Estimation without temperature¶
Calling trace without a temperature input will cause it to estimate temperature from salinity and coordinates via a neural network. This is not recommended, but will yield results (with a warning) as in TRACEv1:
output = trace(
output_coordinates=np.array([[0, 0, 0], [0, 0, 0]]),
dates=np.array([2000, 2010]),
predictor_measurements=np.array([[35], [35]]),
predictor_types=np.array([1]),
atm_co2_trajectory=1
)
UserWarning: Temperature is being estimated from salinity and coordinate information.
>>> output
<xarray.Dataset> Size: 448B
Dimensions: (loc: 2)
Coordinates:
year (loc) <U20 160B '2000-01-01T00:00:00Z' '2010-01-01T00:0...
lon (loc) int64 16B 0 0
lat (loc) int64 16B 0 0
depth (loc) int64 16B 0 0
Dimensions without coordinates: loc
Data variables:
canth (loc) float64 16B 56.06 66.46
mean_age (loc) float64 16B 1.883 1.883
mode_age (loc) float64 16B 0.4424 0.4424
dic (loc) float64 16B 1.925e+03 1.935e+03
dic_ref (loc) float64 16B 1.869e+03 1.869e+03
pco2 (loc) float64 16B 322.4 337.9
pco2_ref (loc) float64 16B 252.0 252.0
preformed_ta (loc) float64 16B 2.282e+03 2.282e+03
preformed_si (loc) float64 16B 1.787 1.787
preformed_p (loc) float64 16B 0.08551 0.08551
temperature (loc) float64 16B 26.47 26.47
salinity (loc) float64 16B 35.0 35.0
u_canth (loc) float64 16B 9.699 11.08
delta_over_gamma (loc) float64 16B 1.3 1.3
scale_factors (loc) float64 16B 0.01341 0.01341
Attributes:
Conventions: CF-1.10
description: Results of Tracer-based Rapid Anthropogenic Carbon Es...
history: TRACE version 0.2.0 (beta), 2025-07-16 19:36:55.79208...
date_created: 2025-07-16 19:36:55.792097
references: doi.org/10.5194/essd-2024-560
co2sys_parameters: opt_pH_scale: 1, opt_k_carbonic: 10, opt_k_HSO4: 1, o...
trace_parameters: per_kg_sw_tf: True, canth_diseq: 1.0, eos: seawater, ...
>>> output.canth.data
array([56.059132, 66.45668126])
The same result was obtained in TRACEv1: Canth = [56.0591 66.4567] for the same inputs.