Publication Abstract

Long Term Coastal Ocean Forecasting

Jacobs, G. A., Aikman, F., Anderson, D., Banas, N., Bryan, F. O., Chant, R., Curchitser, E., DiMarco, S., Dunne, J. P., Fennel, K., Friedrichs, M. A. M., Harding, J. M., He, R., Lewitus, A., McGillicuddy, D., & Schofield, O. (2013). Long Term Coastal Ocean Forecasting. Proceedings of the 93rd Annual Conference of the American Meteorological Society. Austin, TX: American Meteorological Society.


Management of coastal resources requires extended range forecasts. For example, presently statistical information is used at seasonal scales for predicting conditions related to biological activity and thus hazards to human activity along the coastlines. As part of the Earth System Prediction Capability efforts, numerical forecast accuracy impact to coastal environment and consequent coastal management will be demonstrated. There are a range of expected processes expected to have predictability at time scales longer than those presently forecasted weather operations. The dynamical connections from the predictable physics within an ESPC lead to changes in the coastal ocean both through local forcing as well as remote forcing through processes such as river runoff. The local atmospheric forcing changes vertical mixing and thus stratification that drives coastal dynamic flows. The predictability of events or the occurrence of events that inject turbulent mixing into the ocean are related to long term modulating processes. Examples include the variations in the Gulf of Mexico of vertical stratification that in part controls the formation of hypoxic (low oxygen) conditions affecting local biology. Typical summer stratification due to low winds and surface heating lead to low oxygen at the bottom of the coastal waters. In years of high tropical cyclone activity, sufficient mixing occurs such that the stratification is eliminated, and hypoxic conditions are eliminated. As a remote forcing to this system, rainfall and hydrological river runoff lead to increased fresh water and nutrient loads injected in the Gulf of Mexico. The long term predictability associated with ENSO rainfall leads to increased predictability in the coastal environment. Prediction of ENSO also leads to predictability in local physical ocean response as. One example is provided off the coast of Chile. As planetary Kelvin waves propagate from the equator to the poles along the continental coasts in response to changed wind forcing along the equatorial Pacific, the deep low oxygen waters are either pulled toward or pushed further from the ocean surface. The process results in predictability in local environmental coastal conditions affecting coastal management. Predictability of extreme meteorological events also is related to coastal conditions. Examples of upwelling due to extremely long wind events have been recorded off the Oregon coast resulting in upwelling from deep ocean water depleted in oxygen. Extensive damage to the benthic life has also been recorded