CYGNSS Level 2 Ocean Surface Heat Flux Science Data Record Version 1.0

Description

This dataset contains the Version 1.0 CYGNSS Level 2 Ocean Surface Heat Flux Science Data Record, which provides the time-tagged and geolocated ocean surface heat flux parameters with 25x25 kilometer footprint resolution from the Delay Doppler Mapping Instrument (DDMI) aboard the CYGNSS satellite constellation. The reported sample locations are determined by the specular points corresponding to the Delay Doppler Maps (DDMs). Only one netCDF-4 data file is produced each day (each file containing data from a combination of up to 8 unique CYGNSS spacecraft) with a latency of approximately 1 to 2 months from the last recorded measurement time. Version 1.0 represents the first release. The Cyclone Global Navigation Satellite System (CYGNSS), launched on 15 December 2016, is a NASA Earth System Science Pathfinder Mission that was launched with the purpose to collect the first frequent space-based measurements of surface wind speeds in the inner core of tropical cyclones. Made up of a constellation of eight micro-satellites, the CYGNSS observatories provide nearly gap-free Earth coverage with a mean (i.e., average) revisit time of seven hours and a median revisit time of three hours. The 35 degree orbital inclination allows CYGNSS to measure ocean surface winds between approximately 38 degrees North and 38 degrees South latitude using an innovative combination of all-weather performance Global Positioning System (GPS) L-band ocean surface reflectometry to penetrate the clouds and heavy precipitation. The Coupled Ocean-Atmosphere Response Experiment (COARE) algorithm is what is used in this dataset to estimate the latent and sensible heat fluxes and their respective transfer coefficients. While COARE's initial intentions were for low to moderate wind speeds, the version used for this product, COARE 3.5, has been verified with direct in situ flux measurements for wind speeds up to 25 m/s. As CYGNSS does not provide air/sea temperature, humidity, surface pressure or density, the producer of this dataset obtains these values from the NASA Modern-Era Retrospective Analysis for Research and Applications Version 2 (MERRA-2), which uses data assimilation to combine all available in situ and satellite observation data with an initial estimate of the atmospheric state, provided by a global atmospheric model. Since the MERRA-2 data is only updated on monthly intervals, this corresponding heat flux dataset is likewise updated on a monthly interval to reflect the latest data available from MERRA-2, thus accounting for measurement latency, with respect to CYGNSS observables, ranging from 1 to 2 months. The data from this release compares well with in situ buoy data, including: Kuroshio Extension Observatory (KEO), National Data Buoy Center (NDBC), Ocean Sustained Interdisciplinary Time-series Environment observation System (OceanSITES), Prediction and Research Moored Array in the Tropical Atlantic (PIRATA), Research Moored Array for African-Asian-Australian Monsoon Analysis and Prediction (RAMA), and the Tropical Atmosphere Ocean (TAO) array. As this marks only the first data release, future work is expected to provide comparisons and validation with various field campaigns (e.g., PISTON, CAMP2Ex) as well as more buoy data, especially at higher flux estimates.

Resources

Name Format Description Link
21 Clarizia, M. P., and C. S. Ruf, 'Wind Speed Retrieval Algorithm for the Cyclone Global Navigation Satellite System (CYGNSS) Mission', IEEE Trans Geosci. Remote Sens., doi:10.1109/TGRS.2016.2541343, 2016. https://doi.org/10.1109/TGRS.2016.2541343
21 Spacecraft Attitude Tables Updated Monthly https://archive.podaac.earthdata.nasa.gov/podaac-ops-cumulus-docs/cygnss/open/L1/docs/att_tables/Attitude_Table_FM_8.txt
21 Search results for publications that cite this dataset by its DOI. https://scholar.google.com/scholar?q=10.5067%2FCYGNS-L2H10
33 User Guide for the CYGNSS Surface Flux Dataset https://archive.podaac.earthdata.nasa.gov/podaac-ops-cumulus-docs/cygnss/open/L2/docs/cygnss_l2_heat_flux_user_guide_v1.pdf
21 Generic Data Readers https://github.com/podaac/data-readers
21 CYGNSS Mission Page at University of Michigan https://cygnss.engin.umich.edu/
21 Ruf, C., R. Balasubramaniam, 'Development of the CYGNSS Geophysical Model Function for Wind Speed', IEEE J. Sel. Topics Appl. Earth Obs. Remote Sens., doi: 10.1109/JSTARS.2018.2833075, 2018. https://doi.org/10.1109/JSTARS.2018.2833075
21 CYGNSS Handbook https://doi.org/10.3998/mpub.12741920
21 Crespo, J. A., Posselt, D. J., & Asharaf, S. (2019). CYGNSS Surface Heat Flux Product Development. Remote Sens. 2019, 11, 2294. DOI: 10.3390/rs11192294. https://doi.org/10.3390/rs11192294
22 Thumbnail https://podaac.jpl.nasa.gov/Podaac/thumbnails/CYGNSS_L2_SURFACE_FLUX_V1.0.jpg
33 Deriving Surface Winds from Tropical Cyclones https://cygnss.engin.umich.edu/wp-content/uploads/sites/534/2021/06/CYGNSS_Handbook_April2016.pdf
21 Data Variable Dictionary https://archive.podaac.earthdata.nasa.gov/podaac-ops-cumulus-docs/cygnss/open/L2/docs/148-0382-1_Level2_Surface_Flux_netCDF_Data_Dictionary.xlsx
21 Data Use and Citation Policy https://podaac.jpl.nasa.gov/CitingPODAAC
21 HTTPS endpoint for data browse and download https://cmr.earthdata.nasa.gov/virtual-directory/collections/C2036882055-POCLOUD
21 Browse granule search results in Earthdata Search https://search.earthdata.nasa.gov/search/granules?p=C2036882055-POCLOUD
21 OPeNDAP Access for Data in the Cloud https://podaac.jpl.nasa.gov/OPeNDAP-in-the-Cloud
21 Spacecraft Attitude Tables Updated Monthly https://archive.podaac.earthdata.nasa.gov/podaac-ops-cumulus-docs/cygnss/open/L1/docs/att_tables/Attitude_Table_FM_2.txt
21 Spacecraft Attitude Tables Updated Monthly https://archive.podaac.earthdata.nasa.gov/podaac-ops-cumulus-docs/cygnss/open/L1/docs/att_tables/Attitude_Table_FM_4.txt
21 Spacecraft Attitude Tables Updated Monthly https://archive.podaac.earthdata.nasa.gov/podaac-ops-cumulus-docs/cygnss/open/L1/docs/att_tables/Attitude_Table_FM_5.txt
21 Spacecraft Attitude Tables Updated Monthly https://archive.podaac.earthdata.nasa.gov/podaac-ops-cumulus-docs/cygnss/open/L1/docs/att_tables/Attitude_Table_FM_6.txt
21 Google Sheet Log of Anomalous CYGNSS Sampling Events https://docs.google.com/spreadsheets/d/1AFAZanVGDApLSnJQAAdPfOKoJQs0jnB8ZvIuD1Z5mAc/edit#gid=0
21 Spacecraft Attitude Tables Updated Monthly https://archive.podaac.earthdata.nasa.gov/podaac-ops-cumulus-docs/cygnss/open/L1/docs/att_tables/Attitude_Table_FM_1.txt
21 Spacecraft Attitude Tables Updated Monthly https://archive.podaac.earthdata.nasa.gov/podaac-ops-cumulus-docs/cygnss/open/L1/docs/att_tables/Attitude_Table_FM_3.txt
21 Spacecraft Attitude Tables Updated Monthly https://archive.podaac.earthdata.nasa.gov/podaac-ops-cumulus-docs/cygnss/open/L1/docs/att_tables/Attitude_Table_FM_7.txt
21 Ruf, C., S. Asharaf, R. Balasubramaniam, S. Gleason, T. Lang, D. McKague, D. Twigg, and D. Waliser. (2019). In-Orbit Performance of the Constellation of CYGNSS Hurricane Satellites. Bull. Amer. Meteor. Soc., 100, 2009 - 2023, https://doi.org/10.1175/BAMS-D-18-0337.1. https://doi.org/10.1175/BAMS-D-18-0337.1
33 Level 2 Wind Speed Retrieval Algorithm Theoretical Basis Document, M. P. Clarizia, V. Zavarotny, C. Ruf, CYGNSS Project Document 148-0138, Rev 5, 17 Aug. 2018. https://archive.podaac.earthdata.nasa.gov/podaac-ops-cumulus-docs/cygnss/open/L2/docs/148-0138_ATBD_L2_Wind_Speed_Retrieval_Rev5_Aug2018_release.pdf
21 Ruf, C., R. Atlas, P. Chang, M. Clarizia, J. Garrison, S. Gleason, S. Katzberg, Z. Jelenak, J. Johnson, S. Majumdar, A. O'Brien, D. Posselt, A. Ridley, R. Rose, V. Zavorotny (2015). New Ocean Winds Satellite Mission to Probe Hurricanes and Tropical Convection. Bull. Amer. Meteor. Soc., doi:10.1175/BAMS-D-14-00218.1. https://doi.org/10.1175/BAMS-D-14-00218.1

Tags

  • ocean-heat-budget
  • oceans
  • ocean-temperature
  • earth-science

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