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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 127 records · Page 7
All sourcesNASA NTRSDOE OSTI
NASA NTRS1998

Coupling Processes Between Atmospheric Chemistry and Climate

The overall objective of this project is to improve the understanding of coupling processes between atmospheric chemistry and climate. Model predictions of the future distributions of trace gases in the atmosphere constitute an important component of the input necessary for quantitative assessments of global change. We will concentrate on the changes in ozone and stratospheric sulfate aerosol, with emphasis on how ozone in the lower stratosphere would respond to natural or anthropogenic changes. The key modeling tools for this work are the AER two-dimensional chemistry-transport model, the AER two-dimensional stratospheric sulfate model, and the AER three-wave interactive model with full chemistry. We will continue developing our three-wave model so that we can help NASA determine the strength and weakness of the next generation assessment models.

Ko, M. K. W.↗
NASA NTRS1998

Coupling Processes Between Atmospheric Chemistry and Climate

The overall objective of this project is to improve the understanding of coupling processes between atmospheric chemistry and climate. Model predictions of the future distributions of trace gases in the atmosphere constitute an important component of the input necessary for quantitative assessments of global change. We will concentrate on the changes in ozone and stratospheric sulfate aerosol, with emphasis on how ozone in the lower stratosphere would respond to natural or anthropogenic changes. The key modeling tools for this work are the AER 2-dimensional chemistry-transport model, the AER 2-dimensional stratospheric sulfate model, and the AER three-wave interactive model with full chemistry. We will continue developing our three-wave model so that we can help NASA determine the strength and weakness of the next generation assessment models.

Ko, Malcolm K. W.↗
NASA NTRSDate not supplied

Planning Satellite Swarm Measurements for Climate Models: Comparing Dynamic Constraint Processing and MILP Methods

We present D-SHIELD, a challenging climate science application to plan coordinated measurements (observations) for a constellation of satellites, each containing two different sensors, each with 61 pointing angle options. The L-band and P-band radar sensors collect data fed into a soil moisture model which tracks and predicts soil moisture across 1.67 million Ground Positions (GP). Soil moisture is an important predictor of wildfires, and then a predictor of floods, landslides and debris flow after a fire. Each measurement covers multiple GP due to the sensor footprint. Each GP has a "model error" which represents the uncertainty of the the soil moisture state prediction. Model error changes at different rates for each GP as the time since last observation increases and after significant events like rain. The planner's goal is to select measurements which maximize soil moisture model improvement (reduce model uncertainty). This problem is combinatorically explosive, involving many degrees of freedom for planner choices. Good domain heuristics can find solutions within a reasonable time for our application needs but cannot be proven optimal. In this paper we compare two different planning approaches to this problem: Dynamic Constraint Processing (DCP) and Mixed Integer Linear Programming (MILP). We match inputs and metrics for both DCP and MILP algorithms to enable a direct apples-to-apples comparison. We demonstrate and discuss the trades between DCP flexibility and performance vs. MILP's promise of provable optimality.

Rich Levinson↗
NASA NTRS1987

Valley development on Hawaiian volcanoes

Work in progress on Hawaiian drainage evolution indicates an important potential for understanding drainage development on Mars. Similar to Mars, the Hawaiian valleys were initiated by surface runoff, subsequently enlarged by groundwater sapping, and eventually stabilized as aquifers were depleted. Quantitative geomorphic measurements were used to evaluate the following factors in Hawaiian drainage evolution: climate, stream processes, and time. In comparing regions of similar climate, drainage density shows a general increase with the age of the volcani island. With age and climate held constant, sapping dominated valleys, in contrast to runoff-dominated valleys, display the following: lower drainage densities, higher ratios of valley floor width to valley height, and more positive profile concavities. Studies of stream junction angles indicate increasing junction angles with time on the drier leeward sides of the major islands. The quantitative geomorphic studies and earlier field work yielded important insights for Martian geomorphology. The importance of ash mantling in controlling infiltration on Hawaii also seems to apply to Mars. The Hawaiian valley also have implications for the valley networks of Martian heavily cratered terrains.

Baker, Victor R.↗
NASA NTRS1997

Role of Boreal Vegetation in Controlling Ecosystem Processes and Feedbacks to Climate

In the field, dark respiration rates are greatest in cores from more northerly locations. This is due in part to greater amounts of dwarf shrub biomass in the more northerly cores, but also to differences in soil organic matter quality. Laboratory incubations of these soils under common conditions show some evidence for greater pools of available carbon in soils from more northerly tundra sites, although the most northerly site does not fit this pattern for reasons which are unclear at this time. While field measurements of cores transplanted among different vegetation types at the same location (Toolik Lake) show relatively small differences in whole ecosystem carbon flux, laboratory incubation of these same soils shows that there are large differences in soil respiration rates under common conditions. This is presumably due to differences in organic matter quality. Microenvironmental site factors (temperature, soil moisture, degree of anaerobiosis, etc.) may be responsible for evening out these differences in the field. These site factors, which differ with slope, aspect, and drainage within a given location along the latitudinal gradient, appear to exert at least as strong a control over carbon fluxes as do macroclimatic factors among sites across the latitudinal gradient. While our field measurements indicate that, in the short term, warming will tend to increase ecosystem losses Of CO2 via respiration more than they will increase plant gross assimilation, the degree to which different topographically-defined plant communities will respond is likely to vary.

Chapin, F. S., III↗
NASA NTRS2013

Physical Processes Controlling Earth's Climate

As background for consideration of the climates of the other terrestrial planets in our solar system and the potential habitability of rocky exoplanets, we discuss the basic physics that controls the Earths present climate, with particular emphasis on the energy and water cycles. We define several dimensionless parameters relevant to characterizing a planets general circulation, climate and hydrological cycle. We also consider issues associated with the use of past climate variations as indicators of future anthropogenically forced climate change, and recent advances in understanding projections of future climate that might have implications for Earth-like exoplanets.

climate↗
NASA NTRS1999

Coupling Processes Between Atmospheric Chemistry and Climate

This is the final report. The overall objective of this project is to improve the understanding of coupling processes among atmospheric chemistry, aerosol and climate, all important for quantitative assessments of global change. Among our priority are changes in ozone and stratospheric sulfate aerosol, with emphasis on how ozone in the lower stratosphere would respond to natural or anthropogenic changes. The work emphasizes two important aspects: (1) AER's continued participation in preparation of, and providing scientific input for, various scientific reports connected with assessment of stratospheric ozone and climate. These include participation in various model intercomparison exercises as well as preparation of national and international reports. and (2) Continued development of the AER three-wave interactive model to address how the transport circulation will change as ozone and the thermal properties of the atmosphere change, and assess how these new findings will affect our confidence in the ozone assessment results.

Ko, Malcolm K. W.↗
NASA NTRS1995

Approaches for averaging surface parameters and fluxes over heterogeneous terrain

Successful prediction of possible climate change depends on realistic parameterization of land surface processes in climate models. Such parameterizations must take appropriate account of the heterogeneities that are found in most earth surfaces. In this study, different averaging strategies for aggregating patch-scale heterogeneities to scales that are appropriate for mesoscale and climate model grids have been explored. A simple model for estimating area-average 'effective' surface flux parameters is evaluated. The model satisfies the energy balance equation and leads to a set of relationships between local and effective parameters in the governing equations for the surface energy balance. One outcome is that the resulting effective surface temperature is not a simple area-weighted average of component temperatures, but is a function of a specific combination of different resistances of the individual surface elements. A set of heterogeneous surfaces has been simulated to study the effective fluxes obtained using the described model. A comparison with results obtained by other investigators using different averaging methods is also performed.

Chehbouni, A.↗
NASA NTRS2005

Applications and Improvement of a Coupled, Global and Cloud-Resolving Modeling System

Recently Grabowski (2001) and Khairoutdinov and Randall (2001) have proposed the use of 2D CFWs as a "super parameterization" [or multi-scale modeling framework (MMF)] to represent cloud processes within atmospheric general circulation models (GCMs). In the MMF, a fine-resolution 2D CRM takes the place of the single-column parameterization used in conventional GCMs. A prototype Goddard MMF based on the 2D Goddard Cumulus Ensemble (GCE) model and the Goddard finite volume general circulation model (fvGCM) is now being developed. The prototype includes the fvGCM run at 2.50 x 20 horizontal resolution with 32 vertical layers from the surface to 1 mb and the 2D (x-z) GCE using 64 horizontal and 32 vertical grid points with 4 km horizontal resolution and a cyclic lateral boundary. The time step for the 2D GCE would be 15 seconds, and the fvGCM-GCE coupling frequency would be 30 minutes (i.e. the fvGCM physical time step). We have successfully developed an fvGCM-GCE coupler for this prototype. Because the vertical coordinate of the fvGCM (a terrain-following floating Lagrangian coordinate) is different from that of the GCE (a z coordinate), vertical interpolations between the two coordinates are needed in the coupler. In interpolating fields from the GCE to fvGCM, we use an existing fvGCM finite- volume piecewise parabolic mapping (PPM) algorithm, which conserves the mass, momentum, and total energy. A new finite-volume PPM algorithm, which conserves the mass, momentum and moist static energy in the z coordinate, is being developed for interpolating fields from the fvGCM to the GCE. In the meeting, we will discuss the major differences between the two MMFs (i.e., the CSU MMF and the Goddard MMF). We will also present performance and critical issues related to the MMFs. In addition, we will present multi-dimensional cloud datasets (i.e., a cloud data library) generated by the Goddard MMF that will be provided to the global modeling community to help improve the representation and performance of moist processes in climate models and to improve our understanding of cloud processes globally (the software tools needed to produce cloud statistics and to identify various types of clouds and cloud systems from both high-resolution satellite and model data will be also presented).

Tao, W.-K.↗
NASA NTRS2022

Measuring, mapping, and anticipating climate gentrification in Florida: Miami and Tampa case studies

This article introduces an experimental methodology to identify proxy indicators that are conceptually consistent with the processes of Climate Gentrification (“CG”), in which a change in demand preferences among consumers and investors drives the increased consumption for real estate, in part, on lower measures of physical risk from climate change. Evaluated through case studies in the state of Florida, this article builds on the integration of multiple datasets concerning rental properties, evictions, and socioeconomic data, as well as environmental risk indices to build a Climate Gentrification Risk Index (CGRI). In the Miami case study, we find that the CGRI identifies a hotly contested neighborhood that is already known to be in a state of transition consistent with the processes of CG. In the Tampa case, the index highlights a district that exhibits strong metrics for the future accelerated occurrence of CG. Our findings suggest that transitional land uses and flexible zoning in low-exposure areas are key elements for attracting new development consistent with CG and offer insight into the challenges that local governments face understanding the types and rates of change that may be catalyzed in the broader urban processes of public and private sector climate adaptation in the built environment.

Climate change↗
NASA NTRS1998

Coupling Processes between Atmospheric Chemistry and Climate

This is the third semi-annual report for NAS5-97039, covering January through June 1998. The overall objective of this project is to improve the understanding of coupling processes between atmospheric chemistry and climate. Model predictions of the future distributions of trace gases in the atmosphere constitute an important component of the input necessary for quantitative assessments of global change. We will concentrate on the changes in ozone and stratospheric sulfate aerosol, with emphasis on how ozone in the lower stratosphere would respond to natural or anthropogenic changes. The key modeling for this work are the AER 2-dimensional chemistry-transport model, the AER 2-dimensional stratospheric sulfate model, and the AER three-wave interactive model with full chemistry. We will continue developing our three-wave model so that we can help NASA determine the strengths and weaknesses of the next generation assessment models.

Ko, M. K. W.↗
NASA NTRS2010

Developing Coastal Adaptation to Climate Change in the New York City Infrastructure-Shed: Process, Approach, Tools, and Strategies

While current rates of sea level rise and associated coastal flooding in the New York City region appear to be manageable by stakeholders responsible for communications, energy, transportation, and water infrastructure, projections for sea level rise and associated flooding in the future, especially those associated with rapid icemelt of the Greenland and West Antarctic Icesheets, may be beyond the range of current capacity because an extreme event might cause flooding and inundation beyond the planning and preparedness regimes. This paper describes the comprehensive process, approach, and tools developed by the New York City Panel on Climate Change (NPCC) in conjunction with the region s stakeholders who manage its critical infrastructure, much of which lies near the coast. It presents the adaptation approach and the sea-level rise and storm projections related to coastal risks developed through the stakeholder process. Climate change adaptation planning in New York City is characterized by a multi-jurisdictional stakeholder-scientist process, state-of-the-art scientific projections and mapping, and development of adaptation strategies based on a risk-management approach.

Rosenzweig, Cynthia↗
NASA NTRS1997

Coupling Processes Between Atmospheric Chemistry and Climate

This is the first semi-annual report for NAS5-97039 summarizing work performed for January 1997 through June 1997. Work in this project is related to NAS1-20666, also funded by NASA ACMAP. The work funded in this project also benefits from work at AER associated with the AER three-dimensional isentropic transport model funded by NASA AEAP and the AER two-dimensional climate-chemistry model (co-funded by Department of Energy). The overall objective of this project is to improve the understanding of coupling processes between atmospheric chemistry and climate. Model predictions of the future distributions of trace gases in the atmosphere constitute an important component of the input necessary for quantitative assessments of global change. We will concentrate on the changes in ozone and stratospheric sulfate aerosol, with emphasis on how ozone in the lower stratosphere would respond to natural or anthropogenic changes. The key modeling tools for this work are the AER two-dimensional chemistry-transport model, the AER two-dimensional stratospheric sulfate model, and the AER three-wave interactive model with full chemistry.

Ko, M. K. W.↗
NASA NTRS1998

Coupling Processes between Atmospheric Chemistry and Climate

This is the fourth semi-annual report for NAS5-97039, covering the time period July through December 1998. The overall objective of this project is to improve the understanding of coupling processes between atmospheric chemistry and climate. Model predictions of the future distributions of trace gases in the atmosphere constitute an important component of the input necessary for quantitative assessments of global change. We will concentrate on the changes in ozone and stratospheric sulfate aerosol, with emphasis on how ozone in the lower stratosphere would respond to natural or anthropogenic changes. The key modeling tools for this work are the Atmospheric and Environmental Research (AER) two-dimensional chemistry-transport model, the AER two-dimensional stratospheric sulfate model, and the AER three-wave interactive model with full chemistry. For this six month period, we report on a modeling study of new rate constant which modify the NOx/NOy ratio in the lower stratosphere; sensitivity to changes in stratospheric water vapor in the future atmosphere; a study of N2O and CH4 observations which has allowed us to adjust diffusion in the 2-D CTM in order to obtain appropriate polar vortex isolation; a study of SF6 and age of air with comparisons of models and measurements; and a report on the Models and Measurements II effort.

Ko, Malcolm K. W.↗
NASA NTRS1999

Coupling Processes Between Atmospheric Chemistry and Climate

This is the final report for NAS5-97039 for work performed between December 1996 and November 1999. The overall objective of this project is to improve the understanding of coupling processes among atmospheric chemistry, aerosol and climate, all important for quantitative assessments of global change. Among our priority are changes in ozone and stratospheric sulfate aerosol, with emphasis on how ozone in the lower stratosphere would respond to natural or anthropogenic changes. The work emphasizes two important aspects: (1) AER's continued participation in preparation of, and providing scientific input for, various scientific reports connected with assessment of stratospheric ozone and climate. These include participation in various model intercomparison exercises as well as preparation of national and international reports. (2) Continued development of the AER three-wave interactive model to address how the transport circulation will change as ozone and the thermal properties of the atmosphere change, and assess how these new findings will affect our confidence in the ozone assessment results.

Ko, Malcolm↗
NASA NTRS2002

Advances in Data Assimilation and Weather Prediction Using TRMM Observations

Understanding the Earth's climate and how it responds to climate perturbations requires knowledge of how atmospheric moisture, clouds, latent heating, the large-scale circulation and energy fluxes vary with changing climatic conditions. The physical process linking these climate elements is precipitation. Accurate knowledge of how precipitation varies in space and time and how it couples with other atmospheric variables is essential for understanding the global water and energy cycle. In recent years, TRMM data products have played a key role in advancing the field of data assimilation to provide better global analyses for climate research and numerical weather prediction. TRMM research has demonstrated the effectiveness of microwave-based rainfall and total precipitable water (TPW) observations in improving the quality of assimilated datasets and upgrading forecast skills. TRMM latent heating products have also stimulated experimentation with innovative techniques to use this type of information to improve global analyses. We discuss strategies of assimilating TRMM observations at NASA s Data Assimilation Office and present results on the impact assimilating TRMM data on the Goddard Earth Observing System (GEOS) analyses and forecast capabilities.

Atlas, Robert↗
NASA NTRSDate not supplied

The NASA Aerosols, Clouds, Convection, and Precipitation (ACCP) Observing System

NASA’s new Earth System Observatory (ESO) will provide key information related to understanding climate change processes, mitigating natural hazards, fighting forest fires, and improving real-time agricultural processes. The ACCP observing system will address two of the five major focus areas: aerosols, which determine air quality and affect the global energy balance, a key source of uncertainty in predicting climate change; and clouds, convection, and precipitation, whose processes are also a large source of uncertainty in future projections of climate change as well as predictions of severe weather. ACCP, currently in the concept investigation phase, is made up of two projects, one in an inclined orbit and the other in a polar orbit, with both projects addressing synergistic A and CCP science. Suborbital science is also a significant element of ACCP. This talk will describe the science objectives of ACCP and their relationship to the 2017 NASA Earth Science Decadal Survey as well as summarize the orbital architecture and major science activities during the concept investigation phase.

Scott Braun↗