RESEARCH POSTER PRESENTATION DESIGN © 2015 www.PosterPresentations.com RAN2 Summary & Remaining Work 1. NOAA STAR, 2. GST Inc. Olafur Jonasson1,2, Alexander Ignatov1 ACSPO VIIRS SST Reanalysis 2 (RAN2) GHRSST XX Science Team Meeting, Frascati, Italy, June 3-7, 2019 olafur.jonasson@noaa.gov Acknowledgement. This work is supported by the NOAA JPSS program. Thank to M. Goldberg, L. Gumley, S. Dutcher, J. Stroup for setting up and conducting SNPP ACSPO RAN1. We thank our SST colleagues Y. Kihai, B. Petrenko, M. Pennybacker, I. Gladkova for help. We thank Edward Armstrong and Wen-Hao Li for assistance with archival at PO.DAAC. The views, opinions, and findings in this report are those of the authors and should not be construed as an official NOAA or U.S. government position or policy. Background & Objectives of VIIRS SST Reanalyses (RANs) • Suomi NPP launched 28 Oct 2011; Cryoradiator door opened 18 Jan 2012. • N20 (aka “J1”) launched 18 Nov 2017; Cryoradiator door opened 3 Jan 2018. • VIIRS SST produced 1-2 days after opening the cryoradiator doors using NOAA Advanced Clear Sky Processor for Ocean (ACSPO) enterprise system. • This poster summarizes SST Reanalysis 2 (RAN2), from NPP & N20. • L2P (swath) & L3U (0.02º; gridded) data reported in 10-min granules (144/day). • Regression (‘sub-skin’) SST & SSES (used to derive ‘depth’ SST) are reported. • Cal/Val is performed using match-ups with in situ data from NOAA in situ SST Quality Monitor (iQuam; www.star.nesdis.noaa.gov/sod/sst/iquam) • Quality Control and Cal/Val statistics are published in the NOAA SST Quality Analysis Monitor (SQUAM; www.star.nesdis.noaa.gov/sod/sst/squam) • ACSPO Regional Monitor for SST (www.star.nesdis.noaa.gov/sod/sst/arms/; ARMS) monitors regional performance of VIIRS SST imagery, and compares it with other polar AVHRR/MODIS and geostationary ABI/AHI SST products. • Monitoring IR Clear-sky Radiances (www.star.nesdis.noaa.gov/sod/sst/micros/; MICROS) compares measured brightness temperatures (BTs) in VIIRS SST bands to simulations using the Community Radiative Transfer Model (CRTM) • Data in GDS2 format archived in NASA PO.DAAC & NOAA CoastWatch/NCEI. VIIRS SST Reanalysis 1 (RAN1; NPP only) • RAN1 was performed in 2015 in conjunction with U. Wisconsin CSPP Team, using ACSPO v2.40, and covered a period from Mar’2012-Dec’2015. Period from Dec’2015-on was supplemented from NRT processing (ACSPO v2.41/2.60/2.61). • Results of NPP RAN1 are available on the NOAA CW website. Its monitoring was included in SQUAM and MICROS. • Fig. 1 show results of validation of RAN1 ‘sub-skin’ and ‘depth’ L2P SSTs vs. iQuam in situ SSTs (drifters + tropical moorings). Each point represents 24hr global statistics. Statistics for the full period are summarized in Table 1. • Global mean biases ‘Sub-skin minus in situ SST’ and ‘Depth minus in situ SST’ in Figs. 1a-b are fairly stable in time, with residual seasonal variations up to ~0.1 K (more during the daytime, likely due to increased skin-depth SST difference). • The standard deviations are larger for ‘sub-skin’ SST (Fig. 1c), especially during the daytime, due to increased skin-depth differences. The standard deviations and day-night differences, are reduced for ‘depth’ SST (shown in Fig. 1d). Figure 1. Daily statistics of global (a-b) mean biases and (c-d) standard deviations (SDs) of ACSPO L2P minus iQuam SSTs. From mid-Dec’2015 – Apr’2019, NPP RAN1 (Mar’2012 – mid-Dec’2015) is supplemented by operational data. (Left) Global Regression (GR; proxy for ‘sub-skin’ SST); (right) Piece-Wise Regression (PWR; proxy for ‘depth’ SST). RAN1 (NPP) L2P (‘sub-skin’) L3U (‘sub-skin’) L2P (‘depth’) L3U (‘depth’) Bias (night) [K] +0.029 +0.045 +0.012 +0.017 Bias (day) [K] +0.014 +0.009 +0.032 +0.027 SD (night) [K] 0.32 0.32 0.27 0.27 SD (day) [K] 0.39 0.39 0.30 0.30 Table 1: NPP VIIRS RAN1 SST biases and standard deviations (SD) from 1 Mar 2012 – 30 Apr 2019. “L2P ‘sub-skin’ minus in situ” statistics are from Fig. 1a,c and “L2P ‘depth’ minus