Supporting Data for "Impact of the AMOC Weakening on Upper Troposphere/Lower Stratosphere Warming over the Extratropical North Pacific"

This repository contains the supporting data in the NetCDF format for the following paper:

Joshi, R. and Zhang, R. (2026). Impact of the AMOC Weakening on Upper Troposphere/Lower Stratosphere Warming over the Extratropical North Pacific, Geophysical Research Letters, 53, e2026GL122116. https://doi.org/10.1029/ 2026GL122116

In this study, we analyze an idealized water hosing ensemble in comparison with the control ensemble conducted with a high-resolution fully coupled climate (GFDL CM4C192) to understand how a substantially weakened AMOC induces the UTLS response over the extratropical North Pacific during boreal winter.

Descriptions of data files in this repository:

1. Long-term mean boreal winter response in precipitation, temperature at 200hPa, velocity potential at 200hPa, and omega at 200hPa, along with the two-sided student t-test for statistical testing for the response (Figure 1a-d). 

Precipitation_Response.nc, Temperature_Response_200hPa.nc, Velocity_Potential_Response_200hPa.nc, Omega_Response_200hPa.nc

2. Long-term mean boreal winter divergent wind response at 200hPa (Figure 1c).

Divergent_Wind_Response_200hPa.nc

3. Contribution from the response in omega to the vertical advection of mean potential temperature at 200hPa during boreal winter, along with the two-sided student t-test for statistical testing of the contribution term (Figure 1e).

Omega_Contribution_Term_200hPa.nc

4. Time series (11-year running mean) of the estimated vs. modeled boreal winter temperature response at 156°W and 200 hPa, shown in Figure 1f.

Time_Series_Temp_Response_156W.nc

5. Long-term mean boreal winter response in the zonal wind and air temperature averaged zonally over the extratropical North Pacific, along with the two-sided student t-test for statistical testing for the response (Figure 2a). 

Zonal_Wind_Response_NP.nc, Temperature_Response_NP.nc

6. Time series (11-year running mean) of the thermal wind balance terms at 200hPa during boreal winter shown in Figure 2b.

Thermal_Wind_Balance_Terms.nc

7. The leading Principal Component (PC1) of the smoothed (11-year running mean) 200 hPa streamfunction response with the zonal mean removed (Figure 3a). 

PC1.nc

8. Leading Empirical Orthogonal Function (EOF1) of the smoothed (11-year running mean) 200hPa streamfunction response with the zonal mean removed (Figure 3b).

EOF1.nc

8. Regression of the response in the relative vorticity at 200 hPa on the PC1 of the North Pacific of the smoothed 200hPa streamfunction response (Figure 3c).

Regression_Vorticity_200hPa.nc

9. The wave activity associated with the leading EOF1  of the smoothed (11-year running mean) 200hPa streamfunction response shown in Figure 3b. 

Wave_Activity_Flux_Associated_With_EOF1.nc

10. Regression of the response in the tropical North Pacific zonal mass overturning on the PC1 of the North Pacific of the smoothed 200hPa streamfunction response (Figure 4a).

Regression_TNP.nc

11. Regression of the response in the eastern Pacific meridional mass overturning streamfunction on the PC1 of the North Pacific of the smoothed 200hPa streamfunction response (Figure 4b).

Regression_ENP.nc

12. Regression of the response in the OLR on the PC1 of the North Pacific of the smoothed 200hPa streamfunction response (Figure 4c).

Regression_OLR.nc

Acknowledgments

We acknowledge the use of the following model code in this study:

The code of the Geophysical Fluid Dynamics Laboratory coupled climate model version 4 (GFDL-CM4) is publicly available at https://zenodo.org/records/3339397.

本仓库包含对应下述论文的网络通用数据格式（NetCDF）支撑数据：

Joshi, R. 与 Zhang, R. (2026). 大西洋经向翻转环流（AMOC）减弱对北太平洋副热带以外区域对流层上层/平流层下层（UTLS）增温的影响，《地球物理研究快报》，53卷，e2026GL122116。https://doi.org/10.1029/2026GL122116

本研究采用理想化淡水注入试验集合，与采用高分辨率全耦合气候模式（GFDL CM4C192）开展的对照试验集合进行对比分析，以阐明大幅减弱的AMOC如何在北半球冬季诱导北太平洋副热带以外区域的UTLS响应。

本仓库内的数据文件说明如下：
1. 北半球冬季降水、200hPa温度、200hPa速度势以及200hPa垂直速度（ω）的长期平均响应，以及针对该响应的双侧Student t检验统计结果（对应图1a-d）。对应数据文件：Precipitation_Response.nc、Temperature_Response_200hPa.nc、Velocity_Potential_Response_200hPa.nc、Omega_Response_200hPa.nc。
2. 200hPa散度风响应的北半球冬季长期平均结果（对应图1c）。对应数据文件：Divergent_Wind_Response_200hPa.nc。
3. 北半球冬季期间，200hPa平均位温的垂直平流对ω响应的贡献项，以及针对该贡献项的双侧Student t检验统计结果（对应图1e）。对应数据文件：Omega_Contribution_Term_200hPa.nc。
4. 156°W、200hPa处估算与模拟的北半球冬季温度响应的时间序列（11年滑动平均），对应图1f。对应数据文件：Time_Series_Temp_Response_156W.nc。
5. 北太平洋副热带以外区域纬向平均的北半球冬季纬向风与气温的长期平均响应，以及针对该响应的双侧Student t检验统计结果（对应图2a）。对应数据文件：Zonal_Wind_Response_NP.nc、Temperature_Response_NP.nc。
6. 北半球冬季200hPa处热成风平衡项的时间序列（11年滑动平均），对应图2b。对应数据文件：Thermal_Wind_Balance_Terms.nc。
7. 移除纬向平均后的200hPa流函数响应（经11年滑动平均平滑）的第一主成分（PC1），对应图3a。对应数据文件：PC1.nc。
8. 移除纬向平均后的200hPa流函数响应（经11年滑动平均平滑）的第一经验正交函数（EOF1），对应图3b。对应数据文件：EOF1.nc。
8. 针对平滑后的200hPa流函数响应（移除纬向平均后）的北太平洋PC1，回归得到的200hPa相对涡度响应，对应图3c。对应数据文件：Regression_Vorticity_200hPa.nc。
9. 对应图3b的、移除纬向平均且经11年滑动平均平滑的200hPa流函数响应的第一经验正交函数（EOF1）相关的波活动通量。对应数据文件：Wave_Activity_Flux_Associated_With_EOF1.nc。
10. 针对平滑后的200hPa流函数响应的北太平洋PC1，回归得到的热带北太平洋纬向质量翻转环流响应，对应图4a。对应数据文件：Regression_TNP.nc。
11. 针对平滑后的200hPa流函数响应的北太平洋PC1，回归得到的东太平洋经向质量翻转环流函数响应，对应图4b。对应数据文件：Regression_ENP.nc。
12. 针对平滑后的200hPa流函数响应的北太平洋PC1，回归得到的向外长波辐射（OLR）响应，对应图4c。对应数据文件：Regression_OLR.nc。

致谢
本研究使用了下述模式代码：
地球物理流体动力学实验室耦合气候模式第4版（GFDL-CM4）的代码可在https://zenodo.org/records/3339397公开获取。