Obtaining UHSLC Data
There are currently three ways to obtain tide gauge data from the UHSLC:
- The legacy data portal remains online. A new data portal with increased functionality is under construction.
Citing UHSLC Data
If you use UHSLC tide gauge data in your research or applications, please cite the dataset as:
Caldwell, P. C., M. A. Merrfield, P. R. Thompson (2015), Sea level measured by tide gauges from global oceans — the Joint Archive for Sea Level holdings (NCEI Accession 0019568), Version 5.5, NOAA National Centers for Environmental Information, Dataset, doi:10.7289/V5V40S7W.
This citation refers to the Research Quality dataset archived by the NOAA National Centers for Environmental Information as the Joint Archive for Sea Level. As discussed below, Fast Delivery data is replaced by Research Quality as it becomes available. Only the most recent Fast Delivery values are not included in the Research Quality archive. If you use Fast Delivery data, please use the citation above and note the date through which Fast Delivery data was obtained.
What datasets are available?
The UHSLC offers tide gauge data with two levels of quality-control (QC), where more rigorous QC requires more effort and a greater time-lag.
- Fast Delivery (FD) data are released within 1-2 months of data collection and receive only basic QC focused on large level shifts and obvious outliers. FD data are replaced in the data stream by RQD (see below) as the latter becomes available.
- Research Quality Data (RQD) receive thorough QC and are considered to be the final science-ready data set. This final QC process is time-consuming, and as a result, the RQD are released 1-2 years after data is received from the data originators by the UHSLC.
Real-Time (RT) data, which feeds the international tsunami networks, are available from the UNESCO IOC Sea Level Monitoring website hosted by the Flanders Marine Institute (VLIZ).
Other important notes:
- The UHSLC maintains one of the largest global networks of tide gauges that feed the FD stream, but there are numerous other international agencies that contribute. These FD data are received from partner agencies on a monthly basis and incorporated into the FD stream.
- The RQD is maintained by Pat Caldwell and archived as the NOAA Joint Archive for Mean Sea Level (JASL). FD data is included in the RQD after final quality-control, but the RQD includes many more sites from countries with less technical capacity for fast data turn-around. The JASL is also active in historical data rescue.
- The Permanent Service for Mean Sea Level is the primary GLOSS repository for monthly data, and in order to avoid confusion, the RQD is only available from the UHSLC at hourly and daily resolution. All RQD are sent in annual updates to the PSMSL to be incorporated into the monthly data stream.
Frequently Asked Questions
The UHSLC datasets are GLOSS data streams (read more here). There are many tide gauge records in the UHSLC database, but the backbone is the GLOSS Core Network (GCN) – a global set of ~300 tide gauge stations that serve as the foundation of the global in situ sea level network. The network is designed to provide evenly distributed sampling of global coastal sea level variation at a variety of time-scales. For more information on the selection and standards required of GCN stations, please see the GLOSS Implementation Plan 2012.
The maps to the right show the status of GCN stations in the UHSLC data streams (graphics courtesy of PSMSL). For each stream, the colored circles indicate whether a site is operational (green marker), has been operational in the past (orange marker), or never operated successfully for that particular stream (white marker).
All full summary of the network status for all GLOSS data streams is available here: glossCoreNetwork.xml