87 research outputs found
Multi-satellite altimetry and GOCE geoid based surface and subsurface currents in the Mediterranean Sea
Peer ReviewedPostprint (published version
A New Estimate of North American Mountain Snow Accumulation From Regional Climate Model Simulations
Despite the importance of mountain snowpack to understanding the water and energy cycles in North America's montane regions, no reliable mountain snow climatology exists for the entire continent. We present a new estimate of mountain snow water equivalent (SWE) for North America from regional climate model simulations. Climatological peak SWE in North America mountains is 1,006 km3, 2.94 times larger than previous estimates from reanalyses. By combining this mountain SWE value with the best available global product in nonmountain areas, we estimate peak North America SWE of 1,684 km3, 55% greater than previous estimates. In our simulations, the date of maximum SWE varies widely by mountain range, from early March to mid-April. Though mountains comprise 24% of the continent's land area, we estimate that they contain ~60% of North American SWE. This new estimate is a suitable benchmark for continental- and global-scale water and energy budget studies
Feasibility of GNSS-R Altimetry Using CyGNSS 8-Satellite Constellation Mission Data
Ponencia expuesta en Scientific Assembly of the International Association of Geodesy (2021) celebrado en Beijing del 28 de junio al 2 de juli
CYGNSS Ocean Altimetry: A Status Report
ComunicaciĂłn expuesta online en el CYGNSS Science Team Summer Meeting celebrado del 27 al 29 de julio de 202
Global River Radar Altimetry Time Series (GRRATS): New river elevation earth science data records for the hydrologic community
The capabilities of radar altimetry to measure inland water bodies are well established, and several river altimetry datasets are available. Here we produced a globally distributed dataset, the Global River Radar Altimeter Time Series (GRRATS), using Envisat and Ocean Surface Topography Mission (OSTM)/Jason-2 radar altimeter data spanning the time period 2002–2016. We developed a method that runs unsupervised, without requiring parameterization at the measurement location, dubbed virtual station (VS) level, and applied it to all altimeter crossings of ocean-draining rivers with widths > 900m (> 34% of the global drainage area). We evaluated every VS, either quantitatively for VS locations where in situ gages are available or qualitatively using a grade system. We processed nearly 1.5 million altimeter measurements from 1478 VSs. After quality control, the final product contained 810 403 measurements distributed over 932 VSs located on 39 rivers. Available in situ data allowed quantitative evaluation of 389 VSs on 12 rivers. The median standard deviation of river elevation error is 0.93 m, Nash–Sutcliffe efficiency is 0.75, and correlation coefficient is 0.9. GRRATS is a consistent, well-documented dataset with a user-friendly data visualization portal, freely available for use by the global scientific community. Data are available at https://doi.org/10.5067/PSGRA-SA2V1 (Coss et al., 2016)
Innovative sea surface monitoring with GNSS-REflectometry aboard ISS: overview and recent results from GEROS-ISS
GEROS-ISS (GEROS hereafter) stands for GNSS REflectometry, Radio Occultation and Scatterometry onboard the International Space Station. It is a scientific experiment, proposed to the European Space Agency (ESA) in 2011 for installation aboard the ISS. The main focus of GEROS is the dedicated use of signals from the currently available Global Navigation Satellite Systems (GNSS) for remote sensing of the System Earth with focus to Climate Change characterisation. The GEROS mission idea and the current status are briefly reviewed.Peer ReviewedPostprint (author's final draft
Signal contents of combined monthly gravity field models derived from Swarm GPS data
The Swarm satellite constellation?s GPS receivers provide valuable
gravimetric data, with which it is possible to observe Earth?s large-scale mass transport process. These data have become increasingly relevant given the on-going GRACE/GRACE-FO gap, and are thus needed to provide continuous observations of the Earth system.
In this context, the overall accuracy and maximum resolution of the Swarm temporal gravity field models are parameters with interest to the wider geophysical community.
We assess the signal contents of the gravity field model resulting from the combination at the solution level of four individual solutions produced considering different
gravity field estimation approaches. The combination considers Variance Component Estimation (VCE) and is a service kindly provided by the European Gravity Service for Improved Emergency Management (EGSIEM) initiative.
We assume that past GRACE solutions provide an accurate measure of the signal at the spatial lengths captured by the Swarm solutions. On the basis of this, we derive per-degree correlation coefficients and spatial correlation maps for a selection of monthly solutions that were obtained under diverse conditions of geomagnetic and ionospheric activities, as well as variability of
non-gravitational accelerations
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