Input Data

Required inputs

The function canyonb requires seven input parameters for prediction:

Parameter	Description	Units	Range	Typical Error
Time	Measurement date	UTC or decimal year	Any	-
Latitude	Geographic latitude	degrees	-90 to 90	-
Longitude	Geographic longitude	degrees	-180 to 180	-
Pressure	Water pressure	dbar	0 to 10000	0.5
Temperature	In-situ temperature	°C	-2 to 35	0.005
Salinity	Practical salinity	PSU	0 to 45	0.005
Oxygen	Dissolved oxygen	μmol·kg−1	0 to 400	1% of value

Data Format

Array Requirements

All input arrays must:

• Have the same shape
• Be numpy arrays or convertible to numpy arrays
• Can contain non-finite values (np.nan), but not recommanded for coordinates (time, longitude, latitude, pressure)

import numpy as np
from datetime import datetime

# Single point
data = {
    'gtime': [datetime(2024, 1, 1)],
    'lat': np.array([45.0]),
    'lon': np.array([-20.0]),
    'pres': np.array([100.0]),
    'temp': np.array([15.0]),
    'psal': np.array([35.0]),
    'doxy': np.array([250.0])
}

# Multiple points/profile
depths = np.array([0, 100, 200, 500])
data_profile = {
    'gtime': [datetime(2024, 1, 1)] * len(depths),
    'lat': np.full_like(depths, 45.0),
    'lon': np.full_like(depths, -20.0),
    'pres': depths,
    'temp': np.array([20.0, 15.0, 12.0, 8.0]),
    'psal': np.full_like(depths, 35.0),
    'doxy': np.array([250.0, 220.0, 200.0, 180.0])
}

Time Format

CANYON-B accepts two time formats:

1. Python datetime objects:

   from datetime import datetime
   time = [datetime(2024, 1, 1)]
   

2. Decimal years:

   time = [2024.0]  # January 1st, 2024
   

Geographic Coordinates

Latitude

• Must be between -90° and 90°
• Negative values for Southern hemisphere and positive values for Northern hemisphere

Longitude

Can be in either (Automatically converted internally):

• -180° to 180° format (preferred)
• 0° to 360° format

Arctic Region Handling

For measurements in the Arctic basin west of the Lomonosov ridge:

• Latitude values are automatically adjusted
• Adjustments account for water mass distribution
• No user action required