The Bay-Delta SCHISM model connects to coastal models on its ocean boundary for salinity and temperature, using Newtonian relaxation or "nudging". The files in this dataset are cached and subsetted copies of the netcdf output from the CenCOOS/ROMS (https://www.cencoos.org/) and HYCOM (hycom.org) ocean models that are needed to populate those nudging inputs. The CenCOOS forecasting program ended in 2022, and the Delta Modeling Section transitions to HYCOM after 2020. To bridge (actually overlap) the gap, HYCOM (hycom.org) data are given starting in December 2018. The datasets are broken into multi-year blocks, but the files are still quite large (up to 7Gb). There is overlap between the files marked SF Bay, CenCoos and the HYCOM.

The files have undergone some processing and reformatting and CenCOOS data were bias corrected based on their inluence on coastal and San Francisco Bay temperature. HYCOM is not bias corrected. Note that (infrequently) some dates are missing in the original products and we have filled in the data usually by forward copying the prior available day. These files are not used directly by SCHISM, but rather are a prerequisite data source for preparing nudging inputs. Please see (https://cadwrdeltamodeling.github.io/BayDeltaSCHISM/topics/nudging.html) for more on the topic

The data are updated only occasionally. In the Delta Modeling Section program, the download_hycom utility (command line derived from download_hycom.py) is available in the https://github.com/CADWRDeltaModeling/dms_datastore package. The authors based this on a similar utility in the pyschism package. https://github.com/schism-dev/pyschism.

The resources on this page all extract into a common parent directory called "coastal"