If you think monitoring daily or hourly weather conditions across the entire nation seems like a daunting task, just think what monitoring the nation’s climate (or atmospheric conditions) over much longer time scales (decades and centuries) would be like.
While weather describes atmospheric conditions that can change quickly over relatively short periods of time (primarily days or hours), climate is how the atmosphere "behaves" more gradually over relatively long periods of time (on decade to century time scales). Knowing this, you may wonder exactly how NOAA collects, analyzes and archives all that data it needs to monitor the nation’s climate?
“It’s a rather complex process,” said Jay Lawrimore, former chief of the Climate Monitoring Branch of NOAA’s National Climatic Data Center in Asheville, N.C, where the official archives of U.S. weather and climate information are kept. “It’s not a simple matter of collecting surface data from around the world and averaging the individual station data into a U.S. or global average.”
Hurricane Dean, 2007.
Climate Monitoring is essential to understanding the Earth system and its influence on human health, safety and welfare. While observed changes in the Earth’s climate have been well documented, there remains much that is not known regarding how the Earth’s climate will vary and change in the future, how these changes will affect societies and economies of developed and developing nations, and how changes in one part of the climate system will influence other aspects of climate.
With projections of continued, and possibly more rapid, climate changes in the coming decades, the capacity to monitor all areas of the Earth’s climate system on an ongoing basis has taken on growing importance. The growth and distribution of world population to vulnerable environments such as coastal areas, and growing strains on natural resources as societies develop and grow, further highlight the need to understand the changing state of the Earth’s climate.
To effectively monitor the Earth’s climate, NOAA pprocessed extensive and diverse data including, current and historical, instrumental and proxy, and on site and remotely sensed. NOAA observing systems, as well as those of partners within and outside the U.S., continuously monitors the Earth’s climate system from land, sea, and the atmosphere.
Essential climate variables of the atmosphere include air temperature, precipitation, winds, pressure, clouds, and trace gases. On and below the surface of the Earth’s oceans, observing systems routinely monitor variables such as temperature, currents, salinity, carbon content and flux. Measurements of land variables such as glaciers, sea ice, snow cover, and soil moisture are also essential in the global observing system.
While a continued focus on improving observing and reporting technologies is essential to meeting climate monitoring needs, developing and maintaining historical high quality climate records is equally important. This provides context for the climate of today, makes possible the understanding of how the Earth’s climate is varying and changing, and provides perspectives on the range of climates that may be possible in the future. In addition to instrumental records of global climate conditions that date to the late 1880’s, proxy (paleoclimate) data from sources such as tree rings, ice cores, lake and ocean sediments, and corals, provide for the understanding of the Earth’s climate centuries and millennia in the past.
NOAA incorporates a broad spectrum of state-of-the-art measurements, including those from on siteand satellite systems, to accomplish its climate goals.
On site surface observing networks measure variables such as air temperature, precipitation, soil moisture, snowfall, snow depth, humidity, winds, and air pressure on every continent. Although NOAA networks such as the Cooperative Observers Network and Automated Surface Observing System were not designed specifically to monitor the Earth’s climate, NOAA recognized the need to develop networks with a specific focus on climate observations.
The world’s oceans are monitored by thousands of ships, buoys, and floats. There are nearly 3,000 drifting floats in the Argo array that measure not only conditions at the ocean interface, but also below the surface to record profiles of temperature, salinity, and current.
Balloons and satellites are critical to providing NOAA’s atmospheric and large-area observations. Balloon-borne radiosondes and radar measure variables including temperature, precipitation, winds, humidity, and pressure from the surface to heights more than 10 miles above the Earth’s surface. Satellite observing systems observe weather systems for weather forecasting purposes, but they are also critical for monitoring climate by providing consistent and continuous coverage of regional and global areas.
Geostationary and polar orbiting satellites enhance on site measurements by observing unique variables and by extending coverage to areas not measured with sensors on location. They routinely capture information such as sea ice extent, glacier melting rates, sea level height and winds, global cloudiness, wildfires and vegetation health.
Monthly State of the Climate reports — These online reports place climate conditions for the past month or season into historical perspective using an array of observing systems combined with historical data from instrumental and paleoclimate sources. Each report includes analysis of the global and U.S. climate, global hazards and extremes, U.S. drought, and U.S. extremes.
Web-based analysis tool — Analyzes variability and change in monthly, seasonal, and annual temperature and precipitation, the U.S. Climate At A Glance Web site provides historical perspectives on today’s climate of the contiguous U.S., regions, states, and selected cities. An easy-to-use interface that includes mapping, graphing, and table displays of mean temperature and precipitation, as well as rankings and trend information, make this one of the most popular services for the past seven years.
U.S. records query tool — Provides easily access to new daily, monthly, and all-time maximum and minimum temperature records. In addition, weekly monitoring of hazards and extremes provides highlights of weather and climate events such as flooding, drought, heat waves, severe winter weather and tropical cyclones that affect societies around the world.
U.S. Drought Monitor — Provides continous updates of drought conditions across the 50 U.S. states and Puerto Rico. These organizations, along with Agriculture Agrifood Canada, Environment Canada, and the Meteorological Service of Mexico, provide monthly monitoring of drought conditions across the continent as part of the North American Drought Monitor program.
Each year, NOAA leads an effort in cooperation with the World Meteorological Organization (WMO) and scientists from over 30 countries to produce an annual State of the Climate Report. This effort is focused on transforming observations collected from the global array of observing systems into information that places today’s climate in historical context and provides information on trends and changes that affect societies and the environment.
The State of the Climate report uses integrated global Earth observations to monitor and enhance the understanding of climate variability and change. While many observing and analysis systems are unique to countries or regions of the world, through this effort the information from each system is openly shared and has proven essential to transitioning data to operational use and filling critical gaps in current knowledge about the state of the global climate system.