Parameterization of downward long-wave radiation based on long-term baseline surface radiation measurements in China
Downward long-wave radiation (DLR) affects energy exchange between the land surface and the atmosphere and plays an important role in weather forecasting, agricultural activities, and the development of climate models. Because DLR is seldom observed at conventional radiation stations, numerous empir...
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Published in | Atmospheric chemistry and physics Vol. 23; no. 7; pp. 4419 - 4430 |
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Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
Katlenburg-Lindau
Copernicus GmbH
14.04.2023
Copernicus Publications |
Subjects | |
Online Access | Get full text |
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Summary: | Downward long-wave radiation (DLR) affects energy exchange
between the land surface and the atmosphere and plays an important role in
weather forecasting, agricultural activities, and the development of climate
models. Because DLR is seldom observed at conventional radiation stations,
numerous empirical parameterizations have been presented to estimate DLR
from screen-level meteorological variables. The reliability and
representativeness of parameterization depend on the coefficients regressed
from the simultaneous observations of DLR and meteorological variables. Only
a few previous studies have attempted to build parameterizations over
regions in China such as the Tibetan Plateau and East China. In this study,
a long-term (2011–2022) hourly dataset of DLR and meteorological elements,
obtained from seven stations of the China Baseline Surface Radiation
Network, was used to recalculate the coefficients of the Brunt and Weng
models and to develop a new model. Results showed that the mean bias error
(MBE) and relative MBE (rMBE) between the measured clear-sky DLR and that
estimated using the Brunt, Weng, and new models were −4.3, −5.1, and 3.7 W m−2 and −1.5 %, −1.8 %, and 1.3 %, respectively. The
root mean square errors (RMSEs) were in the range of 13.8–14.3 W m−2, and the relative RMSEs (rRMSEs) were approximately 5.0 %. The MBEs
(rMBEs) of the Brunt, Weng, and new models under all-sky conditions were
−2.8 W m−2 (−1.0 %), −6.1 W m−2 (−2.1 %), and −1.5 W m−2 (−0.5 %), respectively. The RMSE (rRMSE) of the
parameterization models in retrieving all-sky DLR was ∼ 17.5 W m−2 (∼ 6.1 %). Therefore, the models are considered
suitable for retrieval of DLR over China. |
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ISSN: | 1680-7324 1680-7316 1680-7324 |
DOI: | 10.5194/acp-23-4419-2023 |