Showing papers in "Bulletin of the American Meteorological Society in 2013"
National Center for Atmospheric Research1, Pacific Northwest National Laboratory2, University of Toronto3, Los Alamos National Laboratory4, Cornell University5, University of Wisconsin-Madison6, Lawrence Livermore National Laboratory7, Lawrence Berkeley National Laboratory8, Oak Ridge National Laboratory9, University of Calgary10
TL;DR: The Community Earth System Model (CESM) as discussed by the authors is a community tool used to investigate a diverse set of Earth system interactions across multiple time and space scales, including biogeochemical cycles, a variety of atmospheric chemistry options, the Greenland Ice Sheet, and an atmosphere that extends to the lower thermosphere.
Abstract: The Community Earth System Model (CESM) is a flexible and extensible community tool used to investigate a diverse set of Earth system interactions across multiple time and space scales. This global coupled model significantly extends its predecessor, the Community Climate System Model, by incorporating new Earth system simulation capabilities. These comprise the ability to simulate biogeochemical cycles, including those of carbon and nitrogen, a variety of atmospheric chemistry options, the Greenland Ice Sheet, and an atmosphere that extends to the lower thermosphere. These and other new model capabilities are enabling investigations into a wide range of pressing scientific questions, providing new foresight into possible future climates and increasing our collective knowledge about the behavior and interactions of the Earth system. Simulations with numerous configurations of the CESM have been provided to phase 5 of the Coupled Model Intercomparison Project (CMIP5) and are being analyzed by the broad com...
2,075 citations
TL;DR: In this paper, a program called the Heihe Watershed Allied Telemetry Experimental Research (HiWATER) was implemented to improve the observability of hydrological and ecological processes, to build a world-class watershed observing system, and to enhance the applicability of remote sensing in integrated ecohydrological studies and water resource management at basin scale.
Abstract: A major research plan entitled “Integrated research on the ecohydrological process of the Heihe River Basin” was launched by the National Natural Science Foundation of China in 2010. One of the key aims of this research plan is to establish a research platform that integrates observation, data management, and model simulation to foster twenty-first-century watershed science in China. Based on the diverse needs of interdisciplinary studies within this research plan, a program called the Heihe Watershed Allied Telemetry Experimental Research (HiWATER) was implemented. The overall objective of HiWATER is to improve the observability of hydrological and ecological processes, to build a world-class watershed observing system, and to enhance the applicability of remote sensing in integrated ecohydrological studies and water resource management at the basin scale. This paper introduces the background, scientific objectives, and experimental design of HiWATER. The instrumental setting and airborne mission plans a...
703 citations
TL;DR: The Madden-Julian oscillation exerts broad influences on global weather and climate as its center of convection moves from the tropical Indian Ocean into the Pacific. as mentioned in this paper provides a brief summary of the connections between the Madden and climate phenomena.
Abstract: The Madden–Julian oscillation exerts broad influences on global weather and climate as its center of convection moves from the tropical Indian Ocean into the Pacific. Weather events under the influence of the MJO include precipitation, surface temperature, tropical cyclones, tornadoes, flood, wildfire, and lightning, among others. Several climate phenomena are also affected by the MJO. They are the monsoons, El Nino–Southern Oscillation, the North Atlantic Oscillation, the Pacific and North American pattern, the Arctic and Antarctic Oscillations or northern and southern annual modes, the Indian Ocean dipole, the Wyrtki jets, and the Indonesian Through-flow. This article provides a brief summary of the connections between the MJO and these weather and climate phenomena. These connections demonstrate the critical role of the MJO in the weather–climate continuum and its prediction.
589 citations
TL;DR: The Rainfall Atlas of Hawai'i as discussed by the authors is a set of digitalmaps of the spatial patterns of the 1978-2007 meanmonthly and annual rainfall for the major Hawaiian islands.
Abstract: nteraction among trade winds,terrain, land thermal effects, andthe trade-wind inversion give theHawaiian Islands one of the mostvaried rainfall patterns on Earth.Distinct, persistent patterns of upliftlead to dramatic rainfall gradientsand, together with elevation-relatedtemperature differences, producenearly the full range of climate types.This microcosm of global environ-mental diversity provides a uniquenatural laboratory for world-classresearch on topics such as terres-trial ecosystem carbon dynamics, soilgeochemistry, and the mechanics ofspecies invasion. Knowledge of meanrainfall patterns in Hawai'i is criticallyimportant in support of these researchendeavors as well as for managing andprotecting groundwater and surfacewater resources, controlling and eradicating invasivespecies, protecting and restoring native ecosystems,and planning for the effects of global climate change.The Rainfall Atlas of Hawai'i is a set of digitalmaps of the spatial patterns of 1978-2007 meanmonthly and annual rainfall for the major Hawaiian
556 citations
North Carolina State University1, National Oceanic and Atmospheric Administration2, University at Albany, SUNY3, Northern Illinois University4, University of South Carolina5, Colorado State University6, Massachusetts Institute of Technology7, National Center for Atmospheric Research8, Geophysical Fluid Dynamics Laboratory9, Florida State University10, University of California, Berkeley11, Desert Research Institute12, Rutgers University13, Purdue University14, Lawrence Berkeley National Laboratory15, University of Colorado Boulder16, University of Illinois at Urbana–Champaign17
TL;DR: The state of knowledge regarding trends and an understanding of their causes for a specific subset of extreme weather and climate types is presented in this paper for severe convective storms (tornadoes, hailstorms, and severe thunderstorms).
Abstract: The state of knowledge regarding trends and an understanding of their causes is presented for a specific subset of extreme weather and climate types. For severe convective storms (tornadoes, hailstorms, and severe thunderstorms), differences in time and space of practices of collecting reports of events make using the reporting database to detect trends extremely difficult. Overall, changes in the frequency of environments favorable for severe thunderstorms have not been statistically significant. For extreme precipitation, there is strong evidence for a nationally averaged upward trend in the frequency and intensity of events. The causes of the observed trends have not been determined with certainty, although there is evidence that increasing atmospheric water vapor may be one factor. For hurricanes and typhoons, robust detection of trends in Atlantic and western North Pacific tropical cyclone (TC) activity is significantly constrained by data heterogeneity and deficient quantification of internal variab...
468 citations
École Polytechnique1, City College of New York2, Max Planck Society3, University of Wisconsin-Madison4, University of Illinois at Urbana–Champaign5, National Oceanic and Atmospheric Administration6, Langley Research Center7, Goddard Space Flight Center8, Rutherford Appleton Laboratory9, Centre national de la recherche scientifique10
TL;DR: The Global Energy and Water Cycle Experiment (GEWEX) Cloud Assessment as discussed by the authors provides the first coordinated intercomparison of publicly available, standard global cloud products (gridded monthly statistics) retrieved from measurements of multispectral imagers (some with multiangle view and polarization capabilities).
Abstract: Clouds cover about 70% of Earth's surface and play a dominant role in the energy and water cycle of our planet. Only satellite observations provide a continuous survey of the state of the atmosphere over the entire globe and across the wide range of spatial and temporal scales that compose weather and climate variability. Satellite cloud data records now exceed more than 25 years; however, climate data records must be compiled from different satellite datasets and can exhibit systematic biases. Questions therefore arise as to the accuracy and limitations of the various sensors and retrieval methods. The Global Energy and Water Cycle Experiment (GEWEX) Cloud Assessment, initiated in 2005 by the GEWEX Radiation Panel (GEWEX Data and Assessment Panel since 2011), provides the first coordinated intercomparison of publicly available, standard global cloud products (gridded monthly statistics) retrieved from measurements of multispectral imagers (some with multiangle view and polarization capabilities), IR soun...
463 citations
Russian Academy of Sciences1, University of Cologne2, Norwegian Meteorological Institute3, Stockholm University4, University of Salento5, University of Reading6, Environment Canada7, University of Hamburg8, Free University of Berlin9, Shirshov Institute of Oceanology10, European Centre for Medium-Range Weather Forecasts11, Hokkaido University12, University of Melbourne13, Royal Netherlands Meteorological Institute14, Bjerknes Centre for Climate Research15, University of Birmingham16, University of Trás-os-Montes and Alto Douro17, University of Bern18, Embry–Riddle Aeronautical University19, ETH Zurich20, University of Lisbon21
TL;DR: In this article, the variability of results from different automated methods of detection and tracking of extratropical cyclones is assessed in order to identify uncertainties related to the choice of method.
Abstract: The variability of results from different automated methods of detection and tracking of extratropical cyclones is assessed in order to identify uncertainties related to the choice of method. Fifteen international teams applied their own algorithms to the same dataset—the period 1989–2009 of interim European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis (ERAInterim) data. This experiment is part of the community project Intercomparison of Mid Latitude Storm Diagnostics (IMILAST; see www.proclim.ch/imilast/index.html). The spread of results for cyclone frequency, intensity, life cycle, and track location is presented to illustrate the impact of using different methods. Globally, methods agree well for geographical distribution in large oceanic regions, interannual variability of cyclone numbers, geographical patterns of strong trends, and distribution shape for many life cycle characteristics. In contrast, the largest disparities exist for the total numbers of cyclones, the detection of wea...
431 citations
TL;DR: An international field campaign aiming at atmospheric and oceanic processes associated with the Madden-Julian oscillation (MJO) was conducted in and around the tropical Indian Ocean during October 2011-March 2012 as discussed by the authors.
Abstract: An international field campaign aiming at atmospheric and oceanic processes associated with the Madden–Julian oscillation (MJO) was conducted in and around the tropical Indian Ocean during October 2011–March 2012. The objective of the field campaign was to collect observations urgently needed to expedite the progress of understanding the key processes of the MJO, focusing on its convective initiation but also including propagation and maturation, and ultimately to improve skills of numerical simulation and prediction of the MJO. Primary targets of the field campaign included interaction of atmospheric deep convection with its environmental moisture, evolution of cloud populations, and air– sea interaction. Several MJO events were captured by ground-based, airborne, and oceanic instruments with advanced observing technology. Numerical simulations and real-time forecasts were integrated components of the field campaign in its design and operation. Observations collected during the campaign provide unprecede...
393 citations
TL;DR: The representation of the atmospheric boundary layer is an important part of weather and climate models and impacts many applications such as air quality and wind energy as mentioned in this paper, and the authors review these issues and provide an overview of the current understanding and model performance.
Abstract: The representation of the atmospheric boundary layer is an important part of weather and climate models and impacts many applications such as air quality and wind energy. Over the years, the performance in modeling 2-m temperature and 10-m wind speed has improved but errors are still significant. This is in particular the case under clear skies and low wind speed conditions at night as well as during winter in stably stratified conditions over land and ice. In this paper, the authors review these issues and provide an overview of the current understanding and model performance. Results from weather forecast and climate models are used to illustrate the state of the art as well as findings and recommendations from three intercomparison studies held within the Global Energy and Water Exchanges (GEWEX) Atmospheric Boundary Layer Study (GABLS). Within GABLS, the focus has been on the examination of the representation of the stable boundary layer and the diurnal cycle over land in clear-sky conditions. For thi...
380 citations
National Oceanic and Atmospheric Administration1, United States Geological Survey2, Oak Ridge National Laboratory3, Stanford University4, Earth System Research Laboratory5, United States Department of the Army6, University Corporation for Atmospheric Research7, University of California, San Diego8, National Center for Atmospheric Research9, University of Washington10, University of California, Berkeley11, Goddard Space Flight Center12, Silver Spring Networks13, University of Iowa14, University of Alaska Fairbanks15, Lawrence Berkeley National Laboratory16, University of Arizona17, University of Illinois at Urbana–Champaign18
TL;DR: In this article, the authors show that decadal variations in the number of U.S. heat and cold waves do not correlate well with the observed global warming during the last century, and the analysis of trends in river flooding is multiyear and even multidecadal variability likely caused by both large-scale atmospheric circulation changes and basin-scale "memory" in the form of soil moisture.
Abstract: Weather and climate extremes have been varying and changing on many different time scales. In recent decades, heat waves have generally become more frequent across the United States, while cold waves have been decreasing. While this is in keeping with expectations in a warming climate, it turns out that decadal variations in the number of U.S. heat and cold waves do not correlate well with the observed U.S. warming during the last century. Annual peak flow data reveal that river flooding trends on the century scale do not show uniform changes across the country. While flood magnitudes in the Southwest have been decreasing, flood magnitudes in the Northeast and north-central United States have been increasing. Confounding the analysis of trends in river flooding is multiyear and even multidecadal variability likely caused by both large-scale atmospheric circulation changes and basin-scale “memory” in the form of soil moisture. Droughts also have long-term trends as well as multiyear and decadal variability...
357 citations
TL;DR: In this article, the authors developed a method to generate a near-real-time remotely sensed drought severity index (DSI) to monitor and detect drought globally at 1-km spatial resolution and regular 8-day, monthly, and annual frequencies.
Abstract: Regional drought and flooding from extreme climatic events are increasing in frequency and severity, with significant adverse ecosocial impacts. Detecting and monitoring drought at regional to global scales remains challenging, despite the availability of various drought indices and widespread availability of potentially synergistic global satellite observational records. The authors have developed a method to generate a near-real-time remotely sensed drought severity index (DSI) to monitor and detect drought globally at 1-km spatial resolution and regular 8-day, monthly, and annual frequencies. The new DSI integrates and exploits information from current operational satellite-based terrestrial evapo-transpiration (ET) and vegetation greenness index [normalized difference vegetation index (NDVI)] products, which are sensitive to vegetation water stress. Specifically, this approach determines the annual DSI departure from its normal (2000–11) using the remotely sensed ratio of ET to potential ET (PET) and ...
Deutscher Wetterdienst1, University of Edinburgh2, Met Office3, European Space Agency4, University of Bremen5, Centre National D'Etudes Spatiales6, University of Alcalá7, Université catholique de Louvain8, Finnish Meteorological Institute9, Technical University of Denmark10, German Aerospace Center11, University of Zurich12, Remote Sensing Center13, Plymouth Marine Laboratory14, Vienna University of Technology15
TL;DR: The Climate Change Initiative (CCI) as discussed by the authors provides a forum to bring the data and modeling communities together to provide a climate system perspective and a forum for bringing data and modelling communities together.
Abstract: Observations of Earth from space have been made for over 40 years and have contributed to advances in many aspects of climate science. However, attempts to exploit this wealth of data are often hampered by a lack of homogeneity and continuity and by insufficient understanding of the products and their uncertainties. There is, therefore, a need to reassess and reprocess satellite datasets to maximize their usefulness for climate science. The European Space Agency has responded to this need by establishing the Climate Change Initiative (CCI). The CCI will create new climate data records for (currently) 13 essential climate variables (ECVs) and make these open and easily accessible to all. Each ECV project works closely with users to produce time series from the available satellite observations relevant to users' needs. A climate modeling users' group provides a climate system perspective and a forum to bring the data and modeling communities together. This paper presents the CCI program. It outlines its benefit and presents approaches and challenges for each ECV project, covering clouds, aerosols, ozone, greenhouse gases, sea surface temperature, ocean color, sea level, sea ice, land cover, fire, glaciers, soil moisture, and ice sheets. It also discusses how the CCI approach may contribute to defining and shaping future developments in Earth observation for climate science.
TL;DR: A multidecadal ensemble reforecast dataset is available that is approximately consistent with the operational 0000 UTC cycle of the 2012 NOAA Global Ensemble Forecast System (GEFS).
Abstract: A multidecadal ensemble reforecast database is now available that is approximately consistent with the operational 0000 UTC cycle of the 2012 NOAA Global Ensemble Forecast System (GEFS) The reforecast dataset consists of an 11-member ensemble run once each day from 0000 UTC initial conditions Reforecasts are run to +16 days As with the operational 2012 GEFS, the reforecast is run at T254L42 resolution (approximately 1/2° grid spacing, 42 levels) for week +1 forecasts and T190L42 (approximately 3/4° grid spacing) for the week +2 forecasts Reforecasts were initialized with Climate Forecast System Reanalysis initial conditions, and perturbations were generated using the ensemble transform with rescaling technique Reforecast data are available from 1985 to present Reforecast datasets were previously demonstrated to be very valuable for detecting and correcting systematic errors in forecasts, especially forecasts of relatively rare events and longer-lead forecasts What is novel about this reforecast dat
National Oceanic and Atmospheric Administration1, University of New South Wales2, University of Oxford3, University of Málaga4, Complutense University of Madrid5, University of Melbourne6, National Institute of Water and Atmospheric Research7, Centre national de la recherche scientifique8, Chinese Academy of Sciences9, China Meteorological Administration10, Met Office11, Royal Netherlands Meteorological Institute12, University of Edinburgh13, Stanford University14, Natural Environment Research Council15, University of California, Santa Barbara16, University of Tokyo17, Oregon University System18, University of Lisbon19
TL;DR: In this paper, 19 analyses by 18 different research groups, often using quite different methodologies, of 12 extreme events that occurred in 2012 are presented, and the differences also provide insights into the structural uncertainty of event attribution, the uncertainty that arises directly from the differences in analysis methodology.
Abstract: Attribution of extreme events is a challenging science and one that is currently undergoing considerable evolution. In this paper are 19 analyses by 18 different research groups, often using quite different methodologies, of 12 extreme events that occurred in 2012. In addition to investigating the causes of these extreme events, the multiple analyses of four of the events, the high temperatures in the United States, the record low levels of Arctic sea ice, and the heavy rain in northern Europe and eastern Australia, provide an opportunity to compare and contrast the strengths and weaknesses of the various methodologies. The differences also provide insights into the structural uncertainty of event attribution, that is, the uncertainty that arises directly from the differences in analysis methodology. In these cases, there was considerable agreement between the different assessments of the same event. However, different events had very different causes. Approximately half the analyses found some evidence that anthropogenically caused climate change was a contributing factor to the extreme event examined, though the effects of natural fluctuations of weather and climate on the evolution of many of the extreme events played key roles as well.
TL;DR: In this article, the variability of results from different automated methods of detection and tracking of extratropical cyclones is assessed in order to identify uncertainties related to the choice of method.
Abstract: The variability of results from different automated methods of detection and tracking of extratropical cyclones is assessed in order to identify uncertainties related to the choice of method. Fifteen international teams applied their own algorithms to the same dataset - the period 1989-2009 of interim European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis (ERAInterim) data. This experiment is part of the community project Intercomparison of Mid Latitude Storm Diagnostics (IMILAST; see www.proclim.ch/imilast/index.html). The spread of results for cyclone frequency, intensity, life cycle, and track location is presented to illustrate the impact of using different methods. Globally, methods agree well for geographical distribution in large oceanic regions, interannual variability of cyclone numbers, geographical patterns of strong trends, and distribution shape for many life cycle characteristics. In contrast, the largest disparities exist for the total numbers of cyclones, the detection of weak cyclones, and distribution in some densely populated regions. Consistency between methods is better for strong cyclones than for shallow ones. Two case studies of relatively large, intense cyclones reveal that the identification of the most intense part of the life cycle of these events is robust between methods, but considerable differences exist during the development and the dissolution phases.
TL;DR: In this article, the authors established a dense monitoring network on the central Tibetan Plateau to measure two state variables (soil moisture and temperature) at three spatial scales (1.0°, 0.3°, and 0.1°) and four soil depths (0-5, 10, 20, and 40 cm).
Abstract: Multisphere interactions over the Tibetan Plateau directly impact its surrounding climate and environment at a variety of spatiotemporal scales. Remote sensing and modeling are expected to provide hydrometeorological data needed for these process studies, but in situ observations are required to support their calibration and validation. For this purpose, we have established a dense monitoring network on the central Tibetan Plateau to measure two state variables (soil moisture and temperature) at three spatial scales (1.0°, 0.3°, and 0.1°) and four soil depths (0–5, 10, 20, and 40 cm). The experimental area is characterized by low biomass, high soil moisture dynamic range, and typical freeze–thaw cycle. The network consists of 56 stations with their elevation varying over 4470–4950 m. As auxiliary parameters of this network, soil texture and soil organic carbon content are measured at each station to support further studies. To guarantee continuous and high-quality data, tremendous efforts have been made t...
TL;DR: The Atmospheric Radiation Measurement (ARM) Climate Research Facility (www.arm.gov) provides atmospheric observations from diverse climatic regimes around the world as mentioned in this paper, including water vapor, cloud/aerosol extinction, and Doppler lidars.
Abstract: The Atmospheric Radiation Measurement (ARM) Climate Research Facility (www.arm.gov) provides atmospheric observations from diverse climatic regimes around the world. Because it is a U.S. Department of Energy (DOE) user facility, ARM data are freely available to anyone through the ARM Data Archive. With 20 years of operations, the facility recently added two mobile facilities and an aerial facility to its network of fixed-location sites. Research using ARM data has led to advances in areas ranging from radiative transfer to cloud microphysics. The American Recovery and Reinvestment Act of 2009 allowed ARM to enhance its observational capabilities with a broad array of new instruments at its fixed and mobile sites and the aerial facility. Instruments include scanning radars; water vapor, cloud/aerosol extinction, and Doppler lidars; aerosol instruments for measuring optical, physical, and chemical properties; and aircraft probes for measuring cloud and aerosol properties. Taking full advantage of these inst...
Langley Research Center1, Goddard Space Flight Center2, Harvard University3, California Institute of Technology4, Imperial College London5, University of Wisconsin-Madison6, Lawrence Berkeley National Laboratory7, National Physical Laboratory8, University of Michigan9, McGill University10, University of Maryland, College Park11, University of Colorado Boulder12, National Oceanic and Atmospheric Administration13, National Institute of Standards and Technology14, University of Miami15
TL;DR: The Climate Absolute Radiance and Refractivity Observatory (CLARREO) mission as discussed by the authors provides a calibration laboratory in orbit for the purpose of accurately measuring and attributing climate change.
Abstract: The Climate Absolute Radiance and Refractivity Observatory (CLARREO) mission will provide a calibration laboratory in orbit for the purpose of accurately measuring and attributing climate change. CLARREO measurements establish new climate change benchmarks with high absolute radiometric accuracy and high statistical confidence across a wide range of essential climate variables. CLARREO's inherently high absolute accuracy will be verified and traceable on orbit to Systeme Internationale (SI) units. The benchmarks established by CLARREO will be critical for assessing changes in the Earth system and climate model predictive capabilities for decades into the future as society works to meet the challenge of optimizing strategies for mitigating and adapting to climate change. The CLARREO benchmarks are derived from measurements of the Earth's thermal infrared spectrum (5–50 μm), the spectrum of solar radiation reflected by the Earth and its atmosphere (320–2300 nm), and radio occultation refractivity from which...
TL;DR: The Hurricane Forecast Improvement Project (HFIP) as discussed by the authors was established by the National Oceanic and Atmospheric Administration (NOAA) to significantly increase the agency's capability to address this vulnerability and begin to mitigate the impacts.
Abstract: Over the decade prior to 2007, the increasing vulnerability of the United States to damage and economic disruption from tropical storms and hurricanes was dramatically demonstrated by the impacts of a number of land-falling storms. In 2008, the National Oceanic and Atmospheric Administration (NOAA) established the Hurricane Forecast Improvement Project (HFIP) to significantly increase the agency's capability to address this vulnerability and begin to mitigate the impacts. In fiscal year 2009, The White House amended the president's budget and Congress appropriated funding to achieve a 20% reduction in forecast error (track and intensity) in 5 years with 50% reduction in 10 years. Over the past 3 years, HFIP has built computational infrastructure and implemented a focused set of cross-organizational research and development (R&D) activities to develop, demonstrate, and implement enhanced operational modeling capabilities to improve the numerical forecast guidance made available to the National Hurricane Ce...
TL;DR: The Persistent Cold-Air Pool Study (PCAPS) as mentioned in this paper was conducted in Utah's Salt Lake valley from 1 December 2010 to 7 February 2011 to improve understanding of the physical processes governing the evolution of multiday cold-air pools (CAPs).
Abstract: The Persistent Cold-Air Pool Study (PCAPS) was conducted in Utah's Salt Lake valley from 1 December 2010 to 7 February 2011. The field campaign's primary goal was to improve understanding of the physical processes governing the evolution of multiday cold-air pools (CAPs) that are common in mountain basins during the winter. Meteorological instrumentation deployed throughout the Salt Lake valley provided observations of the processes contributing to the formation, maintenance, and destruction of 10 persistent CAP episodes. The close proximity of PCAPS field sites to residences and the University of Utah campus allowed many undergraduate and graduate students to participate in the study. Ongoing research, supported by the National Science Foundation, is using the PCAPS dataset to examine CAP evolution. Preliminary analyses reveal that variations in CAP thermodynamic structure are attributable to a multitude of physical processes affecting local static stability: for example, synoptic-scale processes impact ...
TL;DR: The Suomi National Polar-Orbiting Partnership (NPP) satellite was launched on 28 October 2011, heralding the next generation of operational U.S. polar-orbiting satellites as discussed by the authors.
Abstract: The Suomi National Polar-Orbiting Partnership (NPP) satellite was launched on 28 October 2011, heralding the next generation of operational U.S. polar-orbiting satellites. It carries the Visible– Infrared Imaging Radiometer Suite (VIIRS), a 22-band visible/infrared sensor that combines many of the best aspects of the NOAA Advanced Very High Resolution Radiometer (AVHRR), the Defense Meteorological Satellite Program (DMSP) Operational Linescan System (OLS), and the National Aeronautics and Space Administration (NASA) Moderate Resolution Imaging Spectroradiometer (MODIS) sensors. VIIRS has nearly all the capabilities of MODIS, but offers a wider swath width (3,000 versus 2,330 km) and much higher spatial resolution at swath edge. VIIRS also has a day/night band (DNB) that is sensitive to very low levels of visible light at night such as those produced by moonlight reflecting off low clouds, fog, dust, ash plumes, and snow cover. In addition, VIIRS detects light emissions from cities, ships, oil flares, and ...
TL;DR: In this paper, the authors assess the impact of Saharan dust on the Caribbean Basin because of the dearth of studies in this region, and a better understanding is needed of the factors that affect the transport of dust, the physical and chemical properties of the transported materials, and how these might change during transport.
Abstract: Every year huge quantities of soil dust are carried by winds from Africa, across the Atlantic, and to the Caribbean. No other ocean region is so extensively and persistently impacted by such high concentrations of dust, a region that extends over 7000 km from the coast of Africa to the Caribbean and to the bounding continental shores of the Americas. In effect, the Caribbean Basin can be thought of as the “receptor” site of the Saharan dust “source,” a source that accounts for over half of global dust emissions. It is generally recognized that on a global scale mineral dust can affect many aspects of climate, marine biogeochemical processes, soil fertility, air quality, and human health. However, it is difficult to assess the impact on the Caribbean Basin because of the dearth of studies in this region. A better understanding is needed of the factors that affect the transport of dust, the physical and chemical properties of the transported materials, and how these might change during transport. Of particu...
Woods Hole Oceanographic Institution1, Massachusetts Institute of Technology2, Princeton University3, University of Maine4, University of Texas at Austin5, British Antarctic Survey6, University of Washington7, University of Alaska Fairbanks8, University of Colorado Boulder9, Los Alamos National Laboratory10, California Institute of Technology11, University of California, Irvine12, Durham University13
TL;DR: A working group on Greenland Ice Sheet-Ocean Interactions (GRISO), composed of representatives from the multiple disciplines involved, was established in January 2011 to develop strategies to address dynamic response of Greenland's glaciers to climate forcing as mentioned in this paper.
Abstract: A working group on Greenland Ice Sheet-Ocean Interactions (GRISO), composed of representatives from the multiple disciplines involved, was established in January 2011 to develop strategies to address dynamic response of Greenland's glaciers to climate forcing. Critical aspects of Greenland's coupled ice sheet-ocean system are identified, and a research agenda is outlined that will yield fundamental insights into how the ice sheet and ocean interact, their role in Earth's climate system, their regional and global effects, and probable trajectories of future changes. Key elements of the research agenda are focused process studies, sustained observational efforts at key sites, and inclusion of the relevant dynamics in Earth system models. Interdisciplinary and multiagency efforts, as well as international cooperation, are crucial to making progress on this novel and complex problem. This will prove as a significant step toward fulfilling the goal of credibly projecting sea level rise over the coming decades and century.
TL;DR: How the availability and continuity of precipitation data records from recent and upcoming space missions is transforming the ways that scientific and societal issues are addressed, in ways that would not be otherwise possible is demonstrated.
Abstract: Of the three primary sources of spatially contiguous precipitation observations (surface networks, ground-based radar, and satellite-based radar/radiometers), only the last is a viable source over ocean and much of the Earth's land. As recently as 15 years ago, users needing quantitative detail of precipitation on anything under a monthly time scale relied upon products derived from geostationary satellite thermal infrared (IR) indices. The Special Sensor Microwave Imager (SSMI) passive microwave (PMW) imagers originated in 1987 and continue today with the SSMI sounder (SSMIS) sensor. The fortunate longevity of the joint National Aeronautics and Space Administration (NASA) and Japan Aerospace Exploration Agency (JAXA) Tropical Rainfall Measuring Mission (TRMM) is providing the environmental science community a nearly unbroken data record (as of April 2012, over 14 years) of tropical and sub-tropical precipitation processes. TRMM was originally conceived in the mid-1980s as a climate mission with relatively modest goals, including monthly averaged precipitation. TRMM data were quickly exploited for model data assimilation and, beginning in 1999 with the availability of near real time data, for tropical cyclone warnings. To overcome the intermittently spaced revisit from these and other low Earth-orbiting satellites, many methods to merge PMW-based precipitation data and geostationary satellite observations have been developed, such as the TRMM Multisatellite Precipitation Product and the Climate Prediction Center (CPC) morphing method (CMORPH. The purpose of this article is not to provide a survey or assessment of these and other satellite-based precipitation datasets, which are well summarized in several recent articles. Rather, the intent is to demonstrate how the availability and continuity of satellite-based precipitation data records is transforming the ways that scientific and societal issues related to precipitation are addressed, in ways that would not be otherwise possible. These developments have taken place in parallel with the growth of an increasingly interconnected scientific environment. Scientists from different disciplines can easily interact with each other via information and materials they encounter online, and collaborate remotely without ever meeting each other in person. Likewise, these precipitation datasets are quickly and easily available via various data portals and are widely used. Within the framework of the NASA/JAXA Global Precipitation Measurement (GPM mission, these applications will become increasingly interconnected. We emphasize that precipitation observations by themselves provide an incomplete picture of the state of the atmosphere. For example, it is unlikely that a richer understanding of the global water cycle will be possible by standalone missions and algorithms, but must also involve some component of data, where model analyses of the physical state are constrained alongside multiple observations (e.g., precipitation, evaporation, radiation). The next section provides examples extracted from the many applications that use various high-resolution precipitation products. The final section summarizes the future system for global precipitation processing.
TL;DR: In this article, the authors presented a global lightning climatology based on data from the ground-based World Wide Lightning Location Network (WWLLN), for which global observations began in 2004.
Abstract: The seasonally and diurnally varying frequency of lightning flashes provides a measure of the frequency of occurrence of intense convection and, as such, is useful in describing the Earth's climate. Here we present a few highlights of a global lightning climatology based on data from the ground-based World Wide Lightning Location Network (WWLLN), for which global observations began in 2004. Because WWLLN monitors global lightning continuously, it samples ~100 times as many lightning strokes/flashes per year as the Tropical Rainfall Measuring Mission's (TRMM) Lightning Imaging Sensor (LIS). Using WWLLN data it is possible to generate a global lightning climatology that captures seasonal variations, including those associated with the midlatitude storm tracks, and resolves the diurnal cycle, thereby illuminating the interplay between sea breezes, mountain–valley wind systems, and remotely forced gravity waves in touching off thunderstorms in a wide variety of geographical settings. The text of the paper sho...
TL;DR: In this article, the authors focus on European Centre for Medium-Range Weather Forecasts (ECMWF) day-6 forecasts for Europe and reveal a coherent "Rex type" blocking situation, with a high over northern Europe and a low over the Mediterranean.
Abstract: Medium-range weather prediction has become more skillful over recent decades, but forecast centers still suffer from occasional very poor forecasts, which are often referred to as “dropouts” or “busts.” This study focuses on European Centre for Medium-Range Weather Forecasts (ECMWF) day-6 forecasts for Europe. Although busts are defined by gross scores, bust composites reveal a coherent “Rex type” blocking situation, with a high over northern Europe and a low over the Mediterranean. Initial conditions for these busts also reveal a coherent flow, but this is located over North America and involves a trough over the Rockies, with high convective available potential energy (CAPE) to its east. This flow type occurs in spring and is often associated with a Rossby wave train that has crossed the Pacific. A composite on this initial flow type displays enhanced day-6 random forecast errors and some-what enhanced ensemble forecast spread, indicating reduced inherent predictability. Mesoscale convective systems, as...
TL;DR: In this article, a comprehensive set of interpolated climate data for western North America, including monthly data for the last century (1901-2009), future projections from atmosphere-ocean general circulation models (A2, A1B, and B1 scenarios of the WCRP CMIP3 multimodel dataset), as well as decadal averages and multiple climate normals, is presented.
Abstract: We present a comprehensive set of interpolated climate data for western North America, including monthly data for the last century (1901–2009), future projections from atmosphere–ocean general circulation models (A2, A1B, and B1 scenarios of the WCRP CMIP3 multimodel dataset), as well as decadal averages and multiple climate normals for the last century. For each of these time periods, we provide a large set of basic and derived biologically relevant climate variables, such as growing and chilling degree days, growing season length descriptors, frost-free days, extreme minimum temperatures, etc. To balance file size versus accuracy for these approximately 20,000 climate surfaces, we provide a stand-alone software solution that adds or subtracts historical data and future projections as medium-resolution anomalies (deviations) from the high resolution 1961–90 baseline normal dataset. The program further downscales the baseline data through a combination of bilinear interpolation and elevation adjustment us...
Vienna University of Technology1, Princeton University2, World Meteorological Organization3, National Oceanic and Atmospheric Administration4, Commonwealth Scientific and Industrial Research Organisation5, University of Reading6, UNESCO-IHE Institute for Water Education7, European Centre for Medium-Range Weather Forecasts8, Goddard Space Flight Center9, Bureau of Meteorology10, Utrecht University11, National Institute for Space Research12, Morgan State University13
TL;DR: A key goal of a GDEWS is to maximize the lead time for early warning, allowing drought managers and disaster coordinators more time to put mitigation measures in place to reduce the vulnerability to drought.
Abstract: Drought has had a significant impact on civilization throughout history in terms of reductions in agricultural productivity, potable water supply, and economic activity, and in extreme cases this has led to famine. Every continent has semiarid areas, which are especially vulnerable to drought. The Intergovernmental Panel on Climate Change has noted that average annual river runoff and water availability are projected to decrease by 10 percent-13 percent over some dry and semiarid regions in mid and low latitudes, increasing the frequency, intensity, and duration of drought, along with its associated impacts. The sheer magnitude of the problem demands efforts to reduce vulnerability to drought by moving away from the reactive, crisis management approach of the past toward a more proactive, risk management approach that is centered on reducing vulnerability to drought as much as possible while providing early warning of evolving drought conditions and possible impacts. Many countries, unfortunately, do not have adequate resources to provide early warning, but require outside support to provide the necessary early warning information for risk management. Furthermore, in an interconnected world, the need for information on a global scale is crucial for understanding the prospect of declines in agricultural productivity and associated impacts on food prices, food security, and potential for civil conflict. This paper highlights the recent progress made toward a Global Drought Early Warning Monitoring Framework (GDEWF), an underlying partnership and framework, along with its Global Drought Early Warning System (GDEWS), which is its interoperable information system, and the organizations that have begun working together to make it a reality. The GDEWF aims to improve existing regional and national drought monitoring and forecasting capabilities by adding a global component, facilitating continental monitoring and forecasting (where lacking), and improving these tools at various scales, thereby increasing the capacity of national and regional institutions that lack drought early warning systems or complementing existing ones. A further goal is to improve coordination of information delivery for drought-related activities and relief efforts across the world. This is especially relevant for regions and nations with low capacity for drought early warning. To do this requires a global partnership that leverages the resources necessary and develops capabilities at the global level, such as global drought forecasting combined with early warning tools, global real-time monitoring, and harmonized methods to identify critical areas vulnerable to drought. Although the path to a fully functional GDEWS is challenging, multiple partners and organizations within the drought, forecasting, agricultural, and water-cycle communities are committed to working toward its success.
Florida State University1, Woods Hole Oceanographic Institution2, University of California, San Diego3, University of Washington4, British Antarctic Survey5, Pacific Marine Environmental Laboratory6, University of Miami7, Earth System Research Laboratory8, University of California, Irvine9, University of Maryland, College Park10, University of Colorado Boulder11
TL;DR: In this paper, the deficiencies in the current state of knowledge about air-sea surface fluxes in high latitudes, the sensitivity of various high-latitude processes to changes in surface flux, and the scientific requirements for surface flux products do not meet these requirements.
Abstract: Polar regions have great sensitivity to climate forcing; however, understanding of the physical processes coupling the atmosphere and ocean in these regions is relatively poor. Improving our knowledge of high-latitude surface fluxes will require close collaboration among meteorologists, oceanographers, ice physicists, and climatologists, and between observationalists and modelers, as well as new combinations of in situ measurements and satellite remote sensing. This article describes the deficiencies in our current state of knowledge about air–sea surface fluxes in high latitudes, the sensitivity of various high-latitude processes to changes in surface fluxes, and the scientific requirements for surface fluxes at high latitudes. We inventory the reasons, both logistical and physical, why existing flux products do not meet these requirements. Capturing an annual cycle in fluxes requires that instruments function through long periods of cold polar darkness, often far from support services, in situations subject to icing and extreme wave conditions. Furthermore, frequent cloud cover at high latitudes restricts the availability of surface and atmospheric data from visible and infrared (IR) wavelength satellite sensors. Recommendations are made for improving high-latitude fluxes, including 1) acquiring more in situ observations, 2) developing improved satellite-flux-observing capabilities, 3) making observations and flux products more accessible, and 4) encouraging flux intercomparisons.