OMI L 2 G and L 3 Status

OMI L 2 G and L 3 Status Peter Leonard – OSST June 21, 2006

OMTO 3 e (0. 25 o x 0. 25 o) Total Column Ozone for September 30, 2005

OMTO 3 e (0. 25 o x 0. 25 o) Reflectivity at 331 nm for September 30, 2005

OMTO 3 e (0. 25 o x 0. 25 o) UV Aerosol Index for September 30, 2005

Status of L 2 G and L 3 PGEs PGE OMTO 3 G OMCLDRRG OMNO 2 G OMAERUVG OMDOAO 3 G OMCLDO 2 G OMTO 3 d OMTO 3 e Description L 2 G for OMTO 3 L 2 G for OMCLDRR L 2 G for OMNO 2 L 2 G for OMAERUV L 2 G for OMDOAO 3 L 2 G for OMCLDO 2 L 3 for OMTO 3 (1. 25 o x 1. 00 o) L 3 e for OMTO 3 (0. 25 o x 0. 25 o) Status In Production In Test SIPS In Production Ready for Production

OMI L 2 G Products • The “G” in L 2 G represents “Gridded”. • Each OMI L 2 G product file contains 24 UTC hours of L 2 data subsetted onto 0. 25 o x 0. 25 o longitude-latitude grid. • Most L 2 G data and geolocation fields are threedimensional: longitude, latitude, and candidate number. • Each L 2 G grid cell contains as many as twelve L 2 observations with centers in grid cell, ordered in time. • L 2 G data are not averaged or weighted in any way. • Can reproduce L 2 swath product files from L 2 G files. • L 2 G products follow “Definitions of OMI Grids for Level 3 and Level 4 Data Products” by Pepijn Veefkind et al. • L 2 G products follows “HDF-EOS Aura File Format Guidelines” by Cheryl Craig et al.

OMI L 2 G Products (Continued) • L 2 G product files are in HDF-EOS 5 grid format. • L 2 G product files contain required HDF-EOS 5 Metadata. • Geolocation and data fields are gzip internally compressed (done via HDF-EOS 5 function calls). • L 2 G product files also contain complete suite of ECS Metadata. • OMTO 3 G, OMCLDRRG, OMNO 2 G and OMAERUVG PGEs are in production. • OMDOAO 3 G and OMCLDO 2 G PGEs are in Test SIPS. • Is there any demand for OMBROG, OMHCHOG, OMOCLOG, OMSAO 3 G and/or OMSO 2 G products?

OMTO 3 d Product • OMTO 3 d is classic TOMS-like Level 3 product (the “Mc. Peters” Product) based on OMTO 3 L 2 product. • The “d” in OMTO 3 d represents “daily”. • Geographic Projection with 1. 25 o x 1. 00 o longitudelatitude grid. • Same calendar date on ground for all L 3 grid cells. • Resulting map is continuous cylinder. • Each OMTO 3 d product file is generated from three consecutive OMTO 3 G product files. • Need final orbit (or two) from previous UTC day and first orbit (or two) from next UTC day to complete map, since each L 2 G file contains data from three calendar dates on ground.

OMTO 3 d (1. 25 o x 1. 00 o) 08/07/05 on Ground 08/06/05 on Ground 08/05/05 on Ground

OMTO 3 d Product (Continued) • OMTO 3 d PGE produces total ozone, reflectivity at 331 nm, and UV aerosol index product files in classic TOMS Level 3 ASCII format. • OMTO 3 d product files are used to generate maps displayed on TOMS Web Site.

http: //toms. gsfc. nasa. gov/

OMTO 3 e Product • OMTO 3 e is high-resolution “Mc. Peters” Product. • The “e” in OMTO 3 e represents “expanded”. • Geographic projection with 0. 25 o x 0. 25 o longitudelatitude grid. • Each L 3 e grid cell is populated with L 2 observation that has shortest path length [ = 1/cosine(solar zenith angle) + 1/cosine(viewing zenith angle) ]. • Same calendar date on ground for all L 3 e grid cells. • Resulting map is continuous cylinder. • Each OMTO 3 e product file is generated from three consecutive OMTO 3 G product files. • Need final orbits from previous UTC day and first orbits from next UTC day to complete map, since each L 2 G file contains data from three calendar dates on ground.

OMTO 3 e Product (Continued) • Classic TOMS-like Level 3 tessellation scheme adopted. • Total ozone, reflectivity at 331 nm, and UV aerosol index product files in classic TOMS Level 3 ASCII format. • OMTO 3 e ASCII product files are 20 times larger in size than OMTO 3 d product files. • OMTO 3 e PGE also produces single HDF-EOS 5 product file for each day containing above three fields. • L 3 e HDF-EOS 5 product files follow “Definitions of OMI Grids for Level 3 and Level 4 Data Products” by Pepijn Veefkind et al. • L 3 e HDF-EOS 5 product files follow “HDF-EOS Aura File Format Guidelines” by Cheryl Craig et al. • L 3 e HDF-EOS 5 product contains required HDF-EOS 5 Metadata, but does not contain any ECS Metadata.

OMTO 3 e (0. 25 o x 0. 25 o) Total Column Ozone for October 31, 2005

Other OMI L 3 Products • Jerry Ziemke (GSFC & UMBC) is creating MLS/OMI Tropospheric O 3 L 3 product. • Mark Wenig (GSFC & NRC) is creating OMI NO 2 L 3 product. • Thomas Kurosu (SAO) may be working on OMI Br. O, HCHO and OCl. O L 3 products. • Nick Krotkov et al. (UMBC) may be working on OMI SO 2 L 3 product. • Help is available from OSST for creation of L 3 e or L 3 products.

MLS/OMI Tropospheric Ozone L 3 (0. 25 o x 0. 25 o) Jerry Ziemke – GSFC & UMBC