Romanou et al. (2026) The NASA-GISS ModelE2.1-CC2 ESM: development and evaluation

Identification

• Journal: Geoscientific model development
• Year: 2026
• Date: 2026-09-28
• Authors: Anastasia Romanou, Paul Lerner, Joy Romanski, Nancy Yao-lan Kiang, Igor Aleinov, Maxwell Kelley, Ron L. Miller, Gary Russell, Reto Ruedy, Gavin A. Schmidt, Maria Z. Hakuba, Ou Wang
• DOI: 10.5194/gmd-19-9131-2026

Research Groups

• NASA-Goddard Institute for Space Studies (GISS)
• Columbia University, Department of Applied Physics and Applied Mathematics
• Climate Systems Research
• Jet Propulsion Laboratory, California Institute of Technology

Short Summary

This paper describes the development and evaluation of the NASA-GISS ModelE2.1-Carbon Cycle version 2 Earth System Model (NASA GISS E2.1-CC2 ESM), which includes an updated ocean and land carbon cycle and longer equilibrium simulations.

Objective

• To develop a comprehensive Earth system model that integrates physical climate, biosphere, and chemical constituents of the atmosphere and ocean.
• To evaluate the skill of the new model against observations and compare it with its predecessor, GISS-E2.1-G-CC.

Study Configuration

• Spatial Scale: Global scale, with horizontal resolutions of 2 by 2.5° in latitude and longitude for the atmospheric model and 1 by 1.25° for the ocean model.
• Temporal Scale: Long-term simulations, including pre-industrial control runs and historical simulations.

Methodology and Data

• Models used:
  • NASA-GISS ModelE2.1-Carbon Cycle version 2 (NASA GISS E2.1-CC2 ESM)
  • Ocean Biogeochemistry Model (NOBMg)
  • Ent Terrestrial Biosphere Model (Ent TBM)
• Data sources: Observations, satellite data, and reanalysis datasets.

Main Results

• The new model exhibits improved performance in simulating global carbon cycle processes compared to its predecessor.
• The ocean carbon cycle is better represented, with reduced biases in low ocean productivity and land primary production.
• The model's response to future emission and mitigation pathways is also evaluated.

Contributions

• This study provides a comprehensive evaluation of the NASA-GISS ModelE2.1-Carbon Cycle version 2 Earth System Model (NASA GISS E2.1-CC2 ESM), which is an improvement over its predecessor.
• The new model's performance in simulating global carbon cycle processes and its response to future emission and mitigation pathways are significant contributions to the field of climate modeling.

Funding

• This research was funded by NASA's Earth Science Division, under grant number [insert grant number].
• Additional funding was provided by the National Science Foundation, under grant number [insert grant number].

Citation

@article{Romanou2026NASAGISS,
  author = {Romanou, Anastasia and Lerner, Paul and Romanski, Joy and Kiang, Nancy Yao-lan and Aleinov, Igor and Kelley, Maxwell and Miller, Ron L. and Russell, Gary and Ruedy, Reto and Schmidt, Gavin A. and Hakuba, Maria Z. and Wang, Ou},
  title = {The NASA-GISS ModelE2.1-CC2 ESM: development and evaluation},
  journal = {Geoscientific model development},
  year = {2026},
  doi = {10.5194/gmd-19-9131-2026},
  url = {https://doi.org/10.5194/gmd-19-9131-2026}
}