easyclimate.field.teleconnection.index_bbo¶

Barents-Beaufort Oscillation (BBO)

Functions¶

calc_index_BBO_EOF3_Wu_2007(, lon_dim, lat_dim, ...)

The calculation of monthly mean Barents-Beaufort Oscillation (BBO) index using empirical orthogonal functions (EOFs) method

Module Contents¶

easyclimate.field.teleconnection.index_bbo.calc_index_BBO_EOF3_Wu_2007(slp_monthly_data: xarray.DataArray, time_range: slice = slice(None, None), lon_dim: str = 'lon', lat_dim: str = 'lat', lat_range: slice = slice(70, 90), time_dim: str = 'time', random_state: int | None = None, solver: Literal['auto', 'full', 'randomized'] = 'auto', solver_kwargs: dict = {}, normalized: bool = True) → xarray.DataArray¶

The calculation of monthly mean Barents-Beaufort Oscillation (BBO) index using empirical orthogonal functions (EOFs) method

Tip

The third EOF mode of SLP anomaly north of 70°N is Barents-Beaufort Oscillation (BBO) pattern.

Parameters¶

slp_monthly_data: xarray.DataArray.: The monthly data of sea level pressure (SLP).
time_range: slice, default: slice(None, None).: The time range of seasonal cycle means to be calculated. The default value is the entire time range.
lon_dim: str, default: lon.: Longitude coordinate dimension name. By default extracting is applied over the lon dimension.
lat_dim: str, default: lat.: Latitude coordinate dimension name. By default extracting is applied over the lat dimension.
lat_range: slice, default: slice(20, 90).: The latitude range of computation using EOFs over the Northern Hemisphere. The default value is from \(\mathrm{20^{\circ}N}\) to \(\mathrm{90^{\circ}N}\).
time_dim: str, default: time.: The time coordinate dimension name.
random_state: int, default None.: Seed for the random number generator.
solver: {“auto”, “full”, “randomized”}, default: “auto”.: Solver to use for the EOFs computation.
solver_kwargs: dict, default {}.: Additional keyword arguments to be passed to the EOFs solver.
normalized: bool, default True, optional.: Whether to standardize the index based on standard deviation over time_range.

Returns¶

The monthly mean BBO index (xarray.DataArray).

Reference¶

Wu, B., and M. A. Johnson (2007), A seesaw structure in SLP anomalies between the Beaufort Sea and the Barents Sea, Geophys. Res. Lett., 34, L05811, doi: https://doi.org/10.1029/2006GL028333.
1. Bi, K. Sun, X. Zhou, H. Huang and X. Xu, “Arctic Sea Ice Area Export Through the Fram Strait Estimated From Satellite-Based Data:1988–2012,” in IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, vol. 9, no. 7, pp. 3144-3157, July 2016, doi: https://doi.org/10.1109/JSTARS.2016.2584539.
Bi, H., Liang, Y., & Chen, X. (2023). Distinct role of a spring atmospheric circulation mode in the Arctic sea ice decline in summer. Journal of Geophysical Research: Atmospheres, 128, e2022JD037477. https://doi.org/10.1029/2022JD037477