TY - JOUR
T1 - The Modeled Seasonal Cycles of Surface N2O Fluxes and Atmospheric N2O
AU - Sun, Qing
AU - Joos, Fortunat
AU - Lienert, Sebastian
AU - Berthet, Sarah
AU - Carroll, Dustin
AU - Gong, Cheng
AU - Ito, Akihiko
AU - Jain, Atul K.
AU - Kou-Giesbrecht, Sian
AU - Landolfi, Angela
AU - Manizza, Manfredi
AU - Pan, Naiqing
AU - Prather, Michael
AU - Regnier, Pierre
AU - Resplandy, Laure
AU - Séférian, Roland
AU - Shi, Hao
AU - Suntharalingam, Parvadha
AU - Thompson, Rona L.
AU - Tian, Hanqin
AU - Vuichard, Nicolas
AU - Zaehle, Sönke
AU - Zhu, Qing
N1 - Publisher Copyright:
© 2024 The Author(s).
PY - 2024/7
Y1 - 2024/7
N2 - Nitrous oxide (N2O) is a greenhouse gas and stratospheric ozone-depleting substance with large and growing anthropogenic emissions. Previous studies identified the influx of N2O-depleted air from the stratosphere to partly cause the seasonality in tropospheric N2O (aN2O), but other contributions remain unclear. Here, we combine surface fluxes from eight land and four ocean models from phase 2 of the Nitrogen/N2O Model Intercomparison Project with tropospheric transport modeling to simulate aN2O at eight remote air sampling sites for modern and pre-industrial periods. Models show general agreement on the seasonal phasing of zonal-average N2O fluxes for most sites, but seasonal peak-to-peak amplitudes differ several-fold across models. The modeled seasonal amplitude of surface aN2O ranges from 0.25 to 0.80 ppb (interquartile ranges 21%–52% of median) for land, 0.14–0.25 ppb (17%–68%) for ocean, and 0.28–0.77 ppb (23%–52%) for combined flux contributions. The observed seasonal amplitude ranges from 0.34 to 1.08 ppb for these sites. The stratospheric contributions to aN2O, inferred by the difference between the surface-troposphere model and observations, show 16%–126% larger amplitudes and minima delayed by ∼1 month compared to Northern Hemisphere site observations. Land fluxes and their seasonal amplitude have increased since the pre-industrial era and are projected to grow further under anthropogenic activities. Our results demonstrate the increasing importance of land fluxes for aN2O seasonality. Considering the large model spread, in situ aN2O observations and atmospheric transport-chemistry models will provide opportunities for constraining terrestrial and oceanic biosphere models, critical for projecting carbon-nitrogen cycles under ongoing global warming.
AB - Nitrous oxide (N2O) is a greenhouse gas and stratospheric ozone-depleting substance with large and growing anthropogenic emissions. Previous studies identified the influx of N2O-depleted air from the stratosphere to partly cause the seasonality in tropospheric N2O (aN2O), but other contributions remain unclear. Here, we combine surface fluxes from eight land and four ocean models from phase 2 of the Nitrogen/N2O Model Intercomparison Project with tropospheric transport modeling to simulate aN2O at eight remote air sampling sites for modern and pre-industrial periods. Models show general agreement on the seasonal phasing of zonal-average N2O fluxes for most sites, but seasonal peak-to-peak amplitudes differ several-fold across models. The modeled seasonal amplitude of surface aN2O ranges from 0.25 to 0.80 ppb (interquartile ranges 21%–52% of median) for land, 0.14–0.25 ppb (17%–68%) for ocean, and 0.28–0.77 ppb (23%–52%) for combined flux contributions. The observed seasonal amplitude ranges from 0.34 to 1.08 ppb for these sites. The stratospheric contributions to aN2O, inferred by the difference between the surface-troposphere model and observations, show 16%–126% larger amplitudes and minima delayed by ∼1 month compared to Northern Hemisphere site observations. Land fluxes and their seasonal amplitude have increased since the pre-industrial era and are projected to grow further under anthropogenic activities. Our results demonstrate the increasing importance of land fluxes for aN2O seasonality. Considering the large model spread, in situ aN2O observations and atmospheric transport-chemistry models will provide opportunities for constraining terrestrial and oceanic biosphere models, critical for projecting carbon-nitrogen cycles under ongoing global warming.
KW - ocean biogeochemistry model
KW - seasonal cycle
KW - surface NO emissions
KW - terrestrial biosphere model
KW - tropospheric NO
UR - http://www.scopus.com/inward/record.url?scp=85198719897&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85198719897&partnerID=8YFLogxK
U2 - 10.1029/2023GB008010
DO - 10.1029/2023GB008010
M3 - Article
AN - SCOPUS:85198719897
SN - 0886-6236
VL - 38
JO - Global Biogeochemical Cycles
JF - Global Biogeochemical Cycles
IS - 7
M1 - e2023GB008010
ER -