Datasets
CESM2 Large Ensemble Community Project (LENS2) climate data
Domain: Climate
Spatial Resolution: 1 degree
Temporal Frequency: 3 hours; 6 hours; daily; monthly; annual
Temporal Coverage: 1850 - 2100
Spatial Extent: Global
Source: NCAR; ICCP
Update Type: Static
Update Frequency: NA
Update Detail: NA
Description:
The CESM2 Large Ensemble (LENS2) consists of 100 members at 1-degree spatial resolution covering the period 1850-2100 under CMIP6 historical and SSP370 future radiative forcing scenarios. Data sets from this ensemble are available via the Climate Data Gateway.
Unlike the CESM1 Large Ensemble (LENS1), LENS2 uses a combination of different oceanic and atmospheric initial states to create ensemble spread as follows.
1. Members 1-10: These begin from years 1001, 1021, 1041, 1061, 1081, 1101, 1121, 1141, 1161, and 1181 of the 1400-year pre-industrial control simulation. This segment of the control simulation was chosen to minimize drift.
2. Members 11-90: These begin from 4 pre-selected years of the pre-industrial control simulation based on the phase of the Atlantic meridional overturning circulation (AMOC). For each of the 4 initial states, there are 20 ensemble members created by randomly perturbing the atmospheric potential temperature field by order 10^-14K. The chosen start dates (model years 1231, 1251, 1281, and 1301) sample AMOC and sea surface height (SSH) in the Labrador Sea at their maximum, minimum, and transition states.
3. Members 91-100: These begin from years 1011, 1031, 1051, 1071, 1091, 1111, 1131, 1151, 1171, and 1191 of the 1400-year pre-industrial control simulation. This group includes an extensive “MOAR” output (mother of all runs) which can be used to drive regional climate models.
This initialization design is intended to enable an assessment of oceanic (AMOC) and atmospheric contributions to ensemble spread, and the impact of AMOC initial-condition memory on the global Earth system.
Citation:
Rodgers, K.B., Lee, S., Rosenbloom, N., Timmermann, A., Danabasoglu, G., Deser, C., Edwards, J., Kim, J., Simpson, I.R., Stein, K., Stuecker, M.F., Yamaguchi, R., Bodai, T., Chung, E., Huang, L., Kim, W.M., Lamarque, J., Lombardozzi, D.L., Wieder, W.R, and Yeager, S.G., 2021, Ubiquity of human-induced changes in climate variability: European Geosciences Union, v. 12, no. 4, p. 1393-1411, https://doi.org/10.5194/esd-12-1393-2021