ENSO-driven terrestrial carbon flux variability in a coupled climate-carbon cycle model
Abstract
Inter-annual terrestrial carbon flux variability has been explored through observations, but there are relatively few studies examining the processes underlying this variability in coupled climate-carbon cycle models. Carbon flux variability related to the El Nino Southern Oscillation (ENSO) is examined using a 500-year pre-industrial control simulation. This simulation was performed with NOAA-GFDL's new ESM2M Earth System Model that was developed for the CMIP5 / IPCC AR5 project. In addition, we explore how negative and positive phases of ENSO interact with the seasonal carbon dynamics in the tropical regions. The GFDL-ESM2M model produces realistic - if not slightly too large - ENSO variability in the tropics through direct effects and a realistic response in the middle and high latitudes through teleconnections. The largest climate response to ENSO occurs in the tropics and corresponds well to the regions of largest variability of land carbon fluxes. Among composites of NPP, soil respiration, and fire during both the positive and negative phases of ENSO, changes in NPP are the best explanation for the large carbon flux variability. In the tropical regions, both precipitation changes and the partitioning between direct and diffuse radiation are responsible for the vegetation response (and associated NPP) to ENSO.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2011
- Bibcode:
- 2011AGUFM.B14C..04K
- Keywords:
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- 0429 BIOGEOSCIENCES / Climate dynamics;
- 0466 BIOGEOSCIENCES / Modeling;
- 1622 GLOBAL CHANGE / Earth system modeling;
- 1631 GLOBAL CHANGE / Land/atmosphere interactions