Decade-long isotope dataset (δ2H and δ18O) of rainfall and non-rainfall water samples in the central Namib Desert, Namibia@en

The long-term rainfall and non-rainfall (i.e., fog and dew) water samples were collected at the Gobabeb - Namib Research Institute in the central Namib Desert, Namibia (-23°33′39.3″S, 15°02′24.6″E) between 2014 and 2023. This research institute is situated on the outer edge of the Namib fog zone, where visible fog is present along the Namib coast, about 60 km from the South Atlantic Ocean (Eckardt et al. (2013, doi:10.1016/j.jaridenv.2012.01.011; Kaseke et al. (2017, doi:10.1175/1520-0450(1994)033)). The Gobabeb - Namib Research Institute is located downstream of the Kuiseb River catchment, which flows from the eastern Knomas Highland to western Walvis Bay. The climate at Gobabeb is hyper-arid, with a multi-year (1962-2022) average annual rainfall of 30.5 mm and a multi-year (1966.1-2003.12 and 2006.10-2022.12) average annual fog amount of 112.1 mm. In addition, the spatial fog samples were collected from 13 stations across the central Namib Desert during two periods: June 10−19, 2016, and June 27-July 10, 2017. The 13 stations include Coastal MET, Kleinberg, Soophies Hoogte, Marble koppie, Vogelfederberg, Station 8, Aussinanis, Gobabeb, Station 1, Station 2, Station 3, Station 4, and Station 5. The 13 stations collectively covered an area of approximately 1,700 km², with a complete roundtrip visit spanning about 250 km (Kaseke et al. (2018, doi:10.4209/aaqr.2017.01.0062)). Before each roundtrip field campaign, we inspected the fog collector at the Gobabeb-Namib Research Institute and monitored real-time meteorological data (leaf wetness and relative humidity) from other stations to identify fog events across the central Namib Desert. If fog was present, we immediately conducted sampling roundtrips to all 13 sites using alternating routes (Gobabeb-Aussinanis-Coastal MET-Gobabeb). The Standard Fog Collectors (SFCs), designed according to Schemenauer and Cereceda (1994), were used to collect event-scale (i.e., daily) fog water samples for isotopic analysis. All the captured fog water ran down from the bottom of the collectors into a 1 L glass bottle anchored to the ground through a pipe sealed at both ends to minimize water evaporation. After fog water sample collections in the morning, they were transferred into a 15 ml Qorpak French square bottle and sealed with a Black Phenolic Pulp/Vinyl Lined Cap. Dew was captured using a dew collector consisting of a 1 m² metal sheet covered by a glass plate, inclined at 30° and elevated 0.5 m above the ground. […]2014年至2023年间，研究团队于纳米比亚中部纳米布沙漠的戈巴布-纳米布研究所（-23°33′39.3″S，15°02′24.6″E）采集了长期降雨及非降雨（即雾与露）水样。该研究所地处纳米布雾区的外缘地带，该雾区沿纳米布海岸分布，距南大西洋约60公里（Eckardt等人，2013，doi:10.1016/j.jaridenv.2012.01.011；Kaseke等人，2017，doi:10.1175/1520-0450(1994)033）。戈巴布-纳米布研究所坐落于奎西河流域下游，该河流从东部的克诺马斯高地流向西部的沃尔维斯湾。戈巴布地区属超干旱气候，1962-2022年的多年平均年降雨量为30.5毫米，1966.1-2003.12及2006.10-2022.12时段的多年平均年雾水量为112.1毫米。 此外，研究团队于2016年6月10日至19日、2017年6月27日至7月10日两个时段，在纳米布沙漠中部的13个站点采集空间雾样。这13个站点分别为：Coastal MET（海岸气象站）、Kleinberg（克莱因贝格）、Soophies Hoogte（索菲高地）、Marble koppie（大理石山）、Vogelfederberg（沃格尔费德贝格）、Station 8（8号站）、Aussinanis（奥西纳尼斯）、Gobabeb（戈巴布）、Station 1（1号站）、Station 2（2号站）、Station 3（3号站）、Station 4（4号站）及Station 5（5号站）。13个站点的覆盖总面积约1700平方公里，单次完整往返巡查路程约250公里（Kaseke等人，2018，doi:10.4209/aaqr.2017.01.0062）。 在每次往返野外采样作业前，研究团队会对戈巴布-纳米布研究所的雾水收集器进行检查，并监测其他站点的实时气象数据（叶面湿度与相对湿度），以识别纳米布沙漠中部的雾天事件。若出现雾天，研究团队会立即沿交替路线（戈巴布→奥西纳尼斯→海岸气象站→戈巴布）前往全部13个站点开展往返采样。本研究采用依据Schemenauer与Cereceda（1994）设计的标准雾水收集器（Standard Fog Collectors，SFCs），采集事件尺度（即单日）的雾水水样用于同位素分析。所有收集到的雾水会沿收集器底部的管道流入固定于地面的1L玻璃瓶中，该管道两端均做密封处理，以尽可能减少水分蒸发。当日上午完成雾水样品采集后，会将样品转移至15ml Qorpak方形玻璃瓶中，并使用黑色酚醛纸基/乙烯基衬里瓶盖密封。 露水则通过露水收集器采集，该收集器由一块覆盖有玻璃板的1㎡金属薄板构成，薄板以30°倾角安装，距地面高度为0.5米。……