Evolving the Geodetic Infrastructure to Meet New Scientific Needs (2020) / Chapter Skim
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6 Weather and Climate
6 Weather and Climate
Pages 59-70
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From page 59... ...
ponent of the Global Observing System, and their value to operational numerical weather prediction at the short The geodetic infrastructure needs associated with and medium range is well established. These integrated these questions are summarized in the Weather and water vapor products can be used to monitor climate Climate Science and Applications Traceability Matrix (Wang and Zhang, 2009; Ning and Elgered, 2012)
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From page 60... ...
The direct asstructure to specify the GNSS orbits and clocks.1 similation of GNSS-RO observations into the analysis GNSS-RO measurements have been used to study fields improves the initial conditions used for forecastlarge-scale atmospheric dynamics, such as the El Niño ing. Multiple studies have demonstrated the value of Southern Oscillation and sudden stratospheric warm- GNSS-RO to improve analysis fields for numerical ing, and to understand atmospheric gravity waves so weather prediction (Healy, 2008, 2013; Aparicicio and they can be parameterized in global climate models Deblonde, 2009; Cucurull, 2010; Nie et al., 2019)
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From page 61... ...
When dual-frequency GNSS occultation measurements are made, the data can provide vertical profiles of atmospheric pressure, temperature, water vapor, and total electron content from the atmospheric boundary layer through the troposphere, stratosphere, and ionosphere. The demonstrated precision of the technique (see Figure 6.2)
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From page 62... ...
The red line shows the mean difference and the green lines show the standard deviation in percentage of difference. The number of paired occultations decreases at altitudes less than 5 km because of GNSS tracking errors, super refraction of the atmosphere, and low signal-to-noise of attenuation of the GNSS signal in the lower atmosphere.
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From page 63... ...
path delay, which becomes an error in the retrieval of These geodetic products are used to estimate the lowthe vertical profiles of temperature, water vapor pres- Earth orbit satellite orbit and clocks, and to remove sure, and, to a lesser extent, the total electron content the geometric portion of delay from the RO signals. of the ionosphere (Kuo et al., 2004)
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From page 64... ...
can resolve the filamentary structure of atmospheric rivers and their extent and motion, but not their vertical structure. However, GNSS-RO soundings from COSMIC-1 provide high-resolution vertical profile information not available in the numerical weather models based mostly on the SSM/I data (Neiman et al., 2008; see Figure 6.4)
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From page 65... ...
has a maximum roughly matching the location of the peak in the SSM/I image. SOURCES: Republished with permission of American Meteorological Society, from Neiman et al., 2008; permission conveyed through Copyright Clearance Center, Inc.
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From page 66... ...
for mutual calibration and validation. Same as for "Improvements in Weather Models." REDUCING UNCERTAINTY IN SUMMARY CLIMATE PROJECTIONS A robust and resilient geodetic infrastructure has Question C-2 concerns reducing uncertainty in underpinned the rapid GNSS-RO progress in both projections of global warming to better understand numerical weather prediction and climate applications future economic impacts and to devise appropriate ad- since the 1990s.
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From page 67... ...
This will Infrastructure to Enhance Scientific Returns require stable and predictable funding. • Improve the GNSS instrumentation on the lowEnhancements to the Geodetic Infrastructure Earth orbiting satellites and IGS sites to include Navigation Data Message data collection (for RO • Upgrade the global IGS sites (at least the National open-loop processing)
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From page 68... ...
constellation of GPS Radio Occultation receivers in weather • Use the global GNSS constellation and low-Earth forecasting. Weather Forecasting 25:749-767.
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2004. assessment of the scalability of GPS radio occultations impact Impact of GPS zenith tropospheric delay data on precipitation in numerical weather prediction.
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