An Observing System Simulation Experiment to Assess the Potential Impact of a Virtual Mobile Communication Tower–based Observation Network on Weather Forecasting Accuracy in China. Part 1: Weather Stations with a Typical Mobile Tower Height of 40 m

The importance of a national or regional network of meteorological stations for improving weather predictions has been recognized for many years.Ground-based automatic weather stations typically observe weather at a height of 2-10 m above ground level(AGL);however,these observations may have two major shortcomings.Large portions of data cannot be used if the station height is significantly lower than the model surface level;and such observations may contain large representativity errors as near-surface observations are often affected by the local environment,such as nearby buildings and tall trees.With the recent introduction of a significant number of mobile communication towers that are typically over40 m AGL in China,a campaign has been proposed to use such towers to build a future observing system with an observing height of 40 m.A series of observing system simulation experiments has been conducted to assess the potential utility of such a future observing system as part of a feasibility study.The experiments were conducted using the Weather Research and Forecasting model and its Rapid Update Cycle data assimilation system.The results revealed the possibility of improving weather forecasting by raising present weather stations to a height of 40 m;this would not only enable more observations to pass the terrain check,but should also reduce interpolation errors.Additionally,improvements for temperature,humidity and wind forecasting could be achieved as the accuracy of the initial conditions increases.

Long-Term Exposure to Low-Level Ambient Air Pollution and Mortality among 0.3 Million Chinese Older Adults

Objective Evidence that long-term exposure to ambient air pollution increases mortality among older adults,particularly those residing in low-level air pollution locations,remains scarce.This study investigated the potential links between long-term low-level air pollution exposure and mortality among Chinese older adults.Methods A population-based study with 317,464 individuals aged≥65 years was conducted in Shenzhen,China during 2018 and 2020.Logistic regression models were used to analyze the associations between long-term exposure to air pollution and all-cause mortality,as the primary outcome,as well as non-accidental,cancer and cardiovascular mortality.Results Significant associations of PM1,PM_(2.5),PM_(10),SO_(2),CO,and O3 exposures with a higher risk of all-cause mortality were found.Adjusted odds ratio(OR)for each 1μg/m^(3) increment was 1.49[95%confidence interval(CI):1.46,1.53]for PM1,1.30(1.27,1.32)for PM_(2.5),1.05(1.04,1.06)for PM_(10),5.84(5.39,6.32)for SO_(2),1.04(1.04,1.05)for CO,and 1.02(1.00,1.03)for O3,respectively.Long-term PM1,PM_(2.5),PM_(10),SO_(2),and CO exposures also elevated the risks of non-accidental,cancer and cardiovascular mortality.Conclusion Long-term low-level air pollution exposure was associated with an increased mortality risk among Chinese older adults.