Table 3.
Hidden Markov Model results for regime change in spring climatology at the Cloquet Forestry Center (CFC) and Marcell Experimental Forest (MEF) for both station and Climate Research Unit (CRU) climate data. Model performance for the one-state and two-state model was evaluated by the change in Akaike Information Criterion (Δ AIC). Model log-likelihood is also indicated for all models and is compared among models using a log-likelihood test (• = p < 0.1, *p < 0.05, **p < 0.01). The transition year (T) is indicated if a single transition year was identified. The superior model is in bold
| Record | n state = 1 | n state = 2 | Model selection | |||||
|---|---|---|---|---|---|---|---|---|
| AIC | BIC | Log L | AIC | BIC | Log L | Δ AIC | T Year | |
| CFC station | 385.7 | 390.97 | −190.85 | 374.07 | 392.52 | −180.04** | −11.63 | 1976 |
| MEF station | 221.62 | 225.6 | −108.81 | 224.63 | 238.56 | −105.32 | 3.01 | – |
| CFC CRU | 438.54 | 444.01 | −217.27 | 423.06 | 442.21 | −204.53** | −15.48 | 1976 |
| MEF CRU | 452.89 | 458.36 | −224.44 | 444.66 | 463.81 | −215.33** | −8.23 | 1976 |
| Models with CMIP6 + PNA covariates (1961–2014) | ||||||||
| Record | n state = 2 | n state = 2 + covariates | ||||||
| AIC | BIC | Log L | AIC | BIC | Log L | Δ AIC | T Year | |
| CFC station | 259.45 | 274.67 | −122.72 | 258.17 | 277.74 | −120.08 • | −1.28 | 1976 |
| MEF station | 224.63 | 238.56 | −105.32 | 226.42 | 244.32 | −104.21 | 1.79 | – |
| CFC CRU | 261.97 | 277.19 | −123.99 | 260.45 | 280.02 | −121.22 • | −1.52 | – |
| MEF CRU | 273.95 | 289.17 | −129.98 | 273.32 | 292.89 | −127.66 • | −0.63 | – |