Dr. Gerald North
| Title | Distinguished Professor and Holder of the Harold J. Haynes Endowed Chair in Geosciences |
| Research Interests | Climate analysis. Climate and hydrological modeling. Satellite remote sensing, mission planning. Statistical methods in atmospheric science. |
| Education | Ph.D. in Physics, University of Wisconsin, 1966 |
| Office Location | Room 1205, O&M Bldg |
| Office Phone | 979-845-8077 |
| Fax | 979-862-4466 |
| g-north@tamu.edu | |
| Mailing Address |
Department of Atmospheric Sciences Texas A&M University 3150 TAMU College Station, TX 77843-3150 |
Research Interests
North and his research group are interested in climate change and the determination of its origins. We work with simplified climate models which lend themselves to analytical study, estimation theory as applied to observing systems, and the testing of all climate models through statistical approaches. Often all three themes are combined for a particular application.
Over a period of 25 years North and associates have studied a hierarchy of simplified models known as Energy Balance Climate Models (EBCMs). Both linear, nonlinear, and stochastic versions of these models have been shown to be good analogs to the real climate of the surface temperature field including the two dimensional seasonal cycle and the field of fluctuations. These models have very interesting properties from mathematical as well as physical points of view. For instance, multiple solutions occur for the present external conditions and their stability properties are amenable to analysis. Stochastic versions of the models are useful analogs to more comprehensive models making them a useful laboratory for preliminary analyses before expensive experiments are performed.
The group also collaborates with statisticians and mathematicians on problems of observing system error analysis. For example, we continue to be interested in the ground validation program and the sampling error problems for the Tropical Rainfall Measuring Mission. We also are interested in the problem of estimating climate parameters (e.g., global average, spherical harmonic coefficients, space-time power spectra, EOFs, etc.) from observing systems consisting of a finite number of point gauges distributed over the globe or from satellite orbital observing systems. We also want to know how data from disparate sources can be optimally combined.
Most recent works have been along the lines of estimating the strengths of forced response signals in the climate system over the last century. We use various models for estimating the natural variability and the signal waveforms. Then we perform a signal analysis to determine the strengths of the greenhouse gas, the anthropogenic aerosol, the solar variability, and the volcanic signals. We are particularly interested in the 11-year solar cycle signal since it presents a rare opportunity to observe the sensitivity of climate to an external forcing at such a decadal frequency.
Selected Publications
Wu, W. and G. R. North, 2007: Thermal Decay Modes in Simple Climate Models, Tellus, 59, 618-626.
Pujol, T., and G. R. North, 2003: Analytical investigation of the atmospheric radiation limits in semigray atmospheres in radiative equilibrium. Tellus, 55, 328-337.
North, G. R. and Q. Wu, 2001: Detecting climate signals using space-time EOFs. J. Climate, 14, 1839-1862.
Kim, K.-Y., G. R. North and G. C. Hegerl, 1996: Comparisons of the Second-Moment Statistics of Climate Models. J. Climate, 9, 2,204-2,221.
North, G. R., K.-Y. Kim, S. S. Shen and J. W. Hardin, 1995: Detection of Forced Climate Signals, Part I: Filter Theory. J. Climate, 8, 401-408.
Kim, K.-Y., and G. R. North, 1991: Surface Temperature Fluctuations in a Stochastic Model. J. Geophys. Res., 96, 18,573-18,580.
Short, D. A., J. G. Mengel, T. J. Crowley, W. T. Hyde and G. R. North, 1991: Filtering of Milankovitch Cycles by Earth's Geography. Quaternary Res., 35, 157-173.
Leung, L.-Y and G. R. North, 1990: Information Theory and Climate Prediction. J. Climate, 3, 5-14.
North, G. R., and S. Nakamoto, 1989: Formalism for Comparing Rain Estimation Designs. J. Atmos. & Ocn. Tech., 6, 985-992.
Simpson, J., R. F. Adler and G. R. North, 1988: Proposed Tropical Rainfall Measuring Mission (TRMM) Satellite. Bull. Am. Meteorol. Soc., 69, 278-295.
McConnell, A. and G. R. North, 1987: Sampling Errors in Satellite Estimates of Tropical Rain. J. Geophys. Res., 92, 9,567-9,570.
North, G. R. and T. J. Crowley, 1985: Application of a Seasonal Climate Model to Cenozoic Glaciation. J. Geolog. Soc. (London), 142, 475-482.
North, G. R., 1984: Empirical Orthogonal Functions and Normal Modes. J. Atmos. Sci., 41, 879-886.
North, G. R., J. G. Mengel and D. A. Short, 1983: A Simple Energy Balance Model Resolving the Seasons and the Continents: Application to the Milankovitch Theory of the Ice Ages. J. Geophys. Res., 88, 6,576-6,586.
North, G. R., F. Moeng, T. L. Bell and R. F. Cahalan, 1982: The Latitude Dependence of the Variance of Zonally Averaged Quantities. Mon. Wea. Res., 110, 319-326.
North, G. R., 1975: Theory of Energy-Balance Climate Models. J. Atmos. Sci., 32, 2,033-2,043.
North, G. R., 1975: Analytical Solution to a Simple Climate Model With Diffusive Heat Transport. J. Atmos. Sci., 32,1,301-1,307.
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