What variables are used to develop the multivariate ENSO index?
v2) has been created that uses 5 variables (sea level pressure (SLP), sea surface temperature (SST), surface zonal winds (U), surface meridional winds (V), and Outgoing Longwave Radiation (OLR)) to produce a time series of ENSO conditions from 1979 to present.
What are the 3 parts of ENSO?
We can use surface-water temperatures in the eastern equatorial Pacific to designate conditions as one of three phases of the El Nino-Southern Oscillation (ENSO) system — neutral (or “normal”), warm (El Nino), and cold (La Nina).
What does ENSO stand for and what does it mean?
Southern Oscillation
El Niño and the Southern Oscillation, also known as ENSO is a periodic fluctuation in sea surface temperature (El Niño) and the air pressure of the overlying atmosphere (Southern Oscillation) across the equatorial Pacific Ocean.
What is the ENSO 3.4 index?
The Niño 3.4 index typically uses a 5-month running mean, and El Niño or La Niña events are defined when the Niño 3.4 SSTs exceed +/- 0.4C for a period of six months or more. The TNI thus measures the gradient in SST anomalies between the central and eastern equatorial Pacific.
How do hurricanes seasons relate with ENSO cycles?
The hurricane activity in a given season often reflects a combination of the multi-decadal signals and ENSO. During an Atlantic high-activity era, El Niño typically results in a near-normal season, and La Niña produces an above-normal season.
What is Mei climate?
The Multivariate ENSO Index (MEI) is said to capture a more holistic representation of the atmospheric and oceanic anomalies that occur during ENSO events than do single-variables timeseries like the NinoSST indices. The MEIv2 is based on five variables from the tropical Pacific.
What is NINO 34?
Weekly Monthly. The NINO3. 4 index is one of several El Niño/Southern Oscillation (ENSO) indicators based on sea surface temperatures. NINO3. 4 is the average sea surface temperature anomaly in the region bounded by 5°N to 5°S, from 170°W to 120°W.
What is a positive SST anomaly?
To calculate the Sea Surface Temperature (SST) Anomaly, we first needed to know the long-term mean SSTs globally. Areas in purple to blue mean a negative anomaly; that is, the water temperature is cooler than the mean. Orange to red means a positive anomaly: the temperature is warmer than the mean.
What does the Southern Oscillation Index measure?
The SOI compares the difference from average air pressure in the western Pacific, measured in Darwin, Australia, to the difference from average pressure in the central Pacific, measured at Tahiti.
What is ENSO index Mei?
The Multivariate ENSO Index (MEI) is said to capture a more holistic representation of the atmospheric and oceanic anomalies that occur during ENSO events than do single-variables timeseries like the NinoSST indices. The MEIv2 is based on five variables from the tropical Pacific.
What does ENSO stand for?
ENSO Indices. Southern Oscillation Index (SOI) standardized anomaly of the mean sea level pressure difference between Tahiti and Darwin. traditional ENSO index. correlates strongly with SST anomaly indices.
Is there a reliable ENSO index for the historical record?
Here we attempt to create a reliable ENSO index for much of the historical record by basing the extended Multivariate ENSO Index (MEI.ext) on the two main observed variables over the tropical Pacific that have been reconstructed by the Hadley Centre back to 1871.
What is the coupled ENSO index (CEI)?
The Coupled ENSO Index (CEI) uses a combination of both the SOI and Niño 3.4 SST to account for both an atmospheric and oceanic component. Developed by Braganza, et al., 2009, this index uses coral, tree ring and ice core data to characterize ENSO events from 1525 – 1982.