NOAA National Environmental Satellite, Data, and Information Service National Climatic Data Center, U.S. Department of Commerce
NOAA Paleoclimatology Program, NCDC Paleoclimatology Branch  
Paleoclimatology Navigation Bar Bookmark and Share
NOAA National Environmental Satellite, Data, and Information Service National Oceanic and Atmospheric Administration NOAA National Climatic Data Center U.S. Department of Commerce Paleo Home Data Paleo Projects Paleo Perspectives Education and Outreach About Paleo Program Site Map
Data Access Tutorial Glossary About CTL CTL Site Map
CTL Overview white space
Today white space
1 Year white space
10 Years white space
100 Years white space
1,000 Years white space
10,000 Years white space
100,000 Years white space

white space

RESOURCES: 100 Year Time Scale
Do Sunspots Influence Climate


Here are a number of online resources about climate forces that relate to theImage of PDO positive phrasedecadal to centennial time scale as well as climate events that have occurred during the past 100 years.

Pacific Decadal Oscillation

The Pacific Decadal Oscillation (PDO) Overview of PDO from the University of Washington

The Pacific Decadal Oscillation (PDO) from NASA/JPL

North Pacific Decadal Climate Variability Since AD 1661 from NOAA Paleoclimatology Program- Biondi, et. al.

See overview on PDO by Mantua for more.

North Atlantic Oscillation

Lamont-Doherty Earth Observatory NAO website provides an overview of research being conducted on NAO.

Significant Floods in the United States During the 20th Century from USGS.

Global Warming & Climate Change
Exploratorium Global Climate Change Researcher_Explorer offers a variety of tools and tutorials on data analysis.

EPA Global Warming Website contains a wealth of information on the human dimension to climate change and anthropogenic forcing.

How Often Does a 100 Year Flood Occur?
Image of flood damage on South Boulder Creek
Photo of 1938 flood on South Boulder Creek from Denver Public Library.

When experts talk about a "100 year flood" or a "500 year event," they don't actually mean that the event-- whether it is a flood or a severe storm-- will happen once every 100 years or 500 years. Rather, it is a statistical way of expressing the probability of something happening in any given year.

A "100 year" storm event has a one in one hundred or 1% chance of happening in any given year. A "500 year" event has a one in five hundred or .2% chance of happening in any year. In the United States, the Federal Emergency Management Agency, FEMA has established the Federal Flood Insurance Program to protect homeowners and businesses against the risk of floods that cause billions of dollar of damage every year. Flood maps have been developed for communities throughout the nation indicating where the "100 year" and "500 year" floodplains are located, and citizens who live in the 100 year zone must pay flood insurance.

Paleoclimatic records may allow us to provide better calculations of the probability of 100 year and 500 year events in the future.

But exactly how the flood zones are calculated can be a matter of controversy since weather records of severe storms are limited primarily to the past century, which may not be representative of long-term climate patterns. Also, there are many variables involved with surveying and mapping out where floods are likely to occur and modeling the hydrology of a particular drainage.

Make your own Online Hazards Map, including flood maps from the ESRI/FEMA website.

Do Sunspots Influence Climate?
Annual Sunspots Numbers- 1700-1995 from NGDCOne measure of solar activity is to record the activity of sunspots. Every 11.1 years the sun cycles between its "solar maximum" and "solar minimum". During solar maximum there are increased numbers of solar flares, and sunspots-- vortices of gases on the surface of the Sun associated with strong local magnetic activity. These forces can affect communications and weather here on Earth. During the solar minimum there are fewer such events.

While exactly how sunspots and related activity impact climate has yet to be fully understood, many scientists, including Galileo, Rudolph Wolf of the Zurich Observatory, and A.E. Douglas, who helped establish the science of dendrochronology and founded the tree ring laboratory at the University of Arizona, have been interested in the role of sunspots on the Earth's dynamic environmental systems. For more, see
Sunspot Numbers at NGDCat NGDC's Solar Terrestrial Physics Lab and the online exhibit at Exploratorium Sunspots.

Dividing Line
Privacy Policy information User Survey link First Gov logo Disclaimer information
Dividing Line
Downloaded Tuesday, 17-Jan-2017 12:07:04 EST
Last Updated Wednesday, 03-Oct-2012 12:37:12 EDT by
Please see the Paleoclimatology Contact Page or the NCDC Contact Page if you have questions or comments.