G02168 Timing and Statistics of Autumn and Spring Annual Snow Cover for the Northern Hemisphere Dye, D. Timing and Statistics of Autumn and Spring Annual Snow Cover for the Northern Hemisphere 2005-12-21 Boulder, Colorado USA NSIDC: National Snow and Ice Data Center http://nsidc.org/data/g02168.html http://dx.doi.org/10.7265/N5F18WNC Investigator Dennis Dye 81 45-778-5594 81 45-778-5706

Frontier Research Center for Global Change

Group Leader, Ecosystem Change Research Program

Yokohama Japan Investigator Dennis Dye 81 45-778-5594 81 45-778-5706

Frontier Research Center for Global Change

Group Leader, Ecosystem Change Research Program

Yokohama Japan Technical Contact NSIDC User Services nsidc@nsidc.org 1 303 492-6199 x 1 303 492-2468 x

National Snow and Ice Data Center

CIRES, 449 UCB

University of Colorado

Boulder CO 80309-0449 USA EARTH SCIENCE Cryosphere Snow/Ice Snow Cover Duration, Timing EARTH SCIENCE Terrestrial Hydrosphere Snow/Ice Snow Cover Duration, Timing Climatology/Meteorology/Atmosphere NOAA Northern Hemisphere NSIDC > National Snow and Ice Data Center AVHRR Advanced Very High Resolution Radiometer GOES I-M IMAGER SSM/I Special Sensor Microwave/Imager DMSP Defense Meteorological Satellite Program GEOSTATIONARY SATELLITES GROUND-BASED OBSERVATIONS NOAA POES NOAA Polar Orbiting Environmental Satellites SATELLITES 1972-01-01 2000-12-31 complete 0 90 -180 180 GEOGRAPHIC REGION NORTHERN HEMISPHERE By inspecting visible band satellite imagery, analysts from the NOAA Office of Satellite Data Processing and Distribution (OSDPD), Satellite Services Division (SSD), Satellite Analysis Branch (SAB), produced an analogue Northern Hemisphere snow/ice map. (More recently, production of this product has taken place in a digital environment. (See IMS Daily Northern Hemisphere Snow and Ice Analysis at 4 km and 24 km Resolution and NOAA Operational Daily Snow Cover Analysis pages at http://nsidc.org for more information.) The weekly version of this product is the basis for the subject data set. Studies cited in Dye (2002) note that the NOAA snow charts have limitations because they are created using visible band imagery. For example, the snow cover can be difficult to detect due to 'low solar illumination and high solar zenith angles, dense forest cover and cloud cover'. According to Dye, these limitations reduce the reliability of the data set more significantly for local or regional scale studies than for global analyses. This study did not incorporate direct validation techniques, because there is not a practical way to validate broad scale estimates of snow-covered area. Instead, the author used the relationship between the snow cover cycle and the snow-covered area as an alternative method for assessing validity of the data, stating that 'a strong correlation between interannual fluctuations in SCA [snow covered area] and WLS, WFS and DSF can provide additional confidence in results from the snow-cover cycle analysis.' See Dye (2002) for more information. The NOAA snow product has been widely used in climate studies, but it is important to note that it is an operational product. That is, it is produced in near real time to meet operational needs, and may have inconstancies that render it unsuitable for climatological studies. Work done at the Rutgers University Climate Laboratory Global Snow Lab addresses these inconsistencies. English NSIDC_NOAA NSIDC National Snow and Ice Data Center http://nsidc.org Data Center Contact NSIDC User Services nsidc@nsidc.org 1 303 492-6199 1 303 492-2468

National Snow and Ice Data Center

CIRES, 449 UCB

University of Colorado

Boulder CO 80309-0449 USA NSIDC_NOAA NSIDC National Oceanic and Atmospheric Administration http://nsidc.org/noaa/ Data Center Contact NSIDC NOAA User Services nsidc@nsidc.org 1 303 492-6199 1 303 492-2468

National Snow and Ice Data Center

CIRES, 449 UCB

University of Colorado

Boulder CO 80309-0449 USA FTP 40 KB Binary FTP 951 KB ASCII Text Dye, D.G. 2002. Variability and trends in the annual snow-cover cycle in Northern Hemisphere land areas, 1972-2000. Hydrological Processes 16: 3065-3077. Robinson, D.A., Dewey, K.F., and R.R. Heim Jr. 1993. Global snow cover monitoring: an update. Bulletin of the American Meteorological Society 74: 1689-1696. Robinson, D.A. Frei, A. and M. C. Serreze. 1995. Recent variations and regional relationships in Northern Hemisphere snow cover. Annals of Glaciology 21:71-76.

The National Snow and Ice Data Center hosts a time-series data set comprising annual snow cover data for the Northern Hemisphere (covering land primarily over 45 degrees North) from 1972 to 2000. Data are presented for land areas that exhibited snow cover in each of the 29 years. Variables are the week of snow disappearance, the week of snow cover onset, and the duration of the snow-free period. These variables were derived from operational NOAA weekly snow cover charts that have been quality controlled by the Rutgers University Global Snow Lab. For each year of the 29-year period, there are three binary files with data in an 89 x 89 cell grid. The week of the first detected snow cover in the fall is included in the WFS file, the week of the last observed snow cover in the spring is given in the WLS file, and the duration of snow-free period in weeks is given in the DSF file. Data are also provided in ASCII format summary files. In addition, summary statistics for each parameter are provided. These are grids of the mean and the standard deviation for the three parameters. Gridded latitude and longitude files are also included with this data set.

VIEW PROJECT HOME PAGE http://climate.rutgers.edu/snowcover/ Rutgers University Global Snow Lab VIEW RELATED INFORMATION http://nsidc.org/data/g02156.html IMS Daily Northern Hemisphere Snow and Ice Analysis at 4 km and 24 km Resolutio VIEW RELATED INFORMATION http://nsidc.org/data/g02156.html IMS Daily Northern Hemisphere Snow and Ice Analysis at 4 km and 24 km Resolution VIEW RELATED INFORMATION http://nsidc.org/data/nsidc-0046.html Northern Hemisphere EASE-Grid Weekly Snow Cover and Sea Ice Extent Version 3 CEOS IDN DIF 9.7 2005-12-21 2013-03-25 Fixed broken data access link.