Annotated TS-diagram
In [1]:
import gsw
import numpy as np
Te = np.linspace(0, 13, 25)
Se = np.linspace(34.4, 35.4, 25)
Tg, Sg = np.meshgrid(Te, Se)
sigma_theta = gsw.sigma0(Sg, Tg)
cnt = np.linspace(sigma_theta.min(), sigma_theta.max(), 10)
In [2]:
import pandas as pd
df = pd.read_csv('data/water_mass.csv', index_col='p')
df
| SP | CT | |
|---|---|---|
| p | ||
| 0.0 | 35.239437 | 12.669123 |
| 20.0 | 35.265523 | 12.557223 |
| 50.0 | 35.294104 | 12.129957 |
| 100.0 | 35.301038 | 11.044503 |
| 150.0 | 35.222396 | 10.271577 |
| 250.0 | 34.935177 | 8.331906 |
| 400.0 | 34.716915 | 6.418602 |
| 600.0 | 34.514237 | 4.232079 |
| 800.0 | 34.461589 | 3.018598 |
| 1000.0 | 34.506734 | 2.473099 |
| 1200.0 | 34.587903 | 2.271567 |
| 1400.0 | 34.667830 | 2.161632 |
| 1750.0 | 34.755579 | 1.969424 |
| 2500.0 | 34.801034 | 1.565978 |
| 3500.0 | 34.771211 | 0.923388 |
| 4500.0 | 34.702501 | 0.104218 |
In [3]:
%matplotlib inline
import matplotlib.pyplot as plt
from matplotlib.ticker import MaxNLocator
fig, ax = plt.subplots(figsize=(7, 7))
cs = ax.contour(Sg, Tg, sigma_theta, colors='grey', levels=cnt, zorder=1)
kw = dict(color='blue', fontsize=14, fontweight='black')
ax.text(35.00, 11.9, 'SACW', **kw)
ax.text(34.50, 3.12, 'AAIW', **kw)
ax.text(34.82, 1.72, 'NADW', **kw)
kw = dict(color='darkorange', linestyle="none", marker='*')
ax.plot(df['SP'], df['CT'], **kw)
ax.set_xlabel('Salinity [g kg$^{-1}$]')
ax.set_ylabel('Temperature [$^\circ$C]')
ax.set_title('T-S Diagram')
ax.xaxis.set_major_locator(MaxNLocator(nbins=5))
