Abstract's details
Satellite Altimetry Sea Level Height and Related In Situ DART® and Tide Gauge Products Stewardship and Comparison Study in NOAA/NCEI
CoAuthors
Event: 2023 Ocean Surface Topography Science Team Meeting
Session: Coastal Altimetry
Presentation type: Type Oral
Contribution: PDF file
Abstract:
The NOAA National Centers for Environmental Information (NCEI) provides near real-time and delayed-mode product distribution, archive services, and long-term data stewardship for the OSTM/Jason-2 and Jason-3 products. NCEI Satellite Oceanography Group in Silver Spring, Maryland (NCEI-MD) supports ingest, archival storage, and basic access to mission level-2 and related products through the NOAA Comprehensive Large Array-data Stewardship System (CLASS). NCEI-MD has also instituted a mirror service to provide the public with all level-2 Geophysical Data Records (GDR) through FTP, HTTP, OPeNDAP, and THREDDS servers. The NCEI Hazards Group in Boulder, Colorado (NCEI-CO) is hosting an archive of high-resolution water-level data as part of the US National Tsunami Hazards Mitigation Program (NTHMP), which includes over 300 NOAA/NWS Deep-ocean Assessment and Reporting of Tsunamis (DART®) records covering over 20 years, high-resolution tide gauge records from NOAA “tsunami-ready” network maintained by the NOAA/NOS Center for Operational Oceanographic Products and Services (CO-OPS), high-resolution water level data from the regional networks of the Pacific Tsunami Warning Center (PTWC), and the National Tsunami Warning Center (NTWC).
In one of our data comparison studies, we investigate the representativity of the DART® bottom pressure observations by comparing them to the satellite altimeter and coastal tide gauge data. DART® records represent the pressure of the water column above the bottom pressure recorders (BPR) on the ocean floor and the effect of the atmospheric pressure at the ocean surface. We used cross-spectral and wavelet analysis, and direct comparison with coastal tide gauge records. We found that the DART® Sea Surface Height Anomalies (SSHA) agree with the altimeter SSHA and coastal or island tide gauge records in regions with high atmospheric dynamics in time frames up to 2-3 days. These regions include the North Pacific Ocean along Japan, the Aleutian Islands and Alaska, the Hawaii Islands, the West Atlantic along the US East Coast, and the Caribbean Basin. Our findings indicate that in these regions DART® SSHA characterizes the open-ocean water level variations in the frequency band equal to or less than one cycle per day. For lower frequencies (long-period variations), DART® systems do not record the long-period pressure variations due to the plastic deformations of the alloy containers with the BPR sensors on the ocean floor. For frequencies higher than 0.3-0.5 cycles per day, local conditions at DART® deployment sites and the coastal stations are dominating. We will also present the results of applying the Jason-3 Interim GDR SSHA data in tracking the Tsunami wave, which was triggered by the volcano eruption at Hunga Tonga-Hunga Ha'apai in Tonga on January 15, 2022. At the moment in case of a “good luck” satellite altimeter tracks are the unique observational data for the propagation of the front of the tsunamis.
In one of our data comparison studies, we investigate the representativity of the DART® bottom pressure observations by comparing them to the satellite altimeter and coastal tide gauge data. DART® records represent the pressure of the water column above the bottom pressure recorders (BPR) on the ocean floor and the effect of the atmospheric pressure at the ocean surface. We used cross-spectral and wavelet analysis, and direct comparison with coastal tide gauge records. We found that the DART® Sea Surface Height Anomalies (SSHA) agree with the altimeter SSHA and coastal or island tide gauge records in regions with high atmospheric dynamics in time frames up to 2-3 days. These regions include the North Pacific Ocean along Japan, the Aleutian Islands and Alaska, the Hawaii Islands, the West Atlantic along the US East Coast, and the Caribbean Basin. Our findings indicate that in these regions DART® SSHA characterizes the open-ocean water level variations in the frequency band equal to or less than one cycle per day. For lower frequencies (long-period variations), DART® systems do not record the long-period pressure variations due to the plastic deformations of the alloy containers with the BPR sensors on the ocean floor. For frequencies higher than 0.3-0.5 cycles per day, local conditions at DART® deployment sites and the coastal stations are dominating. We will also present the results of applying the Jason-3 Interim GDR SSHA data in tracking the Tsunami wave, which was triggered by the volcano eruption at Hunga Tonga-Hunga Ha'apai in Tonga on January 15, 2022. At the moment in case of a “good luck” satellite altimeter tracks are the unique observational data for the propagation of the front of the tsunamis.