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Title: Ground heat flux: An analytical review of 6 models evaluated at 88 sites and globally

Uncertainty in ground heat flux (G) means that evaluation of the other terms in the surface energy balance (e.g., latent and sensible heat fluxes (LE and H)) remains problematic. Algorithms that calculate LE and H require available energy, the difference between net radiation, R NET, and G. There are a wide range of approaches to model G for large-scale applications, with a subsequent wide range of estimates and accuracies. Here, we provide the largest review of these methods to date (N = 6), evaluating modeled G against measured G from 88 FLUXNET sites. The instantaneous midday variability in G is best captured by models forced with net radiation, while models forced by temperature show the least error at both instantaneous and daily time scales. We produce global decadal data sets of G to illustrate regional and seasonal sensitivities, as well as uncertainty. Global model mean midmorning instantaneous G is highest during September, October, and November at 63.42 (±16.84) Wm -2, while over December, January, and February G is lowest at 53.86 (±18.09) Wm -2 but shows greater intermodel uncertainty. Results from this work have the potential to improve evapotranspiration estimates and guide appropriate G model selection and development for variousmore » land uses.« less
Authors:
ORCiD logo [1] ; ORCiD logo [2] ;  [1] ;  [3]
  1. Univ. of California, Irvine, CA (United States). Dept. of Earth System Science
  2. California Inst. of Technology (CalTech), La Canada Flintridge, CA (United States). Jet Propulsion Lab.
  3. Univ. of California, Irvine, CA (United States). Dept. of Earth System Science; California Inst. of Technology (CalTech), La Canada Flintridge, CA (United States). Jet Propulsion Lab.
Publication Date:
Grant/Contract Number:
FG02-04ER63917; FG02-04ER63911
Type:
Accepted Manuscript
Journal Name:
Journal of Geophysical Research. Biogeosciences
Additional Journal Information:
Journal Volume: 121; Journal Issue: 12; Journal ID: ISSN 2169-8953
Publisher:
American Geophysical Union
Research Org:
Oregon State Univ., Corvallis, OR (United States)
Sponsoring Org:
USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23)
Country of Publication:
United States
Language:
English
Subject:
58 GEOSCIENCES; ground heat flux; soil heat flux; energy balance; evapotranspiration; remote sensing; evaporation; water/energy interactions; modeling (1952, 4316)
OSTI Identifier:
1466315
Alternate Identifier(s):
OSTI ID: 1402245

Purdy, A. J., Fisher, J. B., Goulden, M. L., and Famiglietti, J. S.. Ground heat flux: An analytical review of 6 models evaluated at 88 sites and globally. United States: N. p., Web. doi:10.1002/2016JG003591.
Purdy, A. J., Fisher, J. B., Goulden, M. L., & Famiglietti, J. S.. Ground heat flux: An analytical review of 6 models evaluated at 88 sites and globally. United States. doi:10.1002/2016JG003591.
Purdy, A. J., Fisher, J. B., Goulden, M. L., and Famiglietti, J. S.. 2016. "Ground heat flux: An analytical review of 6 models evaluated at 88 sites and globally". United States. doi:10.1002/2016JG003591. https://www.osti.gov/servlets/purl/1466315.
@article{osti_1466315,
title = {Ground heat flux: An analytical review of 6 models evaluated at 88 sites and globally},
author = {Purdy, A. J. and Fisher, J. B. and Goulden, M. L. and Famiglietti, J. S.},
abstractNote = {Uncertainty in ground heat flux (G) means that evaluation of the other terms in the surface energy balance (e.g., latent and sensible heat fluxes (LE and H)) remains problematic. Algorithms that calculate LE and H require available energy, the difference between net radiation, RNET, and G. There are a wide range of approaches to model G for large-scale applications, with a subsequent wide range of estimates and accuracies. Here, we provide the largest review of these methods to date (N = 6), evaluating modeled G against measured G from 88 FLUXNET sites. The instantaneous midday variability in G is best captured by models forced with net radiation, while models forced by temperature show the least error at both instantaneous and daily time scales. We produce global decadal data sets of G to illustrate regional and seasonal sensitivities, as well as uncertainty. Global model mean midmorning instantaneous G is highest during September, October, and November at 63.42 (±16.84) Wm-2, while over December, January, and February G is lowest at 53.86 (±18.09) Wm-2 but shows greater intermodel uncertainty. Results from this work have the potential to improve evapotranspiration estimates and guide appropriate G model selection and development for various land uses.},
doi = {10.1002/2016JG003591},
journal = {Journal of Geophysical Research. Biogeosciences},
number = 12,
volume = 121,
place = {United States},
year = {2016},
month = {12}
}