NOAA Space Environment Research Articles

Meteorological situations that generated exceptional discharges along the Danube River. (Case study- the situation of April 2006).

For Europe, the undisputed importance of the Danube can be rendered by some general data: Its hydrographic basin surface exceeds 817000 km2, i.e. about 10% of that of the continent, its length is 2857 km and its mean multiannual discharge is about 6500 m3/s, thus ranking second to Volga river. Romania is the country with the largest surface situated within Danube’s basin (97.4%), representing 29% of Danube’s hydrographic basin. The water resources of the Danube in Bazias section amount to 173 billion m3, 30 billion m3 of which are technically usable resources.Our analysis aimed at determining those complex meteorological situations at the European continent level that triggered exceptional discharges along the Danube river, resulting in severe flooding, causing in turn heavy damages, fatalities, population evacuations and considerable rehabilitation costs. A complex analysis was performed, of statistical-synoptic type and those complex meteorological situations were identified that determined the occurrence of such disasters. Discharges and levels of the Danube were used along the whole measuring period, data from the archive of the National Meteorological Administration, and data, map and image archives from Wetterzentrale (Kartenarchiv, NCEP, NCAR, AVN etc.). The complex meteorological situations at the level of the European continent that triggered exceptional discharges along the Danube correlate with intense cyclonic activity, of both the Icelandic and the Mediterranean cyclones, with the negative phase of the North-Atlantic Oscillation and with decreasing or minimum solar activity (according to data from NOAA's Space Environment Center). The most disastrous floods occurred in the spring of 2006. The paper is important for meteorologists, in their weather forecasting activity, for hydrologists, in their hydrological forecasting and for the institutions involvedin flood management.

On Some Properties of SEP Effective CMEs

Solar energetic particles (SEP) are believed to originate from two different sources, solar flares and coronal mass ejections (CMEs). The large SEP events constitute a serious radiation hazard. The high-energy solar proton data obtained from NOAA Space Environment Services Center are used to investigate some statistical properties such as speed, apparent width, acceleration, latitude, mass, kinetic energy, and occurrence rate of SEP effective CMEs observed during the period 1997–2006 covering the solar cycle 23. It is found that SEP effective CMEs are nearly halo in nature, and they follow solar cycle variation. Such CMEs have higher speeds than those of non-SEP effective CMEs.

Space Weather Workshop: A Catalyst for Partnerships

Space Weather Workshop: A Catalyst for Partnerships

Characteristics of solar proton events associated with ground level enhancements

In certain explosive events, the Sun emits large numbers of protons with energy up to tens of GeV. Particle acceleration processes on the Sun can be understood through the observation of such energetic particles. According to the definition of NOAA Space Environment Services Center, a solar proton event (SPE) is defined as an event with a peak intensity of >10 pfu (particle flux unit; 1 particle cm−2 sr−1 s−1) for >10 MeV protons. Major SPEs are not always associated with ground level enhancements (GLEs), whereas relatively minor SPEs are sometimes associated with GLEs. We examined the peak intensities of 85 SPEs after 1986 using the intensity of proton differential energy channels (P3–P10) from GOES. We identified 31 SPEs associated with GLEs having well‐defined profiles with a large increase and clear peak for each proton channel. They have larger peak intensity and fluence and shorter delay time between onset and peak than SPEs without GLEs. Fluences and peak intensities of SPEs have a good correlation with percent increases of GLEs, with the best correlation coefficients obtained for the peak intensities and fluences of channels P8, P9, and P10. For these energy channels (spanning 350–700 MeV), we find that there are threshold values for GOES fluence and peak intensity such that most SPEs above the threshold are associated with GLEs, whereas almost none below the thresholds are.

An ‘Ionospheric Weather’ Index

This note explains a method for deriving a daily ' ionospheric weather ' index for a given geographic location, and displays the behaviour of this index for the Boulder ionosphere during 8 months of 1968. ' Ionospheric weather ' means the dynamic state of the ionosphere at a particuIar time and place, as influenced by the number and intensity of ionization ' irregularities ' present. Such an index should be useful in attempts to associate short-term fluctuations in ionospheric electron density with other geophysical events, and ultimately, if such associations can be found, in forecasting the dynamic properties of ionospheric telecommunication circuits. The index is derived from continuous, steep-incidence, HF Doppler ionospheric soundings of the type described by Davies & Baker (1966). Ionospheric irregularities cause changes in the radio reflection height, which are recorded as fluctuations in the received frequency (Doppler shifts) of a stable 5 MHz radio wave reflected from heights of about 200 km in the F region. A great variety of irregularity ' signatures ' appear on Doppler-shift-vs-time records, many of which are attributable to the passage of atmospheric waves, whose properties can be measured with spaced sounders (Georges 1968; Davies & Jones 1971). At other times, the fluctuations are nearly random in appearance, defying most quantitative analyses. It was quickly learned, however, that the intensity of the fluctuations seemed to wax and wane on time scales of a few days, and also that intensity bore no obvious relation to other geophysical phenomena (except that high Doppler activity characteristically accompanies geomagnetic storms). Fig. 1 shows representative samples of ' quiet ' and ' disturbed ' Doppler records, as well as one containing wavelike frequency fluctuations. The Boulder data cited here were made available through the courtesy of Dr K. Davies of the NOAA Space Environment Laboratory. The unanswered question is: what causes the variations in ionospheric weather that are not associated with magnetic disturbances? In order to examine possible connections with other geophysical events (specifically, tropospheric weather) it was necessary to find a way to quantify the degree of ionospheric activity represented by a given Doppler record. Although it is often easy to subjectively classify a given record as ' quiet ' or ' disturbed ', many fall in between, and it seemed desirable to develop a more quantitative and objective indicator of' ionospheric activity. After several attempts that need not be discussed here, it was found that measuring the total length of the Doppler trace for a fixed time interval, though physically meaningless, provided a single number that agreed well with subjective feelings about the degree of activity present. To quantify one day's activity in a single number, the line length for the 8-hr interval centred on local noon was measured and divided by the length of the time

Collaboration Between Government and Commercial Space Weather Information Providers

Many systems and situations require up-to-date space weather information. These include navigation systems in cars, boats, and commercial freight; the specific location information needed for construction and oil drilling; communications; airline navigation; avionic systems; and passengers and personnel on polar airline flights. Thus, as the world’s industries become increasingly more reliant on satellite data and more vulnerable to space weather conditions, new collaborations will have to be formed between commercial providers of space weather information and the government scientists who monitor space weather. To tackle this issue, a meeting of the Commercial Space Weather Interest Group (CSWIG) and the NOAA Space Weather Prediction Center (SWPC; formerly the NOAA Space Environment Center) was held to discuss opportunities for further joint development and collaboration between commercial providers and SWPC. The meeting, held on 27 June 2007 at NOAA SWPC in Boulder, Colorado, was coordinated by CSWIG and was open to all interested parties, including those who wished to hear sessions by phone. Thomas Bogdan, director of SWPC, opened the meeting stating that the commercial providers and SWPC were convening at a historic moment, just as the space weather enterprise—including space tourism, commercial satellites, and commercial aviation—is opening up to new customers who are reliant on space weather information. He mentioned that many people do not know that they are or will be in need of space weather information; rather, they will wake up with a surprise in 2012 at solar maximum when a solar flare shorts out their gadgets, requiring them or the companies that service them to seek help from new products and warnings. Bogdan stated that in the current era of constrained budgets, SWPC requires key partnerships to function effectively so as to coordinate and leverage SWPC capabilities. Thus, SWPC may need to move away from certain activities in order to address the growing needs of new customers. He acknowledged that commercial providers stand ready to fill any gaps and ensure continuity of products and services. Bogdan emphasized that SWPC personnel present at the meeting were seeking to understand what products and services the commercial providers wanted and the financial and operational impacts on the SWPC if certain products were emphasized or discontinued. John Kappenman, of Metatech Corporation and chair of CSWIG, discussed the importance of growing the commercial sector for space weather into a thriving industry, citing the National Space Weather Program assessment report (http:// www.nswp.gov/nswp_acreport0706.pdf) commissioned by the Office of the Federal Coordinator for Meteorology. He stressed that commercial providers, because they are running a business, focus on their investments and whether infrastructure exists to support these investments. Thus, the reliability, promptness, lack of latency, high cadence, and validation of spacecraft data, such as those from the Geostationary Operational Environmental Satellites (GOES) series and the Advanced Composition Explorer (ACE), as well as ground-based data, such as from magnetometer networks and the Continuously Operating Reference Stations (CORS), are “musts” for commercial providers in order that they can expand their own capabilities. Further, Kappenman emphasized that commercial providers must know what SWPC considers its “core” versus “noncore” capabilities, so that steps can be taken to ensure continuity of data given to the commercial space weather providers should the SWPC choose to cut programs. To address this, Terry Onsager, of SWPC, presented SWPC’s priorities for future activities, new data and models, data sources, possible data products, and models considered for transition to operational use in the SWPC forecast center. This was followed by discussions on nonexclusive licensing; data provision by NOAA SWPC, the National Geophysical Data Center (NGDC), or the National Geodetic Survey

Commercial Space Tourism and Space Weather

Commercial Space Tourism and Space Weather

STEREO Space Weather and the Space Weather Beacon

The Solar Terrestrial Relations Observatory (STEREO) is primarily a solar and interplanetary research mission, with one of the natural applications being in the area of space weather. The obvious potential for space weather applications is so great that NOAA has worked to incorporate the real-time data into their forecast center as much as possible. A subset of the STEREO data will be continuously downlinked in a real-time broadcast mode, called the Space Weather Beacon. Within the research community there has been considerable interest in conducting space weather related research with STEREO. Some of this research is geared towards making an immediate impact while other work is still very much in the research domain. There are many areas where STEREO might contribute and we cannot predict where all the successes will come. Here we discuss how STEREO will contribute to space weather and many of the specific research projects proposed to address STEREO space weather issues. The data which will be telemetered down in the Space Weather Beacon is also summarized here. Some of the lessons learned from integrating other NASA missions into the forecast center are presented. We also discuss some specific uses of the STEREO data in the NOAA Space Environment Center.

Next solar cycle expected to be intense

Solar Cycle 24 will be a period of intense solar storms that will peak in late 2011 to mid‐2012, according to the NOAA‐led Solar Cycle 24 Prediction Panel's consensus forecast that was released on 25 April. The forecast will be used for planning by government and industry groups; power and communication networks, satellites, and airplanes can be affected by sunspot activity. The panel evaluated more than 40 predictions, which ranged from 42 to 185 sunspots total for the cycle. The consensus prediction was based on six techniques, three based on statistics and three based on physics and theory of the Sun's dynamo conveyor belt. The validity of the prediction will soon get its first test; if it does not accurately predict the Solar Cycle 23 minimum, it will also likely fail to predict the timing, duration, and intensity of the next peak, said panel chair Douglas Biesecker, a solar physicist with the NOAA Space Environment Center.

A hybrid heliospheric modeling system: Background solar wind

We describe a Sun‐to‐Earth system of coupled models. Our main goal is to create a real‐time, three‐dimensional (3‐D), MHD‐based system to aid in the operational forecasting of geomagnetic activity, but we expect the system to have other uses. We give here our initial survey of the system's characteristics. The Hybrid Heliospheric Modeling System (HHMS) is composed of two physics‐based models, combined with two simple empirical models. The physics‐based models are a source surface (potential field) current sheet model for the corona and a time‐dependent 3‐D MHD solar wind model. The system is driven by a sequence of photospheric magnetic maps composed from daily magnetograms. An empirical relationship between magnetic flux tube expansion factor and solar wind speed at 0.1 AU is a key element of the system. The solar wind model gives a predicted time series of MHD parameters at the location of Earth in the model grid; this is verified against Omni, Wind, or ACE satellite data, depending on the time period. The predicted solar wind at Earth is used as input to the second, data‐based, empirical model to predict the geomagnetic Ap index. We compare test results for simulated 1 day ahead Ap forecasts for the years 1993 through 2002 with forecast skill of the official Ap forecasts that were issued by the NOAA Space Environment Center in that time interval. Results show the HHMS would have been useful to forecasters in some years. Simulations of transient events such as coronal mass ejections and interplanetary shocks with the HHMS will be reported on later.

New Director Named for NOAA's Space Environment Center

New Director Named for NOAA's Space Environment Center

NOAA's Space Weather Week Scheduled for Late April

U.S. Space Weather Week, an annual conference for industry, academia, and government agencies to discuss topics related to space weather, will be held 25–28 April 2006 in Boulder, Colorado. Sponsored and hosted by NOAA's Space Environment Center (SEC), with additional support from NASA and the National Science Foundation, the conference will address the effects of space weather on current technology, such as the maintenance of communications, navigation systems, spacecraft operations, aviation, and electric power. Sessions will also help identify high-priority needs for future research, with the goal of fostering communication among scientists, space weather service provides, and users of space weather services. The event will open with a keynote speech by John Phillips, a space weather scientist and a former Navy pilot who joined NASA in 1996. Phillips, who flew aboard the STS-100/Endeavour in 2001 and served a six-month tour of duty aboard the International Space Station in 2005, will speak about his experiences and the future of deep space exploration, as outlined by NASA's Space Exploration Initiative. “There are a lot of things going on, even though this is a solar minimum,” said William Murtagh, a space weather forecaster at the SEC and the lead conference coordinator for Space Weather Week. “You'd think otherwise, but it's really not the case.” For example, presenters will give updates on long-term, large-scale modeling efforts of the ionosphere and Sun-to-Earth coupled systems. Session topics and poster presentations will also include current research on dosimeters, radiation hazards on missions to the Moon and Mars, international activities and collaborations, and the status of satellite missions, such as the expected launch of NASA's Solar Terrestrial Relations Observatory (STEREO) to study the Sun and the nature of coronal mass ejections. In addition, Space Weather Week will strongly feature the aviation community. As the number of commercial flights increases, with more flights directed over the poles, “the airline industry has identified space weather as a primary concern,” explained Murtagh. “Moreover, commercial space transportation is no longer a fringe business.” Longer flights that take a more orbital phase, and space tourism will be discussed at the conference. Attendees will include representatives from the Federal Aviation Administration and Virgin Galactic. Though the conference officially starts on 25 April, on 24 April Space Weather Week will unofficially kick off with a half-day information session for local high school juniors and seniors. Phillips will speak about his experiences as an astronaut, and representatives from Lockheed Martin, graduate students from the University of Colorado at Boulder, and others will address more than 300 expected high school attendees. “The goal is to enlighten students on the career opportunities available in space science and industry,” said Murtagh. More information about Space Weather Week can be found at http://www.sec.noaa.gov/sww/index.html. Mohi Kumar is a staff writer for the American Geophysical Union.

Qualitative comparison of ACE/EPAM data from different detector heads: Implications for NOAA RTSW users

The NOAA space environment center (SEC) facilitates the tracking and near real-time data distribution of interplanetary magnetic field, solar wind, and energetic particle observations from the advanced composition explorer near the Earth’s first Lagrangian point. In early 2004, the SEC switched from one set of low energy ion observations to another of a similar energy range. To assist users who now must rely upon a different set of observations, this manuscript documents the similarities and differences between the two sets of data. Although the two sets of observations are very similar most of the time, there are occasionally significant differences that users need to be aware of and must account for, especially those using data for operational purposes.

Major Leader of U.S. Space Weather Forecasting Retires

The U.S. space weather community took a hit in early August when Ernest Hildner retired as director of NOAA's Space Environment Center (SEC). For nearly two decades, Hildner steered the world's premier forecasting agency with a passionate devotion cited by scientists and administrators alike.

A Workshop for the Aviation Community

On 23‐24 February 2004 at NOAA's Space Environment Center in Boulder, Colo., the SEC, Virgin Atlantic Airways, and SolarMetrics hosted an aviation workshop on integrating space weather information into the operating procedures for commercial airlines. The meeting, with representatives from the industrial and academic communities, led to the formation of the International Committee for Space Weather Impacts on Aviation Safety working group.

Premier Forecasting Center Avoids Ax

Last fall, the U.S. Senate proposed eliminating all 2004 funding for NOAA's Space Environment Center (SEC), but fortunately for the world's premier space weather forecasting center and its myriad customers, the Senate did not get its way. When the full Congress passed the final budget on 22 January, the Center's budget for the year was restored—at least partially.

Lessons From the U.S. Meteorological Public‐Private Sector Services Partnership

Together, the NOAA Space Environment Center (SEC) and private sector vendors need to develop mechanisms for communicating their future development needs and for defining their evolving partnership. While the SEC does hold an annual vendors meeting and continues to foster relationships within the space weather industry, there are additional steps it can take.

Integrating Space Weather and Meteorological Products for Aviation

NOVEMBER 2003 AMERICAN METEOROLOGICAL SOCIETY | ne might think that solar flares, coronal mass ejections, and geomagnetic storms are phenomena that only interest space scientists. However, conditions on the sun, in the solar wind, and within the Earth’s magnetic field, otherwise known as “space weather,” can affect a wide variety of ground and space technologies. For example, solar and geomagnetic events can impact satellite operations, navigation, space shuttle and space activities, high-altitude polar flights, electric power distribution, long-line telephone communication, high-frequency (HF) radio communication, and geophysical exploration. As the nation’s reliance on technological systems grows, so does our vulnerability to space weather. The aviation industry is just one of the many user groups that are trying to understand how space weather impacts their operations and what can be done to mitigate disruptions. Airlines are becoming more concerned with flying transpolar routes, losing HF communication, radiation hazards to crews, and the possibility of global positioning system (GPS) errors. Many space weather hazards can be mitigated or avoided if reliable space weather forecasts are available. In response to this need, the federal government has formed the National Space Weather Program, an interagency program under the auspices of the Office of the Federal Coordinator for Meteorology started in 1994, to “achieve an active, synergistic interagency system to provide timely, accurate, and reliable space environment observations, specification, and forecasts.” Currently, space environmental support services are provided by the NOAA Space Environment Center (SEC) and the U.S. Air Force (USAF), which jointly operate the Space Weather Operations (SWO) Forecast and Analysis Center. It is the national and world warning center for disturbances that can affect people and equipment working in space, and provides forecasts, warnings, and alerts of solar and geomagnetic activity to users in government, industry, and the private sector. NOAA/SEC is the official source of space weather alerts and warnings for commercial and public sector customers. INTEGRATING SPACE WEATHER AND METEOROLOGICAL PRODUCTS FOR AVIATION

Modeling 3-D solar wind structure

Recent advances in numerical methods and computer systems make it possible to tackle complicated, more realistic ambient and transient solar wind flows. An overview of the ongoing work performed at the NOAA Space Environment Center is presented with examples illustrating: (a) global.3-D interaction of a CME propagating in structured background solar wind, (b) incorporation of a more realistic ambient solar wind, (c) merging of coronal and heliospheric models to track CMEs, and (d) near-Earth solar wind simulations. The aim is to highlight the complexities confronting numerical modelers in meeting challenges imposed by space weather research and forecasting.

New scales help public, technicians understand space weather

The Space Weather Scales of the US. National Oceanic and Atmospheric Administration were recently developed by NOAA's Space Environment Center (SEC) to improve understanding of space weather events among technical operators and the general public alike. The scales (see tables) serve as a sort of Richter scale that correlates space weather events with their likely effects on electric power, satellites, and other systems. To many who view space weather as an obscure field, the NOAA Space Weather Scales will convey useful information and perhaps pique new scientific interest.The SEC has forecasted the space environment for more than 35 years, alerting users to existing conditions between the Sun and Earth. Demand for these services has grown as technology susceptible to space weather damage has increased in use. Satellites, for example—which were once rare and only government‐owned—are now numerous, and many are commercially owned. Transmissions to and from those satellites now carry weather information and military surveillance, television and other communications signals, credit card and pager information, navigation data, and cell phone conversations.