Extended Reconstructed Sea Surface Temperature, Version 5 (ERSSTv5): Upgrades, Validations, and Intercomparisons

Abstract

The monthly global 28 3 28 Extended Reconstructed Sea Surface Temperature (ERSST) has been revised and updated from version 4 to version 5. This update incorporates a new release of ICOADS release 3.0 (R3.0), a decade of near-surface data from Argo floats, and a new estimate of centennial sea ice from HadISST2. A number of choices in aspects of quality control, bias adjustment, and interpolation have been substantively revised. The resulting ERSST estimates have more realistic spatiotemporal variations, better representation of high-latitude SSTs, and ship SST biases are now calculated relative to more accurate buoy measurements, while the global long-term trend remains about the same. Progressive experiments have been undertaken to highlight the effects of each change in data source and analysis technique upon the final product. The reconstructed SST is systematically decreased by 0.0778C, as the reference data source is switched from ship SST in ERSSTv4 to modern buoy SST in ERSSTv5. Furthermore, high-latitude SSTs are decreased by 0.18-0.28C by using sea ice concentration from HadISST2 over HadISST1. Changes arising from remaining innovations are mostly important at small space and time scales, primarily having an impact where and when input observations are sparse. Cross validations and verifications with independent modern observations show that the updates incorporated in ERSSTv5 have improved the representation of spatial variability over the global oceans, the magnitude of El Niño and La Niña events, and the decadal nature of SST changes over 1930s-40s when observation instruments changed rapidly. Both long-(1900Both long-( -2015 and short-term (2000-15) SST trends in ERSSTv5 remain significant as in ERSSTv4.

The salience of nonlinearities in the boreal winter response to ENSO: North Pacific and North America

“…ENSO events are identified based on the November through February (NDJF) seasonal mean SST anomalies in the ERSSTv5 dataset (Huang et al 2017) with a 1981-2010 base period. EN events are identified when SST anomalies in the Niño3.4 region (5S-5N, 170W-120W), are larger than 0.5 K, and LN events are identified when SST anomalies in this region are more negative than − 0.5 K. EN and LN events are further categorized into four groups similar to Hurwitz et al (2014): Eastern Pacific (EP) EN, characterized by positive SST anomalies in the Niño-3 region (5S-5N, 210E-270E), and Central Pacific (CP) EN, characterized by positive SST anomalies in the Niño-4 region (5S-5N, 160E-210E), as well as EP and CP LN events, characterized by negative SST anomalies in the same two regions.…”

FAIR v1.3: a simple emissions-based impulse response and carbon cycle model

“…Historical temperatures were also constrained using the Had-CRUT4 dataset without infilling (Morice et al, 2012), along with the GISTEMP (Hansen et al, 2010), Berkeley Earth (Berkeley Earth, 2017) and NOAA (Zhang et al, 2017) observational datasets. The linear 1880-2016 trends are 0.91 ± 0.18 K, 0.99±0.22 K, 1.07±0.16 K and 0.93±0.24 K respectively.…”

Assessing the Pattern Differences between Satellite-Observed Upper Tropospheric Humidity and Total Column Water Vapor during Major El Niño Events

“…The stripes near 30°E and 60°W in the TCWV panel indicate land surfaces over which TCWV data are unavailable. The onset of the 1997-98 El Niño, as defined by the Oceanic Niño Index (ONI) (calculated using the three-month running mean of Extended Reconstructed Sea Surface Temperature (ERSST) v5 [47] SST anomalies in the Niño 3.4 region (5°N-5°S, 120°-170°W)), started in May 1997. Both the TCWV and UTH series show that preceding this El Niño event (at the end of 1996), there was a positive anomaly of water vapor near 5a-c shows that the three El Niño events all exhibited the strongest positive anomalies over the equatorial central Pacific, extending to the eastern Pacific.…”