TY - JOUR
T1 - Application of the Extended Force-restore Model to Estimating Soil-frost Depth in the Tokachi District of Hokkaido, Japan
AU - Nemoto, Manabu
AU - Hirota, Tomoyoshi
AU - Iwata, Yukiyoshi
N1 - Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 2008
Y1 - 2008
N2 - In the present study, we tested the applicability of the extended force-restore model (eFRM) to estimating soil-frost depth in the Tokachi district where the soil is a type of volcanic ash. The optimal thermal conductivity of the snow (TC-S) in each cold period varied from 0.074 to 0.172 W m-1 K-1, with root-mean-square errors (RMSEs) ranging from 0.020 to 0.039 m. The difference between observed and estimated maximum soil frost depth (SFDmax) was less than 0.03 m. The fixed TC-S through the six cold periods from 2001 to 2007 was optimized as the value of 0.173 W m-1 K-1 with minimum RMSE of 0.043 m. When this optimal value of TC-S was used to estimate SFDmax, the difference between the observed and estimated values was 0.04 m at most, with the exception of 2003-2004 and 2004-2005, when little soil-frost developed. Our results showed that even though we considered the TC-S to be invariant over time, the eFRM was able to estimate soil-frost depth with an accuracy of a few centimeters using only mean daily air temperature and snow depth as inputs.
AB - In the present study, we tested the applicability of the extended force-restore model (eFRM) to estimating soil-frost depth in the Tokachi district where the soil is a type of volcanic ash. The optimal thermal conductivity of the snow (TC-S) in each cold period varied from 0.074 to 0.172 W m-1 K-1, with root-mean-square errors (RMSEs) ranging from 0.020 to 0.039 m. The difference between observed and estimated maximum soil frost depth (SFDmax) was less than 0.03 m. The fixed TC-S through the six cold periods from 2001 to 2007 was optimized as the value of 0.173 W m-1 K-1 with minimum RMSE of 0.043 m. When this optimal value of TC-S was used to estimate SFDmax, the difference between the observed and estimated values was 0.04 m at most, with the exception of 2003-2004 and 2004-2005, when little soil-frost developed. Our results showed that even though we considered the TC-S to be invariant over time, the eFRM was able to estimate soil-frost depth with an accuracy of a few centimeters using only mean daily air temperature and snow depth as inputs.
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U2 - 10.2480/agrmet.64.3.7
DO - 10.2480/agrmet.64.3.7
M3 - Article
AN - SCOPUS:80052791302
VL - 64
SP - 177
EP - 183
JO - J. AGRICULTURAL METEOROLOGY
JF - J. AGRICULTURAL METEOROLOGY
SN - 0021-8588
IS - 3
ER -