Southern Ocean related remote sensing datasets used by the Nilas Southern Ocean Mapping Platform.

This dataset contains multiple variables with spatio-temporal information relating to sea-ice and the southern ocean. This collection of data is utilised by the nilas.org platform for dynamically visualising these variables in the web browser. Together they provide a valuable resource for understanding the interactions between physical, climate and biogeochemical parameters. These include variables to understand sea-ice in three dimensions, chlorophyll and sea surface temperature. The time range of these data covers from 1980 until the present and the spatial coverage is Antarctic circumpolar.

Name: Daily Sea Ice Concentration
Desc: Sea ice concentration is a measure of the amount of size ice over an area. It is calculated from satellite observations of sea ice for all areas adjacent the Antarctic coastline. The minimum area of sea ice naturally occurs in February and the maximum in September.
Product: ARTIST (ASI 5) (Spreen et al. 2008)
Source: Universität Bremen
Resolution: 6.125 km nominal
Timeframe: 2012 to present
Notes: Concentrations of less than 15% have been removed.

Name: Monthly Sea Ice Concentration
Desc: Sea ice concentration is a measure of the amount of size ice over an area. It is calculated from satellite observations of sea ice for all areas adjacent the Antarctic coastline. The minimum area of sea ice naturally occurs in February and the maximum in September.
Product: Sea Ice Index (Windnagel et al. 2017)
Source: NSIDC (National Snow and Ice Data Center)
Resolution: 25 km nominal
Timeframe: 1980 to present
Notes: Concentrations of less than 15% have been removed.

Name: Monthly Anomalies in Sea Ice Concentration
Desc: Anomalies in sea ice concentration show the monthly variation from the long term mean.
Product: Climate Data Record and Near Real-Time Sea Ice Concentration (Windnagel et al. 2021)
Source: NSIDC (National Snow and Ice Data Center)
Resolution: 25km nominal
Timeframe: 1980 to present
Notes: Anomalies are calculated as the difference between the sea ice concentration and the 1981-2010 mean sea ice concentration for that month. Anomalies less than 7.5% are not shown.

Name: Long term monthly mean sea ice extent
Desc: Sea ice extent is calculated as contour lines at 15% and 80% sea ice concentration.
Product: Sea Ice Index (Windnagel et al. 2017)
Source: Climate Data Record and Near Real-Time Sea Ice Concentration (Windnagel et al. 2021)
Resolution: -
Timeframe: 1980 to present
Notes: Contours with less than 15 vertices are discarded.

Name: Long Term Monthly Mean Sea Ice Extent
Desc: Mean monthly sea ice extent over the 1981-2010 time interval. This is calculated as contour lines at 15% and 80% long term mean (1981-2010) sea ice concentration.
Product: Sea Ice Index (Windnagel et al. 2017)
Source: NSIDC (National Snow and Ice Data Center)
Resolution: -
Timeframe: Long term monthly mean (1981-2010)
Notes: Contours with less than 15 vertices are discarded.

Name: Gridded Freeboard (ATL20) IceSat2
Desc: Sea ice freeboard is the distance between the waterline and the surface height of sea ice in open leads. This dataset contains monthly gridded estimates of sea ice freeboard, derived from along-track freeboard estimates in the ATLAS/ICESat-2 L3A Sea Ice Freeboard product (ATL10,V3).
Product: ATL20 (Petty et al. 2020)
Source: NSIDC
Resolution: 25 km nominal
Timeframe: Oct 2018 to July 2022
Notes: Data greater than 1 metre is shown as 1 metre height.

Name: Annual Sea Ice Duration
Desc: Sea ice duration (contour lines) is the number of days sea ice concentrations above 15% occur between consecutive sea ice minima (assumed to occur on Feb 16 each year).
Product: Climate Data Record and Near Real-Time Sea Ice Concentration (Windnagel et al. 2021)
Source: NSIDC (National Snow and Ice Data Center)
Resolution: 25km nominal
Timeframe: 1980 to 2021
Notes:

Name: Sea Ice Duration Anomalies
Desc: Anomalies in sea ice duration show difference in duration of sea ice from the long term mean, where sea ice duration is the number of days sea ice concentrations above 15% occur between consecutive sea ice minima.
Product: Climate Data Record and Near Real-Time Sea Ice Concentration (Windnagel et al. 2021)
Source: NSIDC (National Snow and Ice Data Center)
Resolution: 25km nominal
Timeframe: 1980 to 2021
Notes: Anomalies in sea ice duration are calculated relative to the 1981 to 2010 mean.

Name: Annual Sea Ice Advance
Desc: Sea ice advance is the date when sea ice concentrations persist above 15% after the sea ice minimum.
Product: Climate Data Record and Near Real-Time Sea Ice Concentration (Windnagel et al. 2021)
Source: NSIDC (National Snow and Ice Data Center)
Resolution: 25km nominal
Timeframe: 1980 to 2022
Notes:

Name: Sea Ice Advance Anomalies
Desc: Anomalies in sea ice advance show number of days (early/late) from the long term mean, where sea ice advance is the date when sea ice concentrations persist above 15% after the sea ice minimum.
Product: Climate Data Record and Near Real-Time Sea Ice Concentration (Windnagel et al. 2021)
Source: NSIDC (National Snow and Ice Data Center)
Resolution: 25km nominal
Timeframe: 1980 to 2022
Notes: Anomalies in sea ice advance are calculated relative to the 1981 to 2010 mean.

Name: Annual Sea Ice Retreat
Desc: Sea ice retreat is the date when sea ice concentrations persist below 15% occur after the sea ice maximum.
Product: Climate Data Record and Near Real-Time Sea Ice Concentration (Windnagel et al. 2021)
Source: NSIDC (National Snow and Ice Data Center)
Resolution: 25km nominal
Timeframe: 1980 to 2021
Notes:

Name: Annual Sea Ice Retreat
Desc: Anomalies in sea ice retreat show number of days (early/late) from the long term mean, where sea ice retreat is the date when sea ice concentrations persist below 15% occur after the sea ice maximum.
Product: Climate Data Record and Near Real-Time Sea Ice Concentration (Windnagel et al. 2021)
Source: NSIDC (National Snow and Ice Data Center)
Resolution: 25km nominal
Timeframe: 1980 to 2021
Notes: Anomalies in sea ice retreat are calculated relative to the 1981 to 2010 mean.

Name: Monthly Chlorophyll Concentration
Desc: Chlorophyll-a is a proxy for phytoplankton activity in the ocean and is estimated through ocean colour remote sensing.
Product: Ocean Colour Climate Change Initiative (Sathyendranath et al. 2019)
Source: Ocean Colour
Resolution: 4km nominal, displayed at 10km
Timeframe: 1998-Jun 2022
Notes: This product relies on reflectance in the visible spectrum and does not perform well at Southern Hemisphere high latitudes during periods of low light (April to August) or where there is dense sea ice cover.

Name: Monthly Chlorophyll Concentration Anomalies
Desc: Anomalies in the monthly chlorophyll concentration are calculated relative to the 1998-2020 average for that month.
Product: Ocean Colour Climate Change Initiative (Sathyendranath et al. 2019)
Source: Ocean Colour
Resolution: 4km nominal, displayed at 10km
Timeframe: 1998-Jun 2022
Notes: This product relies on reflectance in the visible spectrum and does not perform well at Southern Hemisphere high latitudes during periods of low light (April to August) or where there is dense sea ice cover.

Name: Monthly Sea Surface Temperature
Desc: Sea Surface Temperature (SST) is an estimate of the water temperature at the ocean surface calculated from satellite and surface observations.
Product: Met Office OSTIA (Operational Sea Surface Temperature and Sea Ice Analysis) Near Real Time (Good et al. 2020)
Source: Copernicus
Resolution: 0.05° × 0.05° Nominal
Timeframe: Oct 1981 to present
Notes: There is limited validation of SST remote sensing datasets in the marginal ice zone and close to Antarctica. SST within polynyas and within areas of low concentration sea ice are included but not well validated. Where SST under high concentration sea ice cannot be calculated from observations, it defaults to -1.8°C.

Name: Monthly Sea Surface Temperature Anomalies
Desc: Anomalies in the monthly Sea Surface Temperature (SST) are calculated relative to the 1981 to 2010 average for that month.
Product: Met Office OSTIA (Operational Sea Surface Temperature and Sea Ice Analysis) Near Real Time (Good et al. 2020)
Source: Copernicus
Resolution: 0.05° × 0.05° Nominal
Timeframe: Oct 1981 to present
Notes: There is limited validation of SST remote sensing datasets in the marginal ice zone and close to Antarctica. SST within polynyas and within areas of low concentration sea ice are included but not well validated. Where SST under high concentration sea ice cannot be calculated from observations, it defaults to -1.8°C.

Name: International Bathymetric Chart of the Southern Ocean Version 2 (IBCSO v2) (Dorschel et al. 2022)
Desc: Bathymetry is a measure of the depth of the ocean, provided for the areas south of 50° S. The product chosen is a digital bathymetric model for the area south of 50° S with special emphasis on the bathymetry of the Southern Ocean. The total data coverage of the seafloor is 23.79% with a multibeam-only data coverage of 22.32%. The remaining 1.47% include singlebeam and other data.
Product: International Bathymetric Chart of the Southern Ocean Version 2 (IBCSO v2) (Dorschel et al. 2022)
Source: Pangaea
Resolution: 5km nominal
Timeframe: Released 2022
Notes: The source product is provided at 500m nominal resolution, which has been regridded to the 5km nominal resolution displayed.

See the metadata record "AAS_4506_NILAS_SOFTWARE" for information about the Nilas software package.

这个数据集包含多个与海冰和南大洋相关的时空（spatio-temporal）信息变量。该数据集被nilas.org平台用于在网页浏览器中动态可视化这些变量，共同为理解物理、气候和生物地球化学参数之间的相互作用提供了宝贵资源。这些变量包括用于三维分析海冰的参数、叶绿素浓度及海表温度（Sea Surface Temperature，SST）。数据的时间范围从1980年至今，空间覆盖范围为南极环极区域。

名称：每日海冰浓度
描述：海冰浓度（sea ice concentration）是衡量某一区域内海冰覆盖量的指标，由南极海岸线附近所有区域的卫星海冰观测数据计算得出。海冰的最小面积自然出现在2月，最大面积出现在9月。
产品：ARTIST（ASI 5）（Spreen等，2008）
来源：不来梅大学
分辨率：标称6.125千米
时间范围：2012年至今
备注：已移除浓度低于15%的数据。

名称：月度海冰浓度
描述：海冰浓度是衡量某一区域内海冰覆盖量的指标，由南极海岸线附近所有区域的卫星海冰观测数据计算得出。海冰的最小面积自然出现在2月，最大面积出现在9月。
产品：海冰指数（Windnagel等，2017）
来源：NSIDC（国家冰雪数据中心，National Snow and Ice Data Center）
分辨率：标称25千米
时间范围：1980年至今
备注：已移除浓度低于15%的数据。

名称：月度海冰浓度异常值
描述：海冰浓度异常值反映了月度数据与长期平均值的偏差。
产品：气候数据记录与近实时海冰浓度（Windnagel等，2021）
来源：NSIDC（国家冰雪数据中心）
分辨率：标称25千米
时间范围：1980年至今
备注：异常值计算为当月海冰浓度与1981-2010年同期平均值的差值，低于7.5%的异常值未显示。

名称：长期月度平均海冰范围
描述：海冰范围通过15%和80%海冰浓度的等值线计算得出。
产品：海冰指数（Windnagel等，2017）
来源：气候数据记录与近实时海冰浓度（Windnagel等，2021）
分辨率：-
时间范围：1980年至今
备注：顶点少于15个的等值线已被丢弃。

名称：长期月度平均海冰范围
描述：1981-2010年期间的月度平均海冰范围，通过15%和80%长期平均（1981-2010）海冰浓度的等值线计算得出。
产品：海冰指数（Windnagel等，2017）
来源：NSIDC（国家冰雪数据中心）
分辨率：-
时间范围：长期月度平均值（1981-2010）
备注：顶点少于15个的等值线已被丢弃。

名称：网格化干舷（ATL20）IceSat2
描述：海冰干舷（sea ice freeboard）是开阔水道中海冰吃水线与表面高度之间的距离。该数据集包含月度网格化海冰干舷估算值，源自ATLAS/ICESat-2 L3A海冰干舷产品（ATL10，V3）的沿轨干舷估算值。
产品：ATL20（Petty等，2020）
来源：NSIDC
分辨率：标称25千米
时间范围：2018年10月至2022年7月
备注：高于1米的数据显示为1米高度。

名称：年度海冰持续时间
描述：海冰持续时间（等值线）是连续海冰最小值（假设每年2月16日出现）之间海冰浓度高于15%的天数。
产品：气候数据记录与近实时海冰浓度（Windnagel等，2021）
来源：NSIDC（国家冰雪数据中心）
分辨率：标称25千米
时间范围：1980年至2021年
备注：

名称：海冰持续时间异常值
描述：海冰持续时间异常值反映了其与长期平均值的偏差，其中海冰持续时间指连续海冰最小值之间海冰浓度高于15%的天数。
产品：气候数据记录与近实时海冰浓度（Windnagel等，2021）
来源：NSIDC（国家冰雪数据中心）
分辨率：标称25千米
时间范围：1980年至2021年
备注：海冰持续时间异常值相对于1981-2010年平均值计算。

名称：年度海冰推进
描述：海冰推进指海冰最小值后海冰浓度持续高于15%的日期。
产品：气候数据记录与近实时海冰浓度（Windnagel等，2021）
来源：NSIDC（国家冰雪数据中心）
分辨率：标称25千米
时间范围：1980年至2022年
备注：

名称：海冰推进异常值
描述：海冰推进异常值反映了其与长期平均值的偏差（提前/延迟天数），其中海冰推进指海冰最小值后海冰浓度持续高于15%的日期。
产品：气候数据记录与近实时海冰浓度（Windnagel等，2021）
来源：NSIDC（国家冰雪数据中心）
分辨率：标称25千米
时间范围：1980年至2022年
备注：海冰推进异常值相对于1981-2010年平均值计算。

名称：年度海冰消退
描述：海冰消退指海冰最大值后海冰浓度持续低于15%的日期。
产品：气候数据记录与近实时海冰浓度（Windnagel等，2021）
来源：NSIDC（国家冰雪数据中心）
分辨率：标称25千米
时间范围：1980年至2021年
备注：

名称：海冰消退异常值
描述：海冰消退异常值反映了其与长期平均值的偏差（提前/延迟天数），其中海冰消退指海冰最大值后海冰浓度持续低于15%的日期。
产品：气候数据记录与近实时海冰浓度（Windnagel等，2021）
来源：NSIDC（国家冰雪数据中心）
分辨率：标称25千米
时间范围：1980年至2021年
备注：海冰消退异常值相对于1981-2010年平均值计算。

名称：月度叶绿素浓度
描述：叶绿素a是海洋浮游植物活动的替代指标，通过海洋水色遥感估算得出。
产品：海洋水色气候变化倡议（Sathyendranath等，2019）
来源：海洋水色
分辨率：标称4千米，显示为10千米
时间范围：1998年至2022年6月
备注：该产品依赖可见光反射率，在南半球高纬度地区低光照期（4月至8月）或海冰密集覆盖区域表现不佳。

名称：月度叶绿素浓度异常值
描述：月度叶绿素浓度异常值相对于该月1998-2020年平均值计算。
产品：海洋水色气候变化倡议（Sathyendranath等，2019）
来源：海洋水色
分辨率：标称4千米，显示为10千米
时间范围：1998年至2022年6月
备注：该产品依赖可见光反射率，在南半球高纬度地区低光照期（4月至8月）或海冰密集覆盖区域表现不佳。

名称：月度海表温度
描述：海表温度（Sea Surface Temperature，SST）是通过卫星和表面观测计算得出的海洋表面水温估算值。
产品：英国气象局OSTIA（业务海表温度与海冰分析）近实时产品（Good等，2020）
来源：哥白尼（Copernicus）
分辨率：标称0.05°×0.05°
时间范围：1981年10月至今
备注：冰缘带和南极附近的SST遥感数据集验证有限；冰间湖（polynyas）和低浓度海冰区域的SST数据已包含但验证不足；高浓度海冰下无法通过观测计算的SST默认值为-1.8°C。

名称：月度海表温度异常值
描述：月度海表温度（SST）异常值相对于该月1981-2010年平均值计算。
产品：英国气象局OSTIA（业务海表温度与海冰分析）近实时产品（Good等，2020）
来源：哥白尼
分辨率：标称0.05°×0.05°
时间范围：1981年10月至今
备注：冰缘带和南极附近的SST遥感数据集验证有限；冰间湖和低浓度海冰区域的SST数据已包含但验证不足；高浓度海冰下无法通过观测计算的SST默认值为-1.8°C。

名称：国际南大洋海底地形图版本2（IBCSO v2）（Dorschel等，2022）
描述：海底地形（bathymetry）是海洋深度的测量指标，覆盖南纬50°以南区域。该产品是南纬50°以南区域的数字海底地形模型，重点关注南大洋海底地形。海底数据总覆盖率为23.79%，其中纯多波束数据覆盖率22.32%，剩余1.47%为单波束及其他数据。
产品：国际南大洋海底地形图版本2（IBCSO v2）（Dorschel等，2022）
来源：Pangaea
分辨率：标称5千米
时间范围：2022年发布
备注：源产品标称分辨率为500米，已重新网格化至显示所用的标称5千米分辨率。

有关Nilas软件包的信息，请参见元数据记录“AAS_4506_NILAS_SOFTWARE”。