Semi-quantitative surface ozone observations from station Ponta-Delgada

The dataset consists of a set of semi-quantitative surface ozone observations (hereinafter O3), together with relative humidity observations at the same temporal scales. The dataset consists of monthly mean observations from 23 observatories, listed on Table 1. The datasets are from the period 1872 to 1888 at 22 of the observatories. They're extensions in times range between 17 and 3 years for monthly mean observations. The other dataset from the Observatory Infante D. Luiz, the longest semi-quantitative surface ozone observations data series known to date, spans 58 years for monthly data (1855 to 1913). For more details see Tables 2a and 2b in Añel et al., 2024. The O3 observations were recovered and manually digitalized from the Annaes do Observatory Infante D. Luiz published between 1863 and 1915 (Fradesso da Silveira, 1863; De Almeida, 1915). The O3 observations were part of the regular meteorological observations conducted at Portugal and former colonies network of meteorological observatories and outstations controlled by the Infante D. Luis Meteorological Observatory (Lisbon), created in 1857 (Raposo, 2017). Geographically the dataset consists of O3 observations at the 23 observatories listed on Table 1, between 42°N and 9°S in latitude and 27°W and 15°E. Eighteen observatories are located at the Iberian Peninsula and five in Africa. Three of those observatories are insular, two at the Azores islands and one at Madeira Island. The O3 observations were conducted using Schönbein test-paper method, also called "ozonoscope". It was based on the color-change of an indicator strip of blotting paper coated with starched potassium iodide. The paper strip was exposed to air between 8 and 24 hours protected from solar radiation and rain. The method applied in the Portuguese observatories was the one from Berigny (1958) who defined the operating procedure, introducing a more precise chromatic scale graduated from 0 to 21 and selected he best quality of impregnated paper. That on was the Berzelius paper manufactured by James a chemist at Sédan (Marenco et al, 1994) that is often referred in logbooks containing measurements as the cale of "James de Sédan". (Añel et al., 2024).

本数据集包含一组半定量地面臭氧（surface ozone）观测数据（以下简称O₃），以及相同时间尺度下的相对湿度观测数据。数据集包含来自表1所列23个观测站的月均观测值：其中22个观测站的数据集覆盖1872至1888年，其月均观测值的时间范围延伸了3至17年不等；另一组来自Infante D. Luiz观测站的数据集是目前已知最长的半定量地面臭氧观测序列，其月数据跨度达58年（1855年至1913年）。更多细节参见Añel等人2024年发表的表2a和表2b。
O₃观测数据是从1863至1915年出版的《Infante D. Luiz观测站年报》（Annaes do Observatory Infante D. Luiz）中复原并手动数字化的（Fradesso da Silveira，1863；De Almeida，1915）。这些O₃观测数据是1857年成立的Infante D. Luiz气象观测站（里斯本）所管控的葡萄牙及前殖民地气象观测站与分站网络开展的常规气象观测的一部分（Raposo，2017）。
从地理分布看，数据集涵盖表1所列23个观测站的O₃观测数据，这些站点位于北纬42°至南纬9°、西经27°至东经15°之间：其中18个观测站位于伊比利亚半岛，5个位于非洲；3个为岛屿观测站，2个在亚速尔群岛，1个在马德拉岛。
O₃观测采用舍恩拜因试纸法（Schönbein test-paper method），又称“臭氧测定仪法（ozonoscope）”。该方法基于涂有淀粉碘化钾的吸水指示试纸的颜色变化：试纸暴露于空气中8至24小时，期间需避免太阳辐射和雨水影响。葡萄牙观测站采用的是贝里尼（Berigny，1958）定义的操作流程，该流程引入了0至21级的更精确色阶，并选用了最高质量的浸渍试纸——即Sedan化学家James制造的贝采利乌斯试纸（Berzelius paper）（Marenco等人，1994），在包含测量数据的日志中常被称为“James de Sedan尺度”（Añel等人，2024）。