications, pro-
posing a profound revision of the Southern
Ocean carbon budget, with reduced summer-
time uptake and larger wintertime outgassing
( 9 , 10 ). Given the Southern Ocean’s critical role
as a sink for anthropogenic CO 2 , as well as
SCIENCEscience.org 3 DECEMBER 2021•VOL 374 ISSUE 6572 1275
(^1) National Center for Atmospheric Research, Boulder, CO, USA. (^2) Cooperative Institute for Research in Environmental Sciences,
University of Colorado, Boulder, CO, USA.^3 Global Monitoring Laboratory, National Oceanic and Atmospheric Administration,
Boulder, CO, USA.^4 Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA, USA.^5 Department
of Climate and Space Sciences and Engineering, University of Michigan, Ann Arbor, MI, USA.^6 National Institute of Environmental
Studies, Tsukuba, Japan.^7 Laboratoire des Sciences du Climat et de l’Environnement, IPSL-LSCE, CEA-CNRS-UVSQ, UMR8212
91191, France.^8 Department of Earth and Environmental Sciences, Lamont-Doherty Earth Observatory of Columbia University,
Palisades, NY, USA.^9 Department of Earth and Planetary Sciences, Harvard University, Cambridge, MA, USA.^10 Climate
Science Centre, CSIRO Oceans and Atmosphere, Aspendale, Victoria, Australia.^11 Department of Meteorology and Air Quality,
Environmental Sciences Group, Wageningen University, Netherlands.^12 Research Institute for Global Change, Japan Agency for
Marine-Earth Science and Technology (JAMSTEC), Yokohama, Japan.^13 Centre for Isotope Research, University of Groningen,
Groningen, Netherlands.^14 Max Planck Institute for Biogeochemistry, Jena, Germany.^15 Harvard John A. Paulson School of
Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA.
*Corresponding author. Email: [email protected]
†Present address: Picarro, Inc., Santa Clara, CA, USA.
‡Present address: Research Institute for Global Change, JAMSTEC, Yokohama, Japan.
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