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Merging remotely sensed data with geophysical models

Published online by Cambridge University Press:  27 October 2009

Craig Searcy
Affiliation:
Geophysical Institute, University of Alaska Fairbanks, Fairbanks, Alaska 99775-7320, USA
Ken Dean
Affiliation:
Geophysical Institute, University of Alaska Fairbanks, Fairbanks, Alaska 99775-7320, USA
William Stringer
Affiliation:
Geophysical Institute, University of Alaska Fairbanks, Fairbanks, Alaska 99775-7320, USA

Abstract

Geophysical models are usually derived from the idealistic viewpoint that all required external parameters are, in principle, measurable. The models are then driven with the best available data for those parameters. In some cases, there are few measurements available, because of factors such as the location of the phenomena modeled. Satellite imagery provides a synoptic overview of a particular environment, supplying spatial and temporal variability as well as spectral data, making this an ideal source of data for some models. In other cases, although frequent satellite-image observations are available, they are of little use to the modeler, because they do not provide values for the parameters demanded by the model. This paper contains two examples of geophysical models that were derived expressly to utilize measurements and qualitative observations taken from satellite images as the major driving elements of the model. The methodology consists of designing a model such that it can be ‘run’ by numerical data extracted from image data sets, and using the image data for verification of the model or adjustment of parameters. The first example is a thermody namic model of springtime removal of nearshore ice from an Arctic river delta area, using the Mackenzie River as a study site. In this example, a multi-date sequence of AVHRR images is used to provide the spatial and temporal patterns of melt, allowing the required physical observations in the model to be parameterized and tested. The second example is a dynamic model simulating thq evolution of a volcanic ash cloud under the influence of atmospheric winds. In this case, AVHRR images are used to determine the position and size of the ash cloud as a function of time, allowing tuning of parameters and verification of the model.

Type
Articles
Copyright
Copyright © Cambridge University Press 1995

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References

Brower, W., Baldwin, R., Williams, C., Wise, J., and Leslie, L.. 1988. Climatic atlas of the outer continental shelf waters and the coastal regions of Alaska. Volume III: Chukchi and Beaufort seas. Washington, DC: Department of Defense (NAVAIR Document 50-1 C-553).Google Scholar
Dean, K., Bowling, S., Shaw, G., and Tanaka, H.. 1994a. Satellite analysis of movement and characteristics of the Redoubt Volcano plume, January 8,1990. Journal of Volcanic and Geothermal Research 62: 339352.CrossRefGoogle Scholar
Dean, K., Stringer, W., Ahlnaes, K., Searcy, S., and Weingartner, T.. 1994b. The influence of river discharge on the thawing of sea ice: Mackenzie River delta: albedo and temperature analysis. Polar Research 13: 8394.CrossRefGoogle Scholar
Josberger, E. 1987). Bottom ablation and heat transfer coefficients from the 1983 Marginal Ice Zone Experiments. Journal of Geophysical Research 92 (C7): 70127016.CrossRefGoogle Scholar
Kienle, J., and Shaw, G.. 1979. Plume dynamics, thermal energy and long distance transport of vulcanian eruption clouds from Augustine Volcano, Alaska. Journal of Volcanic and Geothermal Research 6: 139164.CrossRefGoogle Scholar
Macdonald, R., and Carmack, E.. 1991. The role of largescale under-ice topography in separating estuary and ocean on an Arctic shelf. Atmosphere-Ocean 29 (1): 3753.CrossRefGoogle Scholar
Maykut, G., and Perovich, D.. 1987. The role of shortwave radiation in the summer decay of a sea ice cover. Journal of Geophysical Research 92 (C7): 70327044.CrossRefGoogle Scholar
Searcy, S., Dean, K., and Stringer, W.. In press. A rivercoastal sea ice interaction model: Mackenzie River delta. Journal of Geophysical Research.Google Scholar
Tanaka, H. 1991. Development of a prediction scheme for the volcanic ash fall from Redoubt Volcano. In: First International Symposium on Volcanic Ash and Aviation Safety, Seattle, Washington. Washington, DC: US Government Printing Office (US Geological Survey Circular 1065).Google Scholar
Woods, A., and Self, S.. 1992. Thermal disequilibrium at the top of volcanic clouds and its effect on estimates of the column heights. Nature 355: 632–630.CrossRefGoogle Scholar