Table 1
Code used to process and analyze the collection and available on GitHub (Hakim et al., 2018).
| Code | Purpose |
|---|---|
| LMR_proxy_preprocess.py | Process NOAA text files, perform QC, standardize on LMR conventions, build data frames and save frames as Python Pickle files. |
| LMR_PSMbuild.py | Build proxy system models using user-specified calibration files and options. Currently linear univariate and bivariate regressions are supported; classes allow for other models to be developed. |
| summarize_proxy_database.py | Calculates summary statistics for the collection organized by archive types listed in Table 2. |
| summarize_linearPSM.py | Analyzes linear univariate regression models. |
| Map_proxies.py | Maps proxy records. |
Table 2
Assignment of original data variables to LMR archive and variable categories. (Note that some entries here are associated with processing of PAGES 2k Consortium (2017) data).
| Archive | Variable | Original Variable Name |
|---|---|---|
| Tree Rings | WidthPages2 | trsgi |
| Tree Rings | WidthBreit | trsgi |
| Tree Rings | WoodDensity | max_d, min_d, early_d, earl_d, late_d, MXD, density |
| Tree Rings | Isotopes | d18O |
| Corals and Sclerosponges | d180 | d18O, delta18O, d18o, d18O_stk, d18O_int, d18O_norm, d18o_avg, d18o_ave, dO18, d18O_4 |
| Corals and Sclerosponges | SrCa | Sr/Ca, Sr_Ca, Sr/Ca_norm, Sr/Ca_anom, Sr/Ca_int |
| Corals and Sclerosponges | Rates | ext, calc, calcification, calcification rate, composite |
| Ice Cores | d180 | d18O, delta18O, delta18o, d18o, d18o_int, d18O_int, d18O_norm, d18o_norm, dO18, d18O_anom |
| Ice Cores | dD | deltaD, delD, dD |
| Ice Cores | accumulation | accum, accumu |
| Ice Cores | MeltFeature | MFP, melt |
| Lake Cores | Varve | varve’, ‘varve_thickness’, ‘varve thickness’, ‘thickness’ |
| Lake Cores | Biomarkers | Uk37, TEX86, tex86 |
| Lake Cores | GeoChem | Sr/Ca, Mg/Ca, Cl_cont |
| Lake Cores | Misc | RABD660_670, X_radiograph_dark_layer, massacum |
| Marine Cores | d18O | d18O |
| Marine Cores | tex86 | tex86 |
| Marine Cores | uk37 | uk37, UK37 |
| Speleothems | d18O | d18O |
| Bivalve | d18O | d18O |
Figure 1
Proxy site locations (coded by archive) and proxy coverage through time for the additional data (top) and the complete database LMRdb 1.0.0 (bottom).
Table 3
Processing of additional proxy record files.
| Proxy Variable | PAGES 2k | Additions | Calibrated Additions |
|---|---|---|---|
| Bivalve_d18O | 1 | 0 | 0 |
| Corals and Sclerosponges_Rates | 8 | 1 | 1 |
| Corals and Sclerosponges_SrCa | 28 | 7 | 3 |
| Corals and Sclerosponges_d18O | 65 | 19 | 11 |
| Ice Cores_Accumulation | 0 | 3 | 3 |
| Ice Cores_MeltFeature | 2 | 0 | 0 |
| Ice Cores_d18O | 39 | 77 | 61 |
| Ice Cores_dD | 8 | 8 | 5 |
| Lake Cores_Misc | 3 | 0 | 0 |
| Lake Cores_Varve | 6 | 2 | 2 |
| Marine Cores_d18O | 1 | 0 | 0 |
| Speleothems_d18O | 4 | 20 | 6 |
| Tree Rings_Isotopes | 0 | 1 | 1 |
| Tree Rings_WidthBreit | 0 | 2152 | 2152 |
| Tree Rings_WidthPages2 | 347 | 0 | 0 |
| Tree Rings_WoodDensity | 59 | 0 | 0 |
| Total | 571 | 2290 | 2244 |
Table 4
Regression summary statistics for each proxy type. Signal to noise ratio (SNS) and coefficient of efficiency (CE) minimum (Min), Mean, and maximum (Max), based on linear regression with respect to annual temperature and comparison to observed values. Struck-through values are based on fewer than 10 proxy records.
| Proxy | Min | Mean | Max | Min | Mean | Max |
|---|---|---|---|---|---|---|
| Corals and Sclerosponges_SrCa | 2.57 | 13.70 | 35.39 | 0.03 | 0.17 | 0.42 |
| Corals and Sclerosponges_d18O | 0.00 | 37.82 | 175.81 | 0.00 | 0.24 | 0.62 |
| Ice Cores_Accumulation | 1.61 | 12.32 | 32.74 | 0.02 | 0.14 | 0.39 |
| Ice Cores_d18O | 0.00 | 5.39 | 33.96 | 0.00 | 0.06 | 0.25 |
| Ice Cores_dD | 2.07 | 6.42 | 17.21 | 0.05 | 0.08 | 0.14 |
| Lake Cores_Varve | 2.89 | 5.03 | 7.16 | 0.03 | 0.04 | 0.06 |
| Speleothems_d18O | 0.01 | 2.06 | 9.61 | 0.00 | 0.02 | 0.08 |
| Tree Rings_Isotopes | 16.16 | 16.16 | 16.16 | 0.13 | 0.13 | 0.13 |
| Tree Rings_WidthBreit | 0.00 | 3.51 | 44.73 | 0.00 | 0.03 | 0.28 |