Isotopes in Project for Intercomparison of Land-Surface Parameterization Schemes (iPILPS) - Tropical Rainforest, Manaus, Brazil

Isotopes are one of the most useful and innovative tools for understanding complex processes in the water cycle, paleoclimate and biogeochemistry on many timescales. iPILPS is a new type of PILPS experiment in which the process of international intercomparison will educate the land-surface scheme (LSS) parameterization community while new aspects of LSS are being developed. A land-surface scheme (LSS) is an algorithm for determining the exchanges of energy, mass and momentum between the atmosphere and continents. iPILPS is a component of the current initiative to add isotopic (stable and radioactive) representation to atmospheric and land-surface models. The forcing data includes magnitudes of each isotope (1H2 18O and 1H2H16O) in precipitation and in water vapour at the atmospheric lowest level plus all the standard Assistance for Land-surface Modelling Activities (ALMA) meteorological forcing including 'regular' water (1H216O). Phase 1 included a Tropical Rainforest, at Manaus, Brazil (3'S 60'W). Forcing was provided at this location for four years. The experimental design directed each ILSS to use the first year's forcing repeatedly for as many years as that ILSS required to achieve equilibrium (this experimental component was designated EQY1), and then use the next three years' forcing to create three years' simulations (this 'Basin Comparison' was designated BC24).

同位素（Isotopes）是探究多时间尺度下水循环、古气候及生物地球化学领域复杂过程的最具实用性与创新性的工具之一。iPILPS是一种新型PILPS实验，其开展的国际比对流程将在陆面方案（Land-surface scheme, LSS）参数化研究群体开发新型陆面方案的过程中，为该群体提供学术赋能与交流学习机会。陆面方案（LSS）是一类用于计算大气与陆地之间能量、质量及动量交换的算法。iPILPS是当前一项倡议的组成部分，该倡议旨在为大气与陆面模型添加同位素（稳定同位素与放射性同位素）表征模块。强迫数据涵盖了降水及大气近地面层水汽中各同位素的含量，具体包括¹H₂¹⁸O与¹H²H¹⁶O两种同位素；同时还包含标准陆面模拟活动援助（Assistance for Land-surface Modelling Activities, ALMA）提供的所有气象强迫数据，其中涵盖了常规水（¹H₂¹⁶O）。第一阶段实验设置了位于巴西马瑙斯（南纬3°，西经60°）的热带雨林站点，该站点的强迫数据时长为四年。本次实验设计要求每个陆面方案反复使用第一年的强迫数据，直至该方案达到平衡状态所需的年限（该实验环节被命名为EQY1）；随后使用后续三年的强迫数据开展三年时长的模拟实验（该“流域比对”环节被命名为BC24）。