Showing papers in "Eos, Transactions American Geophysical Union in 2008"
TL;DR: The HydroSHEDS (Hydrological Data and Maps Based on Shuttle Elevation Derivatives at Multiple Scales) dataset as mentioned in this paper provides high-quality data at a resolution and quality unachieved by previous global data sets, such as HYDRO1k.
Abstract: To study the Earth system and to better understand the implications of global environmental change, there is a growing need for large-scale hydrographic data sets that serve as prerequisites in a variety of analyses and applications, ranging from regional watershed and freshwater conservation planning to global hydrological, climate, biogeochemical, and land surface modeling. Yet while countless hydrographic maps exist for well-known river basins and individual nations, there is a lack of seamless high-quality data on large scales such as continents or the entire globe. Data for many large international basins are patchy, and remote areas are often poorly mapped.
In response to these limitations, a team of scientists has developed data and created maps of the world's rivers that provide the research community with more reliable information about where streams and watersheds occur on the Earth's surface and how water drains the landscape. The new product, known as HydroSHEDS (Hydrological Data and Maps Based on Shuttle Elevation Derivatives at Multiple Scales), provides this information at a resolution and quality unachieved by previous global data sets, such as HYDRO1k [U.S. Geological Survey (USGS), 2000].
1,505 citations
TL;DR: Arctic sea ice declined rapidly to unprecedented low extents in the summer of 2007, raising concern that the Arctic may be on the verge of a fundamental transition toward a seasonal ice cover.
Abstract: Arctic sea ice declined rapidly to unprecedented low extents in the summer of 2007, raising concern that the Arctic may be on the verge of a fundamental transition toward a seasonal ice cover.
Arctic sea ice extent typically attains a seasonal maximum in March and minimum in September. Over the course of the modern satellite record (1979 to present), sea ice extent has declined significantly in all months, with the decline being most pronounced in September. By mid-July 2007, it was clear that a new record low would be set during the summer of 2007.
511 citations
TL;DR: Energy plays a vital role in the origin and evolution of all complex systems in the universe, including galaxies, stars, planets, and life forms, and it can be shown that over billions of years since the Big Bang, the energy rate densities (watts per kilogram) of these systems have risen with the cosmic march of time as discussed by the authors.
Abstract: The topic of energy is in the news a lot these days. Not only are we concerned about having enough energy for today's civilization and tomorrow's needs, but also energy is at the core of our understanding of the inner workings of the Sun, Earth, and life itself. Indeed, energy may well be the most common currency in all of natural science, helping us to appreciate where we came from and guiding us toward a sustainable society in the future.
Energy plays a vital role in the origin and evolution of all complex systems in the universe, including galaxies, stars, planets, and life forms. Treating each of these systems as open thermodynamic structures that acquire, store, and express energy, it can be shown that over billions of years since the Big Bang, the energy rate densities (watts per kilogram) of these systems have risen with the cosmic march of time. General, coherent worldviews, based largely on the concept of energy, are now being developed by many researchers around the world. I certainly share many of my colleagues' enthusiasm for the fundamental function of energy in our world and for the need to study it more.
327 citations
TL;DR: In this article, the future health of a variety of marine organisms, particularly shellfish, was discussed, in light of increasing acidity, which in the United States is a $1.6 billion industry.
Abstract: Increasing atmospheric CO2 is likely to cause a corresponding increase in oceanic acidity by lowering pH by 0.20.5 pH units by the end of the 21st century [Royal Society, 2005]. In light of increasing acidity, there are growing concerns about the future health of a variety of marine organisms, particularly shellfish, which in the United States is a $1.6 billion industry.
Shellfish predominantly inhabit coastal regions, and in addition to the projected stress caused by the global trend in ocean acidification, some coastal ecosystems receive persistent or episodic acid inputs as a result of interactions with river water, bottom sediments, or atmospheric deposition of terrigenous materials. Most river plumes are acidic relative to the receiving ocean, and river water is mixed extensively over the continental shelf. Moreover, the chemical nature and magnitude of discharge are changing rapidly due to climate change and land-use practices.
269 citations
TL;DR: The authors contrast competing theories for the response of the tropical Pacific to global warming, illustrate the utility of models for understanding and reconciling these theories, and highlight the need for improved instrumental and paleoclimatic reconstructions to better evaluate the fidelity of current model projections.
Abstract: The response of the tropical Pacific to increasing greenhouse gases represents an exciting intersection of theory, modeling, and observations. In this article, we contrast competing theories for the response of the tropical Pacific to global warming, illustrate the utility of models for understanding and reconciling these theories, and highlight the need for improved instrumental and paleoclimatic reconstructions to better evaluate the fidelity of current model projections.
There is a long-standing debate in the climate community as to how the tropical Pacific will respond to increased greenhouse gases: Will the structure of changes in the ocean surface temperature more closely resemble an El Nino or a La Nina [e.g., Knutson and Manabe, 1995; Clement et al., 1996; Meehl and Washington, 1996; Cane et al., 1997; Cobb et al., 2003; Collins et al., 2005; Vecchi et al., 2006; Zhang and Song, 2006]? This distinction is of profound significance because conditions in the tropical Pacific affect a range of weather phenomena including tropical cyclone activity, global patterns of drought and flood, agricultural productivity, and oceanic biological activity. The debate extends beyond global warming, with El Nino- and La Nina-like responses being invoked as frameworks for interpreting past climate changes on timescales of centuries to millions of years [e.g., Koutavas et al., 2002; Stott et al., 2002; Mann et al., 2005; Wara et al., 2005].
222 citations
TL;DR: In this paper, a public safety program in Japan is proposed to take advantage of the fact that seismic energy travels slower than electronic communication, and the information is delivered immediately to government officials, representatives from various industries, members of the news media, and individuals before strong ground shaking reaches them.
Abstract: When an earthquake occurs, a certain amount of time elapses before destructive seismic energy hits nearby population centers. Though this time is measured on the order of seconds, depending on the proximity of the rupture to a given city or town, a new public safety program in Japan is taking advantage of the fact that seismic energy travels slower than electronic communication.
In this program, the Japan Meteorological Agency (JMA) rapidly determines the hypocenter (earthquake epicenter and focal depth) and magnitude of the earthquake by using real-time data from stations near the hypocenter. The distribution of strong ground shaking is anticipated quickly, and then the information is delivered immediately to government officials, representatives from various industries, members of the news media, and individuals before strong ground shaking reaches them. For example, on receiving the warning, the control room of a railway company can send an emergency notice to all train drivers to stop their trains immediately, elevators in buildings can be triggered to stop at the nearest floor and open their doors automatically, and surgeons can temporarily suspend their surgical operations to avoid risk to patients on operating tables.
166 citations
TL;DR: In this paper, a physically-based representation of the sub-mesoscales of the ocean is presented, i.e., scales of 1100 kilometers, that are important for turbulent transport and energy dissipation.
Abstract: Observations made by satellite altimeters since the 1980s have provided progressively improved views of the global ocean mesoscale eddy field, which contains most of the kinetic energy of the ocean circulation. Along with these improved views, ocean models have progressed from coarseresolution, highly dissipative mesh grids to higher resolutions where mesoscale eddies dominate the model simulations. We are now able to produce simulations of the present state of the ocean that compare increasingly well with observations. However, the skill of these models in making long-range predictions of the ocean is still very limited, because the models lack a physically based representation of the submesoscales, i.e., scales of 1100 kilometers, that are important for turbulent transport and energy dissipation. Ocean models running at sufficient resolutions to address submesoscale dynamics have just recently begun to emerge [e.g., Capet et al., 2008], but we need global observations at these scales to guide the model development.
150 citations
TL;DR: The modeling of lakes, rivers, and estuaries is a fascinating subject that combines interesting facets of mathematics, statistics, physics, chemistry, and biology as mentioned in this paper, and it is for this reason that modeling is not just science but also art.
Abstract: The modeling of lakes, rivers, and estuaries is a fascinating subject that combines interesting facets of mathematics, statistics, physics, chemistry, and biology. Because of the complexity of natural systems, such modeling is always an approximation of the real world—and sometimes not a very good one. It is for this reason that modeling is not just science but also art. It is also for this reason that there are few good texts offering practical advice on modeling.
145 citations
TL;DR: The North American Carbon Program (NACP) as discussed by the authors has highlighted forest disturbance as a critical factor constraining carbon dynamics, and the NACP recommends that scientists use detailed remote sensing of the land surface to characterize disturbance.
Abstract: North America's forests are thought to be a significant sink for atmospheric carbon. Currently, the rate of sequestration by forests on the continent has been estimated at 0.23 petagrams of carbon per year, though the uncertainty about this estimate is nearly 50%. This offsets about 13% of the fossil fuel emissions from the continent [Pacala et al., 2007]. However, the high level of uncertainty in this estimate and the scientific community's limited ability to predict the future direction of the forest carbon flux reflect a lack of detailed knowledge about the effects of forest disturbance and recovery across the continent.
The North American Carbon Program (NACP), an interagency initiative to better understand the distribution, origin, and fate of North American sources and sinks of carbon, has highlighted forest disturbance as a critical factor constraining carbon dynamics [Wofsy and Harris, 2002]. National forest inventory programs in Canada, the United States, and Mexico provide important information, but they lack the needed spatial and temporal detail to support annual estimation of carbon fluxes across the continent. To help with this, the NACP recommends that scientists use detailed remote sensing of the land surface to characterize disturbance.
142 citations
TL;DR: Adaptive management of water resources is increasingly recognized as an important research field, and more refined approaches are required, and adaptive management is one such promising approach.
Abstract: Managing water is like trying to hit a moving target, and adaptive management of water resources is increasingly recognized as an important research field. Many variables impinge on the sociobiophysical water system, and they trigger complex responses due to nonlinear relations and thresholds that may suddenly push the system into another state. Simple (mental or numerical) models are inadequate to predict system response. More refined approaches are required, and adaptive management is one such promising approach.
140 citations
TL;DR: In this article, the authors use optical satellite images to monitor Earth's surface changes due to geologic processes, climate change, or anthropic activity such as agriculture, deforestation, urbanization, and erosion.
Abstract: The increasing availability of high-quality optical satellite images should allow, in principle, continuous monitoring of Earth's surface changes due to geologic processes, climate change, or anthropic activity. For instance, sequential optical images have been used to measure displacements at Earth's surface due to coseismic ground deformation [e.g., Van Puymbroeck et al., 2000], ice flow [Scambos et al., 1992; Berthier et al., 2005], sand dune migration [Crippen, 1992], and landslides [Kaab, 2002; Delacourt et al., 2004].
Surface changes related to agriculture, deforestation, urbanization, and erosion—which do not involve ground displacement—might also be monitored, provided that the images can be registered with sufficient accuracy. Although the approach is simple in principle, its use is still limited, mainly because of geometric distortion of the images induced by the imaging system, biased correlation techniques, and implementation difficulties.
TL;DR: Wang et al. as mentioned in this paper reported that floating algae have appeared since mid-June in coastal waters off Qingdao, China, where the Olympic sailing competitions will be held on 9-23 August.
Abstract: Extensive patches of floating algae have appeared since mid-June in coastal waters off Qingdao, China, where the Olympic sailing competitions will be held on 9–23 August. By 27 June, field surveys showed that the patches occupied about 30%, or 15 square kilometers, of the 50-square-kilometer region designated for the competitions, posing potential problems for them, according to reports in local news media. The floating algae, whose spatial extent is the largest ever reported in the literature for the world's oceans (as revealed by satellite estimates indicated below), have attracted wide national and international attention since late June.
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TL;DR: The Agulhas Current as discussed by the authors is a large, western boundary current of the southern Indian Ocean that flows southward along the continental slope of the African continent and is about as large as the Gulf Stream.
Abstract: Many people in the United States know about the Gulf Stream, the impressive boundary current along the eastern U.S. coast that carries large amounts of heat poleward and, after separation from the coast, across the North Atlantic. Its impact on warming the eastern United States and the North Atlantic region including western Europe is also well known to the general public.
But who in the United States knows about the Agulhas Current? This warm, western boundary current of the southern Indian Ocean flows southward along the continental slope of the African continent and is about as large as the Gulf Stream. It brings heat and moisture to the coastal regions of southeastern Africa. Variations in its transport lead to significant rainfall anomalies over this region. On a larger scale, its influence may even extend as far as the North Atlantic.
TL;DR: The most evident signal of this warming is the shrinking and thinning of the ice cover of the Arctic Ocean as discussed by the authors, as global climate models predict, the Arctic will change from a perennially ice-covered to a seasonally ice free ocean.
Abstract: The Arctic is undergoing significant environmental changes due to climate warming. The most evident signal of this warming is the shrinking and thinning of the ice cover of the Arctic Ocean. If the warming continues, as global climate models predict, the Arctic Ocean will change from a perennially ice-covered to a seasonally ice-free ocean. Estimates as to when this will occur vary from the 2030s to the end of this century. One reason for this huge uncertainty is the lack of systematic observations describing the state, variability, and changes in the Arctic Ocean.
TL;DR: In this paper, the authors proposed a method for quantifying agricultural N2O emissions from biofuel cropping systems, which can improve greenhouse gas inventories, allow for better evaluation of the environmental impacts, and increase the understanding of the nitrogen cycle in general.
Abstract: Emissions of nitrous oxide (N2O), a potent greenhouse gas, tend to be underestimated by standard methods of quantifi cation provided by the Intergovernmental Panel on Climate Change (IPCC) [IPCC, 2006], recent research suggests. Better quantification of agricultural N2O emissions improves greenhouse gas inventories, allows for better evaluation of the environmental impacts of different cropping systems, and increases the understanding of the nitrogen (N) cycle in general. Proper quantifi cation of N2O emissions is particularly important in the context of calculating net greenhouse gas emissions from biofuel cropping systems because these emissions offset the greenhouse gas benefits of displacing fossil fuel and can even lead to biofuel systems being a net greenhouse gas source [Crutzen et al., 2008].
The global warming potential of N2O is approximately 300 times that of carbon dioxide, and N2O emissions represent approximately 6% of the global anthropogenic greenhouse gas source [IPCC, 2007]. N2O also contributes to stratospheric ozone destruction. N2O is produced in soils through the microbial processes of nitrifi cation and denitrification. Soil water content, temperature, texture, and carbon availability infl uence N2O emissions, but the strongest correlate is usually N inputs to the system, especially at large scales [Stehfest and Bouwman, 2006]. In addition to direct emissions, N inputs to agricultural soils also contribute to N2O emissions indirectly [IPCC, 2006] when nitrate that has leached or run off from soil is converted to N2O via aquatic denitrifi cation and when volatilized non-N2O N-oxides and ammonia are redeposited on soils and converted to N2O.
TL;DR: In this article, the authors used remote sensing data in the thermal-infrared (TIR) band (8-14 microns) to diagnose biospheric stress resulting from soil moisture deficiency.
Abstract: Water lost to the atmosphere through evapotranspiration (ET; soil evaporation + canopy transpiration) serves to cool the Earth's surface. Just as a thermometer is used to diagnose stress in the human body, land surface temperature (LST) derived from remote sensing data in the thermalinfrared (TIR) band (8–14 microns) is a valuable diagnostic of biospheric stress resulting from soil moisture deficiencies. Soil surface temperature increases with decreasing water content, while moisture depletion in the plant root zone leads to stomatal closure, reduced transpiration, and elevated canopy temperatures that can be effectively detected from space. In land surface modeling, TIR imagery can serve as an effective substitute for precipitation data, providing much needed water information in data-poor regions of the world.
TL;DR: The authors summarizes results from these monitoring efforts and interprets the changes that have occurred at Kilauea since June 2007, concluding that these events were well documented by geological, geophysical, and geochemical monitoring.
Abstract: Mid-2007 was a time of intense activity at Kilauea Volcano, Hawaii (see Figure 1). In June, the long-lived Pu'u 'Ō'ō—Kupaianaha eruption, a dual-vent system along the east rift zone (ERZ) that has been erupting since 1983 [Heliker et al., 2003], paused due to the outbreak of a new vent farther up the rift (see Figure 2). The Pu'u 'Ō'ō vent collapsed following that activity, and the resulting reorganization of the magma plumbing system led to the formation of a second new eruptive vent 2 kilometers downrift of Pu'u 'Ō'ō.
These events were well documented by geological, geophysical, and geochemical monitoring. This article summarizes results from these monitoring efforts and interprets the changes that have occurred at Kilauea since June 2007.
TL;DR: A small explosion scattered altered and fresh lithic debris across a 40-hectare area at the summit of Kilauea volcano at 0258 Hawaii-Aleutian Standard Time (HST) on 19 March 2008 as discussed by the authors.
Abstract: At 0258 Hawaii-Aleutian Standard Time (HST) on 19 March 2008, a small explosion scattered altered and fresh lithic debris across a 40-hectare area at the summit of Kilauea volcano. This explosion, the first recorded there since 1924, issued from a vent about 35 meters wide along the east wall of Halema'uma'u Crater. Ballistic fragments—the largest measuring nearly 1 meter across—were propelled upward more than 70 meters onto the Halema'uma'u crater rim. Coarse ash and centimeter-size lithic debris covered part of Crater Rim Drive, and fine ash was deposited farther than 30 kilometers to the southwest.
University of Texas at Austin1, Woods Hole Research Center2, Marine Biological Laboratory3, Texas A&M University4, United States Geological Survey5, University of Maryland Center for Environmental Science6, University of Victoria7, Shirshov Institute of Oceanology8, Yale University9, State Hydrological Institute10
TL;DR: The Pan-Arctic River Transport of Nutrients, Organic Matter, and Suspended Sediments ( PARTNERS) project was initiated in 2002 to help remedy this deficit, and an extraordinary data set has emerged over the past few years as a result of the effort.
Abstract: More than 10% of all continental runoff flows into the Arctic Ocean. This runoff is a dominant feature of the Arctic Ocean with respect to water column structure and circulation. Yet understanding of the chemical characteristics of runoff from the pan-Arctic watershed is surprisingly limited. The Pan- Arctic River Transport of Nutrients, Organic Matter, and Suspended Sediments ( PARTNERS) project was initiated in 2002 to help remedy this deficit, and an extraordinary data set has emerged over the past few years as a result of the effort. This data set is publicly available through the Cooperative Arctic Data and Information Service (CADIS) of the Arctic Observing Network (AON). Details about data access are provided below.
TL;DR: Wang et al. as discussed by the authors presented results from an analysis of that event that demonstrate an application of satellite-derived imagery for inland lake water quality monitoring, assessment, and management.
Abstract: During the spring of 2007, a massive bluegreen algae (Microcystis) bloom broke out in Lake Taihu, one of the largest inland lakes in China. This freshwater lake is located in the Yangtze River delta (Figure 1), one of the world's most urbanized and heavily populated areas. The massive bloom event became an environmental crisis that prompted officials to cut tap water supply to several million residents in nearby Wuxi city in China's Jiangsu province. The outbreak, which the Chinese government identified as a major natural disaster, forced unprepared residents to rush to buy bottled water for their normal usage. This article presents results from an analysis of that event that demonstrate an application of satellite-derived imagery for inland lake water quality monitoring, assessment, and management.
TL;DR: The ArcGP grid version 2.0 as mentioned in this paper has been released and discusses the genesis of the ArcGP project and its use in the study of the Arctic Ocean basin and its structure.
Abstract: The study of the Arctic Ocean has been hampered by incomplete basic knowledge of the basin and its structure. An improved gravity anomaly map (Figure 1) and grid have been developed that complement the new International Chart of the Arctic Ocean [Jakobsson et al., 2008]. This article announces the availability of the Arctic Gravity Project (ArcGP) grid version 2.0 and discusses the genesis of the project.
TL;DR: In this paper, a global infrasound array network, consisting of the International Monitoring System (IMS) and other national networks, has demonstrated a capability for remote detection of Vulcanian to Plinian eruptions that can inject ash into commercial aircraft cruise altitudes (approximately 12 kilometers) near the tropopause.
Abstract: More than 100 separate incidents of interactions between aircraft and volcanic ash were documented between 1973 and 2003. Incidents on international flight paths over remote areas have resulted in engine failures and significant damage and expense to commercial airlines. To protect aircraft from volcanic ash, pilots need rapid and reliable notification of ash- generating events. A global infrasound array network, consisting of the International Monitoring System (IMS) and other national networks, has demonstrated a capability for remote detection of Vulcanian to Plinian eruptions that can inject ash into commercial aircraft cruise altitudes (approximately 12 kilometers) near the tropopause. The identification of recurring sound signatures associated with high- altitude ash injection implies that acoustic remote sensing can improve the reliability and reduce the latency of these notifications.
TL;DR: In this article, the authors proposed a coordinating framework to improve the characterization of uncertainties in regional climate change projections (RCCPs) for making informed decisions based on quantitative risk analysis.
Abstract: The accurate assessment of the potential impacts of climate change on societies and ecosystems requires regional and local-scale climate change information. This assessment is critical for the development of local, national, and international policies to mitigate and adapt to the threat of climate change. Characterizing uncertainties in regional climate change projections (RCCPs) is therefore crucial for making informed decisions based on quantitative risk analysis.
However, information about fine-scale climate change and associated uncertainties is lacking due to the absence of a coordinating framework to improve the characterization of such uncertainties. Here we propose the inception of such a framework.
TL;DR: In this paper, the authors argue that the current lack of productivity and economic marginalization of African agriculture arises from global trade regimes that give a competitive advantage to Western farmers, from low use of agricultural inputs, and from a dearth of infrastructure and services for the agriculture sector.
Abstract: As climate change has emerged as a significant threat, there is much concern about how vulnerable agricultural communities will adapt, particularly as global population continues to rise. Much of the current lack of productivity and economic marginalization of African agriculture arises from global trade regimes that give a competitive advantage to Western farmers, from low use of agricultural inputs, and from a dearth of infrastructure and services for the agriculture sector. For centuries, African farmers have used a wide variety of risk-reducing livelihood strategies, including diversifying income sources, switching crops, and investing in marketing. However, improving their productivity to “modern” levels has remained a distant dream, resulting in a continual reduction in investment in the sector over the past five decades.
TL;DR: In this paper, the authors focus on a possible yet imperfect analog to a future warmer climate and propose a method to reduce the uncertainties of climate change by focusing on the imperfect analog.
Abstract: Future warming projected by the Intergovernmental Panel on Climate Change (IPCC) has the potential to affect every person on Earth. Extreme weather events, rising sea level, and migrating ecosystems and resources may result in socioeconomic stresses. Although we can plan and prepare for what is expected, the most dangerous aspect of our changing climate is the uncertainty in climate sensitivity.
To reduce the uncertainties of climate change, paleoclimatologists are focusing on a possible yet imperfect analog to a future warmer climate.
TL;DR: The need for scientists to communicate more effectively about climate change is urgent as discussed by the authors. But even the most basic facts of this issue (e.g., that the world is warming and that human activity is the dominant cause) are obscure to some decision makers who need to understand them.
Abstract: Science meets policy in the most important challenge of our time: global warming. Yet even the most basic facts of this issue (e.g., that the world is warming and that human activity is the dominant cause) are obscure to some decision makers who need to understand them. How can climate scientists be more effective at communicating what they know, how they know it, and how sure they are of it?
The need for scientists to communicate more effectively about climate change is urgent. For people to take climate change seriously and support appropriate responses, they need to feel sure it is happening and is caused primarily by humans. But while the rise in global temperature is a fact (see, e.g., Intergovernmental Panel on Climate Change (IPCC) [2007], which calls the warming “unequivocal”), 56% of Americans believe there is a lot of disagreement among scientists about whether global warming is even occurring. And while every authoritative scientific body attributes most of the warming of the past 50 years to human activity [see, e.g., IPCC, 2007; American Association for the Advancement of Science, 2006], only 41% of Americans believe that humanity is the dominant cause (42% believe it is due about equally to natural and human causes), according to an April 2007 poll by ABC News, The Washington Post, and Stanford University.
TL;DR: Wentz et al. as mentioned in this paper reported that global mean precipitation increased at a rate of 7.4±2.6% per °C between 1987 and 2006, which is the first time that the record could be considered long enough to investigate longer-term trends and the relationship between global precipitation and global warming.
Abstract: The advent of meteorological satellites during the 1970s made possible the observation of the seasonally shifting patterns of global precipitation. It was not until recently, however, that the record could be considered long enough to investigate longer-term trends and the relationship between global precipitation and global warming. Using data from the Special Sensor Microwave Imager (SSM/I) instrument, Wentz et al. [2007] reported that global mean precipitation increased at a rate of 7.4±2.6% per °C between 1987 and 2006.
Meanwhile, general circulation models (GCMs) used to predict climate change simulate twentieth- and 21st-century mean precipitation increases of about 13% per °C [Held and Soden, 2006]. This difference seems surprising because some GCMs can adequately reproduce the much longer twentieth- century surface-based land-mean precipitation record [Lambert et al., 2005]. Global precipitation changes are tied to the surface energy budget through evaporation and to the tropospheric energy budget through condensation. Thus, if GCMs do underestimate global precipitation changes, the simulation of other climate variables will be affected.
TL;DR: In this article, the authors present a real-time analysis of global atmospheric observations in real time for numerical weather prediction (NWP) without continuity over time as the operational system evolves.
Abstract: Analyses of global atmospheric observations in real time for numerical weather prediction (NWP) lack continuity over time as the operational system evolves. Reanalysis of the observations—with more complete data, improved quality control, and a constant state-of-the-art assimilating model and analysis system—greatly improves the homogeneity of the record and makes it useful for examining climate variations. This whole endeavor is now referred to as “reanalysis.”
TL;DR: The magnitude of phytoplankton blooms has increased significantly in many areas of the world during the past 11 years, as shown in data from ocean color sensors on board satellites as mentioned in this paper.
Abstract: The magnitude of phytoplankton blooms has increased significantly in many areas of the world during the past 11 years, as shown in data from ocean color sensors on board satellites. These areas with increased blooms are likely to be environmentally stressed and undergoing undesirable environmental changes such as a higher frequency of harmful algal blooms and oxygen depletion in bottom layers of oceans, estuaries, and lakes. These changes can disrupt traditional fisheries and recreational use in many coastal areas.
An algal bloom is a rapid increase in the concentration of phytoplankton algae that occurs when conditions turn favorable for algal growth. A typical example of a bloom is the phytoplankton spring bloom. Algal blooms are natural phenomena that remove dissolved carbon and nutrients. In addition, they produce new biomass that supports higher trophic levels including fish and fisheries. However, the blooms also lead to excessive turbidity, oxygen depletion in the bottom layers, and the possible death of fish, benthic animals, and bottom vegetation.
TL;DR: In 2008, there were 2176 preliminary tornado reports logged through mid-December, with 1600 “actual counts” (duplicate reports removed) through September, the highest total in the past half century as discussed by the authors.
Abstract: Tornadoes and other severe thunderstorm phenomena frequently cause as much annual property damage in the United States as do hurricanes, and often cause more fatalities (see http://www.nws.noaa.gov/om/hazstats.shtml). In 2008, there were 2176 preliminary tornado reports logged through mid-December, with 1600 “actual counts” (duplicate reports removed) through September, the highest total in the past half century (Figure 1). The mass media have covered these events extensively, and experts have been deluged with requests for explanations, including possible links to anthropogenic global warming. Although recent research has yielded insight into the connections between global warming and tornado and severe thunderstorm forcing, these relationships remain mostly unexplored, largely because of the challenges in observing and numerically simulating tornadoes.