January 18, 2012
One of the key elements used in looking at the long-term climate change is the temperature on the Earth’s surface. Across the United States, thousands of weather stations are observing daily maximum and minimum temperatures, mostly by volunteers in the Cooperative Observer Program. NOAA’s National Climatic Data Center compiles all of the data from the late 1800s to today from a subset of those stations with long records to produce the long-term surface temperature record for the United States. But many things have changed since the 19th century – stations have moved, the type of thermometer has changed, and many observers have changed the time of day that observations are made. – These changes have impacted temperature measurements through time, but these impacts are unrelated to true climate change. NCDC scientists use a scientific method, called homogenization, to identify and account for these “artificial” elements that can affect the trend in the data. But how do we know that this method is working as intended?
A new paper recently published in the Journal of Geophysical Research-Atmospheres by Williams and colleagues re-evaluates the performance of a key data homogenization algorithm used in calculating the U.S. surface temperature record. In the paper, the researchers applied the algorithm to several simulated datasets that mimic the U.S. temperature record. In all but one of the datasets a known pattern of errors was inserted to simulate the kinds of artificial impacts that may have occurred in the real data. The scientists also created one dataset that was “perfect”. They created multiple estimates of the overall trend by running slight variants of the algorithm to see how much small changes in the algorithm affect the results. By applying the algorithm to the simulated datasets, they could also assess how well the algorithm accounted for the errors in situations where we know exactly what the true climate is.
The results of this analysis demonstrated that when the simulated data were “perfect”, the algorithm did not change the overall trend. However, in cases where errors caused the trend to be too large or too small, the algorithm moved the dataset in the correct direction, essentially taking out much of the pattern of errors and providing an answer closer to the true trend. It hardly ever overestimated the required change, but for hard cases with many small errors it tended to underestimate their impact on the overall trend. The same settings were applied to the real world observations and confirmed that the raw data show too little warming since 1895. “It is much more likely that the U.S. surface temperature record warming is underestimated than that it is overestimated, especially for maximum daily temperature,” according to Dr. Peter Thorne, Senior Scientist for the Cooperative Institute for Climate and Satellites-North Carolina.
By researching how the algorithm functions when we know exactly what the trend should be and how sensitive the trend is to reasonable algorithm variations, we now better understand the surface temperature trends in the United States.
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January 13, 2012
The 2012 Products & Services Guide has been completed. A free pdf copy of the guide is posted at http://www1.ncdc.noaa.gov/pub/data/inventories/2012psguide_hires19Mb.pdf. The National Climatic Data Center offers a wide range of products and services. A look at the guide will give a good overview of them. Hard copies of the guide are also available in the Online Store for purchase.
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January 13, 2012
Release of Updated Online Mapping Service
NCDC has release an updated version, Version 2.0, of its popular Climate Data Online service. Climate Data online or CDO provides access to climate data products through a simple, searchable online web mapping service. Users can find a variety of NCDC products via CDO including the Global Historical Climatology Network-Daily and the new 1981-2010 Annual, Monthly and Daily 30-year Normals. You can check out CDO at http://www.ncdc.noaa.gov/cdo-web/search
CDO v. 1.0 applications will continue to be available, however these will transition to the new system and be discontinued throughout 2012 as the products are replaced in the updated CDO program.
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December 20, 2011
Happy Holidays! This image depicts the historical probability (in percent) that a snow depth of at least 1 inch will be observed on December 25th. The map was based on the 30-year "normals" for ~2800 weather stations that had relatively complete records from 1981-2010. Station-level values were interpolated to a 5km grid. For specific forecast information for your area, check out www.weather.gov
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November 2, 2011
Tropical Cyclone Gonu, June 4, 2007 (courtesy of NASA)
For a tropical cyclone to strengthen, it needs both warm water temperatures and certain wind conditions in the atmosphere. While water temperatures in the Arabian Sea are typically warm enough to allow tropical cyclones to form, winds moving at different speeds and directions at different levels in the atmosphere, called wind shear, have limited the strengthening of cyclones in the region. However, according to new research by an international team of scientists, during the past 30 years, increased amounts of airborne particles, or aerosols, in South Asia have altered the pattern of the sun's heating of the ocean. This has changed the regional wind patterns and weakened the wind shear, making conditions more favorable for intense tropical cyclone development.
"We're showing that pollution from human activity as simple as burning wood or driving a vehicle with a diesel engine can actually change these massive atmospheric phenomena in a significant way," said study lead author Amato Evan, an assistant professor in the Department of Environmental Sciences at the University of Virginia. "It underscores the importance of getting a handle on emissions in the region."
The team of scientists used both observations and models to demonstrate the relationship between decreasing wind shear and the growth of the Atmospheric Brown Cloud, a thick layer of pollution over the North Indian Ocean caused by human emissions of aerosols like black carbon and sulfates. The team then linked the reduced wind shear to an increase in the number of highly intense storms with winds over 120 mph, including five storms since 1998 that have killed more than 3,500 people and caused damages of more than $6.5 billion.
"The research shows that pollution can threaten humans in unexpected ways. In this case, by reducing wind shear in the Arabian Sea and making conditions more favorable for tropical cyclones to intensify," according to James Kossin, climatologist at NCDC and co-author on the paper.
NOAA researchers and their colleagues are engaged in understanding and assessing changes in climate across many regions of the world since regional climate is influenced by global conditions and patterns. Lessons learned from studying tropical cyclones and their relationship to climate in various regions of the world, including the Indian Ocean, are relevant for improving understanding of hurricanes that directly threaten the United States.
The findings appear in a paper published tomorrow in the journal Nature titled "Arabian Sea tropical cyclones intensified by emissions of black carbon and other aerosols". The research was conducted by scientists from the University of Virginia, NOAA's National Climatic Data Center (NCDC) in Asheville, N.C., the Gwangju Institute of Science and Technology, Gwangju, South Korea and the Scripps Institution of Oceanography in La Jolla, Calif.
Press Release from Scripps Institution of Oceanography: (external website)
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September 14, 2011
NOAA's National Climatic Data Center now has a new service agreement in place, which will be handled through the Government Printing Office and covers completing the printing and distribution of the current subscriptions for each of the listed publications. As subscriptions expire, NCDC will not offer subscriptions renewals. Therefore, we encourage you to make use of our online access and subscriptions at www.ncdc.noaa.gov and the Hydrometeorological Prediction Center's website for access to Daily Weather Maps at http://www.hpc.ncep.noaa.gov/dwm/dwm.shtml. Customers may contact NCDC's User Engagement & Services Branch at 828-271-4800 option 2, for assistance with ordering online subscriptions or individual publications.
Publications to fill current subscriptions will be mailed out in 2 to 3 weeks. We are starting with the June 2011 Monthly Climatic Data for the World (MCDW). The next publications to be mailed will be the Hourly Precipitation Data (HPD), the Local Climatological Data (LCD), and then the Climatological Data(CD).
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August 24, 2011
Over recent decades, a scientific look at the temperature on the surface of the Earth has shown that surface temperatures are rising. But surface temperature is only one element of energy content in the lowest part of the atmosphere. Wind speed and humidity are two other types of energy on the Earth's surface that are factors when looking at what is going on with the climate on the ground. In a paper just published August 23, 2011 by the Geophysical Research Letters entitled "Observed Changes in Surface Atmospheric Energy over Land" (Peterson, et al., 2011), scientists at NOAA National Climatic Data Center, the U.K. Met Office, and the Cooperative Institute for Climate and Satellites-North Carolina, determined that in addition to surface temperature, humidity levels have also been increasing since 1973 and providing approximately equal contribution to increases in the heat content of the Earth. Increases in both temperature and humidity are also consistent with what we expect to see in a warming world. The paper quantifies how much energy the air is gaining, concluding that the bottom two meters of the atmosphere over land is gaining 1.9 x 1017 Joules of energy per decade.
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July 20, 2011
The new 30-year normals, released by the NCDC on July 1, 2011 will be used to compare daily climate conditions with recent records. The normals, based on data from 1981 through 2010, show that temperatures across the U.S. are about 0.5F warmer than last decade's normals. Some significant data includes maximum temperature, minimum temperature and monthly precipitation and snowfall statistics.
Check out information on the new normals here: http://www.ncdc.noaa.gov/oa/climate/normals/usnormals.html
How do normals affect gardening? Check out a story here:
http://www.climatewatch.noaa.gov/article/2011/the-new-climate-normals-gardeners-expect-warmer-nights-2
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July 20, 2011
NOAA, in coordination with the American Meteorological Society, released the 2010 State of the Climate Report. The in-depth report, written by more than 350 scientists from around the world, is peer-reviewed and includes detailed data regarding global climate information, as well as an in-depth analysis of the long-term and annual patterns which affected 2010 weather. The key climate patterns which affected 2010, such as the El Nino-Southern Oscillation, Arctic Oscillation and Southern Annual Mode, are clearly explained in the report. The full report, edited by NOAA's National Climatic Data Center, was published along with an easy-to-read highlights document on June 28, 2011.
The full report is available here: http://www.ncdc.noaa.gov/bams-state-of-the-climate
The Highlights document is available here: http://www.ncdc.noaa.gov/bams-state-of-the-climate
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June 21, 2011
The Earth experienced the tenth warmest May since record keeping began in 1880, as the climate phenomenon La Nina ended its 2011 cycle. Last month's combined global land and ocean average surface temperature was the 10th warmest on record for May at 59.50F (15.30 C), which is 0.90 F (0.50 C) above the 20th century average of 58.6 F (14.8 C). The margin of error associated with this temperature is +/- 0.13 F (0.07 C). Northern Hemisphere snow cover extent during May was much-below average, ranking as the third smallest on record. The Arctic sea ice extent was the third smallest extent for May on record.
View the full report at: http://www.ncdc.noaa.gov/sotc/global/2011/5 and the press release at: http://www.noaanews.noaa.gov/stories2011/20110615_globalstats.html
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June 15, 2011
Effective July 1, 2011, NOAA's National Data Centers will not accept checks (nor money orders) in payment for orders. Prepayment is required and the accepted forms of payment are Visa, MasterCard, American Express, Discover, wire transfers and Automated Clearing House. Please refer to the NNDC Non-Federal Customer Payment Policy for additional information.
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June 13, 2011
In May 2011, the contiguous United States had dramatic shifts in regional temperatures, but overall May was slightly cooler and wetter than normal. The spring was marked by record moisture in the Northwest and the Ohio River Valley, while drought conditions intensified across the South. The full U.S State of the Climate report can be viewed here:
www.ncdc.noaa.gov/sotc/national/2011/5
NCDC also published a Special Report highlighting the Climate Extremes that have occurred in the United States this spring. Tornadoes, flooding, drought, and wildfires ravaged many parts of the country during the period, and each of these extremes broke long-standing records and have been compared to the 'worst such cases' in history. While similar extremes have occurred throughout modern American history, never before have they occurred in a single month. You can read the report at :
www.ncdc.noaa.gov/special-reports/2011-spring-extremes/index.php
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May 26, 2011
The Earth experienced the seventh warmest April since record keeping began in 1880, as the climate phenomenon La Nina continued to be a significant factor. April's annual Arctic sea ice extent was the fifth smallest since record keeping began in 1979, while the Antarctic sea ice extent was the fourth smallest. The combined global land and ocean average surface temperature for April 2011 was the seventh warmest on record at 57.76 F (14.29 C), which is 1.06 F (0.59 C) above the 20th century average of 56.7 F (13.7 C). The margin of error associated with this temperature is +/- 0.13 F (0.07 C).
View the full report at: www.ncdc.noaa.gov/sotc/global/2011/4 and the press release at:
www.noaanews.noaa.gov/stories2011/20110516_globalstats.html
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May 12, 2011
Historic flooding, a record-breaking tornado outbreak and devastating wildfire activity made April 2011 a month of historic climate extremes across much of the United States. The average U.S. temperature in April was 52.9 degrees F, which is 0.9 degrees F above the long-term (1901-2000) average. April precipitation was 0.7 inches above the long-term average, the 10th wettest April on record. This monthly analysis, based on records dating back to 1895, is part of the suite of climate services NOAA provides.
The Full Report can be viewed here:
www.ncdc.noaa.gov/sotc/national/2011/4
The NOAA press release can be viewed here:
www.noaanews.noaa.gov/stories2011/20110509_aprilstats.html
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 NCDC Scientist receives the Arthur S. Flemming Award
May 03, 2011
Dr. Kenneth R. Knapp, a scientist at NOAA's National Climatic Data Center, will receive the 2010
Arthur S. Flemming Award for his outstanding public service in the area of applied science.
For the past sixty-one years, the Arthur S. Flemming Awards have recognized outstanding men and women in the federal government. The awards were established in 1948 in honor of Arthur Flemming's commitment to public service throughout his distinguished career, which spanned seven decades and 11 presidencies. Recognized by the President of the United States, agency heads, and the private sector, the winners are selected from all areas of the federal service. The George Washington University and the Arthur S. Flemming Awards Commission present a total of twelve awards annually in three categories: Applied Science, Engineering and Mathematics; Research; and Managerial or Legal Achievement.
Dr. Knapp is receiving the Arthur S. Flemming Award for his pioneering development of new climate-related products and tools based on long-term satellite observations of the Earth's atmosphere. His development of Climate Data Records (CDRs) directly promoted a better and more comprehensive understanding of the Earth's climate system and enabled the scientific community to use his work as a basis to conduct other, more expansive research. Dr. Knapp's ground-breaking work set a baseline for developing other CDRs and far surpassed the common challenges associated with transitioning research products into operational ones.
Dr. Knapp will be formally honored in a ceremony at The George Washington University in early June.
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March 23, 2011
Effective March 11, 2011, the Summary of the Day, 3200/FTP Subscription product was discontinued, as major changes were implemented to the Summary of the Day/3200 dataset. Beginning with the January 2011 data month, the existing 3200/FTP product data (containing 3200, 3201, 3202, 3206) in the ftp3 area has been replaced with the Global Historical Climatology Network-Daily (GHCN-D) data. All users will have access to directories for ftp/ghcn/ and ftp3/3200 & 3210/ data at no charge. For more detailed information on the transition of the 3200 FTP Subscription data, please see ftp://ftp3.ncdc.noaa.gov/pub/data/3200/IMPORTANTINFO.pdf. The GHCN-D web site at http://www.ncdc.noaa.gov/oa/climate/ghcn-daily/ provides detailed information on the dataset.
In the next few months, the Surface Data, Daily (3200/3210/3205/3206) accessed via the Climate Data Online (CDO) system will be replaced with the GHCN-D dataset. Additionally, a new interface for the Climate Data Online (CDO) system will include Dynamic maps and many more updates and features. More information on these improvements will be coming in the next few weeks.
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February 16, 2011
The Billion Dollar U.S. Weather Disasters page is now updated through 2010 with graphs and narratives describing the most costly weather-related tragedies for years back to 1980. This is a great resource for comparing individual years within this range or for researching particular events.
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February 1, 2011
Groundhog Day 2011 Special Report is now available. Every February 2, our attention turns to Punxsutawney Phil for a furry insight to the end of winter. Take a look at Phil's forecasting record along with comparisons to NCDC data, and learn about the folklore behind this tradition. Check NOAA's NCDC Groundhog Day website to see.
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January 20, 2011
The 2011 Products & Services Guide has been completed. A free pdf copy of the guide is posted at http://www1.ncdc.noaa.gov/pub/data/inventories/2011psguide.pdf. The National Climatic Data Center offers a wide range of products and services. A look at the guide will give a good overview of them. Hard copies of the guide are also available in the Online Store for purchase.
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