Spatio-temporal level variations of the Martian Seasonal North Polar Cap

Products and codes for visualization from Xiao et al. (2021, submitted to JGR: Planets in December 2021) titled "Spatio-temporal level variations of the Martian Seasonal North Polar Cap from co-registration of MOLA profiles". Level here denotes the thickness of the Seasonal North Polar Cap (SNPC).

Folder "Animation_spatial_temporal_level_variation_SNPC" contains the gif animation of the spatio-temporal evolution of the level of the SNPC from MY24 to MY25. Unit for the level is [m].

Folder "Early_winter_level_SNPC" contains the text files with longitude, latitude, (precision of the) early winter level at Ls 300° during the early northern winter, and the bash scripts for visualization the early winter level of the SNPC and its associated precision using GMT6.1. Unit is [m] for the early winter level and is [cm] for the precision.

Folder "Maximum_level_SNPC" contains the text files with longitude, latitude, (precision of the) maximum level, and the bash scripts for visualization the maximum level of the SNPC and its associated precision using GMT6.1. Unit is [m] for the maximum level and is [cm] for the precision.

Folder "NP_topography_from_self_registration_of_MOLA_profiles" contains the reference DTM from the self-registration of the reprocessed MOLA profiles from 60°N to 90°N in GeoTiff format, and the bash script for visualization the topography using GMT6.1. Shape files for the polar erg, residual north polar cap and Olympia Undae are also included. Unit for the elevation is [km].

Folder "Off-season_decrease_SNPC_Olympia_Undae" contains the text files with longitude, latitude, (precision of the) off-season level decrease of the SNPC at the dune fields in Olympia Undae during the northern winter, and the bash scripts for visualization the off-season level decrease and its associated precision using GMT6.1. Unit is [m] for the off-season level decrease and is [cm] for the precision.

Folder "Off-season_increase_SNPC_Olympia_Undae" is similar to the folder "Off-season_decrease_SNPC_Olympia_Undae", but instead it entails the off-season level increase of the SNPC in Olympia Undae during the northern spring.

Folder "Tempoal_level_variation_at_grid_elements_SNPC" contains a zip file of csv files on the temporal level variations of the SNPC at each grid element of 10° in longitude and 0.5° in latitude from 60°N to 87°N. Latitude and longitude of the center of the grid element can be calculated using the second and third numbers in each csv file name as Lat = 87° - (2nd_Num-1)*0.5° and Lon = (3rd_Num-1)*10° + 5°. Here, the 2nd_Num ranges from 1 to 55 and the 3rd_Num ranges from 1 to 36. The label for each csv file is:
## ls_binned (solar longitude in [deg]) ## h_series_binned (the temporal level in [m]) ## error_h_series_binned (precision measured as the scaled median absolute deviation in [m]) ## lower_limit (h_series_binned minus error_h_series_binned in [m]) ## upper_limit (h_series_binned plus error_h_series_binned in [m]).

本数据集为Xiao等人于2021年12月提交至《地球物理研究杂志：行星科学分册》（JGR: Planets）的论文《基于火星轨道激光高度计（Mars Orbiter Laser Altimeter, MOLA）剖面共配准的火星季节性北极冠（Seasonal North Polar Cap, SNPC）时空厚度变化》配套的可视化产物与代码集，该论文原文标题为"Spatio-temporal level variations of the Martian Seasonal North Polar Cap from co-registration of MOLA profiles"，文中提及的"厚度（level）"即指季节性北极冠的厚度。

文件夹"Animation_spatial_temporal_level_variation_SNPC"包含火星季节性北极冠厚度从MY24（即火星年24）至MY25（即火星年25）的时空演化动态GIF动画，厚度单位为米（[m]）。

文件夹"Early_winter_level_SNPC"包含文本文件与Bash脚本：其中文本文件记录了北极早冬时节（太阳经度（Solar Longitude, Ls）=300°）的季节性北极冠早冬厚度及其精度数据，字段包含经度、纬度及（厚度）精度；Bash脚本用于通过GMT6.1可视化该时期的季节性北极冠厚度及其对应精度。其中厚度单位为米（[m]），精度单位为厘米（[cm]）。

文件夹"Maximum_level_SNPC"包含文本文件与Bash脚本：文本文件记录了季节性北极冠最大厚度的经度、纬度及其精度数据；Bash脚本用于通过GMT6.1可视化该最大厚度及其对应精度。最大厚度单位为米（[m]），精度单位为厘米（[cm]）。

文件夹"NP_topography_from_self_registration_of_MOLA_profiles"包含基于60°N至90°N纬度范围内再处理后的MOLA剖面自配准得到的参考数字地形模型（Digital Terrain Model, DTM），格式为GeoTiff；同时包含用于通过GMT6.1可视化该地形的Bash脚本，以及极地沙丘场（polar erg）、残余北极冠与奥林匹亚沙丘原（Olympia Undae）的形状文件。地形高程单位为千米（[km]）。

文件夹"Off-season_decrease_SNPC_Olympia_Undae"包含文本文件与Bash脚本：文本文件记录了北极冬季时期奥林匹亚沙丘场内季节性北极冠非旺季厚度缩减量及其精度数据，字段包含经度、纬度及（缩减量）精度；Bash脚本用于通过GMT6.1可视化该厚度缩减量及其对应精度。厚度缩减量单位为米（[m]），精度单位为厘米（[cm]）。

文件夹"Off-season_increase_SNPC_Olympia_Undae"与"Off-season_decrease_SNPC_Olympia_Undae"文件夹内容类似，但该文件夹包含的是北极春季时期奥林匹亚沙丘场内季节性北极冠非旺季厚度增量数据。

文件夹"Tempoal_level_variation_at_grid_elements_SNPC"包含一个压缩包，内有针对60°N至87°N纬度范围内、经度间隔10°、纬度间隔0.5°的每个格网单元的季节性北极冠厚度时空变化的CSV文件。可通过每个CSV文件名的第二、第三组数字计算格网单元中心的经纬度：纬度Lat = 87° - (第二组数字 - 1) × 0.5°，经度Lon = (第三组数字 - 1) × 10° + 5°，其中第二组数字取值范围为1至55，第三组数字取值范围为1至36。每个CSV文件的字段标签依次为：
## 分箱太阳经度（ls_binned，单位：度[deg]）## 分箱时间序列厚度（h_series_binned，单位：米[m]）## 厚度序列误差（error_h_series_binned，以缩放中位数绝对偏差衡量的精度，单位：米[m]）## 厚度下限（lower_limit = h_series_binned - error_h_series_binned，单位：米[m]）## 厚度上限（upper_limit = h_series_binned + error_h_series_binned，单位：米[m]）。