GPS World

Tag: weather observation

  • GNSS reveals fourfold turbulence during Antarctica’s Ross Ice Shelf melt

    GNSS reveals fourfold turbulence during Antarctica’s Ross Ice Shelf melt

    Observations suggest a major melting event at the Ross Ice Shelf was connected to atmospheric turbulence.

    The Ross Ice Shelf in Antarctica typically melts on its underside as warmer ocean water flows beneath. But in January 2016, an unusual melting episode occurred on its topside.

    A team from the Massachusetts Institute of Technology (MIT) Haystack Observatory used data from existing GNSS stations, in conjunction with 13 stations installed on shelf, to examine the turbulent state of the atmosphere. Key were delay differences at each station and between stations that showed the strength (or rockiness) of atmospheric turbulence over the ice shelf.

    Wind, water vapor, and temperature variations drawn in by warm and humid air caused the surface to melt, with turbulence four times greater than usual during the 2016 surface melting event.

    The study also demonstrated a novel application of the GNSS station data to remotely observe unusual atmospheric conditions.

    The open-access study was published Feb. 27 in Geophysical Research Letters.

  • Galileo now predicts the weather

    Galileo now predicts the weather

    Image: Spire
    Image: Spire

    Spire Global, a space-to-cloud analytics company, is now using Galileo to offer GNSS radio occultation (GNSS-RO) products for the weather community. Radio occultation is the process of using satellites to measure how GNSS signals are refracted by the Earth’s atmosphere.

    Two of Spire’s nanosatellites are the first to use Galileo signals to measure GNSS-RO profiles, a service now available to Spire’s global user base as a new tier of data for advanced weather prediction. The satellites launched on Nov. 29, 2018, from Sriharikota, India.

    The satellites are part of the collaborative European Space Agency ARTES Pioneer Space-as-a-Service program, which aims to prove the value of using nanosatellites for space-based GNSS-RO.

    With Galileo, Spire’s weather observation satellites can harvest approximately 25 percent of the total GNSS-RO profiles available from the existing GNSS satellite constellations in orbit today.

    Spire operates 72 nanosatellites — also known as “cubesats” — and more than 30 ground stations throughout the world. The nanosatellites are developed, assembled and tested at Spire’s production facility in Glasgow, Scotland.