Article
 

Satellite and Buoy Observations of Boreal Summer Intraseasonal Variability in the Tropical Northeast Pacific

Public Deposited

Downloadable Content

Download PDF
https://ir.library.oregonstate.edu/concern/articles/4t64gp80f

Descriptions

Attribute NameValues
Creator
Abstract
  • Tropical intraseasonal variability in the eastern North Pacific during June–September of 2000–03 is analyzed using satellite and buoy observations. Quick Scatterometer ocean vector winds and the Tropical Rainfall Measuring Mission (TRMM) precipitation indicate that periods of anomalous surface westerly flow over the east Pacific warm pool during a summertime intraseasonal oscillation (ISO) life cycle are generally associated with an enhancement of convection to the east of 120°W. An exception is a narrow band of suppressed precipitation along 8°N that is associated with negative column-integrated precipitable water anomalies and anticyclonic vorticity anomalies. Periods of surface easterly anomalies are generally associated with suppressed convection to the east of 120°W. Summertime wind jets in the Gulfs of Tehuantepec and Papagayo exhibit heightened activity during periods of ISO easterly anomalies and suppressed convection. Strong variations in east Pacific warm pool wind speed occur in association with the summertime ISO. Anomalous ISO westerly flow is generally accompanied by enhanced wind speed to the east of 120°W, while anomalous easterly flow is associated with suppressed wind speed. Intraseasonal vector wind anomalies added to the climatological flow account for the bulk of the wind speed enhancement in the warm pool during the westerly phase, while the easterly phase shows strong contributions to the negative wind speed anomaly from both intraseasonal vector wind anomalies and suppressed synoptic-scale eddy activity. An analysis using Tropical Atmosphere Ocean buoys and TRMM precipitation suggests that wind–evaporation feedback is important for supporting summertime intraseasonal convection over the east Pacific warm pool. A statistically significant correlation of 0.6 between intraseasonal latent heat flux and precipitation occurs at the 12°N, 95°W buoy. Correlations between precipitation and latent heat flux at the 10°N, 95°W and 8°N, 95°W buoys are positive (0.4), but not statistically significant. Intraseasonal latent heat flux anomalies at all buoys are primarily wind induced. Consistent with the suppressed convection there during the ISO westerly phase, a negative but not statistically significant correlation ( 0.3) occurs between precipitation and latent heat flux at the 8°N, 110°W buoy.
Resource Type
DOI
Date Available
Date Issued
Citation
  • Maloney, Eric D., Steven K. Esbensen, 2007: Satellite and Buoy Observations of Boreal Summer Intraseasonal Variability in the Tropical Northeast Pacific. Monthly Weather Review, 135(1), 3–19.
Journal Title
Journal Volume
  • 135
Journal Issue/Number
  • 1
Rights Statement
Funding Statement (additional comments about funding)
  • This research was prepared by Eric Maloney and Steve Esbensen under Award NA05OAR4310006 from the National Oceanic and Atmospheric Administration, U.S. Department of Commerce. This work was also supported by the Climate Dynamics Program of the National Science Foundation under Grant ATM-0327460 (EDM), and by NASA Grant NAS5-32965 for funding of Ocean Vector Winds Science Team activities.
Publisher
Peer Reviewed
Language
Replaces

Relationships

Parents:

This work has no parents.

Items

Thumbnail Title Date Uploaded Visibility Actions
file details EbensenStevenK.CEOAS.SatelliteandBuoy.pdf 2017-07-24 Public Download