Global Mean Sea Level, Trajectory and Extrapolation

DescriptionGlobal Mean Sea Level, Trajectory and Extrapolation This file contains Global Mean Sea Level (GMSL) variations along, data for the quadratic fit (trajectory) to the GMSL variations, and an extrapolation of this trajectory to 2050. This data is used in the annual NASA Global Mean Sea Level press release. Column 1 provides the calendar year plus the decimal fraction of the current year. The GMSL variations(column 2) are computed are computed as part of the NASA-SSH data products available from PODAAC at: https://podaac.jpl.nasa.gov/NASA-SSH. All units for sea level are in centimeters The GMSL was generated using the NASA-SSH Simple Gridded Sea Surface Height from Standardized Reference Missions Version 1: https://podaac.jpl.nasa.gov/dataset/NASA_SSH_REF_SIMPLE_GRID_V1. It combines Sea Surface Heights from the TOPEX/Poseidon, Jason-1, OSTM/Jason-2, HDR Jason-3, and Sentinel-6 Michael Freilich missions. In addition, the rate and acceleration are estimated from full record of GMSL relative to the midpoint of the record and then used to generate a quadratic fit to the data. This quadratic fit is provided in column 3. The rate associated with this quadratic fit at any time in the record is also provided (column 4). The parameters estimated from the quadratic fit are also used to generated an extrapolated time series out to 2050 (column 5). These are provided at yearly intervals. This is not a projection and is only considered an extrapolation of the current trajectory of GMSL variations. This also differs from Nerem et al. (2022) and Sweet et al. (2022) as additional signals are not removed from GMSL prior to estimating the rate and acceleration parameters. The yearly rate associated with this extrapolation is also provided (column 6). If you use these data please cite:Willis, J.K., Hamlington, B.D., and Fournier, S., Global Mean Sea Level Time Series, Trajectory and Extrapolation. Dataset access [YYYY-MM-DD] at 10.5281/zenodo.7702314. References: Nerem, R. S., Frederikse, T., & Hamlington, B. D. (2022). Extrapolating Empirical Models of Satellite‐Observed Global Mean Sea Level to Estimate Future Sea Level Change. Earth's Future, 10(4), e2021EF002290. Sweet, W. V., Hamlington, B. D., Kopp, R. E., Weaver, C. P., Barnard, P. L., Bekaert, D., ... & Zuzak, C. (2022). Global and regional sea level rise scenarios for the United States: updated mean projections and extreme water level probabilities along US coastlines. Interagency Technical Report.数据集说明：全球平均海平面、变化轨迹及外推 本数据集包含全球平均海平面（Global Mean Sea Level, GMSL）变化数据、针对GMSL变化的二次拟合（变化轨迹）数据，以及该轨迹至2050年的外推数据。本数据用于美国国家航空航天局（National Aeronautics and Space Administration, NASA）年度全球平均海平面新闻发布工作。 第1列为日历年及当年的小数占比。第2列的GMSL变化数据属于NASA-SSH数据集产品的一部分，可从物理海洋学分布式主动归档中心（Physical Oceanography Distributed Active Archive Center, PODAAC）获取：https://podaac.jpl.nasa.gov/NASA-SSH。所有海平面数据的单位均为厘米。本GMSL数据集基于标准化参考任务版本1的NASA-SSH简单网格化海面高度数据生成，获取地址为：https://podaac.jpl.nasa.gov/dataset/NASA_SSH_REF_SIMPLE_GRID_V1。该数据集整合了TOPEX/Poseidon、Jason-1、OSTM/Jason-2、HDR Jason-3及Sentinel-6 Michael Freilich等卫星任务的海面高度观测数据。 此外，本研究基于完整GMSL观测序列，以该序列的中点为参考基准估算速率与加速度参数，并据此生成针对该观测数据的二次拟合模型，拟合结果见第3列。本数据集同时提供该二次拟合模型在观测时段内任意时刻对应的速率值（第4列）。 基于上述二次拟合得到的参数，本数据集还生成了至2050年的外推时间序列（第5列），数据按年间隔提供。需明确的是，本数据并非气候预测，仅为当前GMSL变化轨迹的外推结果。与Nerem等人（2022）及Sweet等人（2022）的研究不同，本研究在估算速率与加速度参数前，未从GMSL观测数据中移除额外的干扰信号。本数据集同时提供该外推序列对应的年速率值（第6列）。 若使用本数据集，请引用以下文献：Willis, J.K.、Hamlington, B.D. 及 Fournier, S.，《全球平均海平面时间序列、轨迹与外推》。数据集获取时间[YYYY-MM-DD]，DOI: 10.5281/zenodo.7702314。 参考文献： 1. Nerem, R. S.、Frederikse, T. 及 Hamlington, B. D.（2022）。《基于卫星观测的全球平均海平面经验模型外推以预估未来海平面变化》。《地球的未来》，10(4)，e2021EF002290。 2. Sweet, W. V.、Hamlington, B. D.、Kopp, R. E.、Weaver, C. P.、Barnard, P. L.、Bekaert, D. 等及 Zuzak, C.（2022）。《美国全球及区域海平面上升情景：美国沿海地区平均预估与极端水位概率更新》。跨部门技术报告。