Detecting Atmospheric Streams with Satellite Observations

Atmospheric rivers, filaments of intense moisture transport in the atmosphere, can now be automatically detected in satellite observations. Credit: NOAA

Atmospheric currents (ARs) are filaments of intense moisture transport in the atmosphere. These weather systems drive a large proportion of heavy rain events in coastal areas. The detection of ARs in satellite observations has long been a difficult task due to the lack of wind information. In a study published in Journal of Geophysical Research: Environmentscientists obtained a 3-dimensional (3D) wind field estimate based on the spatial distribution of satellite-based temperature.

By combining this approximate 3D data with satellite-observed humidity, the scientists developed a method for detecting AR through satellite observations for the first time. Using this newly developed method, the scientists produced the first satellite-based near-global AR dataset.

Scientists have long detected AR using data from numerical model simulations. The use of satellite observations allowed them to a the global approach of ARs was based only on observations, which was more desirable, but such information was out of reach due to the lack of corresponding air data.

Now, using a new method to estimate 3D wind data from satellites, scientists can automatically detect AR using satellite observations, and they have created a benchmark AR data for almost the entire world. The set is prepared. Furthermore, their evaluation of existing AR data shows that reanalysis overestimates the frequency of precipitation produced in ARs but underestimates its intensity.

In their study, the scientists developed a near-global AR detection algorithm that incorporates 3D wind information from satellite observations, providing a more accurate picture of extreme weather events around the world. gave combines both moisture field and wind information, i.e. the two main factors defining AR from satellites. Scientists used a new detection method to create the first satellite-based near-global AR dataset.

Using this new dataset as a benchmark, scientists are learning from the shortcomings of previous AR analyses, such as the width of ARs, and they said the results will inform reanalysis and the representation of ARs and associated precipitation in climate models. can help improve As the quality of satellite observations continues to improve, the methodology presented here can be applied to others. To generate high-resolution or high-frequency AR statistics.

More information:
Weiming Ma et al., Representing Atmospheric Streams and Estimating Associated Precipitation in Reanalysis with Satellite Observations, Journal of Geophysical Research: Environment (2023). DOI: 10.1029/2023JD038937

Reference: Detecting atmospheric rivers with satellite observations (2024, February 19) Retrieved February 20, 2024 from https://phys.org/news/2024-02-atmospheric-rivers-satellite.html

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