2
Major Advances in the Atmospheric Sciences

INTRODUCTION

The committee was charged by the National Science Foundation’s (NSF’s) Atmospheric Science Division (ATM) to assess the balance among the types of activities and modes of support and to make recommendations as to how the balance might need adjustments to ensure the health of the atmospheric sciences into the future. In its interim report the committee recommended that ATM should continue to utilize the current mix of modes of support for a diverse portfolio of activities (i.e., research, observations and facilities, technology development, education, outreach, and applications) (NRC, 2005e). Thus, the committee concluded that the types of activities and the modes of support were appropriate and now addresses the further question of whether the balance among activities or modes should be adjusted.

The committee devoted considerable thought to the appropriate methodology for dealing with this “balance question” in the context of strategic guidance. It decided that the most useful approach would be to create a list of major research accomplishments in the atmospheric sciences, supported at least in part by NSF, and then analyze the role of ATM’s modes and activities. The balance would be judged to be in need of adjustment if various modes or activities had in fact not been crucial in achieving any of these major research accomplishments. Conversely, finding the various modes of support and activities to be well represented among the major achievements of the past decades is good evidence that having a diversity of modes and activities has been a successful strategy. That is, it would show that the mix



The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement



Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.

OCR for page 14
Strategic Guidance for the National Science Foundation‘s Support of the Atmospheric Sciences 2 Major Advances in the Atmospheric Sciences INTRODUCTION The committee was charged by the National Science Foundation’s (NSF’s) Atmospheric Science Division (ATM) to assess the balance among the types of activities and modes of support and to make recommendations as to how the balance might need adjustments to ensure the health of the atmospheric sciences into the future. In its interim report the committee recommended that ATM should continue to utilize the current mix of modes of support for a diverse portfolio of activities (i.e., research, observations and facilities, technology development, education, outreach, and applications) (NRC, 2005e). Thus, the committee concluded that the types of activities and the modes of support were appropriate and now addresses the further question of whether the balance among activities or modes should be adjusted. The committee devoted considerable thought to the appropriate methodology for dealing with this “balance question” in the context of strategic guidance. It decided that the most useful approach would be to create a list of major research accomplishments in the atmospheric sciences, supported at least in part by NSF, and then analyze the role of ATM’s modes and activities. The balance would be judged to be in need of adjustment if various modes or activities had in fact not been crucial in achieving any of these major research accomplishments. Conversely, finding the various modes of support and activities to be well represented among the major achievements of the past decades is good evidence that having a diversity of modes and activities has been a successful strategy. That is, it would show that the mix

OCR for page 14
Strategic Guidance for the National Science Foundation‘s Support of the Atmospheric Sciences of modes and activities has contributed to major advances and it would provide evidence that the balance has been adjusted to accommodate new opportunities and needs. Given that the NSF has multiple mechanisms for assuring that the processes for granting awards are functioning properly, the committee believes that the present task can be addressed by focusing solely on the major scientific results of ATM’s programs. Statistical criteria are often used when judging certain aspects of scientific quality. For example, the number of highly cited papers by field would be a possible approach to identifying the relative effectiveness of fields or modes. This form of measurement is often applied to the contributions of individual Principal Investigators (PIs). However, the committee concluded that such statistical measures are both too imprecise and too beset with complications and biases to be useful for our purposes. They are, moreover, not the type of measurements that are appropriate for other modes of support for the atmospheric sciences. The highly significant accomplishments selected by the committee are shown in Table 2-1 (in no particular order). It is important to note that this list of major achievements and the selection of case studies was made without prior examination or consideration of the roles the modes played in each of the achievements. While this list is not exhaustive, the committee believes that enlarging the set of major achievements would not change our conclusions regarding the adjustment to the balance between modes and activities. The committee selected case studies from all disciplines within NSF’s ATM division. While advances in understanding of climate variability and change are certainly among the most significant accomplishments of the past few decades and a few of the case studies cover aspects of climate TABLE 2-1 List of Selected Major Achievements in the Atmospheric Sciences List of Selected Major Achievements 1. Improvements in severe weather forecasting 2. Development of the dropsonde 3. Identifying causes for the Antarctic ozone hole 4. Development of community computational models 5. Development of the wind profiler to observe turbulent scatter 6. Emergence of space weather as a predictive science 7. Understanding the oxidative capacity of the troposphere 8. Identifying the importance of tropospheric aerosols to climate 9. The role of Mauna Loa measurements in understanding the global carbon cycle 10. Improving El Niño predictions 11. Development of helioseismology 12. Reading the paleoclimate record

OCR for page 14
Strategic Guidance for the National Science Foundation‘s Support of the Atmospheric Sciences science, the broad scope of climate science did not lend itself to a case study. The committee refers the reader to the comprehensive assessments of the Intergovernmental Panel on Climate Change (e.g., IPCC, 2001). Some of the case studies focus on advances in tools, while others emphasize breakthroughs in knowledge and understanding. The committee notes also that certain significant achievements in atmospheric sciences lend themselves to quantitative assessment; that is, objective measures of progress over time are available. Quantitative improvement measures are immediately apparent for items 1, 2, 4, and 5 in Table 2-1. Such metrics have been treated extensively in the context of mission-oriented programs, such as the U.S. Climate Change Science Program, in the recent National Research Council (NRC) report Thinking Strategically: The Appropriate Use of Metrics for the Climate Change Science Program (NRC, 2005d). However, the committee does not believe it is appropriate or possible to expect all of ATM’s major research accomplishments to fit that model of quantitative assessment. In part, quantitative assessment of research is problematic because some of these accomplishments were not planned and therefore do not fit the goal-driven model outlined in this earlier NRC report. Moreover, the type of quantitative measures appropriate for some of the modes is certainly not the appropriate measure for others (e.g., progress in severe weather forecasting vs. productivity and effectiveness of individual PI grants). This raises the issue of how to objectively compare incommensurate measures, a kind of “apples and oranges” problem. This dilemma is another strong reason the committee chose to focus on major accomplishments in addressing the balance issue. In what follows, summaries are provided of what the committee believes are among the most important research results of the past several decades. These summaries are then analyzed for the ways in which NSF ATM’s modes and activities contributed to these achievements, and how, in doing so, they occasionally adjusted the balance between modes and activities. It is clear from our analysis of these case studies that NSF ATM has made effective use of its varied modes of support and that the balance between the modes has evolved over time in response to the needs and opportunities of the field. This chapter also includes many testimonials written by some key participants describing in more personal terms how the achievements were made possible by federal agency or private-sector support. It is important to note that the tenacity and dedication of the investigators, whatever the role of NSF support, was an integral factor in many of the research achievements described. Note that this list is not intended to be exhaustive, but the committee believes it is appropriate to the purpose of this chapter.

OCR for page 14
Strategic Guidance for the National Science Foundation‘s Support of the Atmospheric Sciences CASE STUDIES OF MAJOR ACHIEVEMENTS IN THE ATMOSPHERIC SCIENCES Case Study 1: Improvements in Severe-Weather Forecasting It is difficult to trace the one seed that began research conducted by the National Oceanic and Atmospheric Administration’s (NOAA’s) National Severe Storms Laboratory (NSSL) and the nearby School of Meteorology at the University of Oklahoma (OU), other universities, and the National Center for Atmospheric Research (NCAR), that has led to dramatic improvements in severe-weather forecasting during the last decade or two (Doswell et al., 1993). Using conventional radar and aircraft, NSSL conducted studies of severe convective storms in the 1960s (Bluestein, 1999a). These studies built upon the Thunderstorm Project conducted in the 1940s (Byers and Braham, 1949); further contributions by Chester Newton, Ted Fujita, and Keith Browning in the 1950s and 1960s at the University of Chicago and Air Force Cambridge Research Laboratories (AFCRL) (e.g., Fujita, 1963; Newton, 1963); the Alberta Hail Studies Project; the National Hail Research Experiment; and radar development by Roger Lhermitte, Dave Atlas, Rod Rogers, Alan Bemis, Pauline Austin, and J. Stewart Marshall in France, at AFCRL, Cornell, MIT, and McGill, among others, at the aforementioned institutions and elsewhere. The advent of meteorological Doppler radar in the late 1960s and the development and use of dual-Doppler analysis techniques in the 1970s at NSSL and NCAR provided the most significant leap in the ability to observe the behavior and internal structure of supercells and other convective storms (Davies-Jones et al., 2001). Equally important as the developments in Doppler radar, the concurrent development of three-dimensional numerical cloud models in the mid 1970s at several universities provided the potential to study the dynamics of severe convective storms by performing controlled numerical experiments. As an example, collaboration between the University of Illinois at Urbana-Champaign and NCAR led to the development of the workhorse “Klemp-Wilhelmson” nonhydrostatic cloud model, which was used for two decades (Wilhelmson and Wicker, 2001). Advances in the capabilities of computers, particularly supercomputers at NCAR, permitted the model to be used for severe-storm research. Pioneering work at NCAR in the early to mid 1980s identified quantitatively the basic environmental parameters supportive of supercells, the most prolific producers of severe weather. At NCAR, expertise was at hand also to physically interpret the mechanisms responsible for supercell formation and behavior (Klemp, 1987). The roles of environmental vertical wind shear and potential thermal buoyancy in producing storm rotation and propagation were elucidated. In the late 1980s and 1990s scientists at NCAR and at universities also investigated

OCR for page 14
Strategic Guidance for the National Science Foundation‘s Support of the Atmospheric Sciences the behavior of groups of convective storms, mesoscale convective systems, such as squall lines, again using controlled numerical experiments (e.g., Box 2-1; Rotunno et al., 1988; Weisman and Davis, 1998). The roles of low-level vertical shear and an evaporatively produced cold pool of air in controlling storm structure and evolution were described. The results of these experiments led to an increased awareness and understanding of the conditions leading to damaging, straight-line surface winds. BOX 2-1 Improving Severe-Weather Forecasting Morris L. Weisman, Senior Scientist, Mesoscale and Microscale Meteorology National Center for Atmospheric Research Ph.D., Meteorology, Pennsylvania State University I began my scientific career in 1979 when I joined a science group at the National Center for Atmospheric Research (NCAR). My work involved the exploration of convective storms with the goal of improving our ability to forecast severe convective phenomena such as tornadoes and damaging straight-line winds. This work was fostered at NCAR by the unique juxtaposition of talents and resources that Dr. Doug Lilly brought together, ranging from state-of-the-art numerical cloud modeling, developed by Dr. Joseph Klemp in collaboration with Dr. Bob Wilhelmson (University of Illinois), to theoretical expertise, contributed especially by Dr. Richard Rotunno. My research focused on the simulation of convective storms and mesoscale convective systems to reveal the dependence of observed convective structure on preexisting environmental conditions such as thermodynamic instability and vertical wind shear. This fruitful research collaboration has offered new physical insights into a host of significant convective phenomena, including supercells, squall lines, rear-inflow jets, bow echoes, and mesoscale convective vortices.Outside collaborations with university researchers have lead to new insights into, for instance, how supercell storms may interact within a squall line.Other collaborations with NationalWeather Service forecasters have led to the development of new forecasting techniques such as the improved prediction of convective storm motion. Many of these advances in knowledge are now used by severe-weather forecasters on a daily basis worldwide. Further, they form the basis for four interactive computer-based learning modules produced by COMET (Cooperative Program for Operational Meteorology, Education, and Training), which are used heavily by the National Weather Service, Air Force, and universities. In all of these endeavors, the synergy of a variety of resources and talents available at an NSF-funded national center such as NCAR has been critical. NCAR combines world-class computational and observational facilities with the theoretical expertise covering the full range of atmospheric phenomena, and provides a high level of access to university and other national and international researchers and forecasters.

OCR for page 14
Strategic Guidance for the National Science Foundation‘s Support of the Atmospheric Sciences Many field experiments have been conducted (Table 2-2), in large part with support from NSF, both for field operations and for development of new instrumentation (Figure 2-1). In the early 1970s, storm-intercept field programs began at NSSL and OU, with funding initially from NOAA (Bluestein, 1999b). Early collaborative annual spring field programs led to a conceptual model of supercells used by spotters and nowcasters, and in situ verification of severe weather events that eventually instigated the development of a national network of Doppler radars (NEXRAD) and its implementation in the 1990s. After the radars became operational, the accuracy and lead time of short-term (< 1 h) severe-weather warnings improved greatly. The object of some of these experiments was to study the details of tornado development and other severe-storm features; the object of others was to further understanding of convective storms in general. In many instances, NOAA provided partial or seed support. Quantitative studies in tornadoes began with the Totable Tornado Observatory (TOTO), built by NOAA, in the early 1980s. Pressure falls associated with mesocyclones and thermal aspects of the rear-flank downdraft were documented. The first portable Doppler radar, developed at the Los Alamos National Laboratory, was used in the late 1980s to estimate the maximum wind speed in tornadoes from Doppler spectra. NSF funded part of these efforts well before instrumented storm-intercept projects were recognized by the community to be scientifically valuable. From these efforts, it was determined that the “thermodynamic speed limit” was usually exceeded, thus pointing to the important role of dynamic pressure gradients near the ground in tornadoes. A scanning, airborne Doppler radar (ELDORA—ELectra DOppler RAdar) was developed in large part at NCAR and used by university and NCAR scientists to probe supercells during VORTEX (Verification of the ORigin of Tornadoes EXperiment) in the mid 1990s (Bluestein TABLE 2-2 Some Important Large-scale Field Experiments Conducted in the Last 20 Years Important Large-scale Field Experiments of the Last 20 Years Oklahoma–Kansas Preliminary Regional Experiment for STORM-Central (OK-PRESTORM) 1985 Convective Initiation and Downburst Experiment (CINDE) 1987 Cooperative Oklahoma Profiler Studies (COPS) 1989, 1991 Verification of the Origins of Tornadoes Experiment (VORTEX) 1994, 1995 Severe Thunderstorm Electrification and Precipitation Study (STEPS) 2000 International H2O Project (IHOP_2002) 2002 Bow Echo and Mesoscale Convective Experiment (BAMEX) 2003

OCR for page 14
Strategic Guidance for the National Science Foundation‘s Support of the Atmospheric Sciences FIGURE 2-1 (bottom) Plan view of a radar image, just above the ground, of the radar reflectivity of a tornadic supercell on May 29, 2004, near Calumet, Oklahoma; from the University of Massachusetts mobile X-band, dual-polarization, Doppler radar. The center of the mesocyclone is located at the hole in reflectivity seen in the left, center. (top) Graduate students from the University of Oklahoma probing a tornado near Hodges, Texas, on May 13, 1989, using a portable, CW (continuous wave)/FM-CW, X-band (3-cm wavelength) Doppler radar from the Los Alamos National Laboratory. Photograph copyright Howard B. Bluestein.

OCR for page 14
Strategic Guidance for the National Science Foundation‘s Support of the Atmospheric Sciences and Wakimoto, 2003). Hitherto unseen details of storm evolution during tornadogenesis were examined for the first time and it was found that surface mesocyclogenesis is not a sufficient condition for tornadogenesis. At about the same time as VORTEX, several ground-based, mobile Doppler radars were developed for analyzing the structure of the tornado itself. One effort, supported at the University of Massachusetts at Amherst and OU by NSF, led to the development and use of a mobile, high-frequency, ultra-high-resolution W-band radar; the other led to the development of the Doppler-On-Wheels, an X-band radar. The latter was initially supported by NCAR, OU, and NSSL, with some NSF funding, and has been very widely used ever since, not only for severe-storms research, but also in hurricanes and in mid-latitude storms. Tornadogenesis, which was found to take place on time scales of 10 s or less, in one case appeared to occur when a small-scale bulge in the rear-flank gust front developed, and a small-scale vortex appeared just ahead of it and interacted with a larger-scale low-level mesocyclone. Small-scale shear-induced vortices along the gust front were resolved and hypothesized to potentially play a role in tornado formation. The radial variation of wind speed has been clearly resolved; multiple vortices have been documented, as has the fine structure of weak-echo holes. Since then, other mobile radars have been developed, in part with NSF funding; they promise to add even more significantly to knowledge of tornado structure and formation. It is anticipated that field experiments with these radars, especially during VORTEX-II, which is currently in the planning stage, will further unlock the mysteries of tornado formation and ultimately lead to further improvements in tornado prediction. The results of the numerical-simulation efforts and the storm-intercept field programs have been applied to severe-storm forecasting through the efforts of COMET, a University Corporation for Atmospheric Research (UCAR) program. A number of forecasters who were supported by university NSF grants as students subsequently became employees at National Weather Service Forecast Offices and/or the Storm Prediction Center. NSF has not only supported observational and basic theoretical work, which have indirectly led to the advances mentioned above, but it also has funded efforts to improve severe-storm forecasting more directly, through small centers at universities. One of the first of 11 NSF Science and Technology Centers (STCs), the Center for the Analysis and Prediction of Storms (CAPS) at OU, pioneered storm-scale numerical weather prediction in which fine-scale observations, principally from Doppler radar, along with unobserved quantities retrieved from the Doppler-radar observations, are used to initialize cloud-resolving models. CAPS also developed the world’s first storm-scale prediction system for massively parallel computers, laying the intellectual and technological foundation for what has become a major

OCR for page 14
Strategic Guidance for the National Science Foundation‘s Support of the Atmospheric Sciences area of inquiry including the next-generation Weather Research and Forecast (WRF) model. Other efforts, funded in large part by NSF, continue at NCAR and elsewhere toward perfecting the WRF. An NSF Engineering Research Center, the Center for Collaborative Adaptive Sensing of the Atmosphere, is based at the University of Massachusetts at Amherst, but also has other academic partners including OU, Colorado State University, and the University of Puerto Rico at Mayaguez. It aims to create a distributed, adaptive network of low-power phased-array Doppler radars on existing infrastructure (e.g., cellular towers) to improve severe-weather forecasting and warnings by sensing the region from the ground to 3 km altitude. This effort is jointly funded by the Engineering and Geosciences Directorates at the NSF. Support from and collaboration with industry has also become an important part of these centers. A systems-level testbed of four radars was installed in Oklahoma during January 2006 and will be expanded in the coming years. This case study illustrates that ATM’s diverse portfolio of activities and modes of support were instrumental in the improvements in severe-weather forecasting during the last few decades. In addition to individual PI grants and the support of the large national center, the support of small centers was particularly fruitful for the development of radar technology and numerical modeling tools. In supporting these activities and theoretical work at universities, NSF has also provided essential support for graduate education to many students. Many of them have since become employed not only by NOAA as mentioned earlier, but also as researchers and educators at universities, government laboratories, and at NCAR, thus ensuring the existence of future generations who will further improve severe-weather forecasting. Case Study 2: Development of the Dropsonde The remarkable accuracy of hurricane landfall forecasts during the 2005 hurricane season was largely thanks to the use of dropwindsondes (Figure 2-2). Starting with their use in hurricane reconnaissance in the 1960s by the U.S. Navy and Air Force, dropsondes have become an important part of both research and operations, involving NCAR, NSF-supported university research, NOAA, the Air Force, and the private sector. Hurricane reconnaissance using dropsondes dates from the 1960s, when the U.S. Navy and Air Force used Bendix-made dropsondes to sample tropical cyclones in the Atlantic and the Pacific. In 1966, University of Arizona researcher Walter Evans modified a Bendix sonde to sample the electric field in thunderstorms and dropped them from the NCAR Queen Air, introducing dropsondes to the university research community. Then Robert Bushnell and colleagues at NCAR designed a sonde with a downward-pointing pitot tube

OCR for page 14
Strategic Guidance for the National Science Foundation‘s Support of the Atmospheric Sciences FIGURE 2-2 RD-93 aircraft dropsonde. to measure vertical winds in thunderstorms for the National Hail Research Experiment (NHRE). The NHRE-inspired design started a decades-long effort of dropsonde development by a group of NCAR scientists and engineers (in addition to Bushnell, Harold Cole, Stig Rossby, P.K. Govind, Justin Smalley, Dean Lauritsen, Terry Hock, Walt Dabberdt, and Vin Lally), which is also described in Box 2-2. Advances were spurred by the needs of NSF-sponsored field campaigns, international field campaigns, or requests by the Air Force, NOAA, or the Deutsche Luft-und Raumfahrt (DLR); and by improvements in technology. Wind-measuring capability utilizing the

OCR for page 14
Strategic Guidance for the National Science Foundation‘s Support of the Atmospheric Sciences BOX 2-2 Development of Aircraft Dropsondes for Atmospheric and Hurricane Research Harold L. Cole, Senior Engineer National Center for Atmospheric Research MS, Atmospheric Science, Colorado State University I was hired by NCAR in September of 1970, on a half-time basis, to support the Viking Meteorology Experiment for the Viking Mars Lander program. Consequently, funding for half of my salary was provided to NCAR by Dr. Seymour Hess of Florida State University, who was the science team leader of the Viking Meteorology Experiment. As the Meteorology Team Engineer, I helped develop the requirements for and test the automatic weather station that led to the first-ever daily weather reports from Mars.During that same time, the other half of my salary was provided by NCAR to work as a Project Engineer for development of the Omega dropwindsonde using the Omega Navigation signals to compute winds. This dropsonde was needed for the upcoming Global Atmospheric Research Program’s (GARP’s) AtlanticTropical Experiment (GATE). The NCAR Omega dropsonde system was successfully used during GATE and later in the First GARP Global Experiment (FGGE).The ten aircraft data systems, designed by NCAR and commercially built with NOAA funds for FGGE, were later given by NOAA to the U.S. Air Force and adopted for their hurricane reconnaissance mission. Subsequently, I served as the Project Manager for the joint U.S.–Canadian development of the Automated Shipboard Aerological Program (ASAP), which was supported by NOAA, NCAR, and the Canadian Atmospheric Environment Service. The ASAP development produced a containerized upper-air sounding system (radiosonde) that can be placed on ships-of-opportunity crossing the North Atlantic and North Pacific oceans allowing radiosonde measurements to be taken over the oceans.The first such sounding system was placed on a Japanese car carrier (M.V.Friendship) in April 1982 and went from Vancouver, British Columbia, to Japan and back. The ASAP program became a WMO-sponsored program in the mid 1980s and continues to this day. In 1985 the Air Force Hurricane Hunters were starting to have problems with the old Omega dropwindsondes due to rising costs, obsolete parts, and quality control problems. I worked with the Air Force and the Office of the Federal Coordinator for Meteorology to develop a new smart (i.e., microprocessor-based), lightweight digital dropsonde that incorporated Loran (Lightweight Loran Digital Dropsonde-L2D2) or Omega (LOD2) windfinding.The Omega version of the dropsonde was adopted by the U.S. Air Force in the early 1990s for its hurricane reconnaissance mission. In 1987, I developed plans in collaboration with NOAA’s Office of Global Programs to put an upper-air sounding system and automatic surface station on Kanton Island in the tropical Pacific due to the TOGA Office’s interest in looking at the cause of El Niño and gathering data from the tropical Pacific.Because some of the concepts used on ASAP were directly applicable to the development of a self-contained, easily operated (one person) sounding system, the TOGA Office requested a proposal for the development of the Kanton Island Sounding System (KISS).The system was installed on Kanton Island in August 1988 and continued to operate until after TOGA COARE (~1994). For the follow-up on the TOGA COARE program, which was to understand

OCR for page 14
Strategic Guidance for the National Science Foundation‘s Support of the Atmospheric Sciences scientists in Australia, Denmark, France, Germany, India, Japan, Taiwan, and the United Kingdom. The Solar Terrestrial Research Program in ATM provides an average of roughly $400K–500K per year for helioseismology through its regular grants program, and through the National Space Weather Program (NSWP), Research at Undergraduate Institutions, and NSF faculty early career development program (CAREER) awards. In its first decade, helioseismology has ushered in a golden age in solar research. Solar structure and motions have been clarified. One of the first results from helioseismology was that the convection zone extends downward to 0.713 of the solar radius, significantly deeper than many earlier solar structure models had predicted (Harvey, 1995). Helioseismology has also demonstrated that the zonal flow at the surface (long documented by following the trajectories of sunspots and other surface features) changes little with radius through the convection zone; but there is considerable radial shear between the convection zone and the radiative interior, through a layer called the “tachocline.” Helioseismic measurements have also shown that small variations in solar rotation—so-called torsional oscillations— occur throughout the convection zone, with periods tied to the solar cycle period. Beyond differential rotation, helioseismic inversions have revealed several other motions, including poleward meridional below the photosphere and other “solar weather” patterns near the surface. Inversions are also beginning to reveal the thermal structure below “active regions,” the sites of sunspots. Now solar activity on the side of the Sun opposite the Earth is routinely detected by so-called “far-side imaging.” These findings inspired a new generation of individuals and groups around the world to develop idealized models and full-blown general circulation models of the outer layers of the Sun, designed to explain the solar dynamo and the solar cycle. In 2006, Mausumi Dikpati, Giuliana de Toma, and Peter Gilman, of NCAR’s HAO used a so-called “flux-transport” dynamo model that assimilated data from the previous three solar cycles (borrowing a technique from numerical weather prediction) to predict successfully the relative amplitudes of the new cycle for each of the last nine solar cycles, and to project the amplitude of the next solar cycle in 2012 (Figure 2-6) (e.g., Box 2-9; Dikpati et al., 2006). These predictions and future results coming from helioseismology-inspired research will provide significant contributions to predictions of Space Weather. In addition, helioseismology has offered a new way to constrain the distribution of elements making up the Sun. The elemental abundance has historically been determined by using what we know—luminosity measurements, solar radius, and solar spectral results giving clues to the chemical composition—to build one-dimensional solar and stellar structure models. More recently, helioseismology has been used to determine the sound

OCR for page 14
Strategic Guidance for the National Science Foundation‘s Support of the Atmospheric Sciences FIGURE 2-6 (a) Observed sunspot area, smoothed by ~1-year Gaussian running average, plotted as a function of time; (b) simulated toroidal (zonal) magnetic flux at the bottom of the solar convection zone, which is the source of sunspots. Solid red area and curve are for steady meridional flow; dashed red curve is for time-varying flow since 1996 incorporated. SOURCE: Dikpati et al. (2006). speed, providing an independent route to constrain the composition. Until recently, both approaches were consistent with the same solar abundance of elements—until Australian Martin Asplund and colleagues (Asplund et al., 2005) used spectral data interpreted with the help of three-dimensional simulations to revise the solar chemical composition to reduce the percentage of atoms heavier than helium. Sarbani Basu of Yale University, funded by a CAREER grant through NSF/ATM/Solar Terrestrial Research, was

OCR for page 14
Strategic Guidance for the National Science Foundation‘s Support of the Atmospheric Sciences BOX 2-9 Predicting Solar Cycles Mausumi Dikpati, Scientist NCAR Ph.D., Physics, Indian Institute of Science, Bangalore, India After successfully completing my Ph.D. in India, I decided to come to the United States for my postdoctoral study. I chose the United States because I thought it would be the best place to pursue my area of research, namely the modeling and predicting of solar cycles.I was accepted in the Advanced Study Program of NCAR for a post-doc in 1996 to work with a group of scientists that work in this same area of research. I stayed in this position until 1999, during which time I not only gained much experience in solar cycle modeling but I was also fortunate enough to get the chance to work with Peter Gilman on a new topic, instabilities in the solar tachocline. Interactions with him on professional matters and otherwise have been invaluable in shaping my career and personality. My accomplishments during this post-doc provided me the opportunity to continue my research at NCAR as a NASA-funded project scientist until 2002. During this time I worked on symmetry selection in solar cycle dynamo models.This research led to a paper that was nominated for the UCAR outstanding publication award.These further accomplishments helped me win the NCAR-wide competition for a new NSF base-funded scientist I positions in 2003. I was subsequently promoted to scientist II in 2006. Apart from science, I am very involved in spiritual activities that provide me more focus and insight. These activities also brought up whether I could do research that would benefit society as a whole, for example, whether I could develop a model to predict solar cycles. I realized that I might be able to do that by building a predictive tool from my research on so-called “flux-transport” dynamos applied to the Sun. I actively started the work and, fortunately, found the right colleagues—Charles Nick Arge (AFGL), Paul Charbonneau (University of Montreal), Giuliana de Toma (HAO/ NCAR), David Hathaway (NASA/MSFC), Keith MacGregor (HAO/NCAR), Matthias Rempel (HAO/NCAR), and Dick White (HAO/NCAR)—to work with. Both the NSF and NASA have supported this research. I continued publishing papers in the Astrophysical Journal with results from the development of the predictive tool. Feature articles, discussing my work in popular on a team that found a potential way out of this impasse. By raising the abundance of neon (the most uncertain of the heavier element abundances), they have shown that the rest of the revised abundances are potentially consistent with both helioseismic and spectral results (Bahcall et al., 2006). She and H.M. Antia are now attempting to measure the total solar heavy element abundance through helioseismology (Antia and Basu, 2006). This

OCR for page 14
Strategic Guidance for the National Science Foundation‘s Support of the Atmospheric Sciences magazines such as New Scientist and National Geographic in 2004, have given me great encouragement that this research is of interest and value to society. After our prediction for the next solar cycle was published in Geophysical Research Letters on March 6, 2006, the work received great attention in the worldwide press.When reports were translated into Bengali and reported in “Songbad Protidin” (the daily newspaper in Calcutta), it caused my mother to become very excited about the recognition her daughter was getting. is important because stellar models and models of the universe are tied to solar abundance models. The reach of helioseismology extends beyond solar physics to particle physics. Secondary students all over the world are taught that the Sun is powered by a reaction that converts hydrogen to helium, releasing neutrinos in the process. In the 1960s, Raymond Davis of Brookhaven

OCR for page 14
Strategic Guidance for the National Science Foundation‘s Support of the Atmospheric Sciences National Laboratory (University of Pennsylvania after 1984) set up an experiment to detect solar neutrinos, 4,800 feet below the surface in the Homestake Gold Mine, in Lead, South Dakota. Neutrinos were detected, but only one-third the amount predicted assuming that the commonly accepted helium-to-hydrogen conversion was true; stimulating new detectors around the world—Kamiokande in Japan, SAGE in the former Soviet Union, GALLEX in Italy, and Super Kamiokande (http://nobelprize.org/physics/laureates/2002/davis-autobio.html). Those explaining the “missing” neutrinos invoked a rapidly rotating solar core, contrary to the thinking of the solar physics community. The LOWL instrument revealed a core rotating at a rate similar to the outer layers of the Sun, indicating something else was needed to explain the missing neutrinos. Also, John Bahcall, Sarbani Basu, and Marc Pinsonneault argued that the fact that the sound speed and density in the core of standard solar models are so close to those inferred from helioseismic measurements, also implies that explaining the missing neutrinos would mean invoking nonstandard neutrino physics rather than nonstandard solar models. Finally, in 2001–2002, scientists at the Sudbury Neutrino Observatory in Ontario, Canada, found evidence that the neutrinos could oscillate among three forms. The 2002 Nobel Prize in Physics was awarded to Davis and Masatoshi Koshiba of the University of Tokyo “for pioneering contributions to astrophysics, in particular for the detection of cosmic neutrinos.” Responsibility for funding helioseismic studies has been shared at NSF between ATM and AST, and within the United States has been shared between NSF and NASA. The partnership between NSF’s ATM and AST divisions exemplifies a successful intra-agency partnership across directorates within NSF. The helioseismic observations are made both from space and from worldwide ground-based networks, and analysis of the data is carried out at many U.S. and foreign universities who meet regularly to discuss the latest results. The ground-based GONG network has recently been upgraded to provide much higher spatial resolution with NSF/AST money and within two years the SOHO satellite will be superceded by the new Solar Dynamics Observatory satellite (NASA Living with a Star Program, ESA). NSF/ATM and NASA continue to support helioseismic studies with grants to university PIs. Case Study 12: Reading the Paleoclimate Record Given the relatively short instrumental climate data record, the ability to test climate models depends strongly on the availability of paleoclimate records. Advances in paleostudies over the past few decades have significantly extended the data record, providing a context for the instrumental climate record and the evolution of atmospheric composition (e.g., CO2,

OCR for page 14
Strategic Guidance for the National Science Foundation‘s Support of the Atmospheric Sciences CH4, NO2). Paleorecords are used to infer the impact of anthropogenic contributions on long-term climate trends and to test climate models, particularly regarding the sensitivity of climate to CO2. A major milestone in the field of paleoclimatology was the demonstration that the concentrations of oxygen-18 and deuterium accumulated in deep cores of glacier ice can be used as an indicator of past temperature (Dansgaard, 1964). Radioisotopic dating methods, such as the radiocarbon dating methods developed in the early 1970s for dating sediment or lake cores, were applied to these data sources in order to construct consistent chronologies of past temperature. Since that time, many other radioisotopic dating methods have been tailored and calibrated for specific application to paleoclimate datasets (Cronin, 1999). The first ice cores were obtained from Vostok, Antarctica, in the 1970s by Russian scientists. In the 1980s, French and American scientists subsequently joined this effort, which was supported primarily by NSF’s OPP (Box 2-10). The most recent Vostok drilling yielded the longest record, dating to 420,000 years B.P. (Petit et al., 1999). Similar drilling expeditions to Greenland have yielded data records on atmospheric composition and temperature trends on millennial time scale. These records have revealed the climate’s variability over millenial cycles, and have provided evidence for the correlation between global temperatures and CO2 concentrations. These records also demonstrate the importance of Milankovitch cycles in regulating climate (Imbrie and Imbrie, 1979; Berger et al., 1984). Microfossil records from ocean cores led to the discovery of past systematic changes in sea surface temperatures and changes in the amount of glacial ice stored on the continents. Such records also permit the reconstruction of past global ocean currents, which is important because of the influence of the global thermohaline circulations on climate. Some of these breakthrough discoveries were made during the large CLIMAP (CLimate: Mapping, Analysis, and Prediction) program, a multi-institutional consortium effort funded by the NSF and led by J. Imbrie, J.D. Hays, N. Shackelton, and A. McIntyre. This effort led to a follow-up called COHMAP, which was supported primarily by Climate Dynamics Program of NSF and by DOE (carbon dioxide research division). An important and surprising finding was revealed by the Greenland Ice Core Project, where scientists detected the ability of abrupt climate shifts (5–10°C) during an interglacial period (Dansgaard et al., 1989). For centennial, decadal, or even year-to-year resolution in past climate variability, paleo proxies such as tree-rings, coral records, and lake or bog sediments are used (NRC, 2002a, 2006b). Many of the field-intensive drilling expeditions, such as ocean sediment or glacial ice core drilling, were supported by international efforts and funded by multiple agencies such as NASA, NOAA, NSF, and DOE. While OPP plays the principal role in funding ice core drilling operations and the

OCR for page 14
Strategic Guidance for the National Science Foundation‘s Support of the Atmospheric Sciences BOX 2-10 Reconstruction of the Earth’s Paleoclimate from the Highest Mountain Glaciers Lonnie Thompson, Professor, Ohio State University Ph.D., Geology, Ohio State University In 1973, when I first started thinking about drilling ice cores on tropical mountains as a graduate student at Ohio State University (OSU), it was not possible to get NSF funding for ice core retrieval outside of the polar regions. At that time drilling into high-altitude tropical glaciers was considered technically unfeasible and scientifically misguided.When I began to study the Quelccaya ice cap in southern Peru, I was funded by Jay Zwally at NSF’s OPP from $7,000 left in the budget after all the other projects had been supported.This research produced a record of tropical climate from the snow pit and shallow core studies we retrieved from Quelccaya. In 1978 our proposal to drill through Quelccaya was accepted by NSF’s new Office of Climate Dynamics (OCD).After an attempt to transport a conventional drill up the ice cap failed, we had the idea of developing a light-weight solar-powered drill that could be back-packed in pieces up the mountain. We attempted to convince OCD and the ATM to fund this wild idea, but were dealt a serious setback when one of the reviewers, who was a pioneer in polar ice core drilling, told NSF that he believed Quelccaya was too high for humans to live long enough to achieve this objective. The reviewer went on to remark that the technology did not exist to develop such a drill. However, a new program director at ATM, HassanVirji, gave us an opportunity to test the frontiers of ice core drilling by funding our proposal, while OPP funded the drill development. In 1983 the OSU team and equipment made it to the top of Quelccaya and we drilled the first two ice cores to bedrock from a tropical ice cap. From this precarious start, the Ice Core Paleoclimate Research Group developed at the Byrd Polar Research Center.Since that time we have successfully completed 50 such expeditions with the continued support of NSF, particularly ATM’s Paleoclimate Program and OPP.This year we will conduct a cooperative ice core research program analysis of such ice cores, NSF’s ATM supports most other paleoclimate studies, such as tree-ring, lake sediments, and coral paleoclimate studies. In fact, ATM has consistently led in the support of tree-ring research (e.g., Figure 2-7). The paleoclimate program is in a unique position because, although about 25 percent of all proposals submitted to ATM are in this area, the program has one of the smaller budgets in this division. However, the program is successful because the cross-division collaborations within GEO and NSF reflect the strongly interdisciplinary nature of this area of scientific research.

OCR for page 14
Strategic Guidance for the National Science Foundation‘s Support of the Atmospheric Sciences in the southwestern Himalayas near the source of the Ganges and Indus Rivers, made possible in part through funding from NSF’s ATM-ESH program. We have had many dedicated program mangers over the years who promoted the paleoclimate community and their faith in this effort has produced a rich record of paleoclimate in regions where it once was unknown. ANALYSIS OF THE CASE STUDIES We turn now to the following questions: What light do these major accomplishments shed on the role of NSF ATM in its support of atmospheric sciences? In particular: What do they imply about the balance between the various modes of support, whether that balance has in fact been adjusted over time, and whether they provide evidence that there is a need to alter the balance? The first observation is that NSF ATM has played a role in every one of these major accomplishments. In a few cases, ATM played only a minor

OCR for page 14
Strategic Guidance for the National Science Foundation‘s Support of the Atmospheric Sciences FIGURE 2-7 Tree-ring chronologies for several regional composites. The time series have been loosely grouped according to latitude bands and normalized to a common period. The bottom two panels in the right column show grouped replication plots for both North America and Eurasia. NOTE: ALPS = Alps, CNTA = Central Alaska, CNWT = Central Northwest Territory, CSTA = Coastal Alaska, ICE = Icefields, JAEM = Jaemtland, LAB = Labrador, MAN = Manitoba, MON = Mongolia, NWNA = Northwest North Alaska, POL = Polar Urals, QUE = Quebec, SA = Southern Alaska, SEW = Seward, TAY = Taymir, TORN = Tornetraesk, WRA = Wrangells, YAK = Yaktutia, YUK = Yukon. SOURCE: D’Arrigo et al. (2006). Reproduced by permission of American Geophysical Union; copyright 2006. or supporting role but in the majority of these cases, NSF ATM’s role has been central. Furthermore, the case studies demonstrate that all the modes of support—PI grants, including those for exploratory projects and in response to focused solicitations; small centers; the large national center; cooperative observing facilities; and field programs—have been important to one or more of these major science achievements. Likewise, each major achievement benefited from several modes. For example, much of the early

OCR for page 14
Strategic Guidance for the National Science Foundation‘s Support of the Atmospheric Sciences work in climate modeling was supported by individual PI grants, however, with increasing complexity and the need for ever larger computing power, interagency and intersector support became increasingly important and the available computing facilities at NCAR ever more central to running the models. It is also difficult to envision that the space weather research community would have made the advances without the combination of modes such as small PI grants, support from NCAR for model runs, observing facilities, ATM initiatives, and the pioneering work supported by the small center. Thus, the range of available modes has been a tremendous and necessary asset for the atmospheric sciences. This is a reflection of the nature of atmospheric science and its development over the past decades as discussed in detail in Chapter 3; but it is also evident that ATM’s portfolio of modes of support and the balance among the modes has evolved with the state of the science. For example, at a very early stage, severe weather research was an interagency effort, mostly between NOAA and NSF’s ATM, and within ATM supported by individual grants to University scientists, who worked in close collaboration with NCAR scientists. As it became necessary to integrate field observations, modeling capability and instrument development to advance severe weather research, the field was ripe to take advantage of new modes such as NSF’s STC leading to the development of the world’s first storm-scale prediction system. Another example is carbon cycle research, which began with a single PI effort originally funded by the U.S. Weather Bureau. Eventually, it became an interagency, cross-disciplinary, and multimode effort to support direct CO2 measurements, ice core measurements, and the development of carbon cycle models. Grants to individuals and teams of PIs were instrumental in all of the achievements, while the large national center contributed to nearly all of them. This reflects in part the fact that these have been the two dominant modes of support utilized over the past 40 years. But, more importantly, it reflects that these two modes have been effective at fostering a productive research environment. In addition, in more than half of the major case studies, the science was significantly advanced by field programs, often large efforts requiring significant coordination among researchers, different agencies, and in many cases different nations. The U.S. participation and interagency coordination during TOGA, an effort to further the understanding of ocean–atmosphere processes related to ENSO, exemplifies the success and importance of international and interagency field campaigns in advancing atmospheric research. Some of the newer modes, such as small centers and cooperative observing facilities, have not been available as long and are a smaller portion of the ATM funding portfolio. Even so, the three small centers that have been established in the atmospheric sciences (CAPS, C4, and CISM) have

OCR for page 14
Strategic Guidance for the National Science Foundation‘s Support of the Atmospheric Sciences each been engaged in research that either led to a significant leap in understanding, as in the case of CAPS and C4, or else are helping us to bring to fruition a major achievement, as in the case of CISM. Another advantage of these small centers is the explicit role for technology transfer. Indeed, atmospheric science is special in that one of the key transfer targets is the federal government. The value of partnerships with other disciplines, agencies, and nations is also apparent in reviewing these case studies. Every major achievement analyzed required coordination with other agencies, including NOAA, NASA, DOE, EPA, and the Department of Defense. In some cases, broad interagency programs like the U.S. Global Change Research Program or the NSWP have played an important role in focusing research objectives and applying the collective resources of several agencies. Given the range of partnerships employed in these case studies, it is fair to conclude that NSF has been effective in fostering collaboration. An important lesson to be gleaned from the research activities leading to these major accomplishments is that ATM has adjusted the balance from time to time as opportunities, needs, and scientific progress made necessary and possible. For example, when it became apparent that a concerted, coordinated effort could lead to significant advances in space weather predictions, ATM supported members of the scientific community in their bid for an STC, resulting in the recently formed CISM. The creation of the interagency U.S. Global Change Research Program in the late 1980s is another example of NSF ATM, in coordination with other agencies, identifying the need for greater organization and coordination, and then taking the steps to address this need. In general, ATM has been responsive to evolving needs and has effectively interacted with the community in choosing new directions. It does not in any way detract from this conclusion to note that NSF as a whole has been moving, over the past several decades, to emphasize collaborative and interdisciplinary research. In summary, it is clear from the analysis of the set of major scientific and applied breakthroughs in atmospheric science considered in this chapter that NSF ATM has made effective use of its varied modes of support and that the balance between the modes has evolved over time in response to the needs and opportunities of the field. The committee expects that ATM will continue to evolve the balance between its modes of support as atmospheric science and its applications evolve.