Estimating ground-level CO concentrations across China based on the national monitoring network and MOPITT: potentially overlooked CO hotspots in the Tibetan Plateau
Estimating ground-level CO concentrations across China based on the national monitoring network and MOPITT: potentially overlooked CO hotspots in the Tibetan Plateau
复制标题
基于国家监测网络和MOPITT估算中国地面CO浓度:青藏高原可能被忽视的CO热点
DOI:
10.5194/acp-19-12413-2019
复制
发表时间:
2019-10-08
影响因子:
6.3
通讯作者:
Zhan, Yu
中科院分区:
文献类型:
--
作者:
Liu, Dongren;Di, Baofeng;Zhan, Yu
Abstract. Given its relatively long lifetime in the troposphere, carbon
monoxide (CO) is commonly employed as a tracer for characterizing airborne
pollutant distributions. The present study aims to estimate the
spatiotemporal distributions of ground-level CO concentrations across China
during 2013–2016. We refined the random-forest–spatiotemporal kriging
(RF–STK) model to simulate the daily CO concentrations on a 0.1∘
grid based on the extensive CO monitoring data and the Measurements of
Pollution in the Troposphere CO retrievals (MOPITT CO). The RF–STK model
alleviated the negative effects of sampling bias and variance heterogeneity
on the model training, with cross-validation R2 of 0.51 and 0.71 for
predicting the daily and multiyear average CO concentrations, respectively.
The national population-weighted average CO concentrations were predicted to
be 0.99±0.30 mg m−3 (μ±σ) and showed
decreasing trends over all regions of China at a rate of -0.021±0.004 mg m−3 yr−1. The CO pollution was more severe in North China
(1.19±0.30 mg m−3), and the predicted patterns were generally
consistent with MOPITT CO. The hotspots in the central Tibetan Plateau where
the CO concentrations were underestimated by MOPITT CO were apparent in the
RF–STK predictions. This comprehensive dataset of ground-level CO
concentrations is valuable for air quality management in China.