Publications Published in Bulletin of the American Meteorological Society

1. A historical perspective of U.S. climate divisions. Guttman, Nathaniel B; Quayle, Robert G.
   Bulletin of the American Meteorological Society: 1996
   Notes
   The history of climatic divisions in the contiguous United States has been pieced together from fragmentary documentation. Each of the 48 contiguous states has been subdivided into climatic divisions. Divisional boundaries are now standardized, and a set of climatic variables for time-invariant divisional boundaries has been compiled for the period of record beginning in 1895. This paper documents the origins of climatic divisions, the computational methodology of an area-invariant divisional dataset maintained by the National Climatic Data Center, and the strengths and weaknesses of divisional data.
   
   
   
2. Analog European Heat Waves for U.S. Cities to Analyze Impacts on Heat-Related Mortality. Kalkstein, Laurence S.; Greene, J. Scott; Mills, David M.; Perrin, Alan D.; Samenow, Jason P.; Cohen, Jean-Claude.
   Bulletin of the American Meteorological Society: 2008
   Notes
   Europe experienced an unprecedented excessive heat event (EHE) in 2003, raising the question: What if a similar EHE were experienced in U.S. cities?This study used an airmass-based meteorological method to develop analogs to the 2003 European EHE for five U.S. cities: Detroit, New York, Philadelphia, St. Louis, and Washington, D.C.; and calculated the potential excess mortality for these analogs.Analogs capture the 2003 EHE's characteristics by determining daily deviations from long-term averages for meteorological variables in Paris, France, expressed as a multiple of the standard deviation for each variable's long-term average.The 2003 daily multiples of the standard deviation measured in Paris for 12 meteorological variables, and daily maximum and minimum temperatures, were transferred to each U.S. city, and multiplied by the corresponding standard deviation calculated for each variable, to produce analog meteorological variables. With these data, an airmass calendar for each city was developed, and excess mortality was calculated using existing city-specific airmass algorithms.Results show the analog EHEs breaking all-time records for maximum and high minimum temperatures in all five cities. Excess heat-related mortality for the analog summer is 2 to over 7 times the long-term average, with New York showing the greatest increases. In all cities, calculated excess heat-related mortality for the analog summer exceeds the hottest recorded summer in 35 yr.These study results could be valuable for public health planning and a wide range of additional reliability or sensitivity analyses.
   
   
   
3. A pacific interdecadal climate oscillation with impacts on salmon production. Mantua, N. J.; Hare, S. R.; Zhang, Y.; Wallace, J. M.; Francis, R. C..
   Bulletin of the American Meteorological Society: 1997
   Notes
   Evidence gleaned from the instrumental record of climate data identifies a robust, recurring pattern of ocean- atmosphere climate variability centered over the midlatitude North Pacific basin. Over the past century, the amplitude of this climate pattern has varied irregularly at interannual-to-interdecadal timescales. Then is evidence of reversals in the prevailing polarity of the oscillation occurring around 1925, 1947, and 1977; the last two reversals correspond to dramatic shifts in salmon production regimes in the North Pacific Ocean. This climate pattern also affects coastal sea and continental surface air temperatures, as well as streamflow in major west coast river systems, from Alaska to California.
   
   
   
4. A review of twentieth-century drought indices used in the United States. Heim, R. R..
   Bulletin of the American Meteorological Society: 2002
   Notes
   The monitoring and analysis of drought have long suffered from the lack of an adequate definition of the phenomenon. As a result, drought indices have slowly evolved during the last two centuries from simplistic approaches based on some measure of rainfall deficiency, to more complex problem-specific models. Indices developed in the late nineteenth and early twentieth century included such measures as percent of normal precipitation over some interval, consecutive days with rain below a given threshold, formulae involving a combination of temperature and precipitation, and models factoring in precipitation deficits over consecutive days. The incorporation of evapotranspiration as a measure of water demand by Thornthwaite led to the landmark development in 1965 by Palmer of a water budget-based drought index that is still widely used. Drought indices developed since the 1960s include the Surface Water Supply Index, which supplements the Palmer Index by integrating snowpack, reservoir storage, streamflow, and precipitation at high elevations; the Keetch-Byram Drought Index, which is used by fire control managers; the Standardized Precipitation Index; and the Vegetation Condition Index, which utilizes global satellite observations of vegetation condition. These models continue to evolve as new data sources become available. The twentieth century concluded with the development of the Drought Monitor tool, which incorporates Palmer's index and several other (post Palmer) indices to provide a universal assessment of drought conditions across the entire United States. By putting the development of these drought indices into a historical perspective, this paper provides a better understanding of the complex Palmer Index and of the nature of measuring drought in general.
   
   
   
5. Changes in the onset of spring in the western United States. Cayan, D. R.; Kammerdiener, S. A.; Dettinger, M. D.; Caprio, J. M.; Peterson, D. H..
   Bulletin of the American Meteorological Society: 2001
   Notes
   Fluctuations in spring climate in the western United States over the last 4-5 decades are described by examining changes in the blooming of plants and the timing of snowmelt-runoff pulses. The two measures of spring's onset that are employed are the timing of first bloom of lilac and honeysuckle bushes from a long-term cooperative phenological network, and the timing of the first major pulse of snowmelt recorded from high-elevation streams. Both measures contain year-to-year fluctuations, with typical year-to year fluctuations at a given site of one to three weeks. These fluctuations are spatially coherent, forming regional patterns that cover most of the west. Fluctuations in lilac first bloom dates are highly correlated to those of honeysuckle, and both are significantly correlated with those of the spring snowmelt pulse. Each of these measures, then, probably respond to a common mechanism. Various analyses indicate that anomalous temperature exerts the greatest influence upon both interannual and secular changes in the onset of spring in these networks. Earlier spring onsets since the late 1970s are a remarkable feature of the records, and reflect the unusual spell of warmer-than-normal springs in western North America during this period. The warm episodes are clearly related to larger-scale atmospheric conditions across North America and the North Pacific, but whether this is predominantly an expression of natural variability or also a symptom of global warming is not certain.
   
   
   
6. Declining mountain snowpack in western North America. Mote, Philip W; Hamlet, Alan F; Clark, Martyn P; Lettenmaier, Dennis P.
   Bulletin of the American Meteorological Society: 2005
   Notes
   In western North America, snow provides crucial storage of winter precipitation, effectively transferring water from the relatively wet winter season to the typically dry summers. Manual and telemetered measurements of spring snow-pack, corroborated by a physically based hydrologic model, are examined here for climate-driven fluctuations and trends during the period of 1916–2002. Much of the mountain West has experienced declines in spring snowpack, especially since midcentury, despite increases in winter precipitation in many places. Analysis and modeling show that climatic trends are the dominant factor, not changes in land use, forest canopy, or other factors. The largest decreases have occurred where winter temperatures are mild, especially in the Cascade Mountains and northern California. In most mountain ranges, relative declines grow from minimal at ridgetop to substantial at snow line. Taken together, these results emphasize that the West's snow resources are already declining as earth's climate warms.
   
   
   
7. Evidence for intensification of North Pacific Winter Cyclones since 1948. Graham, Nicholas E; Diaz, Henry F.
   Bulletin of the American Meteorological Society: 2001
   Notes
   Presents a study examining twentieth century trends of precipitation to show how precipitation has changed or varied. Examples of catastrophic flooding episodes in the United states from 1993 to 1997; Reference to a daily precipitation dataset used by Karl et al., (1996); Why trends for precipitation are calculated.
   
   
   
8. Fluxnet: A new tool to study the temporal and spatial variability of ecosystem-scale carbon dioxide, water vapor, and energy flux densities. Baldocchi, D.; Falge, E.; Gu, L.; Olson, R.; Hollinger, D.; Running, S.; Anthoni, P.; Bernhofer, C.; Davis, K.; Evans, R.; Fuentes, J.; Goldstein, A.; Katul, G.; Law, B.; Lee, X.; Malhi, Y.; Meyers, T.; Munger, W.; Oechel, W.; Paw U, K.T.; Pilegaard, K.; Schmid, H.P.; Valentini, R.; Verma, S.; Vesala, T.; Wilson, K.; Wofsy, S..
   Bulletin of the American Meteorological Society: 2001
   Notes
   FLUXNET is a global network of micrometeorological flux measurement sites that measure the exchanges of carbon dioxide, water vapor, and energy between the biosphere and atmosphere. At present over 140 sites are operating on a long–term and continuous basis. Vegetation under study includes temperate conifer and broadleaved (deciduous and evergreen) forests, tropical and boreal forests, crops, grasslands, chaparral, wetlands, and tundra. Sites exist on five continents and their latitudinal distribution ranges from 70°N to 30°S. FLUXNET has several primary functions. First, it provides infrastructure for compiling, archiving, and distributing carbon, water, and energy flux measurement, and meteorological, plant, and soil data to the science community. (Data and site information are available online at the FLUXNET www–eosdis.ornl.gov/FLUXNET/.) Second, the project supports calibration and flux intercomparison activities. This activity ensures that data from the regional networks are intercomparable. And third, FLUXNET supports the synthesis, discussion, and communication of ideas and data by supporting project scientists, workshops, and visiting scientists. The overarching goal is to provide information for validating computations of net primary productivity, evaporation, and energy absorption that are being generated by sensors mounted on the NASA Terra satellite. Data being compiled by FLUXNET are being used to quantify and compare magnitudes and dynamics of annual ecosystem carbon and water balances, to quantify the response of stand–scale carbon dioxide and water vapor flux densities to controlling biotic and abiotic factors, and to validate a hierarchy of soil–plant–atmosphere trace gas exchange models. Findings so far include 1) net CO2 exchange of temperate broadleaved forests increases by about 5.7 g C m–2 day–1 for each additional day that the growing season is extended; 2) the sensitivity of net ecosystem CO2 exchange to sunlight doubles if the sky is cloudy rather than clear; 3) the spectrum of CO2 flux density exhibits peaks at timescales of days, weeks, and years, and a spectral gap exists at the month timescale; 4) the optimal temperature of net CO2 exchange varies with mean summer temperature; and 5) stand age affects carbon dioxide and water vapor flux densities.
   
   
   
9. Heavy Precipitation and High Streamflow in the Contiguous United States: Trends in the Twentieth Century. Groisman, P Y R W K; Thomas, Karl R.
   Bulletin of the American Meteorological Society: 2001
   Notes
   Studies the changes in mean and heavy precipitation in the United States, particularly during the months of high streamflow. Heavy precipitation events; Precipitation changes in the 20th century; Streamflow changes during the month of maximum streamflow.
   
   
   
10. How predictable is El Nino?. Fedorov, A. V.; Harper, S. L.; Philander, S. G.; Winter, B.; Wittenberg, A..
    Bulletin of the American Meteorological Society: 2003
    Notes
    Nobody anticipated that El Nino would be weak and prolonged in 1992, but brief and intense in 1997/98. Why are various El Nino episodes so different, and so difficult to predict? The answer involves the important role played by random atmospheric disturbances (such as westerly wind bursts) in sustaining the weakly damped Southern Oscillation, whose complementary warm and cold phases are, respectively, El Nino and La Nina. As in the case of a damped pendulum sustained by modest blows at random times, so the predictability of El Nino is limited, not by the amplification of errors in initial conditions as in the case of weather, but mainly by atmospheric disturbances interacting with the Southern Oscillation. Given the statistics of the wind fluctuations, the probability distribution function of future sea surface temperature fluctuations in the eastern equatorial Pacific can be determined by means of an ensemble of calculations with a coupled ocean-atmosphere model.