Geodetic Science Snapshots - Atmosphere

The 21 August 2017 total solar eclipse across the United States blocked solar radiation and influenced the ionosphere and the rest of the atmosphere. The total electron content (TEC) in the ionosphere was measured with UNAVCO’s network of U.S. Global Positioning System (GPS)/ Global Navigation Satellite System (GNSS) ground-based sites and other geodetic sites across the country.

The Global Positioning System (GPS) constellation can be used to detect dark matter. Sixteen years of ground-based GPS receiver observations were utilized to look for dark matter passing near Earth. Although no dark matter was detected, the results refine the properties of the universe, the accuracies of atomic clocks and future searches for dark matter.

Two coronal mass ejections impacted the Earth in February 2014 creating disturbances in the Arctic ionosphere. Multiple instruments measured the disturbances, particularly the Greenland GPS network (GNET). Analysis shows the solar inputs heated the polar atmosphere causing an upwelling of nitrogen-rich air that altered the normal ionospheric dynamics.

A new method to compute total electron content (TEC) in the ionosphere to measure perturbations caused by tsunami waves has been shown to work retrospectively for tracking tsunami waves around Hawaii from the 2012 Haida Gwaii, British Columbia M7.8 earthquake.

A network of GPS stations measures atmospheric water vapor over the continental United States. The data tracks annual and seasonal moisture transport from the Gulf of Mexico into the Great Plains and the moisture variability related to the North American monsoon. These measurements are valuable for severe weather forecasts.

Ground-based GPS measurements of the total electron content (TEC) in the ionosphere show discrepancies compared to a global model and suggest that there is a larger difference between the solar flux measured via radio emissions and the extreme ultraviolet flux coming from the Sun.

Deep convection in the atmosphere, leading to cloud development and precipitation has been directly observed in the tropics of Brazil using a GPS meteorological site. These observations will help with modeling of weather in the tropics.

GPS data were used to detect volcanic plumes from eruptions of Mount Redoubt in Alaska. Unlike past research, this study relied on the signal strength, or signal to noise ratio (SNR), data. The new method is powerful because simple models can be used to quickly model SNR data and the SNR data are not sensitive to water vapor.

CMEs are giant bursts of highly energetic plasma that are driven off the surface of the Sun. When a solar storm collides with the Earth it compresses the dayside (facing the Sun) and elongates the nightside of the Earth’s magnetosphere. The hot, energetic ions in the solar storm are driven along and down Earth’s magnetic field lines toward both poles creating magnificent auroras.

Wayan Suparta has used GPS measurements of atmospheric water vapor to predict when lightning is most likely to strike in Malaysia, a region that experiences large lightning storms throughout the Northeast monsoon season (November-March).

Water vapor is the most abundant greenhouse gas on the planet, yet it is the least accurately measured globally. In order to make useful climate models, robust measurements of the amount of water vapor in the atmosphere are needed.

As the climate warms, researchers would like to know if hurricanes will increase in intensity and frequency. To explore this theory, more information is needed on the connection between ocean temperatures and the amount of water vapor in the lower atmosphere.