CYGNSS Surface Heat Flux Product and Low-Latitude Extratropical Cyclone Analysis
Abstract
Latent (LHF) and Sensible (SHF) heat fluxes over the world's oceans play a vital role in the genesis and evolution of various weather phenomena and events, such as tropical and extratropical cyclones, tropical convection, and large-scale weather patterns. While in-situ observations of surface heat fluxes from flux towers and buoys are the standard, these data can have limited temporal and spatial resolution. While fluxes estimated from polar orbiting satellites can provide greater coverage, they still typically have coarse spatial and temporal resolution, especially in the lower latitudes. The NASA CYGNSS (Cyclone Global Navigation Satellite System) constellation of eight small satellites provides estimates of surface winds over the tropical and sub-tropical oceans with higher temporal and spatial sampling rates. Additionally, since CYGNSS utilizes the GPS L1 channel, its signal is less sensitive to heavy precipitation. Combining CYGNSS winds with thermodynamic variables from another source (e.g. MERRA-2), we have developed the CYGNSS Surface Heat Flux Product, providing LHF and SHF estimates for the entire CYGNSS mission (March 18, 2017 to present). This product, validated with buoy data, has been developed and distributed in order to aid the scientific community's understanding of how surface heat fluxes could influence various weather and climate phenomena.
The new CYGNSS Surface Heat Flux Product is used to analyze how latent and sensible heat fluxes vary around low-latitude extratropical cyclones (ETCs) and their fronts. While CYGNSS is a tropical mission, its sampling consistently reach up to the 38th parallel in both hemispheres, allowing it to observe ETCs that develop over the subtropical oceans where surface heat fluxes can be high, such as the Western Atlantic and Western Pacific Oceans. With CYGNSS's higher temporal and spatial resolution, it can provide new insights into ETC cyclogenesis and evolution that were difficult to achieve with previous remote sensing and in-situ measurements. This part of the presentation will highlight overall CYGNSS observations of ETCs, as well as focusing on some marine-based ETCs that CYGNSS has observed.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.A41L2732C
- Keywords:
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- 3307 Boundary layer processes;
- ATMOSPHERIC PROCESSES;
- 3311 Clouds and aerosols;
- ATMOSPHERIC PROCESSES;
- 3322 Land/atmosphere interactions;
- ATMOSPHERIC PROCESSES;
- 3379 Turbulence;
- ATMOSPHERIC PROCESSES