Meridional Overturning Circulation and Heat-flux Array (MOCHA)

In March 2004, an international program began to deploy a system that will continuously observe the meridional mass and heat transport in the subtropical Atlantic. This system will document the variability of the subtropical Atlantic and its relationship to observed climate fluctuations, and the observations will help assess climate model predictions. MOCHA include investigators from the Rapid Climate Change Program funded by the United Kingdom's NERC, National Science Foundation investigators at the University of Miami and NOAA/AOML. NOAA/AOML's contribution includes elements of the OGP funded Global Observing System. Of particular use for MOCHA investigators are (1) transport measurements within the Florida Straits including continuous cable measurements and small boat section estimates, (2) full-water-column hydrographic surveys of the Antilles and Deep Western Boundary Currents and the servicing of moorings, (3) deployment of inverted echo sounder moorings in the western boundary array, and (4) measurements of upper ocean temperature using expendable bathythermographs and profiling floats.

Summary of the proposed observation system for MOC/MHT monitoring in the subtropical North Atlantic. The components are: (a) a trans-basin moored array with clusters at the eastern and western boundaries and Mid-Atlantic Ridge, (b) transbasin and western boundary repeat hydrographic sections, (c) Florida Current monitoring by submarine cable, weekly VOS ADCP sections, and quarterly CTD/LADCP sections, and (d) quarterly high-resolution VOS XBT sections from Gibraltar to Miami.