Identification

Title

Two-year dynamical predictions of ENSO event duration during 1954-2015

Abstract

El Nino and La Nina events show a wide range of durations over the historical record. The predictability of event duration has remained largely unknown, although multiyear events could prolong their climate impacts. To explore the predictability of El Nino and La Nina event duration, multiyear ensemble forecasts are conducted with the Community Earth System Model, version 1 (CESM1). The 10-40-member forecasts are initialized with observed oceanic conditions on 1 March, 1 June, and 1 November of each year during 1954-2015; ensemble spread is created through slight perturbations to the atmospheric initial conditions. The CESM1 predicts the duration of individual El Nino and La Nina events with lead times ranging from 6 to 25 months. In particular, forecasts initialized in November, near the first peak of El Nino or La Nina, can skillfully predict whether the event continues through the second year with 1-yr lead time. The occurrence of multiyear La Nina events can be predicted even earlier with lead times up to 25 months, especially when they are preceded by strong El Nino. The predictability of event duration arises from initial thermocline depth anomalies in the equatorial Pacific, as well as sea surface temperature anomalies within and outside the tropical Pacific. The forecast error growth, on the other hand, originates mainly from atmospheric variability over the North Pacific in boreal winter. The high predictability of event duration indicates the potential for extending 12-month operational forecasts of El Nino and La Nina events by one additional year.

Resource type

document

Resource locator

Unique resource identifier

code

https://n2t.org/ark:/85065/d7pn9901

codeSpace

Dataset language

eng

Spatial reference system

code identifying the spatial reference system

Classification of spatial data and services

Topic category

geoscientificInformation

Keywords

Keyword set

keyword value

Text

originating controlled vocabulary

title

Resource Type

reference date

date type

publication

effective date

2016-01-01T00:00:00Z

Geographic location

West bounding longitude

East bounding longitude

North bounding latitude

South bounding latitude

Temporal reference

Temporal extent

Begin position

End position

Dataset reference date

date type

publication

effective date

2021-05-01T00:00:00Z

Frequency of update

Quality and validity

Lineage

Conformity

Data format

name of format

version of format

Constraints related to access and use

Constraint set

Use constraints

Limitations on public access

None

Responsible organisations

Responsible party

contact position

OpenSky Support

organisation name

UCAR/NCAR - Library

full postal address

PO Box 3000

Boulder

80307-3000

email address

opensky@ucar.edu

web address

http://opensky.ucar.edu/

name: homepage

responsible party role

pointOfContact

Metadata on metadata

Metadata point of contact