United States Historical Climatology Network Daily Temperature and Precipitation Data (1871-1997)

This document describes a database containing daily observations of maximum and minimum temperature, precipitation amount, snowfall amount, and snow depth from 1062 observing stations across the contiguous US. This database is an expansion and update of the original 138-station database previously released by the Carbon Dioxide Information Analysis Center (CDIAC) as CDIAC numeric data package NDP-042. These 1062 stations are a subset of the 1221-station US Historical Climatology Network (HCN), a monthly database compiled by the National Climatic Data Center (Asheville, North Carolina) that has been widely used in analyzing US climate. Data from 1050 of these daily records extend into the 1990s, while 990 of these extend through 1997. Most station records are essentially complete for at least 40 years; the latest beginning year of record is 1948. Records from 158 stations begin prior to 1900, with that of Charleston, South Carolina beginning the earliest (1871). The daily resolution of these data makes them extremely valuable for studies attempting to detect and monitor long-term climatic changes on a regional scale. Studies using daily data may be able to detect changes in regional climate that would not be apparent from analysis of monthly temperature and precipitation data. Such studies may include analyses of trends in maximum and minimum temperatures, temperature extremes, daily temperature range, precipitation ''event size'' frequency, and the magnitude and duration of wet and dry periods. The data are also valuable in areas such as regional climate model validation and climate change impact assessment. This database is available free of charge from CDIAC as a numeric data package (NDP)

Data Preparation and Analysis for Annex III, USA/PRC Cooperation in the Field of Atmospheric Trace Gases

The National Climatic Data Center (NCDC) has been a long-time and very active participant in the joint research program on the Greenhouse Effect created by the bilateral agreement Annex III to the Protocol on Fossil Energy Research and Development on Cooperation in the Field of Atmospheric Trace Gases. This agreement between the US Department of Energy (DOE) and the People's Republic of China, Chinese Academy of Sciences (CAS) has fostered a large amount of data set development and research (Riches et al., 1992) as well as science exchange between the two countries. Within the agreement there have been four basic tasks: (1) to analyze general circulation models, (2) to prepare, validate, and analyze data, (3) analyze the relationship between large scale and local climate, and (4) atmospheric trace gas measurements, particularly methane (Riches et al. 1992). Within this framework the NCDC has had two basic tasks in this program: to develop, validate, analyze and exchange long-term climate data sets suitable for analyzing past climate change, and to perform research into past climate change and linking large-scale and regional climates. Following is a brief review of NCDC's accomplishments in the project

Climate data challenges in the 21st century

International audienceClimate data are dramatically increasing in volume and complexity, just as the users of these data in the scientific community and the public are rapidly increasing in number. A new paradigm of more open, user-friendly data access is needed to ensure that society can reduce vulnerability to climate variability and change, while at the same time exploiting opportunities that will occur