scholarly journals Interannual upper ocean variability in the tropical Indian Ocean

2001 ◽  
Vol 28 (21) ◽  
pp. 4151-4154 ◽  
Author(s):  
Ming Feng ◽  
Gary Meyers ◽  
Susan Wijffels
Keyword(s):  
Indian Ocean ◽  
Tropical Indian Ocean ◽  
Upper Ocean ◽  
Ocean Variability

scholarly journals Processes Associated with the Tropical Indian Ocean Subsurface Temperature Bias in a Coupled Model

2016 ◽  
Vol 46 (9) ◽  
pp. 2863-2875 ◽  
Author(s):  
J. S. Chowdary ◽  
Anant Parekh ◽  
G. Srinivas ◽  
C. Gnanaseelan ◽  
T.S. Fousiya ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Coupled Model ◽  
Tropical Indian Ocean ◽  
Subsurface Water ◽  
Upper Ocean ◽  
Subsurface Temperature ◽  
Seasonal Forecasts ◽  
Coupled Models ◽  
Warm Bias ◽  
Temperature Bias

AbstractSubsurface temperature biases in coupled models can seriously impair their capability in generating skillful seasonal forecasts. The National Centers for Environmental Prediction (NCEP) Climate Forecast System, version 2 (CFSv2), coupled model, which is used for seasonal forecast in several countries including India, displays warm (cold) subsurface (surface) temperature bias in the tropical Indian Ocean (TIO), with deeper than observed mixed layer and thermocline. In the model, the maximum warm bias is reported between 150- and 200-m depth. Detailed analysis reveals that the enhanced vertical mixing by strong vertical shear of horizontal currents is primarily responsible for TIO subsurface warming. Weak upper-ocean stability corroborated by surface cold and subsurface warm bias further strengthens the subsurface warm bias in the model. Excess inflow of warm subsurface water from Indonesian Throughflow to the TIO region is partially contributing to the warm bias mainly over the southern TIO region. Over the north Indian Ocean, Ekman convergence and downwelling due to wind stress bias deepen the thermocline, which do favor subsurface warming. Further, upper-ocean meridional and zonal cells are deeper in CFSv2 compared to the Ocean Reanalysis System data manifesting the deeper mixing. This study outlines the need for accurate representation of vertical structure in horizontal currents and associated vertical gradients to simulate subsurface temperatures for skillful seasonal forecasts.

Role of upper ocean processes in the seasonal SST evolution over tropical Indian Ocean in climate forecasting system

2015 ◽  
Vol 45 (9-10) ◽  
pp. 2387-2405 ◽  
Author(s):  
Jasti S. Chowdary ◽  
Anant Parekh ◽  
Sayantani Ojha ◽  
C. Gnanaseelan
Keyword(s):  
Indian Ocean ◽  
Tropical Indian Ocean ◽  
Upper Ocean ◽  
Climate Forecasting ◽  
Forecasting System ◽  
Ocean Processes

Tropical Indian Ocean surface salinity bias in Climate Forecasting System coupled models and the role of upper ocean processes

2015 ◽  
Vol 46 (7-8) ◽  
pp. 2403-2422 ◽  
Author(s):  
Anant Parekh ◽  
Jasti S. Chowdary ◽  
Ojha Sayantani ◽  
T. S. Fousiya ◽  
C. Gnanaseelan
Keyword(s):  
Indian Ocean ◽  
Tropical Indian Ocean ◽  
Ocean Surface ◽  
Upper Ocean ◽  
Surface Salinity ◽  
Coupled Models ◽  
Climate Forecasting ◽  
Forecasting System ◽  
Ocean Processes

Tropical Indian Ocean variability revealed by self-organizing maps

2008 ◽  
Vol 31 (2-3) ◽  
pp. 333-343 ◽  
Author(s):  
Tomoki Tozuka ◽  
Jing-Jia Luo ◽  
Sebastien Masson ◽  
Toshio Yamagata
Keyword(s):  
Indian Ocean ◽  
Tropical Indian Ocean ◽  
Self Organizing Maps ◽  
Ocean Variability ◽  
Self Organizing

scholarly journals Pacific Ocean Contribution to the Asymmetry in Eastern Indian Ocean Variability

2013 ◽  
Vol 26 (4) ◽  
pp. 1152-1171 ◽  
Author(s):  
Caroline C. Ummenhofer ◽  
Franziska U. Schwarzkopf ◽  
Gary Meyers ◽  
Erik Behrens ◽  
Arne Biastoch ◽  
...  
Keyword(s):  
Pacific Ocean ◽  
Indian Ocean ◽  
Coastal Upwelling ◽  
Heat Content ◽  
Wind Forcing ◽  
Eastern Indian Ocean ◽  
Upper Ocean ◽  
Atmospheric Forcing ◽  
Ocean Variability ◽  
Ocean Properties

Abstract Variations in eastern Indian Ocean upper-ocean thermal properties are assessed for the period 1970–2004, with a particular focus on asymmetric features related to opposite phases of Indian Ocean dipole events, using high-resolution ocean model hindcasts. Sensitivity experiments, where interannual atmospheric forcing variability is restricted to the Indian or Pacific Ocean only, support the interpretation of forcing mechanisms for large-scale asymmetric behavior in eastern Indian Ocean variability. Years are classified according to eastern Indian Ocean subsurface heat content (HC) as proxy of thermocline variations. Years characterized by an anomalous low HC feature a zonal gradient in upper-ocean properties near the equator, while high events have a meridional gradient from the tropics into the subtropics. The spatial and temporal characteristics of the seasonal evolution of HC anomalies for the two cases is distinct, as is the relative contribution from Indian Ocean atmospheric forcing versus remote influences from Pacific wind forcing: low events develop rapidly during austral winter/spring in response to Indian Ocean wind forcing associated with an enhanced southeasterly monsoon driving coastal upwelling and a shoaling thermocline in the east; in contrast, formation of an anomalous high eastern Indian Ocean HC is more gradual, with anomalies earlier in the year expanding from the Indonesian Throughflow (ITF) region, initiated by remote Pacific wind forcing, and transmitted through the ITF via coastal wave dynamics. Implications for seasonal predictions arise with high HC events offering extended lead times for predicting thermocline variations and upper-ocean properties across the eastern Indian Ocean.

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