1.0 Introduction

The goals of the Tropical Oceans-Global Atmosphere research program (TOGA) as stated by the World Climate Research Program were these:

• gain a description of the tropical oceans and the global atmosphere as a time dependent system in order to determine the extent to which the system is predictable on time scales of months to years and to understand the mechanisms and processes underlying its predictability;

• study the feasibility of modeling the coupled ocean atmosphere system for the purpose of predicting its variations on time scales of months to years; and

• provide the scientific background for designing an observing and data transmission system for operational prediction, if this capability is demonstrated by coupled ocean-atmosphere models.

The major recommendation of the U.S. TOGA Workshop on Western Pacific Air-Sea Interaction was that the scientific questions raised at the workshop about the warm pool system required a substantial modeling and observational effort to answer, and an intensive process experiment (Coupled Ocean Atmosphere Response Experiment: COARE) was outlined (Lukas and Webster, 1988; Webster and Lukas, 1992). The goals of COARE are to describe and understand these processes:

• the principal processes responsible for the coupling of ocean and atmosphere in the western Pacific warm pool system;

• the principal atmospheric processes that organize convection in the warm pool region;

• the oceanic response to combined buoyancy and wind stress forcing in the western Pacific warm pool region; and

• the multiple scale interactions that extend the oceanic and atmospheric influence of the western Pacific warm pool system to other regions and vice versa.

COARE was designed to observe, and ultimately model, the variability of the coupled ocean-atmosphere system in the western equatorial Pacific on time scales of minutes to years and over space scales of centimeters to thousands of kilometers. A fundamental aspect of the strategy of COARE was to tie the relatively short duration, intensive observations into the long-term, large-scale datasets being gathered by TOGA scientists. Thus, certain elements of COARE were designed to be kept in place for several years. These make up the enhanced monitoring component of COARE, which included observations reported here.

As a part of the enhanced monitoring for the TOGA-COARE, deployments and maintenance of an array of thermistor chain and conductivity moorings with meteorological packages were made in three cruises conducted during 1992-94 (EQ-1, EQ-2, EQ-3) on board the R/V Moana Wave. CTD (conductivity, temperature, depth) measurements were made during these cruises to help calibrate the moorings and to further define the scales of temperature and salinity variability within the array. Current profile measurements, meteorological observations, and continuous near-surface temperature and salinity observations were also made during these cruises. The major purposes of these expeditions were these:

• determine the scales of surface wind and upper-ocean thermohaline variability within the ``warm water pool'' region;

• obtain time series of the salinity stratification within the nearly isothermal upper layer;

• estimate terms in the upper ocean heat and salinity budgets;

• document and understand the local response of the upper ocean to wind events (especially the strong westerly bursts);

• provide real-time data for experimental operational modeling of the tropical Pacific; and

• determine the minimal array needed for long-term monitoring of the warm pool.

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