Yes, but they are heavily dependent on the underlying theories of climate change. Since a proposed origin for abrupt climate change is a shutdown of the North Atlantic thermohaline circulation (THC), the latter is watched rather closely. This can be done by doing repeating cross-sections of the temperature and salinity fields at various latitudes in the North Atlantic, monitoring deepwater formation in the Nordic Seas, the deep western boundary current running south along the coast of the Americas, or following long-term variations in sea-level (Häkkinen and Rhines, 2004) and other proxies for the intensity of the THC such as chemical tracer distributions. Consistent with theoretical expectations, the most recent evidence points to a freshening of the northern North Atlantic as a result of greenhouse warming (Dickson et al, 2002), and a weakening of the thermohaline circulation (Hansen et al, 2001). However, this happens at a rate far too slow to be considered as "abrupt".

On the other hand, if you believe that abrupt climate change is driven from the Tropics, you will want to maintain a good knowledge of tropical surface and subsurface temperatures, currents and surface pressure. This is how the 76/77 "climate shift" was discovered, and this is what permits us to initialize forecasts of El Niño events on interannual and (hopefully) decadal timescales. A difficulty is that chaotic processes in the climate system may allow the cause of such abrupt climate changes to be undetectably small (NAS Report, 2002)

On the whole, this highlights the importance of maintaining and developing an increasingly accurate and extensive coverage of the Earth's important climate variables. Satellite programs have brought substantial progress on this, but they must be complemented by long-term in situ measurements, such as those developed by Lamont scientists.

References:

Dickson B, Yashayaev I, Meincke J, Turrell B, Dye S, Holfort J, Rapid freshening of the deep North Atlantic Ocean over the past four decades, Nature 416 (6883): 832-837 APR 25 2002

Häkkinen S, Rhines PB, Decline of subpolar North Atlantic circulation during the 1990s, Science 304 (5670): 555-559 APR 23 2004

Hansen, B., W. Turrell, and S. Østerhus. "Decreasing Overflow from the Nordic Seas into the Atlantic Ocean Through the Faroe Bank Channel Since 1950," in Nature, Vol. 411, June 21, 2001.