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Meta Sienkiewicz

Publications and source records attributed to Meta Sienkiewicz.

10 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS2023

Impacts of Marine Surface Pressure Observations From A Spaceborne Differential Absorption Radar Investigated With an Observing System Simulation Experiment

A new instrument has been proposed for measuring surface air pressure over the marine surface with a combined active/passive scanning multi-channel differential absorption radar (DAR) to provide an estimate of the total atmospheric column oxygen content. A demonstrator instrument, the Microwave Barometric Radar and Sounder (MBARS), has been funded by the National Aeronautics and Space Administration (NASA) for airborne test missions. Here, a proof-of-concept study to evaluate the potential impact of spaceborne surface pressure data on numerical weather prediction is performed using the Goddard Modeling and Assimilation Office global observing system simulation experiment (OSSE) framework. This OSSE framework employs the Goddard Earth Observing System model and the hybrid 4D ensemble variational Gridpoint Statistical Interpolation data assimilation system. Multiple flight and scanning configurations of potential spaceborne orbits are examined. Swath width and observation spacing for the surface pressure data are varied to explore a range of sampling strategies. For wider swaths, the addition of surface pressures reduces the root mean square surface pressure analysis error by as much as 20% over some ocean regions. The forecast sensitivity observation impact tool estimates impacts on the Pacific Ocean basin boundary layer 24-hour forecast temperatures for spaceborne surface pressures on par with rawinsondes and aircraft, and greater impacts than the current network of ships and buoys. The largest forecast impacts are found in the southern hemisphere extratropics.

N.C. Privé↗
NASA NTRSDate not supplied

Potential Use of Spaceborne Differential Absorption Radar Measurements of Marine Surface Pressure to Improve Weather and Tropical Cyclone Forecasting

Differential absorption radar (DAR) has been identified as a method to remotely sense surface air pressure, particularly over the marine surface. Such an instrument would provide an estimate of the total atmospheric column oxygen content from which the surface air pressure can be calculated. NASA recently funded the development of a demonstrator instrument, the airborne Microwave Barometric Radar and Sounder (MBARS) to test and evaluate this retrieval. The potential impact of surface pressure observations from a spaceborne sensor is evaluated using the updated NASA/GMAO global Observing System Simulation Experiment framework. Initial experiments showing the impact of different orbital configurations of DAR surface pressure measurements on overall NWP will be shown, including Forecast Sensitivity Observation Impact metrics. Case studies of satellite-based surface air pressure retrievals on tropical cyclones will also be discussed.

DAR↗
NASA NTRSDate not supplied

Implementing JEDI into NASA GMAO’s Real Time Production Suite

NASA’s Global Modeling and Assimilation Office (GMAO) has prepared their first production system involving the Joint Effort for Data assimilation Integration (JEDI) framework. In this system the central analysis, that drives the deterministic forecast, will be provided using JEDI. This talk outlines the phased approach to implementing JEDI into production that GMAO has designed, and how this approach will allow for a careful analysis of the system against the existing data assimilation framework (GSI). In the first phase of implementation the existing data assimilation system will perform certain actions that are still under development in JEDI. These include thinning the observations and producing satellite bias correction coefficients. JEDI is hooked up to the existing workflow so a single line switch can activate whether the existing or JEDI-based analysis is cycled. Outside of the monumental effort to construct JEDI that is ongoing at the Joint Center for Satellite Data Assimilation (JCSDA), GMAO have undertaken two areas of considerable effort. The talk will describe these efforts and highlight the main challenges that have been encountered. The first area of work is to implement the background error model from the existing data assimilation system into JEDI. The second is to validate the observing system in JEDI against the one in GSI, which has involved several new features being added to the observation operators in JEDI. While the longer-term plans involve trying to improve on the GSI in these two areas, GMAO is keen to have JEDI start from a trusted baseline. This is also key to implementing JEDI quickly so other priorities, such as increasing the number of model levels, can be easily worked on in parallel. GMAO is actively working on a framework to shepherd in the next generation coupled data assimilation system and model. As JEDI is implemented for the first time the plan is to ambitiously cycle through implementations, frequently bringing JEDI features to production. Details of these plans will be given in the talk and we will highlight key implementation and product milestones that we hope to achieve, as well as touch on the development environment that we will use to support frequent refreshing of the production system.

JEDI↗
NASA NTRSDate not supplied

A Regional Perspective on Global NWP from North America and Recent Developments in the NASA GEOS System

Satellite data have played an important role in improving model forecast skills. This presentation will give a perspective of data usages of vital satellites on global NWP and show some examples of using existing satellite observations in the GEOS data assimilation system at NASA GMAO. The efforts to utilize emerging satellite data and to prepare for the upcoming new instruments NASA supports will be presented as well.

Yanqiu Zhu↗
NASA NTRSDate not supplied

A Preliminary Comparison of GEOS-GSI with GEOS-JEDI Using the Complete GEOS Observing System

Transitioning the NASA GMAO GEOS data assimilation capabilities to JEDI involves replacing the GEOS Gridpoint Statistical Interpolation (GSI) with a JEDI-based analysis. Performing fair comparisons between the corresponding GEOS-JEDI system and the present GEOS-GSI has involved downgrading the latter's capabilities to compensate for missing capabilities in the former. As the capabilities in JEDI mature and start matching those of GSI’s, experimentation has evolved from simple 3DVAR using only radiosondes, to adding satellite observations without VarBC, to now having GEOS-JEDI use hybrid 4DEnVar and full observing system, VarBC and most of the knobs typically used in the present operational (and experimental) version of GEOS-GSI. This presentation provides a discussion of the process and pathway taken to replace GSI with JEDI in GEOS at GMAO. The presentation also shows latest results of testing in the still relatively simply context of 3D-FGAT, but now having JEDI use the whole of the typical observing system used in GEOS. Results are encouraging but preliminary, with various caveats having been identified during the attempt to cycle JEDI analyses. Solutions to most of the identified problems have been worked out, but a few pending issues are still being worked out.

Ricardo Todling↗