North American precipitation and temperature patterns associated with the El Nino/Southern Oscillation (ENSO)
Journal Article
·
· Mon. Weather Rev.; (United States)
This paper describes an investigation of the typical North American precipitation and temperature patterns associated with the El Nino/Southern Oscillation (ENSO). Monthly composites, covering idealized two-year ENSO episodes, are computed at all stations with data spanning seven or more ENSO events. The first harmonic is extracted from the 24 monthly composite values and plotted in the form of a two-year harmonic dial vector. When plotted on a map of North America, these vectors reveal both the regions of coherent response and the phase of the response with respect to the evolution of the ENSO episode. Time series of temperature and precipitation for the regions identified in the harmonic vector maps are examined to determine the magnitudes of the responses and the percentage of the time that the identified response actually occurred in association with the ENSO events. The analysis shows that above normal precipitation was associated with ENSO in 18 out of 22 cases in the season starting with October of the ENSO year to March of the following year for an area of North America that includes parts of the southeastern US and northern Mexico. Above normal precipitation was also observed in the Great Basin area of the western US in 9 out of 11 cases for the April through October season during ENSO years. No high latitude precipitation signals were indicated by this analysis. Areas of Alaska and western Canada experienced positive temperature anomalies in 17 out of 21 ENSO episodes (81%) during the season defined by December of the ENSO year through the following March. Parts of the southeastern US near the Gulf of Mexico were found to have negative temperature anomalies associated with 20 out of 25 ENSO episodes for the season October of the ENSO year through the following March.
- Research Organization:
- Climate Analysis Center, Washington, DC
- OSTI ID:
- 6130834
- Journal Information:
- Mon. Weather Rev.; (United States), Journal Name: Mon. Weather Rev.; (United States) Vol. 114:12; ISSN MWREA
- Country of Publication:
- United States
- Language:
- English
Similar Records
Can ENSO-Like Convection Force an ENSO-Like Extratropical Response on Subseasonal Time Scales?
Journal Article
·
Sun Sep 30 20:00:00 EDT 2018
· Journal of Climate
·
OSTI ID:1469047