scholarly journals Annual, Seasonal, and Interannual Variability of Air–Sea Heat Fluxes in the Indian Ocean

2007 ◽  
Vol 20 (13) ◽  
pp. 3190-3209 ◽  
Author(s):  
Lisan Yu ◽  
Xiangze Jin ◽  
Robert A. Weller
Keyword(s):  
Heat Flux ◽  
Indian Ocean ◽  
Interannual Variability ◽  
Seasonal Cycle ◽  
Arabian Sea ◽  
Heat Fluxes ◽  
The Other ◽  
Net Heat Flux ◽  
The Indian Ocean ◽  
The Mean

Abstract This study investigated the accuracy and physical representation of air–sea surface heat flux estimates for the Indian Ocean on annual, seasonal, and interannual time scales. Six heat flux products were analyzed, including the newly developed latent and sensible heat fluxes from the Objectively Analyzed Air–Sea Heat Fluxes (OAFlux) project and net shortwave and longwave radiation results from the International Satellite Cloud Climatology Project (ISCCP), the heat flux analysis from the Southampton Oceanography Centre (SOC), the National Centers for Environmental Prediction reanalysis 1 (NCEP1) and reanalysis-2 (NCEP2) datasets, and the European Centre for Medium-Range Weather Forecasts operational (ECMWF-OP) and 40-yr Re-Analysis (ERA-40) products. This paper presents the analysis of the six products in depicting the mean, the seasonal cycle, and the interannual variability of the net heat flux into the ocean. Two time series of in situ flux measurements, one taken from a 1-yr Arabian Sea Experiment field program and the other from a 1-month Joint Air–Sea Monsoon Interaction Experiment (JASMINE) field program in the Bay of Bengal were used to evaluate the statistical properties of the flux products over the measurement periods. The consistency between the six products on seasonal and interannual time scales was investigated using a standard deviation analysis and a physically based correlation analysis. The study has three findings. First of all, large differences exist in the mean value of the six heat flux products. Part of the differences may be attributable to the bias in the numerical weather prediction (NWP) models that underestimates the net heat flux into the Indian Ocean. Along the JASMINE ship tracks, the four NWP modeled mean fluxes all have a sign opposite to the observations, with NCEP1 being underestimated by 53 W m−2 (the least biased) and ECMWF-OP by 108 W m−2 (the most biased). At the Arabian Sea buoy site, the NWP mean fluxes also have an underestimation bias, with the smallest bias of 26 W m−2 (ERA-40) and the largest bias of 69 W m−2 (NCEP1). On the other hand, the OAFlux+ISCCP has the best comparison at both measurement sites. Second, the bias effect changes with the time scale. Despite the fact that the mean is biased significantly, there is no major bias in the seasonal cycle of all the products except for ECMWF-OP. The latter does not have a fixed mean due to the frequent updates of the model platform. Finally, among the four products (OAFlux+ISCCP, ERA-40, NCEP1, and NCEP2) that can be used for studying interannual variability, OAFlux+ISCCP and ERA-40 Qnet have good consistency as judged from both statistical and physical measures. NCEP1 shows broad agreement with the two products, with varying details. By comparison, NCEP2 is the least representative of the Qnet variabilities over the basin scale.

scholarly journals Mechanism of cold water regions observed in winter in the Indian Ocean

MAUSAM ◽  
2021 ◽  
Vol 48 (4) ◽  
pp. 645-656
Author(s):  
MASAHISA KUBOTA ◽  
MORIHERI KAWAGUCHI
Keyword(s):  
Heat Flux ◽  
Arabian Sea ◽  
Cold Water ◽  
The Other ◽  
Sea Surface ◽  
Shortwave Radiation ◽  
Boreal Winter ◽  
Observation Data ◽  
Net Heat Flux ◽  
The Indian Ocean

Two cold sea surface temperature (SST) regions are found in the Arabian Sea in boreal winter. One is located northeast of Madagascar, and another is located in a northern part of Arabian Sea. The mechanism for appearance of the cold water is investigated by using monthly climatological ocean observation data. The cold water found northeast of Madagascar is caused by upwelling owing to Ekman divergence associated with a reversal of wind direction. On the other hand, the decrease in SST in a northern part of Arabian Sea is basically caused by decrease of net heat flux associated with reduced shortwave radiation and increased latent heat flux. These results are consistent with results obtained from a numerical investigation by McCreary and Kundu (1989).    

scholarly journals A new amphipod species from the Indian Ocean (Crustacea: Amphipoda: Lysianassoidea: Podoprionidae)

Zootaxa ◽  
2005 ◽  
Vol 861 (1) ◽  
pp. 1
Author(s):  
TAMMY HORTON
Keyword(s):  
New Species ◽  
Indian Ocean ◽  
Arabian Sea ◽  
The Other ◽  
Amphipod Species ◽  
Northern Arabian Sea ◽  
The Indian Ocean ◽  
A New Species

A new species of the genus Podoprion is described. The species can be distinguished from the other species in the genus, Podoprion bolivari Chevreux, 1891, P. ruffoi Lowry & Stoddart, 1996, and P. mediterraneum Kaim-Malka, 2004, by the shape of gnathopod 2 propodus, coxa 4, number and size of serrations on pereopod 5 basis, and characters of the mouthparts. Material was collected by baited trap at 1185 m off the coast of Pakistan in the northern Arabian Sea.

scholarly journals Variability of Air–Sea Interactions over the Indian Ocean Derived from Satellite Observations

1998 ◽  
Vol 11 (8) ◽  
pp. 1859-1873 ◽  
Author(s):  
Catherine Gautier ◽  
Peter Peterson ◽  
Charles Jones
Keyword(s):  
Heat Flux ◽  
Indian Ocean ◽  
Interannual Variability ◽  
Satellite Data ◽  
Large Scale ◽  
Southwest Monsoon ◽  
Seasonal And Interannual Variability ◽  
The Indian Ocean ◽  
The Difference

Abstract Novel ways of monitoring the large-scale variability of the southwest monsoon in the Indian Ocean are presented using multispectral satellite datasets. The fields of sea surface temperature (SST), surface latent heat flux (LHF), net surface solar radiation (SW), precipitation (P), and SW − LHF over the Indian Ocean are analyzed to characterize the seasonal and interannual variability with special emphasis on the period 1988–90. It is shown that satellite data are able to make a significant contribution to the multiplatform strategy necessary to describe the large-scale spatial and temporal variability of air–sea interactions associated with the Indian Ocean Monsoon. The satellite data analyzed here has shown for the first time characteristics of the interannual variability of air–sea interactions over the entire Indian Ocean. Using monthly means of SST, LHF, SW, P, and the difference SW − LHF, the main features of the seasonal and interannual variability of air–sea interactions over the Indian Ocean are characterized. It is shown that the southwest monsoon strongly affects these interactions, inducing dramatic exchanges of heat between air and sea and large temporal variations of these exchanges over relatively small timescale (with regards to typical oceanic timescales). The analyses indicate an overall good agreement between satellite and in situ (ship) estimates, except in the southern Indian Ocean, where ship sampling is minimal, the disagreement can be large. In the latitudinal band of 10°N–15°S, differences in climatological in situ estimates of surface sensible heat flux and net longwave radiation has a larger influence on the net surface heat flux than the difference between satellite and in situ estimates of SW and LHF.

scholarly journals Verification of reanalysis data for the tropical zone of the Indian ocean. Part 2. Characteristics of the averaged seasonal cycle and interannual variability

2020 ◽  
pp. 119-126
Author(s):  
A.B. Polonsky ◽  
◽  
A.V. Torbinskii ◽  
A.V. Gubarev ◽  
◽  
...  
Keyword(s):  
Indian Ocean ◽  
Interannual Variability ◽  
Seasonal Cycle ◽  
Potential Temperature ◽  
Tropical Indian Ocean ◽  
Reanalysis Data ◽  
Tropical Zone ◽  
Current Vector ◽  
Zonal Component ◽  
The Indian Ocean

The aim of the study is to evaluate the performance of ORAS5/SODA3/GLORYS re-analyses using the RAMA in the tropical Indian Ocean. To assess the reproducibility of the seasonal cycle and characteristics of interannual variability, we used the data on the potential temperature, salinity, and zonal component of the current vector obtained south of the equator for the period 2010–2014. It is shown that at 55°E south of the equator, the GLORYS re-analysis better reproduces the five-year averaged seasonal cycle and interannual variability than the SODA3 and ORAS5 re-analyses.

Natural Convective Heat Transfer From an Array of Square Vertical Plates Mounted on a Large Plane Vertical Adiabatic Surface and With One High Heat Flux Element

2009 ◽  
Author(s):  
Patrick H. Oosthuizen ◽  
Jane T. Paul
Keyword(s):  
Heat Flux ◽  
High Heat ◽  
Heat Fluxes ◽  
The Other ◽  
Uniform Heat Flux ◽  
High Heat Flux ◽  
Wide Range ◽  
The Mean ◽  
Adiabatic Surface ◽  
Flux Element

An array of nine square heated elements mounted in a square three-by-three pattern with no gap between the elements on a large vertical adiabatic surface with natural convective flow over the elements has been considered. Each of the elements has a uniform heat flux over its surface, the heat fluxes over eight of the elements being the same and the heat flux over the ninth element being higher than that over the other eight elements. The basic aim of the study was to determine the effect the position of the higher heat flux element on the mean temperatures of the other eight elements. The situation considered is an approximate model of situations that can arise in electronic cooling. The flow has been assumed to be steady and laminar and it has been assumed that the fluid properties are constant except for the density change with temperature which gives rise to the buoyancy forces, this having been treated by using the Boussinesq approach. The solution has been obtained by numerically solving the full three-dimensional form of the governing equations, these equations being written in terms of dimensionless variables using the commercial cfd code FLUENT. The solution has the heat flux Rayleigh number, the Prandtl number, the ratio of the heat flux over the high heat flux element to the heat flux over the other eight elements, and the position of the high heat flux element as parameters. Because of the application that motivated this work results have only been obtained for Pr = 0.7. Results have been obtained for a wide range of values of the other input parameters and the effect of these parameter values on the mean surface temperatures of each of the elements has been studied.

Salinity maxima in the upper 1000 metres of the North Indian Ocean

1964 ◽  
Vol 15 (1) ◽  
pp. 1 ◽  
Author(s):  
DJ Rochford
Keyword(s):  
Indian Ocean ◽  
Arabian Sea ◽  
Equatorial Region ◽  
North Indian Ocean ◽  
Water Masses ◽  
The Other ◽  
Flow Paths ◽  
Hydrological Data ◽  
The North ◽  
The Indian Ocean

The comprehensive hydrological data from cruise 31 of R.S. Vityaz in the north Indian Ocean have been used to identify all salinity maxima of the upper 1000 m. On the basis of density differences these salinity maxima have been grouped into five water masses. Three of these have been named according to their assumed origin; Red Sea, Persian Gulf, and Arabian Sea. The other two can not as yet be assigned origins, although one is confined largely to the northern part of the Arabian Sea and the other to the equatorial region of the Indian Ocean. Paths of flow of these water masses to the south and east have been established from salinity charts. Submarine topography in the Madagascar-Seychelles and Maldive-Chagos regions provides an explanation for the diversion and separation of the flow paths of these water masses.

Observed extreme air-sea heat flux variations during three tropical cyclones in the tropical southeastern Indian Ocean

2021 ◽  
pp. 1-77
Author(s):  
Xiangzhou Song ◽  
Chunlin Ning ◽  
Yongliang Duan ◽  
Huiwu Wang ◽  
Chao Li ◽  
...  
Keyword(s):  
Heat Flux ◽  
Indian Ocean ◽  
Tropical Cyclones ◽  
Heat Fluxes ◽  
Shortwave Radiation ◽  
Turbulent Heat ◽  
Maximum Magnitude ◽  
Surface Cooling ◽  
Mean Values ◽  
The Mean

AbstractSix-month buoy-based heat flux observations from the poorly sampled tropical southeastern Indian Ocean are examined to document the extremes during three tropical cyclones (TCs) from December 2018 to May 2019. The most striking feature at the mooring site (115.2°E, 16.9°S) during the TCs is the extensively suppressed diurnal cycle of net surface flux, with a mean daytime (nighttime) reduction of 470 (131) W m-2, a peak decrease at approximately noon of 695 W m-2 and an extreme drop during TC Riley of 800 W m-2. The mean surface cooling in the daytime is primarily contributed by the 370 W m-2 decrease in shortwave radiation associated with the increased cloudiness. The air-sea turbulent heat fluxes increase by approximately 151 W m-2 in response to the enhanced wind speed under near-neutral boundary conditions. The daily mean rainfall-induced cooling is 8 W m-2, with a maximum magnitude of 90 W m-2. The mean values, seasonal variation, and synoptic variability of the characteristic heat fluxes are used to assess the new reanalysis data from ERA5 and MERRA2 and the analyzed OAFlux. The overall performance of the high-frequency net heat flux estimates at the synoptic scale is satisfactory, but the four flux components exhibit different quality levels. A serious error is that ERA5 and MERRA2 poorly represent TCs, and they show significant daily mean Qnet biases with opposite directions, -59 W m-2 (largely due to the overestimated latent heat with a bias of -76 W m-2) and 50 W m-2 (largely due to the overestimated shortwave radiation with a bias of 41 W m-2), respectively.

scholarly journals The Indian Summer Monsoon in MetUM-GOML2.0: Effects of air-sea coupling and resolution

2018 ◽  
Author(s):  
Simon C. Peatman ◽  
Nicholas P. Klingaman
Keyword(s):  
Indian Ocean ◽  
Summer Monsoon ◽  
Indian Summer Monsoon ◽  
Seasonal Cycle ◽  
Global Ocean ◽  
Boreal Summer ◽  
Correction Technique ◽  
The Indian Ocean ◽  
The Mean ◽  
Mean State

Abstract. The fidelity of the simulated Indian Summer Monsoon is analysed in the UK Met Office Unified Model Global Ocean Mixed Layer configuration (MetUM-GOML2.0), in terms of its boreal summer mean state and propagation of the Boreal Summer IntraSeasonal Oscillation (BSISO). The model produces substantial biases in mean June--September precipitation, especially over India, in common with other MetUM configurations. Using a correction technique to constrain the mean seasonal cycle of ocean temperature and salinity, the effects of regional air-sea coupling and atmospheric horizontal resolution are investigated. Introducing coupling in the Indian Ocean degrades the atmospheric basic state, compared with prescribing the observed seasonal cycle of sea surface temperature (SST). This degradation of the mean state is attributable to small errors (±0.5 C) in mean SST. However, coupling slightly improves the simulation of northward BSISO propagation over the Indian Ocean, Bay of Bengal and India. Increasing resolution from 200 km to 90 km grid spacing (approximate value at the equator) improves the atmospheric mean state, but increasing resolution again to 40~km offers no substantial improvement. The improvement to intraseasonal propagation at finer resolution is similar to that due to coupling.

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