NEPHELOMETER CD-ROM README FILE - APRIL 2001 (04/26 @ 0910) This CD contains hourly nephelometer-based visibility data from all sites in the IMPROVE visibility monitoring network. It also contains additional nephelometer data collected by Air Resource Specialists, Inc.(ARS) through contracts with the United States Forest Service(USFS), Arizona Department of Environmental Quality(ADEQ), Tahoe Regional Planning Agency(TRPA), Green River Basin Visibility Study(GRVS), and the Colorado Department of Public Health and Environment (CDPHE). All IMPROVE data files are included in the "IMPROVE" directory. ADEQ and USFS datafiles are included in directories labeled "ADEQ" and USFS". TRPA, GRVS, and CDPHE data files are in the directory labeled "SPECIALS". *************************************************************************************************** REVIEW OF NEPHELOMETER DATA PROCESSING The Optec NGN-2 ambient nephelometer was introduced into the IMPROVE network in 1993. IMPROVE Protocol (or equivalent) sites have operated the NGN-2 for many years as well. As the IMPROVE contractor for optical monitoring, ARS developed software for nephelometer data collection, processing, validation, and reporting. In March, 2001, ARS completed an extensive six-month review of this software. The purpose of this review was: - To evaluate whether exixting algorithms best accomplish data processing and validation goals. - To identify and correct past and existing errors. - To prepare an up-to-date nephelometer data set for all IMPROVE and IMPROVE protocol sites. ARS has prepared a summary document describing the changes and corrections resulting from this this review, their effects on the nephelometer data, and providing an analysis of the relative significance of these changes. This document is titled "Review of Nephelometer Data Processing" and is included in the "Readme(neph)" folder on this CD. *************************************************************************************************** DATA FILE FORMAT KEY The data file format key for all nephelometer data files is included in the "Readme(neph)" folder on this CD and is available in: - MS Word format (nephkeyApr2001.doc) - Adobe Acrobat format (nephkeyApr2001.pdf) - Text only (nephkeyApr2001.txt) There are two (2) changes to the nephelometer data format: - The 4-character site abbreviation code has been converted to a 5-character format(4-character alpha and 1-character numeric code) consistent with the current IMPROVE Aerosol Sampler site abbreviation scheme. - Nephelometer sites that are relocated within the same area after initial installation will use the original 4-character alpha site abbreviation code with a new numeric code. Data collected at the initial location has a "1" in the site abbreviation code. Data collected after relocation has a "2" in the site abbreviation code. For example, the nephelometer site at Mammoth Cave NP was relocated on July 23, 1997. Data collected from the original site had a site abbreviation code of "MACA1". Data collected after July 23, 1997 have a site abbreviation code of "MACA2". *************************************************************************************************** FILE NAMING CONVENTIONS Seasonal data files are named XXXXX_N11.YYS, where XXXXX is the site abbreviation, YY is the year, and S is the meteorological season: - 1 = Winter (December, January, and February) - 2 = Spring (March, April, and May) - 3 = Summer (June, July, and August) - 4 = Fall (September, October, and November) For example, MACA2_n11.981 contains Mammoth Cave National Park nephelometer data for the period December 1, 1997 through February 28, 1998. The average size of a seasonal nephelometer file file is 445 Kb. LIST OF SITE NAMES AND DATES OF OPERATION *************************************************************************************************** ----------------------- IMPROVE Nephelometer Sites ------------------------- Site Name Abbr. First Data Last Data Acadia NP ACAD1* Summer 1995 Winter 1998 (Relocated December 8, 1997) ACAD2 Winter 1998 Fall 2000 Big Bend NP BIBE1 Winter 1998 Fall 2000 Boundary Waters Canoe Area W BOWA1* Spring 1993 Fall 1997 Dolly Sods W DOSO1* Spring 1993 Fall 1997 Edwin B. Forsythe NWR EBFO1* Spring 1993 Spring 1994 Great Smoky Mountains NP GRSM1 Spring 1993 Fall 2000 Grand Canyon NP HANC1 Winter 1998 Fall 2000 Jarbidge W JARB1* Spring 1993 Fall 1997 Mammoth Cave NP MACA1* Spring 1993 Summer 1997 (Relocated July 23, 1997) MACA2 Summer 1997 Fall 2000 Mount Rainer NP MORA1 Winter 1993 Fall 2000 Okefenokee NWR OKEF1* Winter 1993 Summer 1997 Shenandoah NP SHEN1 Fall 1996 Fall 2000 Upper Buffalo W UPBU1* Winter 1993 Fall 1997 Virgin Islands NP VIIS1 Spring 1998 Fall 2000 ----------------- U.S. Forest Service Nephelometer Sites ------------------- Site Name Abbr. First Data Last Data Columbia River Gorge NSA CORI1* Fall 1993 Spring 2000 Gila W GICL1 Spring 1994 Fall 2000 Great Gulf W GRGU1 Summer Only (1995 - 2000) Lone Peak W LOPE1 Fall 1993 Fall 2000 Lye Brook W LYBR1 Summer Only (1993 - 2000) Mount Zirkel Wilderness MOZI1* Fall 1993 Summer 1994 (Relocated July 27, 1994) MOZI2 Summer 1994 Fall 2000 Shining Rock W SHRO1* Summer 1994 Fall 1999 Snoqualamie Pass(Alpine Lakes W) SNPA1 Fall 1993 Fall 2000 Three Sisters W THSI1 Fall 1993 Fall 2000 ------------------------- ADEQ Nephelometer Sites -------------------------- Site Name Abbr. Location First Data Last Data Humbolt Mountain HUMB1 Pine Mountain W Spring 1997 Fall 2000 Mount Ord MAZA1* Mazatzal W Spring 1997 Summer 2000 McFadden Peak MCFD1* Sierra Ancha W Fall 1997 Winter 2000 Muleshoe Ranch MUSR1 Galiuro W Summer 1997 Fall 2000 Phoenix Supersite PHON1 Phoenix Spring 1997 Fall 2000 Rucker Canyon RUCA1 Chiricahua W Fall 1997 Fall 2000 Sierra Ancha SIAN1 Sierra Ancha W Summer 2000 Fall 2000 Sycamore Canyon SYCA1 Sycamore Canyon W Summer 1998 Fall 2000 Tucson Central TUCN1 Tucson Spring 1997 Fall 2000 Tucson Mountain TUMO1 Saguaro NP Winter 1997 Fall 2000 --------------------------- Special Nephelometer Sites --------------------------------- Sponsoring Site Name Abbr. Location First Data Last Data Agency Lake Tahoe Blvd. LTBV1 South Lake Tahoe, CA Spring 1996 Fall 2000 TRPA Bliss State Park BLIS1 South Lake Tahoe, CA Fall 1996 Fall 2000 TRPA Fort Collins AFTC1 Fort Collins, CO Fall 1994 Fall 2000 CDPHE Green River Basin GRVS1* Green River, WY Summer 1996 Fall 2000 GRVS * - Identifies nephelometer sites that are no longer in operation.