Estimating critical weather conditions for the generation of storms with heavy rainfall represents one of the main challenges in the scientific community, especially in the warm season. While the use of radiosonde data is a possible option, an important limitation for achieving reliable forecasting of extreme rainfall events is undoubtedly low spatio-temporal resolution. As such, this research work endeavored to provide a special contribution by analyzing radiosonde data specifically collected for such evaluation applied to a tropical area, namely the city of Rio de Janeiro, Brazil. In that context, we applied a method recommended by previously reviewed literature consisting of replacing air temperature of a sounding probe launched in the morning (12 UTC) with forecasted values using data observed in the afternoon in order to gauge the method. Data points measured by radiosondes launched in the afternoon (between 12 and 7 pm local time) were used to evaluate the proposed method. The results showed that the atmosphere presented the highest heating rates in the atmospheric layer closest to the surface during the afternoon for diurnal clouds (DC) days. Similar behaviour was observed for the days of the South Atlantic Convergence Zone (SACZ). For days with frontal system (FS) presence, however, lower temperature values were observed in the afternoon in relation to the measured by morning soundings. Winds presented northeast and southwest components leading to the occurrence of warm and cold advection, respectively, in the analyzed region. Thermodynamic variables tended to be overestimated in relation to observed field results in most of the analyzed days.

中文翻译：

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使用无线电探空仪对巴西里约热内卢市的观测和估计大气热力学不稳定性

估计产生暴雨的临界天气条件是科学界面临的主要挑战之一，尤其是在温暖的季节。虽然使用无线电探空仪数据是一种可能的选择，但实现可靠预测极端降雨事件的一个重要限制无疑是低时空分辨率。因此，这项研究工作力求通过分析专门为此类评估收集的无线电探空仪数据做出特殊贡献，这些数据适用于热带地区，即巴西里约热内卢市。在这种情况下，我们应用了先前审查过的文献推荐的方法，该方法包括使用下午观察到的数据用预测值替换早上（12 UTC）发射的探测探测器的气温，以衡量该方法。下午（当地时间下午 12 点到 7 点之间）发射的无线电探空仪测量的数据点用于评估所提出的方法。结果表明，对于昼夜云 (DC) 天，在下午最靠近地表的大气层中，大气呈现出最高的加热速率。在南大西洋辐合带 (SACZ) 的日子里也观察到了类似的行为。然而，对于有锋面系统 (FS) 存在的日子，下午观察到的温度值与早上探测的测量值相比较低。风呈现东北和西南分量，导致分析区域分别出现暖平流和冷平流。在大多数分析的日子里，热力学变量相对于观察到的现场结果往往被高估。