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Global systems science is a new field of study about the interactions between Earth's natural systems and human activities. The people who study global systems science draw on methods and theories of many different fields from chemistry and biology to economics and politics-in order to predict how today's actions are likely to affect the world of tomorrow - our world and our children's world.
There is an ever-increasing emphasis on the part of government agencies, academia, and industry on enhancing our understanding of atmospheric processes and assessing the impact of human activities on these processes. While issues such as the ozone hole and rising levels of greenhouse gases have received major attention. relatively little is known about the types, concentrations, sources, and sinks of hydrocarbons in the troposphere and stratosphere. Such information would be of tremendous utility in assessing the roles of various anthropogenic and biogenic processes on global carbon cycles. An ion trap mass spectrometer has been developed for monitoring trace levels of hydrocarbons in the atmosphere on NASA's DC-8 "flying laboratory". This aircraft is used to provide measurements in support of a number of "Mission to Planet Earth" activities and tropospheric chemistry experiments. In past missions, specific compounds have been monitored via highly specialized instrumentation, fast GO, or collection of whole air samples for subsequent ground-based analysis. The ion trap has several features. including small size. excellent sensitivity, and broad applicability, which make it highly atttrat:ive for atmospheric monitoring. The design of this instrument, its air sampling interface. and the various complications associated with aircraft-deployment will be described. Data showing the sensitivity of the instrument for detecting hydrocarbons at mixing ratios below one part-per-billion, and the use of MS/MS for direct, on-line, real-time monitoring will be presented.
A very visible impact of human activities is the brownish aerosol haze that pervades many industrialized regions as well as areas in the subtropics and tropics where biomass burning occurs. Well known examples are the Asian Brown Cloud, Arctic Haze and East Coast Haze. Atmospheric transport transforms this haze into regional and hemispheric aerosol layers of significant concentrations. The overall impact on the radiation balance of the atmosphere, surface solar irradiance and other meteorology factors is recognized as a major uncertainty for climate change. In order to understand the impact, the global distribution of aerosol and their properties must be known. . A missing element of observations, but critical for understanding transport has been the height distribution of aerosol. Lidar measurements of aerosol height distribution have been important in GLOBE, ACE, INDOEX and other field studies A network of continuously operating eye safe lidar ground sites has now been established for baseline aerosol profiling. In 2002 NASA will launch the Geoscience Laser Altimeter System (GLAS) mission which will provide for the first time global observations of the height distribution of aerosol. The combination of these and other modem satellite observations, field experiments and models of global aerosol composition and transport should begin to unravel the impacts of particles in the atmosphere.
Recovery of resources from waste streams is essential for future implementation and reliance on a regenerative life support system. The major waste streams of concern are from human activities and plant wastes. Carbon, water and inorganics are the primary desired raw materials of interest. The goal of resource recovery is maintenance of product quality to insure support of reliable and predictable levels of life support function performance by the crop plant component. Further, these systems must be maintained over extended periods of time, requiring maintenance of nutrient solutions to avoid toxicity and deficiencies. Today, reagent grade nutrients are used to make nutrient solutions for hydroponic culture and these solutions are frequently changed during the life cycle or sometimes managed for only one crop life cycle. The focus of this study was to determine the suitability of the ash product following incineration of inedible biomass as a source of inorganic nutrients for hydroponic crop production. Inedible wheat biomass was incinerated and ash quality characterized. The incinerator ash was dissolved in adequate nitric acid to establish a consistent nitrogen concentration in all nutrient solution treatments. Four experimental nutrient treatments were included: control, ash only, ash supplemented to match control, and ash only quality formulated with reagent grade chemicals. When nutrient solutions are formulated using only ash following-incineration of inedible biomass, a balance in solution is established representing elemental retention following incineration and nutrient proportions present in the original biomass. The resulting solution is not identical to the control. This imbalance resulted in suppression of crop growth. When the ash is supplemented with nutrients to establish the same balance as in the control, growth is identical to the control. The ash appears to carry no phytotoxic materials. Growth in solution formulated with reagent grade chemicals but matching the quality of the ash only treatment resulted in growth similar to that of the ash only treatment. The ash product resulting from incineration of inedible biomass appears to be a suitable form for recycle of inorganic nutrients to crop production.
The notion that human activities may endanger the earth's environment has emerged as a leading societal concern in the post industrial era. Under the ever increasing pressures of population growth and industrialization, the problems of local air pollution have now become matters of both local and global concern. Smog, toxic chemicals, acid rain, ozone depletion, and climate change have become household words and an intense public policy debate about the cost and benefits of environmental protection continues. There is a growing realization that the consequences of air pollution can be felt in unpredictable ways in near and far away places. Unpopulated regions of the world such as the arctic now suffer from arctic haze and ozone depletions are the largest in the Antarctic stratosphere. In the last4ol three decades many countries have instituted ambient air quality standards designed to mitigate problems of health and welfare associated with the release of chemicals. Global agreements to prevent the depletion of ozone layer and to slow down climatic warming are being actively debated and formulated. In parallel there has been an intense exploration of the science of air pollution all over the world. The scientific basis behind environmental concerns is imperfect and is central to this debate. I will review our current scientific understanding of some of the major environmental concerns. An assessment of the forthcoming efforts to put this science on a more solid footing will be provided.
The focus of the work funded under this proposal is the exchange between the stratosphere and the troposphere, and between the troposphere and the blaspheme. These two interfaces represent the frontiers of atmospheric chemistry. It is the combination of exchange processes at both interfaces that ultimately controls how the blaspheme (including human activities) affects the ozone layer. The modeling work was motivated by and attempts to integrate information obtained by aircraft, spacecraft, shuttle and oceanic measurements. The model development and research activities accomplished in the past three years provide a technical and intellectual basis for the research in this group. The innovative part of our research program is related to the IAV of ozone and the hydrological cycle. Other related but independently supported work include the study of isotopic fractionation of atmospheric species, e.g., N2O and CO2. Our theory suggests that we now have the ability to probe the middle atmosphere at a level of sensitivity where subtle details such as the isotopic composition of simple molecules can yield measurable systematic effects. This creates the possibility for probing the chemistry and dynamics of the middle atmosphere using all of the N2O and CO2 isotopologues. In the following we will briefly describe the model development and review the highlights of recent accomplishments.
The growth of human population and their use of land, food and energy resources affect the Earth's atmosphere, biosphere and oceans in a complex manner. Many important questions in earth sciences today deal with issues regarding the impact of human activities on our immediate and future environment, ranging in scope from local (i.e. air pollution) to global (i.e. global warming) scale problems. Because the mass of the Earth's atmosphere is negligible compare to that found in the oceans and the biosphere, the atmosphere can respond quickly to natural and/or manmade perturbations. For example, seasonal 'ozone hole' formation in the Antarctic is a result of manmade CFC emissions in just the last 40 years. Also, the observed rise in global temperatures (known as global warming) is linked to a rapid increase in carbon dioxide and other greenhouse gas concentrations (emitted primarily by combustion processes) over the last century. The Earth's atmosphere is composed of a mixture of gases, aerosol and cloud particles. Natural and anthropogenic emissions of gases and aerosols affect the composition of the Earth's atmosphere. Changes in the chemical and physical makeup of the atmosphere can influence how the Earth will interact with the incoming solar radiation and the outgoing infrared radiation and vise versa. While, some perturbations are short-lived, others are long-lived and can affect the Earth's global climate and chemistry in many decades to come, In order to be able to separate the natural effects from anthropogenic ones, it is essential that we understand the basic physics and chemistry of interactions in the gas-aerosol-cloud system in the Earth's atmosphere. The important physics and chemistry that takes place in the coupled gas-aerosol-cloud system as it relates to aircraft observations are discussed.
This paper focuses on biosphere-climate interactions including the influences of human activities. Recognizing this is only one aspect of biospheric processes, this places an emphasis of those biogeochemical processes that have a profound effect on numerous other aspects of the biosphere and the services it provides, services which are critical to sustaining life on Earth. And, the paper will focus on the various scientific aspects of assessing the availability of fresh water, including its sensitivity to climate variance and land use changes. Finally, this paper hopes to emphasize the potential role that greatly expanded space observations and interactive modeling can play in developing our understanding of Earth and its the living systems.
Ultra-lightweight materials have played a significant role in nearly every area of human activity ranging from magnetic tapes and artificial organs to atmospheric balloons and space inflatables. The application range of ultra-lightweight materials in past decades has expanded dramatically due to their unsurpassed efficiency in terms of low weight and high compliance properties. A new generation of ultra-lightweight materials involving advanced polymeric materials, such as TEEK (TM) polyimide foams, is beginning to emerge to produce novel performance from ultra-lightweight systems for space applications. As a result, they require that special conditions be fulfilled to ensure adequate structural performance, shape retention, and thermal stability. It is therefore important and essential to develop methodologies for predicting the complex properties of ultra-lightweight foams. To support NASA programs such as the Reusable Launch Vehicle (RLV), Clark Atlanta University, along with SORDAL, Inc., has initiated projects for commercial process development of polyimide foams for the proposed cryogenic tank integrated structure (see figure 1). Fabrication and characterization of high temperature, advanced aerospace-grade polyimide foams and filled foam sandwich composites for specified lifetimes in NASA space applications, as well as quantifying the lifetime of components, are immensely attractive goals. In order to improve the development, durability, safety, and life cycle performance of ultra-lightweight polymeric foams, test methods for the properties are constant concerns in terms of timeliness, reliability, and cost. A major challenge is to identify the mechanisms of failures (i.e., core failure, interfacial debonding, and crack development) that are reflected in the measured properties. The long-term goal of the this research is to develop the tools and capabilities necessary to successfully engineer ultra-lightweight polymeric foams. The desire is to reduce density at the material and structural levels, while at the same time maintaining or increasing mechanical and other properties.
Some human factors challenges for space missions include: 1) Reduced Gravity; 2) Remote Operation; 3) Information; 4) Multi-Purpose Design. This viewgraph presentation addresses each of these topics. It describes how the design and layout of equipment on spacecraft can accomodate human activity in a microgravity environment. It describes the remote operation of robotic arms and robots. Displays, procedures, information sharing, and automation are means of conveying information. Multi-purpose design facilitates accomodating and supporting tasks onboard a single vehicle.
The characteristics of the cloud drop size distribution near cloud base are initially determined by the aerosol particles that serve as CCN and by the local updraft velocity. Chemical reactions of the emitted gaseous sulfur compounds due to human activities will alter, through gas-to-particle conversion, the aerosol size distribution, total number, and its chemical composition. Recently, Boucher and Rodhe and Jones et.al have each developed parameterizations relating cloud drop concentration to sulfate mass or aerosol number concentration, respectively, and used them to develop estimates of the indirect forcing by anthropogenic sulfate aerosols. THese parameterizations made use of measure relationships in continental and maritime clouds. However, these relationships are inherently noisy, yielding more than a factor of 2 variation in cloud drop concentration for a given aerosol number (or for a given sulfate mass) concentration. The large spatial and temporal variabilities in the concentration, chemical characteristics, and size distribution of aerosols have made it difficult to develop such a parameterization from data. In this paper, our focus is to develop a means for relating the predicted anthropogenic sulfate mass to cloud drop number concentration over the range of expected conditions associated with continental and marine aerosol. We start with an assumed pre-existing particle size distribution and develop an approximation of the altered distribution after addition of anthropogenic sulfate. We thereby develop a conservative estimate of the possible change in cloud drop number concentration due to anthropogenic sulfate.
Saharan dust impacts the Earth radiation balance. It was suggested that anywhere between 20-50% of the dust is anthropogenic, generated from human activity in the Sahel. Recent study By Prospero et al noticed that most of the sources should be north of Latitude of 15 deg. where population density is small. Here we use Aqua and Terra data to study the dust sources and their possible anthropogenic origin. Dust packages emitted from the Bodele depression and other sources in the southern part of the Sahara, are transported in the winter by a Northern East winds over the Sahel to the ocean. We are tracking these packages with MODIS from their sources to the ocean, showing that most of the dust reaching the Ocean from the Sahelian shore is generated in the Sahara, suggesting that the anthropogenic influence in the area is negligible. Saharan dust was suggested to be the main source of nutrients to the Amazon forest. Here we are also showing that these South Saharan sources around the Bodele depression are very active in the winter and rather passive in the summer, suggesting that the type of dust reaching Brazil, and its mineral content from these sources may be different from the dust that arrives to North America and Europe emitted in the summer from different sources.
Urbanization is one of the extreme cases of land use change. Although currently only 1.2% of the land is considered urban, the spatial coverage and density of cities are expected to rapidly increase in the near future. It is estimated that by the year 2025 60% of the world s population will live in cities (UNFP, 1999). Though urban areas are local in scale, human activity in urban environments has impacts at local, to global scale by changing atmospheric composition; impacting components of the water cycle; and modifying the carbon cycle 2nd ecosystems. For example, urban dwellers are undoubtedly familiar with "high" ozone pollution days, flash flooding in city streets, or heat stress on summer days. However, our understanding of urbanization on the total Earth-climate system is incomplete. Better understanding of how the Earth s weather, oceans, and land work together and the influence of the urban environment on this climate system is critical. This paper highlights some of the major and current issues involving interactions between urban environments and the Earth's climate system. It also captures some of the most current thinking and findings of the authors and key experts in the field.
Urbanization is one of the extreme cases of land use change. Most of world s population has moved to urban areas. Although currently only 1.2% of the land is considered urban, the spatial coverage and density of cities are expected to rapidly increase in the near future. It is estimated that by the year 2025,60% of the world s population will live in cities. Human activity in urban environments also alters weather and climate processes. However, our understanding of urbanization on the total Earth-weather-climate system is incomplete. Recent literature continues to provide evidence that anomalies in precipitation exist over and downwind of major cities. Current and future research efforts are actively seeking to verify these literature findings and understand potential cause- effect relationships. The novelty of this study is that it utilizes rainfall data from multiple satellite data sources (e.g. TRMM precipitation radar, TRMM-geosynchronous-rain gauge merged product, and SSM/I) and ground-based measurements to identify spatial anomalies and temporal trends in precipitation for cities around the world. Early results will be presented and placed within the context of weather prediction, climate assessment, and societal applications.
The most important use of atmospheric chemistry and transport models is to predict the future composition of the atmosphere. The amounts of gases like chlorofluorcarbons, methyl bromide, nitrous oxide and methane are changing and the stratospheric ozone layer will change because these gases are changing. Methyl bromide, nitrous oxide and methane all have natural sources, and also change because of human activity. Chlorofluorcarbons are man-made gases; these are known to decrease stratospheric ozone and future production is banned. They are long-lived gases, and many decades will pass before they are insignificant in the atmosphere. The models are used to predict changes in ozone and other gases; this is a straightforward application. The models must be also tested using observations for the present day atmosphere. This is a challenging task, because the model contains more than 50 species and more than 150 chemical reactions. Data from satellites, ground stations, aircraft and balloons are used to evaluate the model. Different models that are used in international assessments produce different results; in the most recent assessment some predict that ozone will return to 1980 levels by 2025 and others predict that this will not happen until 2050. Since all the parts of the models are conceptually the same, there must be differences in implementation that produce these differences, This work takes a single model, two different sets of winds and temperatures, and repeats the same prediction for the future. Here we compare the results for these two simulations with many observations. The purpose is to identify differences in the model results for the present atmosphere that will lead to different predictions. This sort of controlled comparison will reduce uncertainty in the predictions for stratospheric ozone.
The development of Mars for human activity will require the utilization of Martian materials in building habitats and working structures. One approach is to use polymer binders with regolith to form structural elements. Not only can useful composite materials be produced in this way but the radiation protection properties are also increased. This is important since only modest protection from space radiation is provided by the Martian atmosphere. We have studied composites fabricated using Martian regolith simulant and polymers which can be synthesized from local Martian materials for their potential use as radiation shields for manned Mars missions. To validate shielding effectiveness, composites are irradiated with a 55 MeV proton beam and neutron beams up to 800 MeV. Shielding effects on microelectronic devices are measured by placing them behind samples of the composites during irradiation. To measure structural properties of the composites, preliminary characterization and mechanical testing are made for the composites.
NASA's Office of Safety and Mission Assurance sponsors an Agency-wide NDE Program that supports Aeronautics and Space Transportation Technology, Human Exploration and Development of Space, Earth Science, and Space Science Enterprises. For each of these Enterprises, safety is the number one priority. Development of the next generation aero-space launch and transportation vehicles, satellites, and deep space probes have highlighted the enabling role that NDE plays in these advanced technology systems. Specific areas of advanced component development, component integrity, and structural heath management are critically supported by NDE technologies. The simultaneous goals of assuring safety, maintaining overall operational efficiency, and developing and utilizing revolutionary technologies to expand human activity and space-based commerce in the frontiers of air and space places increasing demands on the Agencies NDE infrastructure and resources. In this presentation, an overview of NASA's NDE Program will be presented, that includes a background and status of current Enterprise NDE issues, and the NDE investment areas being developed to meet Enterprise safety and mission assurance needs through the year 2009 and beyond.
The extent of biomass burning has increased significantly over the past 100 years because of human activities, and such burning is much more frequent and widespread than was previously believed. Biomass burning is now recognized as a significant global source of emissions, contributing as much as 40% of gross carbon dioxide and 38% of tropospheric ozone. Most of the world's burned biomass matter is from the savannas, and because two-thirds of the Earth's savannas are located in Africa, that continent is now recognized as the "burn center" of the planet. In the past few years the international scientific community has conducted field experiments using ground-based and airborne measurements in Africa, South America. and Siberia to better assess the global production of gases and particulates by biomass burning. Researchers are gathering this month in Williamsburg, VA, to discuss the results of these and other investigations at the Second Chapman Conference on Biomass Burning and Global Change, sponsored by the American Geophysical Union. The first international biomass burning conference, held in 1990, was attended by atmospheric chemists, climatologists, ecologists, forest and soil scientists, fire researchers, remote- sensins specialists, and environmental planners and managers from more than 25 countries.When we hear about biomass burning, we usually think of the burning of the worlds tropical forests for permanent land clearing. However, biomass burning serves a variety of land use changes, including the clearing of forests and savannas for agricultural and grazing use; shifting agriculture practices; the control of grass, weeds, and litter on agricultural and grazing lands; the elimination of stubble and waste on agricultural lands after the harvest; and the domestic use of biomass matter.