The JRA-25 Reanalysis

Onogi, Kazutoshi; Tsutsui, Junichi; Koide, Hiroshi; Sakamoto, Masami; Kobayashi, Shinya; Hatsushika, Hiroaki; Matsumoto, Takanori; Yamazaki, Nobuo; Kamahori, Hirotaka; Takahashi, K.; Kadokura, Shinji; Wada, Koji; Kato, Koji; Oyama, Ryo; Ose, Tomoaki; Mannoji, Nobutaka; Taira, Ryusuke

doi:10.2151/jmsj.85.369

Cited by 1,537 publications

(1,208 citation statements)

References 77 publications

(62 reference statements)

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“…The Japanese 25-yr Reanalysis represents the first long-term global atmospheric reanalysis undertaken by the Japanese Meteorological Agency (Onogi et al 2007). It uses the JMA numerical assimilation and forecast system and observational and satellite data from many sources including the ECMWF, the National Climatic Data Center (NCDC), and the Meteorological Research Institute of JMA.…”

Section: G Jra-25mentioning

confidence: 99%

Evaluation of Seven Different Atmospheric Reanalysis Products in the Arctic*

et al. 2014

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Atmospheric reanalyses depend on a mix of observations and model forecasts. In data-sparse regions such as the Arctic, the reanalysis solution is more dependent on the model structure, assumptions, and data assimilation methods than in data-rich regions. Applications such as the forcing of ice-ocean models are sensitive to the errors in reanalyses. Seven reanalysis datasets for the Arctic region are compared over the 30-yr period 1981-2010: National Centers for Environmental Prediction (NCEP)-National Center for Atmospheric Research Reanalysis 1 (NCEP-R1) and NCEP-U.S. Department of Energy Reanalysis 2 (NCEP-R2), Climate Forecast System Reanalysis (CFSR), Twentieth-Century Reanalysis (20CR), Modern-Era Retrospective Analysis for Research and Applications (MERRA), ECMWF Interim Re-Analysis (ERA-Interim), and Japanese 25-year Reanalysis Project (JRA-25). Emphasis is placed on variables not observed directly including surface fluxes and precipitation and their trends. The monthly averaged surface temperatures, radiative fluxes, precipitation, and wind speed are compared to observed values to assess how well the reanalysis data solutions capture the seasonal cycles. Three models stand out as being more consistent with independent observations: CFSR, MERRA, and ERA-Interim. A coupled ice-ocean model is forced with four of the datasets to determine how estimates of the ice thickness compare to observed values for each forcing and how the total ice volume differs among the simulations. Significant differences in the correlation of the simulated ice thickness with submarine measurements were found, with the MERRA products giving the best correlation (R 5 0.82). The trend in the total ice volume in September is greatest with MERRA (24.1 3 10 3 km 3 decade 21 ) and least with CFSR (22.7 3 10 3 km 3 decade 21 ).

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Section: G Jra-25mentioning

confidence: 99%

Evaluation of Seven Different Atmospheric Reanalysis Products in the Arctic*

et al. 2014

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“…These reanalyses include the first two generations of global reanalyses produced by the National Centers for Environmental Prediction, NCEP-R1 (Kalnay et al, 1996) and NCEP-R2 (Kanamitsu et al, 2002); the reanalyses produced by the European Centre for MediumRange Weather Forecasts (ECMWF), ERA-15 (Gibson et al, 1997), ERA-40 (Uppala et al, 2005) and ERA-Interim (Dee et al, 2011b); the Japanese Meteorological Agency, JRA-25 (Onogi et al, 2007) and JRA-55 (Kobayashi et al, 2015); and the National Aeronautics and Space Administration, the Modern-Era Retrospective Analysis for Research and Applications (MERRA) (Rienecker et al, 2011) and its updated version, MERRA-2 (Reichle et al, 2017).…”

Section: Introductionmentioning

confidence: 99%

On the suitability of current atmospheric reanalyses for regional warming studies over China

Zhou

Wang

2018

Atmos. Chem. Phys.

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Abstract. Reanalyses are widely used because they add value to routine observations by generating physically or dynamically consistent and spatiotemporally complete atmospheric fields. Existing studies include extensive discussions of the temporal suitability of reanalyses in studies of global change. This study adds to this existing work by investigating the suitability of reanalyses in studies of regional climate change, in which land-atmosphere interactions play a comparatively important role. In this study, surface air temperatures (T a ) from 12 current reanalysis products are investigated; in particular, the spatial patterns of trends in T a are examined using homogenized measurements of T a made at ∼ 2200 meteorological stations in China from 1979 to 2010. The results show that ∼ 80 % of the mean differences in T a between the reanalyses and the in situ observations can be attributed to the differences in elevation between the stations and the model grids. Thus, the T a climatologies display good skill, and these findings rebut previous reports of biases in T a . However, the biases in theT a trends in the reanalyses diverge spatially (standard deviation = 0.15-0.30 • C decade −1 using 1 • × 1 • grid cells). The simulated biases in the trends in T a correlate well with those of precipitation frequency, surface incident solar radiation (R s ) and atmospheric downward longwave radiation (L d ) among the reanalyses (r = −0.83, 0.80 and 0.77; p < 0.1) when the spatial patterns of these variables are considered. The biases in the trends in T a over southern China (on the order of −0.07 • C decade −1 ) are caused by biases in the trends in R s , L d and precipitation frequency on the order of 0.10, −0.08 and −0.06 • C decade −1 , respectively. The biases in the trends in T a over northern China (on the order of −0.12 • C decade −1 ) result jointly from those in L d and precipitation frequency. Therefore, improving the simulation of precipitation frequency and R s helps to maximize the signal component corresponding to regional climate. In addition, the analysis of T a observations helps represent regional warming in ERA-Interim and JRA-55. Incorporating vegetation dynamics in reanalyses and the use of accurate aerosol information, as in the Modern-Era Retrospective Analysis for Research and Applications, version 2 (MERRA-2), would lead to improvements in the modelling of regional warming. The use of the ensemble technique adopted in the twentieth-century atmospheric model ensemble ERA-20CM significantly narrows the uncertainties associated with regional warming in reanalyses (standard deviation = 0.15 • C decade −1 ).

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“…This work used the JRA-25 objective reanalysis data (Onogi et al 2007) for atmospheric parameters including surface variables. The time period is 1979−2013 (35 years) with a six-hour interval.…”

Section: Data and Methodsologymentioning

confidence: 99%

A Precursor of the Monthly-Mean Large-Scale Atmospheric Circulation Anomalies over the North Pacific

Tomita

Yamaura

2017

SOLA

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The North Pacific shows dominant monthly-mean largescale atmospheric circulation anomalies, even after removing the variabilities of the Northern Hemisphere annular mode and the El Niño/Southern Oscillation. This work examines the precursors and their development for these residual anomalous circulations by applying objective reanalysis data to empirical orthogonal function (EOF) analysis. The first EOF mode (EOF1) features a monopole, while a dipole characterizes the second EOF mode (EOF2) over the North Pacific. Transient eddies (TEs) interactively induce the two EOF modes.The precursors of EOF1 and EOF2 are detected in the anomalies of one month earlier; these are the systematic zonal bands detected in surface temperature and baroclinic instability (BI) in the lower troposphere over Eurasia and North America. The BI anomalies further extend into the central North Pacific at different latitudes between EOF1 and EOF2. Coherent zonal bands also appear in the geopotential height anomalies of upper troposphere. Such zonal bands reflect the ovalization of Arctic circumpolar circulation with different continent-ward shifts of the longer axis. The direction of this shift determines which EOF mode develops by the following month through the guided activation of TEs at a designated latitude over the North Pacific.(Citation: Tomita, T., and T. Yamaura, 2017: A precursor of the monthly-mean large-scale atmospheric circulation anomalies over the North Pacific. SOLA, 13, 85−89,

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The JRA-25 Reanalysis

Cited by 1,537 publications

References 77 publications

Evaluation of Seven Different Atmospheric Reanalysis Products in the Arctic*

Evaluation of Seven Different Atmospheric Reanalysis Products in the Arctic*

On the suitability of current atmospheric reanalyses for regional warming studies over China

A Precursor of the Monthly-Mean Large-Scale Atmospheric Circulation Anomalies over the North Pacific

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