El Ni ˜
no and Ocean Observations
85
was 50–100 m deeper than normal did the community realize how badly it had been
fooled (Toole and Borges, 1984). In terms of Lord Kelvin’s famous quote, the sparsity
of accurate oceanic measurements in 1982 exposed not only our ignorance about El
Ni˜ no’s complexity but also the gross inadequacy of existing observing systems to
measure and describe it.
PLANNING FOR TOGA
The Princeton meeting had been called to lay the groundwork for U.S. involvement in
a 10-year international effort to study El Ni˜ no, which eventually became known as the
Tropical Ocean Global Atmosphere (TOGA) program (National Research Council,
1983). As a practical matter, it was clear that in the wake of the 1982–83 El Ni˜ no, plans
would have to emphasize development of both El Ni˜ no observing and, if possible,
forecasting capabilities. Thus, TOGA had three main objectives (WCRP, 1985):
1. To gain a description of the tropical oceans and the global atmosphere as a timedependent system, in order to determine the extent to which this system is predictable on time scales of months to years, and to understand the mechanisms and
processes underlying that predictability;
2. To study the feasibility of modeling the coupled ocean–atmosphere system for the
purpose of predicting its variability on time scales of months to years; and
3. To 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.
To get an early start on addressing the third of these objectives, NOAA’s newly
formed TOGA Project Office directed by Mike Hall convened a meeting at the Atlantic
Oceanographic and Meteorological Laboratory (AOML) in Miami in May 1983 to
discuss strategies for building a basin scale El Ni˜ no observing system in the Pacific
Ocean (U.S. TOGA Project Office, 1988). Surface winds, sea surface temperature,
upper ocean thermal structure, sea level, surface heat fluxes, and current velocity
were identified as the key oceanic variables of interest. For each of these parameters,
different measurement strategies were debated and prioritized. The focus was on in
situ measurements vis-` a-vis satellite measurements because satellite oceanography
was still in its infancy and, except for sea surface temperature, no satellite missions
for winds or sea level were operating or planned for the next several years. Also,
satellites could not provide direct measurements of upper ocean thermal structure
or currents, for which in situ data were essential. Real-time data relay to shore via
satellite, where feasible, was viewed as a high priority to allow for routine monitoring
of evolving climatic conditions and to support model-based prediction efforts.
The workshop arrived at an initial in situ observing system strategy to measure
upper ocean thermal structure (Figure 6.1) based on methods that were considered
no and Ocean Observations
85
was 50–100 m deeper than normal did the community realize how badly it had been
fooled (Toole and Borges, 1984). In terms of Lord Kelvin’s famous quote, the sparsity
of accurate oceanic measurements in 1982 exposed not only our ignorance about El
Ni˜ no’s complexity but also the gross inadequacy of existing observing systems to
measure and describe it.
PLANNING FOR TOGA
The Princeton meeting had been called to lay the groundwork for U.S. involvement in
a 10-year international effort to study El Ni˜ no, which eventually became known as the
Tropical Ocean Global Atmosphere (TOGA) program (National Research Council,
1983). As a practical matter, it was clear that in the wake of the 1982–83 El Ni˜ no, plans
would have to emphasize development of both El Ni˜ no observing and, if possible,
forecasting capabilities. Thus, TOGA had three main objectives (WCRP, 1985):
1. To gain a description of the tropical oceans and the global atmosphere as a timedependent system, in order to determine the extent to which this system is predictable on time scales of months to years, and to understand the mechanisms and
processes underlying that predictability;
2. To study the feasibility of modeling the coupled ocean–atmosphere system for the
purpose of predicting its variability on time scales of months to years; and
3. To 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.
To get an early start on addressing the third of these objectives, NOAA’s newly
formed TOGA Project Office directed by Mike Hall convened a meeting at the Atlantic
Oceanographic and Meteorological Laboratory (AOML) in Miami in May 1983 to
discuss strategies for building a basin scale El Ni˜ no observing system in the Pacific
Ocean (U.S. TOGA Project Office, 1988). Surface winds, sea surface temperature,
upper ocean thermal structure, sea level, surface heat fluxes, and current velocity
were identified as the key oceanic variables of interest. For each of these parameters,
different measurement strategies were debated and prioritized. The focus was on in
situ measurements vis-` a-vis satellite measurements because satellite oceanography
was still in its infancy and, except for sea surface temperature, no satellite missions
for winds or sea level were operating or planned for the next several years. Also,
satellites could not provide direct measurements of upper ocean thermal structure
or currents, for which in situ data were essential. Real-time data relay to shore via
satellite, where feasible, was viewed as a high priority to allow for routine monitoring
of evolving climatic conditions and to support model-based prediction efforts.
The workshop arrived at an initial in situ observing system strategy to measure
upper ocean thermal structure (Figure 6.1) based on methods that were considered