Abstract:

Benthic Disturbance Experiment surveys in the Central Indian Ocean Basin yielded baseline data on surface meteorological conditions during June and August, 1997 together with sea surface temperature (SST) and cloud data to estimate the air-sea heat fluxes and net surface heat gain. Maximum sunshine duration was 1 hour/day in June and 30 minutes/day in August. Southeasterly winds of speed 10 m/s during June contributed to a mean latent heat flux of 220W/m2, leading to net surface heat loss (100W/m2) in June and near heat balance in August. Temporal variation of weather elements and the heat budget parameters showed fluctuations of period 10-13 days in June and 7-8 days in August. Owing to low sunshine duration (<1hour/day) and light attenuation due to surface discharge of mining reject during austral winter, diminishing of light availability in the upper ocean is possible.

Introduction

The prevailing weather and its variability over the sea play a major role in the operational capability of a mining platform at sea and the optimum output of the manganese nodule mining activity. Under the Indian Deep Sea Environment Experiment (INDEX) programme, baseline information on surface meteorological conditions was obtained over the Benthic Disturbance Experiment Site (BDES) in the Central Indian Ocean Basin (CIOB). The surface meteorological data were obtained using Automatic Weather Station (Model: AWS 2700, Aanderaa Instruments, Norway) onboard R. V. Yuzhmorgeologia during austral winter (June & August) 1997. In this paper, the variability of the weather parameters and the associated air-sea heat exchange processes over BDES is presented for austral winter months of 1997.

Data and methods

Two surveys were conducted in BDES by R. V. Yuzhmorgeologia during 6-29 June, 1997 (cruise 3A) and during 8-29 August, 1997 (cruise 3B) for baseline data collection on surface meteorological conditions and as well as water column studies.

This content is only available via PDF.
You can access this article if you purchase or spend a download.