A5070704858- Ionosphere and magnetosphere dynamics
- Geophysics and Gravity Measurements
- Meteorological Phenomena and Simulations
- GNSS positioning and interference
- Precipitation Measurement and Analysis
- Climate variability and models
- Atmospheric aerosols and clouds
- Planetary Science and Exploration
- Astro and Planetary Science
- Soil Moisture and Remote Sensing
- Spacecraft and Cryogenic Technologies
- Radio Astronomy Observations and Technology
- Geomagnetism and Paleomagnetism Studies
- Isotope Analysis in Ecology
- Radiomics and Machine Learning in Medical Imaging
- Atmospheric and Environmental Gas Dynamics
- Radio Wave Propagation Studies
- Atmospheric Ozone and Climate
- Solar and Space Plasma Dynamics
- Tropical and Extratropical Cyclones Research
Jet Propulsion Laboratory
2016-2024
Scripps Institution of Oceanography
2019
Purdue University West Lafayette
2014-2017
Abstract. GNSS radio occultation (GNSS RO) performance in the planetary boundary layer is strongly dependent on retrieval algorithms. In this work, we explore how differences methodology across three major processing centers of RO data — NASA JPL, ROM SAF, and UCAR impact refractivity retrievals layer. Using a shared base occultations from FORMOSAT-3/COSMIC-1 mission, identify key between that are especially strong regions frequent super-refraction. We find minimum penetration height allowed...
Abstract. Polarimetric radio occultations (PROs) of the Global Navigation Satellite System are able to characterize precipitation structure and intensity. Prior studies have shown relationship between water vapor pressure columns, known as “precipitation pickup.” Less is about vertical distributions temperature moisture globally within precipitating scenes measured from space. This work uses cluster analysis PRO explore how – combined into refractivity relate variables. We evaluate ability...
We present a new seasonal planetary boundary layer height (PBLH) climatology product derived from 14 years of Global Navigation Satellite System radio occultation (GNSS-RO) data multiple missions including COSMIC, TerraSAR-X, KOMPSAT-5, and PAZ. PBLH estimates are the minimum gradients retrieved refractivity profiles, with vertical resolution ∼200 m. The is obtained occultations observed between June 2006 December 2019, divided into land ocean regimes on 2-degree grid. provide climatologies...
© 2024 American Meteorological Society. This is an Author Accepted Manuscript distributed under the terms of default AMS reuse license. For information regarding and general copyright information, consult Copyright Policy (www.ametsoc.org/PUBSReuseLicenses). Corresponding author: F. Joseph Turk, jturk@jpl.nasa.gov
Abstract Global Positioning System (GPS) radio occultation (RO) from low Earth‐orbiting satellites has increased the quantity of high‐vertical resolution atmospheric profiles, especially over oceans, and significantly improved global weather forecasting. A new system, Navigation Satellite Systems Instrument for Multistatic Occultation Sensing (GISMOS), been developed RO sounding aircraft. GISMOS also provides profiles that are insensitive to clouds precipitation, in addition, greater control...
Global Positioning System (GPS) radio-occultation (RO) is an atmospheric sounding technique utilizing the received GPS signal through stratified atmosphere to measure refractivity, which provides information on temperature and humidity. The GPS-RO now operational several Low Earth Orbiting (LEO) satellites, cannot provide high temporal spatial resolution soundings necessary observe localized transient events, such as tropical storms. An airborne RO (ARO) system has thus been developed for...
Abstract. Global Navigation Satellite System radio occultation (GNSS-RO) and microwave radiometry (MWR) are two of the most impactful spaceborne remote sensing techniques for numerical weather prediction (NWP). These provide complementary information about atmospheric temperature water vapor structure. GNSS-RO provides high vertical resolution measurements with cloud penetration capability, but moisture coupled in retrieval process their separation requires use a priori or auxiliary...
Due to its high vertical resolution and cloud-penetrating capability, GNSS-Radio Occultation (RO) remote sensing technique has been utilized observe the structure of Planetary Boundary Layer (PBL) in recent years. However, critical refraction, or ducting, caused by large refractivity gradients usually associated with top stratocumulus clouds, can negatively bias retrieved humidity within PBL. Previous research shown that combining RO retrievals external information, such as collocated...
Abstract Observationally, a major source of uncertainty in evaluation climate models arises from the difficulty obtaining globally distributed, fine scale profiles temperature, pressure and water vapor, that probe through convective precipitating clouds, boundary layer to upper levels free troposphere. In this manuscript, two-year analysis data Radio Occultations Heavy Precipitation (ROHP) polarimetric RO demonstration mission onboard Spanish PAZ spacecraft is presented. ROHP measures...
Abstract. Global Navigation Satellite System (GNSS) radio occultation (RO) measurements are promising in sensing the vertical structure of Earth's planetary boundary layer (PBL). However, large refractivity changes near top PBL can cause ducting and lead to a negative bias retrieved within (below ∼ 2 km). To remove bias, reconstruction method with assumption linear inside models has been proposed by Xie et al. (2006). While be reduced drastically as demonstrated simulation, lack high-quality...
Abstract. Polarimetric Radio Occultations (PRO) represent an augmentation of the standard Occultation (RO) technique that provides precipitation and clouds vertical information along with thermodynamic products. A combined dataset contains both PRO observable RO retrievals, resPrf, has been developed aim to foster use these unique observations fully exploit scientific implication having about cloud structures intrinsically collocated state atmosphere. This manuscript describes such detailed...
Abstract. This paper presents the calibration and validation studies for Radio Occultation Heavy Precipitation experiment aboard PAZ satellite. These studies, necessary to assess characterize noise level robustness of differential phase shift (ΔΦ) observable polarimetric radio occultations (PROs), confirm good performance capability this technique in sensing precipitation. It is shown how all predicted effects that could have an impact into PRO observables (e.g., effect metallic structures...
The climate and weather forecast predictive capability for precipitation intensity is limited by gaps in the understanding of basic cloud-convective processes. Currently, a better process lacks observational constraints, due to difficulty obtaining accurate, vertically resolved pressure, temperature, water vapor structure inside near convective clouds. This manuscript describes potential advantages collecting sequential radio occultation (RO) observations from constellation closely spaced...
Abstract. A positive bias at heights between 3 and 8 km has been observed when comparing the radio-occultation (RO)-retrieved refractivity with that of meteorological analyses reanalyses in cases where heavy precipitation is present. The effect RO retrievals investigated as a potential cause bias, using measurements interpolated into actual three-dimensional ray paths to calculate excess phase induced by precipitation. study consisted such extra delay removed from measurement it not. results...
Abstract Airborne radio occultation (ARO) is a remote sensing technique for atmospheric sounding using Global Positioning System signals received by an airborne instrument. The refractivity profile, which depends on pressure, temperature, and water vapor, can be retrieved measuring the signal delay due to refractive medium through traverses. ARO system was developed make repeated observations within individual meteorological event such as tropical storm, regardless of presence clouds...
Abstract To address critical gaps identified by the National Academies of Sciences, Engineering, and Medicine in current Earth system observation strategy, 2017–27 Decadal Survey for Science Applications from Space recommended incubating concepts future targeted observables including atmospheric planetary boundary layer (PBL). A subsequent NASA PBL Incubation Study Team Report measurement requirements activities advancing maturity technologies applicable to their associated science...
Abstract. This manuscript presents the calibration and validation studies for Radio Occultations Heavy Precipitation experiment aboard PAZ satellite. These studies, necessary to assess characterize noise level robustness of ΔΦ observable Polarimetric (PRO), confirm good performance capability this technique in sensing precipitation. It is shown how all predicted effects that could have an impact into PRO observables (e.g. effect metallic structures nearby antenna, Faraday Rotation at...
Abstract Following the successful launch of Spanish PAZ mission proof concept experiment “Radio Occultation and Heavy Precipitation with ” (ROHP- ) started operating in May 2018. The ROHP- observations demonstrated that precise measurements phase shift between horizontal vertical polarizations from Global Navigation Satellite System (GNSS) L-band signals are sensitive to oriented hydrometeors along ray paths. While this differential measurement as a function time has proven very useful,...
Abstract. Airborne radio occultation (ARO) measurements collected during a ferry flight at the end of PRE-Depression Investigation Cloud-systems in Tropics (PREDICT) field campaign from Virgin Islands to Colorado are analyzed. The large contrast atmospheric conditions along path warm and moist Caribbean Sea much drier cooler continental provides unique opportunity address sensitivity ARO tropospheric temperature moisture changes. This long nearly constant altitude (∼ 13 km) provided an...
Abstract Radio occultation is a spacecraft remote sensing technique used to study planetary atmospheres. Among the available techniques, radio offers highest vertical resolution. In this paper, we present for first time implementation of radio‐holographic method called phase matching (PM) analysis signals. We show that by using novel approach (originally developed within Earth atmospheric research community) multi‐path interference can be detected and accounted for. Additionally, complex...
Abstract. Polarimetric radio occultations (PROs) represent an augmentation of the standard occultation (RO) technique that provides precipitation and cloud vertical information along with thermodynamic products. A combined dataset contains both PRO observable retrievals RO retrievals, resPrf, has been developed aim fostering use these unique observations fully exploiting scientific implication having about structures intrinsically collocated state atmosphere. This paper describes such a...
Abstract. The polarimetric phase difference between the horizontal and vertical components of GNSS radio signals is correlated with presence ice precipitation in propagation path those signals. This study evaluates ability k-means clustering to find relationships among difference, refractivity, liquid water (LWP), (IWP), vapor pressure using over two years data matched Global Precipitation Measurement (GPM) mission Radio Occultations through Heavy demonstration onboard Spanish Paz spacecraft...