B.W. Meeson

The ISLSCP initiative I global datasets: Surface boundary conditions and atmospheric forcings for land-atmosphere studies

A comprehensive series of global datasets for land-atmosphere models has been collected, formatted to a common grid, and released on a set of CD-ROMs. This paper describes the motivation for and th...

ISLSCP Initiative II global data sets: Surface boundary conditions and atmospheric forcings for land-atmosphere studies

[1] We report herein the publication and evaluation of the International Satellite Land Surface Climatology Project (ISLSCP) Initiative II global interdisciplinary data record. The record consists of 52 data sets, with a common series in the 10-year period 1985 to 1996. Selected data series extend well beyond this period. All series are coregistered to a common grid and gap-filled for continuity using uniform procedures. We describe briefly the individual data sets within the collection; provide user guidance; and contrast, compare and evaluate those data sets containing similar parameters (land cover, NDVI, albedo, precipitation and near-surface meteorology). We also describe the process used to develop the Initiative II collection which involved a broad international scientific community focused on addressing a well-defined set of carbon, water and energy cycle questions within the context of a specific set of analysis tools. The communities that drove the definition of the Initiative II collection were investigators within the international scientific communities of the Global Energy and Water cycle Experiment, GEWEX, program (http://www.gewex.org/); the International Geosphere/Biosphere Program IGBP (http://www.igbp.kva.se); and the U.S. Global Change Research Program, USGCRP (http://www.usgcrp.gov/). Finally, we report usage statistics based on access and download of files from the ISLSCP Initiative II collection available at http://www.daac.ornl.gov.

ISLSCP II MODIS (Collection 4) IGBP Land Cover, 2000-2001

The objective of the MODIS Land Cover Product is to provide a suite of land cover types useful to global system science modelers by exploiting the information content of MODIS data in the spectral, temporal, spatial, and directional domains.nnThese are global land cover classifications (dominant type, classification confidence and fractional cover) generated using a full year of MODerate Resolution Imaging Spectroradiometer (MODIS) data covering the period from October 2000 to October 2001. These products describe the geographic distribution of the 17 land cover classification scheme proposed by the International Geosphere-Biosphere Programme (IGBP).

ISLSCP II UNH/GRDC Composite Monthly Runoff

The University of New Hampshire (UNH)/Global Runoff Data Centre (GRDC) composite runoff data combines simulated water balance model runoff estimates derived from climate forcing with monitored river discharge. It can be viewed as a data assimilation applied in a water balance model context (conceptually similar to the commonly used 4DDA techniques used in meteorological modeling). Such a data assimilation scheme preserves the spatial specificity of the water balance calculations while constrained by the more accurate discharge measurement. There are 11 data files in this data set and 1 changemap file which shows the differences between the ISLSCP II land/water mask and the original data set.

ISLSCP II C4 Vegetation Percentage

The photosynthetic composition (C3 or C4) of vegetation on the land surface is essential for accurate simulations of biosphere-atmosphere exchanges of carbon, water, and energy. C3 and C4 plants have different responses to light, temperature, CO2, and nitrogen; they also differ in physiological functions like stomatal conductance and isotope fractionation. A fine-scale distribution of these plant types is essential for earth science modeling.nnThe C4 percentage is determined from datasets that describe the continuous distribution of plant growth forms (i.e., the percent of a grid cell covered by herbaceous or woody vegetation), climate classifications, the fraction of a grid cell covered in croplands, and national crop type harvest area statistics. The staff from the International Satellite Land Surface Climatology Project (ISLSCP) Initiative II have made the original data set consistent with the ISLSCP-2 land/water mask. This data set contains a single file in ArcInfo ASCIIGRID format.nnThis data set is one of the products of the International Satellite Land-Surface Climatology Project, Initiative II (ISLSCP II) data collection which contains 50 global time series data sets for the ten-year period 1986 to 1995. Selected data sets span even longer periods. ISLSCP II is a consistent collection of data sets that were compiled from existing data sources and algorithms, and were designed to satisfy the needs of modelers and investigators of the global carbon, water and energy cycle. The data were acquired from a number of U.S. and international agencies, universities, and institutions. The global data sets were mapped at consistent spatial (1, 0.5 and 0.25 degrees) and temporal (monthly, with meteorological data at finer (e.g., 3-hour)) resolutions and reformatted into a common ASCII format. The data and documentation have undergone two peer reviews.nnISLSCP is one of several projects of Global Energy and Water Cycle Experiment (GEWEX) [http://www.gewex.org/] and has the lead role in addressing land-atmosphere interactions -- process modeling, data retrieval algorithms, field experiment design and execution, and the development of global data sets.

ISLSCP II Atmospheric Carbon Dioxide Consumption by Continental Erosion

Estimates for the riverine export of carbon and of sediments: dissolved organic carbon (DOC) export, particulate organic carbon (POC) export, bicarbonate export, export of bicarbonate being of atmospheric origin (atmospheric CO2 consumption by rock weathering), and sediment export. Estimates are based on empirical models for the overall continental area in a spatial resolution of 0.5 x 0.5 degree longitude/ latitude. .

The International Satellite Land Surface Climatology Project (ISLSCP) Initiative II data collection

The International Satellite Land Surface Climatology Project (ISLSCP) Initiative II is compiling and producing a collection of high priority, global, interdisciplinary data sets that is responsive to the requirements of the International GEWEX Project Office (IGPO), and the International Geosphere Biosphere Programme Biospheric Aspects of the Hydrological Cycle (IGBP/BAHC) and ISLSCP scientific communities. The ISLSCP II activities, funded through NASAs Land Surface Hydrology Program, improve upon the original ISLSCP I collection by covering a longer period of time from 1986 to 1995, with at least a monthly time step, but also with many products being provided at spatial resolutions ranging from 1/4 to 1/2 and 1 degree. The satellite-derived vegetation data set that forms the core of the ISLSCP II collection covers the period from 1982 to 1998. The collection includes a variety of remotely-sensed data sets ranging from visible to microwave wavelengths. The data sets also include improved topography, surface radiation, near-surface meteorology, precipitation, runoff, and soil data sets that can be used in a variety of interdisciplinary research activities. Several data sets to support global carbon and biogeochemical studies are also provided. The final ISLSCP II collection is to be published in mid-2002 with any data sets currently available being accessible through the ISLSCP II web page (http://islscp2.gsfc.nasa.gov).

Existing degrees of consolidation

Examples from a range of degrees of data consolidation are presented here. They range from completely independent datasets (of which there are many), through various levels of consolidation. Examples of Consolidated datasets include the products of operational data networks, both general and project specific data archives, and highly Consolidated datasets which adhere strongly to Standards of format, resolution and documentation.