ONI calculation

import pump
from pump import mixpods
import xarray as xr

/glade/u/home/dcherian/miniconda3/envs/pump/lib/python3.10/site-packages/dask_jobqueue/core.py:20: FutureWarning: tmpfile is deprecated and will be removed in a future release. Please use dask.utils.tmpfile instead.
  from distributed.utils import tmpfile

Phase labeling

oni = pump.obs.process_oni().sel(time=slice("2005-Sep", None))
enso_transition = mixpods.make_enso_transition_mask(oni)
mixpods.plot_enso_transition(oni, enso_transition)

Replicate ONI calculation

close enough!

ersst = xr.tutorial.open_dataset("ersstv5")

monthlyersst = (
    ersst.sst.cf.sortby("Y")
    .cf.sel(latitude=slice(-5, 5), longitude=slice(360 - 170, 360 - 120))
    .cf.mean(["X", "Y"])
    .resample(time="M")
    .mean()
    .load()
)

expected = mixpods.calc_oni(monthlyersst)

actual = pump.obs.process_oni()
actual.plot()
expected.plot()

(actual - expected).plot()

[<matplotlib.lines.Line2D>]

Comparing to Warner and Moum code

chipod.eps.sel(time="2007-01-14 10:35:00", method="nearest").load()

<xarray.DataArray 'eps' (depth: 5)>
nan 3.929e-07 2.846e-07 2.234e-07 4.491e-07
Coordinates:
    time        datetime64[ns] 2007-01-14T11:00:00
  * depth       (depth) float64 -69.0 -59.0 -49.0 -39.0 -29.0
    timeSeries  (depth) float64 69.0 59.0 49.0 39.0 29.0
    lat         (depth) float64 0.0 0.0 0.0 0.0 0.0
    lon         (depth) float64 -140.0 -140.0 -140.0 -140.0 -140.0
Attributes:
    long_name:              turbulence dissipation rate
    standard_name:          specific_turbulent_kinetic_energy_dissipation_in_...
    ncei_name:              turbulent kinetic energy (TKE) dissipation rate
    units:                  W kg-1
    FillValue:              -9999
    valid_min:              1e-12
    valid_max:              9.999999999999999e-06
    coverage_content_type:  physicalMeasurement
    grid_mapping:           crs
    source:                 inferred from fast thermistor spectral scaling
    references:             Moum J.N. and J.D. Nash, Mixing measurements on a...
    cell_methods:           depth: point, time: mean
    platform:               mooring
    instrument:             chipod

xarray.DataArray

'eps'

• depth: 5

• nan 3.929e-07 2.846e-07 2.234e-07 4.491e-07

  array([           nan, 3.92899514e-07, 2.84615955e-07, 2.23436769e-07,
         4.49053774e-07])

• Coordinates: (5)
  • time
    ()
    datetime64[ns]
    2007-01-14T11:00:00

    long_name :

    Time, UTC

    standard_name :

    time

    axis :

    T

    array('2007-01-14T11:00:00.000000000', dtype='datetime64[ns]')

  • depth
    (depth)
    float64
    -69.0 -59.0 -49.0 -39.0 -29.0

    long_name :

    depths of sensors along the mooring line

    standard_name :

    depth

    units :

    m

    axis :

    Z

    positive :

    up

    valid_min :

    29.0

    valid_max :

    119.0

    array([-69., -59., -49., -39., -29.])

  • timeSeries
    (depth)
    float64
    69.0 59.0 49.0 39.0 29.0

    long_name :

    depths of Time series of T, dTdz, Nsqr, chi, epsilon, and Jq along a mooring line at 0-140W

    cf_role :

    timeseries_id

    array([69., 59., 49., 39., 29.])

  • lat
    (depth)
    float64
    0.0 0.0 0.0 0.0 0.0

    long_name :

    latitude

    standard_name :

    latitude

    units :

    degrees_north

    axis :

    Y

    valid_min :

    0.0

    valid_max :

    0.0

    array([0., 0., 0., 0., 0.])

  • lon
    (depth)
    float64
    -140.0 -140.0 -140.0 -140.0 -140.0

    long_name :

    longitude

    standard_name :

    longitude

    units :

    degrees_east

    axis :

    X

    valid_min :

    -140.0

    valid_max :

    -140.0

    array([-140., -140., -140., -140., -140.])

• Attributes: (14)

  long_name :

  turbulence dissipation rate

  standard_name :

  specific_turbulent_kinetic_energy_dissipation_in_sea_water

  ncei_name :

  turbulent kinetic energy (TKE) dissipation rate

  units :

  W kg-1

  FillValue :

  -9999

  valid_min :

  1e-12

  valid_max :

  9.999999999999999e-06

  coverage_content_type :

  physicalMeasurement

  grid_mapping :

  crs

  source :

  inferred from fast thermistor spectral scaling

  references :

  Moum J.N. and J.D. Nash, Mixing measurements on an equatorial ocean mooring, J. Atmos. and Oceanic Tech., 26, 317-336, 2009. pdf: http://mixing.coas.oregonstate.edu/papers/mixing_measurements.pdf

  cell_methods :

  depth: point, time: mean

  platform :

  mooring

  instrument :

  chipod

tao_gridded.enso_transition.loc[{"time": slice("2015-12", "2016-01")}]

<xarray.DataArray 'enso_transition' (time: 1488)>
'El-Nino warm' 'El-Nino warm' 'El-Nino warm' ... 'El-Nino warm' 'El-Nino warm'
Coordinates: (12/13)
    deepest             (time) float64 -300.0 -300.0 -300.0 ... -300.0 -300.0
    eucmax              (time) float64 -135.0 -140.0 -135.0 ... -140.0 -135.0
    latitude            float32 0.0
    longitude           float32 -140.0
    mld                 (time) float64 -9.0 -8.0 -8.0 -8.0 ... nan nan nan nan
    mldT                (time) float64 -10.0 -8.0 -8.0 -8.0 ... nan nan nan nan
    ...                  ...
    shallowest          (time) float64 -5.0 -5.0 -5.0 -5.0 ... -10.0 -10.0 -10.0
  * time                (time) datetime64[ns] 2015-12-01 ... 2016-01-31T23:00:00
    oni                 (time) float32 2.53 2.53 2.53 2.53 ... 2.53 2.53 2.53
    warm_mask           (time) bool True True True True ... False False False
    cool_mask           (time) bool False False False False ... True True True
    enso_transition     (time) <U12 'El-Nino warm' ... 'El-Nino warm'
Attributes:
    description:  Warner & Moum (2019) ENSO transition phase; El-Nino = ONI >...

xarray.DataArray

'enso_transition'

• time: 1488

• 'El-Nino warm' 'El-Nino warm' ... 'El-Nino warm' 'El-Nino warm'

  array(['El-Nino warm', 'El-Nino warm', 'El-Nino warm', ...,
         'El-Nino warm', 'El-Nino warm', 'El-Nino warm'], dtype='<U12')

• Coordinates: (13)
  • deepest
    (time)
    float64
    -300.0 -300.0 ... -300.0 -300.0

    description :

    Deepest depth with a valid observation

    units :

    m

    array([-300., -300., -300., ..., -300., -300., -300.])

  • eucmax
    (time)
    float64
    -135.0 -140.0 ... -140.0 -135.0

    units :

    m

    long_name :

    EUC maximum

    positive :

    up

    array([-135., -140., -135., ..., -140., -140., -135.])

  • latitude
    ()
    float32
    0.0

    array(0., dtype=float32)

  • longitude
    ()
    float32
    -140.0

    array(-140., dtype=float32)

  • mld
    (time)
    float64
    -9.0 -8.0 -8.0 -8.0 ... nan nan nan

    long_name :

    $z_{MLD}$

    units :

    m

    array([-9., -8., -8., ..., nan, nan, nan])

  • mldT
    (time)
    float64
    -10.0 -8.0 -8.0 ... nan nan nan

    long_name :

    MLD$_θ$

    units :

    m

    description :

    Interpolate θi to 1m grid. Search for max depth where |dθ| > 0.15

    array([-10.,  -8.,  -8., ...,  nan,  nan,  nan])

  • reference_pressure
    ()
    int64
    0

    array(0)

  • shallowest
    (time)
    float64
    -5.0 -5.0 -5.0 ... -10.0 -10.0

    array([ -5.,  -5.,  -5., ..., -10., -10., -10.])

  • time
    (time)
    datetime64[ns]
    2015-12-01 ... 2016-01-31T23:00:00

    array(['2015-12-01T00:00:00.000000000', '2015-12-01T01:00:00.000000000',
           '2015-12-01T02:00:00.000000000', ..., '2016-01-31T21:00:00.000000000',
           '2016-01-31T22:00:00.000000000', '2016-01-31T23:00:00.000000000'],
          dtype='datetime64[ns]')

  • oni
    (time)
    float32
    2.53 2.53 2.53 ... 2.53 2.53 2.53

    array([2.53, 2.53, 2.53, ..., 2.53, 2.53, 2.53], dtype=float32)

  • warm_mask
    (time)
    bool
    True True True ... False False

    array([ True,  True,  True, ..., False, False, False])

  • cool_mask
    (time)
    bool
    False False False ... True True

    array([False, False, False, ...,  True,  True,  True])

  • enso_transition
    (time)
    <U12
    'El-Nino warm' ... 'El-Nino warm'

    description :

    Warner & Moum (2019) ENSO transition phase; El-Nino = ONI > 0.5 for at least 6 months; La-Nina = ONI < -0.5 for at least 6 months

    array(['El-Nino warm', 'El-Nino warm', 'El-Nino warm', ...,
           'El-Nino warm', 'El-Nino warm', 'El-Nino warm'], dtype='<U12')

• Attributes: (1)

  description :

  Warner & Moum (2019) ENSO transition phase; El-Nino = ONI > 0.5 for at least 6 months; La-Nina = ONI < -0.5 for at least 6 months