Back
Data Length Requirements for Observational Estimates of Land–Atmosphere Coupling Strength
Journal article

Data Length Requirements for Observational Estimates of Land–Atmosphere Coupling Strength

  • Findell, Kirsten L. Geophysical Fluid Dynamics Laboratory, Princeton, New Jersey
  • Gentine, Pierre Department of Earth and Environmental Engineering, and Earth Institute, Columbia University, New York, New York
  • Lintner, Benjamin R. Department of Environmental Sciences, Rutgers, The State University of New Jersey, New Brunswick, New Jersey
  • Guillod, Benoit P. Institute for Atmospheric and Climate Science, ETH Zürich, Zurich, Switzerland
  • 2015-7-29
Published in:
  • Journal of Hydrometeorology. - American Meteorological Society. - 2015, vol. 16, no. 4, p. 1615-1635
Atmospheric Science
English Abstract
Multiple metrics have been developed in recent years to characterize the strength of land–atmosphere coupling in regional and global climate models. Evaluation of these metrics against observations has proven challenging because of limited observations and/or metric definitions based on model experimental designs that are not replicable with observations. Additionally, because observations are limited in time, with only a single realization of the earth’s climate available, metrics of land–atmosphere coupling strength typically assume stationarity and ergodicity, so that an observed time series (or set of time series) can be used in place of an ensemble mean of multiple realizations. The present study evaluates the observational data requirements necessary for robust quantification of a suite of land–atmosphere coupling metrics previously described in the literature. It is demonstrated that the amount of data required to obtain robust estimates of metrics assessing relationships between variables is greater than that necessary to constrain means of directly measured observables. Moreover, while the addition of unbiased noise does not significantly alter the mean of a directly observable quantity, inclusion of such noise degrades metrics based on connections between variables, yielding a unidirectional and negative impact on metric strength estimates. This analysis suggests that longer records of surface observations are required to correctly estimate land–atmosphere coupling strength than are required to estimate mean values of the observed quantities.
Language
  • English
Open access status
hybrid
Identifiers
Persistent URL
https://sonar.ch/global/documents/139765
Statistics
Document views: 25 File downloads: