| Autor: |
Chaves DA; Instituto Federal do Rio de Janeiro, Campus Pinheiral, Rua José Breves, 550, 27197-000 Pinheiral, RJ, Brazil., Lyra GB; Departamento de Ciências Ambientais, Instituto de Florestas, Universidade Federal Rural do Rio de Janeiro, Rodovia BR 465, Km 07, 23851-970 Seropédica, RJ, Brazil., Francelino MR; Universidade Federal de Viçosa/UFV, Departamento de Solos, Av. Peter Henry Rolfs, Campus Universitário, 36570-900 Viçosa, MG, Brazil., DA Silva LDB; Departamento de Engenharia, Universidade Federal Rural do Rio de Janeiro, Rodovia BR 465, Km 07, 23851-970 Seropédica, RJ, Brazil., Schaefer CERG; Universidade Federal de Viçosa/UFV, Departamento de Solos, Av. Peter Henry Rolfs, Campus Universitário, 36570-900 Viçosa, MG, Brazil., Thomazini A; Universidade Federal de São João Del-Rei/UFSJ, Departamento de Ciências Agrárias/DCIAG, Rua Sétimo Moreira Martins, 188, Itapoã, 35702-031 Sete Lagoas, MG, Brazil. |
| Abstrakt: |
Heat transfer process in the soil active layer is important for the knowledge of its thermal properties linked with climate issues. The objective of this work was to analyze the energy flux in different soil profiles by estimating the apparent soil thermal diffusivity ($ATD$). The study was carried out in Keller Peninsula, located at King George Island in four different sites differing by soil characteristics, as well as vegetation coverage and landscape setting. The $ATD$ was estimated in function of the long-term hourly temperature records at different soil depths. In addition, we estimated the seasonal mean of the $ATD$ and the freezing $N$-factor. Results showed that $ATD$ values were smaller at shallow depths and increased with depth. The diffusivity values presented lower variability in colder conditions, especially at deeper soil layers. Water content was the main factor affecting soil thermal diffusivity at sites $1$ and $3$ (more than $70$ and $63\%$ of probability). At sites $3$ and $4$ lower $N$-factors were observed, suggesting higher snow pack and permafrost closer to the soil surface. Hence, positive $ATD$ appears in the summer due to thawing increases soil moisture, while negative $ATD$ appears during the freeze of the snow pack and precipitation. |
