.. _hadisst_nino:

HadISST Nino 3.4 Index
======================

Description
-----------
Nino 3.4 Index is computed from the Hadley-OI sea surface temperature
(SST) and sea ice concentration (SIC) data set. This product was
specifically developed as surface forcing data set for AMIP style
uncoupled simulations of the Community Atmosphere Model (CAM). The
Hadley Centre's SST/SIC version 1.1 (HADISST1), which is derived gridded,
bias-adjusted in situ observations, were merged with the NOAA-Optimal
Interpolation (version 2; OI.v2) analyses. The HADISST1 spanned 1870
onward but the OI.v2, which started in November 1981, better resolved
features such as the Gulf Stream and Kuroshio Current which are important
components of the climate system. Since the two data sets used different
development methods, anomalies from a base period were used to create
a more homogeneous record. Also, additional adjustments were made to
the SIC data set.

Source
------
`NCAR Hadley-NOAA/OI SST website`_

Release Policy
--------------
Acknowledgment: Hurrell, J. W., J. J. Hack, D. Shea, J. M. Caron, and J. Rosinski,
2008: A New Sea Surface Temperature and Sea Ice Boundary Dataset for the Community
Atmosphere Model. Journal of Climate, 21, 5145-5153.

References
----------
`Hurrell et al. (2008)`_

`bibtex file`_

MPAS-Analysis Tasks
-------------------
- :ref:`task_indexNino34`

.. _`NCAR Hadley-NOAA/OI SST website`: https://climatedataguide.ucar.edu/climate-data/merged-hadley-noaaoi-sea-surface-temperature-sea-ice-concentration-hurrell-et-al-2008
.. _`Hurrell et al. (2008)`: https://doi.org/10.1175/2008JCLI2292.1
.. _`bibtex file`: https://web.lcrc.anl.gov/public/e3sm/diagnostics/observations/Ocean/Nino/HadISST/obs.bib