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Abstract (from http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-15-0088.1): A comprehensive understanding of the spatial, seasonal, and diurnal patterns in cloud cover frequency over the Hawaiian Islands was developed using high-resolution image data from the National Aeronautics and Space Administration’s Moderate Resolution Imaging Spectroradiometer (MODIS) sensors aboard the Terra and Aqua satellites. The Terra and Aqua MODIS cloud mask products, which provide the confidence that a given 1-km pixel is unobstructed by cloud, were obtained for the entire MODIS time series (10-plus years) over the main Hawaiian Islands. Monthly statistics were generated from the daily cloud mask data, including mean cloud cover...
Abstract (from http://climatechangeresponses.biomedcentral.com/articles/10.1186/s40665-016-0015-2): Background Detailed assessments of species responses to climate change are uncommon, owing to the limited nature of most ecological and local climate data sets. Exceptions, such as the case of the Haleakalā silversword, can provide important insights into the complexity of biological responses to changing climate conditions. We present a time series of decadal population censuses, combined with a pair of early population projections, which together span the past 80 years of demographic history for this alpine plant. Results The time series suggests a strong population recovery from the 1930s through the 1980s, likely...
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These files contain two datasets. First are vertical fluxes of energy, water vapor and carbon dioxide calculated by the eddy covariance technique using measurements taken at Olaa tower (Flux Data). Second are results of historical and future runs of the Community Land Model (CLM) for the Thurston and Olaa tower sites (CLM Output Data). Output includes time series of energy, water vapor, and carbon dioxide exchanges at each site. The historical runs are forced by gap-filled measured time series at each site. Future data sets were contructed by shifting values in the historical run by increments selected for possible future scenarios. Increments were based on the results of statistical downscaling of future climate...
While there has been rapid advancement in the development and application of statistical downscaling methods for climate projection, determining the best predictive large-scale climate information for the targeted local climate variable remains a challenge. The choice of predictor variables is one of the most influential steps of model development and has the potential to lead to varying results, contributing to the total uncertainty of future projections. Despite being a well-known problem, predictor selection often does not receive adequate attention and the development of a straightforward and feasible prescreening process is needed to provide guidance to simple (e.g., linear regression) and complex (e.g., machine...
Categories: Publication; Types: Citation
Recent work to extend the instrumental record of Hawaiian rainfall (available since the early 1900s ) back several centuries indicates the presence of large and significant variations in rainfall on decadal time scales (see time series graphic above). Parallel efforts to understand agricultural changes in the Hawaiian Islands prior to European influences suggests that after about 1650 CE there was a shift in emphasis to productive maximizing strategies, with implications for the region’s economic and socio-political stability.The above is one of the motivating ideas for conducting this workshop. Previous work by several of the participants argued that an increased reliance on risky product maximization strategies...
Abstract (from AMS100): Spatially continuous data products are essential for a number of applications including climate and hydrologic modeling, weather prediction, and water resource management. In this work, a distance-weighted interpolation method used to map daily rainfall and temperature in Hawaii is described and assessed. New high-resolution (250 m) maps were developed for daily rainfall and daily maximum (Tmax) and minimum (Tmin) near-surface air temperature for the period 1990–2014. Maps were produced using climatologically aided interpolation, in which station anomalies were interpolated using an optimized inverse distance weighting approach and then combined with long-term means to produce daily gridded...
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In the expectation that global climate will change steadily in the coming decades, this research project had the goal to obtain a more detailed view of the climatic changes that Hawai’i could experience by the mid and late 21st century. Given the importance of rainfall for Hawaiian ecosystems and freshwater reserves, this project investigated past seasonal rainfall pattern and developed a statistical model to estimate future rainfall changes for the major islands. As a result of this research, high-resolution maps and data are now available that researchers can use to study potential impacts on endangered species, or use the rainfall changes as input in decision-support tools.This data product provides data files...
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The following files contain source data for use of the Community Land Model 4.0 at two study sites in Volcanoes National Park, Hawai'i. Included are: Biometric data: 1) Growth increment data for Thurston and Olaa, based on dbh surveys done in four 10 m by 10 m plots at over a 12 year time period at Thurston and at six plots overs a 12 year period at Olaa, 2) Field measured leaf area index data. Measurements were made using LAI-2000 and LAI-2200 instruments, 3) Litterfall from Thurston and Olaa over a 17-mo period from June 2014 to Sep 2015. Data were sorted by species/litter type. Data are weights., 4) Field measured soil respiration data scaled to annual values and compared with tower-based measurements of ecosystem...
Abstract: The aim of this paper is to present a statistical downscaling method in which the relationships between present-day daily weather patterns and local rainfall data are derived and used to project future shifts in the frequency of heavy rainfall events under changing global climate conditions. National Centers for Environmental Prediction and the National Center for Atmospheric Research (NCEP/NCAR) reanalysis data from wet season months (November to April) 1958–2010 are composited for heavy rain days at 12 rainfall stations in the Hawaiian Islands. The occurrence of heavy rain events (days with amounts above the 90th percentile estimated from all wet season rain days 1958–2010) was found to be strongly correlated...
Abstract (from http://onlinelibrary.wiley.com/doi/10.1002/2014JD022059/abstract): Seasonal mean rainfall projections for Hawai‘i are given based on statistical downscaling of the latest Coupled Model Intercomparison Project phase 5 (CMIP5) global model results for two future representative concentration pathways (RCP4.5 and RCP8.5). The spatial information content of our statistical downscaling method is improved over previous efforts through the inclusion of spatially extensive, high-quality monthly rainfall data set and the use of improved large-scale climate predictor information. Predictor variables include moisture transport in the middle atmosphere (700 hPa), vertical temperature gradients, and geopotential...
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Surrounded by saltwater, human and natural communities on the Hawaiian Islands depend upon the freshwater supplied by rainfall for survival. Climate change will likely alter rainfall timing and intensity, but global climate models cannot capture the fine-scale dynamics of local rainfall, making future rainfall predictions for the islands uncertain. For this project, scientists used a technique called statistical downscaling (combining coarse-scale climate models with local historical data) to generate high-resolution maps showing seasonal rainfall change projections for Hawaiʻi over the course of this century. Results suggest that Hawaiʻi’s climate will become drier overall in the second half of the century, but...
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Serially complete forcing data for historical and future runs of the Community Land Model (CLM) for the Thurston and Olaa tower sites. The historical (2005-2015) data are derived from measured time series at each site. All gaps were filled to create serially complete time series of each forcing variable. Gap filling was based on the best available information at each time step and made use of statistical relationships with available data, historical analogues and other methods. Future (2071-2100) forcing data sets were contructed by shifting values in the historical data set by increments selected for possible future scenarios. Increments were based on the results of statistical downscaling of future climate by...
Abstract (from http://onlinelibrary.wiley.com/doi/10.1002/joc.4862/abstract): Spatial patterns of rainfall in Hawai‘i are among the most diverse in the world. As the global climate warms, it is important to understand observed rainfall variations to provide context for future changes. This is especially important for isolated oceanic islands where freshwater resources are limited, and understanding the potential impacts of climate change on the supply of freshwater is critical. Utilizing a high-resolution gridded data set of monthly and annual rainfall for Hawai‘i from January 1920 to December 2012, seasonal and annual trends were calculated for every 250-m pixel across the state and mapped to produce spatially...
What became apparent during the course of the workshop was the varying scales at which climatologists and archaeologists analyze and understand their data. Archaeologists are often concerned with the particular historical sequence of a place, and the effects that climatic conditions might have in that fairly limited spatial location. Climatologists tend to evaluate global and regional patterns without specifying localized patterns of variation that would have been important to human populations. The closing of this gap is a primary objective for future studies and this workshop provides the first step in creating space for additional discussion and collaboration. As an example, the organizers have begun to evaluate...
Categories: Data; Tags: biota, biota, environment, environment, report


    map background search result map search result map Developing High-Resolution Rainfall Change Scenarios for the Hawaiian Islands Datasets for "Climate Change Research in Support of Hawaiian Ecosystem Management: An Integrated Approach" Observed ecological inputs to the Community Land Model at two wet montane study sites, 2004-2016, Volcanoes National Park, Hawai'i Historical and future forcing data for the Community Land Model 4.0 used in two study sites in Hawai'i, 2005-2100 Ecosystem fluxes and Community Land Model outputs for Thurston and Olaa study sites, Hawaiʻi Observed ecological inputs to the Community Land Model at two wet montane study sites, 2004-2016, Volcanoes National Park, Hawai'i Historical and future forcing data for the Community Land Model 4.0 used in two study sites in Hawai'i, 2005-2100 Ecosystem fluxes and Community Land Model outputs for Thurston and Olaa study sites, Hawaiʻi Datasets for "Climate Change Research in Support of Hawaiian Ecosystem Management: An Integrated Approach" Developing High-Resolution Rainfall Change Scenarios for the Hawaiian Islands