Accession Number:

AD1039229

Title:

Intraseasonal sea surface warming in the western Indian Ocean by oceanic equatorial Rossby waves

Descriptive Note:

OSTP Journal Article

Corporate Author:

Naval Research Laboratory Stennis Space Center United States

Report Date:

2017-05-09

Pagination or Media Count:

11.0

Abstract:

A novel process is identified whereby equatorial Rossby ER waves maintain warm sea surfacetemperature SST anomalies against cooling by processes related to atmospheric convection in the western Indian Ocean. As downwelling ER waves enter the western Indian Ocean, SST anomalies of 0.15C developnear 60E. These SST anomalies are hypothesized to stimulate convective onset of the Madden-JulianOscillation. The upper ocean warming that manifests in response to downwelling ER waves is examined in amixed layer heat budget using observational and reanalysis products, respectively. In the heat budget,horizontal advection is the leading contributor to warming, in part due to an equatorial westward jet of 80 cm s1 associated with downwelling ER waves. When anomalous currents associated with ER waves areremoved in the budget, the warm intraseasonal temperature anomaly in the western Indian Ocean iseliminated in observations and reduced by 55 in reanalysis.

Subject Categories:

  • Physical and Dynamic Oceanography

Distribution Statement:

APPROVED FOR PUBLIC RELEASE