JRA-55: Notes, Questions, and Discussion

Submitted by mapr8844 on Wed, 08/17/2016 - 13:13

 

 

 


Note: the following comments have been added to the body of this page due to them not migrating during our recent site upgrade:

 

JRA-55: 2016 Data

Submitted by Johanna Yepes (not verified) on Fri, 05/27/2016 - 08:30. 

Hi, Does the 2016 hourly data available? Thank you

Re: JRA-55: 2016 Data

Submitted by Kazutoshi Onogi (not verified) on Wed, 06/01/2016 - 01:53. 

Unfortunately hourly data is not available in JRA-55. Please visit http://jra.kishou.go.jp/JRA-55/index_en.html and read the documents "JRA-55 Product Users' Handbook" at the bottom of the page.

Re: JRA-55: 2016 Data

Submitted by Chiaki Kobayashi (not verified) on Mon, 05/30/2016 - 04:00. 

JRA data are available a couple of days behind the real time from JMA's web site (http://jra.kishou.go.jp/JRA-55/index_en.html) except for 3-dimensional average diagnostic fields and model level forecast fields. Thanks, Chiaki KOBAYASHI Climate Research Department Meteorological Research Institute Tsukuba, Ibaraki, 305-0052, Japan.

Re: JRA-55: 2016 Data

Submitted by gilbert.p.compo on Fri, 05/27/2016 - 13:32. 

It appears that the data are not yet at NCAR in http://rda.ucar.edu/datasets/ds628.0/ . I recommend contacting the Data Specialist mentioned on the page directly.

Gilbert P. Compo
University of Colorado/CIRES
NOAA/ESRL/Physical Sciences Division
http://www.esrl.noaa.gov/psd/people/gilbert.p.compo

JRA-55 assmilation of horizontal wind from land stations

Submitted by gilbert.p.compo on Thu, 05/19/2016 - 13:25. 

Does JRA-55C or JRA-55 assimilate horizontal winds from land surface stations? Thanks.

Gilbert P. Compo
University of Colorado/CIRES
NOAA/ESRL/Physical Sciences Division
http://www.esrl.noaa.gov/psd/people/gilbert.p.compo

Re: JRA-55 assmilation of horizontal wind from land stations

Submitted by Chiaki Kobayashi (not verified) on Fri, 05/20/2016 - 07:47. 

Dear Gil Horizontal winds from land surface stations are assimilated only in the screen-level analysis component, not in the atmospheric analysis component. Screen-level analysis fields are not used as the initial conditions for forecasts, therefore have no impact on subsequent assimilation cycles. Best regards, Chiaki -- Chiaki KOBAYASHI Climate Research Department Meteorological Research Institute Tsukuba, Ibaraki, 305-0052, Japan.

JRA-55C assimilation of horizontal wind from aircraft

Submitted by gilbert.p.compo on Thu, 05/19/2016 - 13:24. 

Does JRA-55C assimilate horizontal wind observations from aircraft? I do not think so based on Kobayashi et al. 2014 but wanted to double check. Thanks.

Gilbert P. Compo
University of Colorado/CIRES
NOAA/ESRL/Physical Sciences Division
http://www.esrl.noaa.gov/psd/people/gilbert.p.compo

Re: JRA-55C assimilation of horizontal wind from aircraft

Submitted by Chiaki Kobayashi (not verified) on Fri, 05/20/2016 - 07:50. 

Dear Gil, No, The observation from air crafts are not assimilated in JRA-55C. I think you are understanding correctly. Best regards, Chiaki -- Chiaki KOBAYASHI Climate Research Department Meteorological Research Institute Tsukuba, Ibaraki, 305-0052, Japan.

Cathy.Smith@noaa.gov

Mon, 10/24/2016 - 10:09

Users should be aware that for 2mT, 2mq, 10m u and v and some others, that they should use the "forecast" variable and not the "analysis" variable. The WRIT pages now have both.

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Table 5 and section 3.2a "screen level analysis" of

Kobayashi, S., Y. Ota, Y. Harada, A. Ebita, M. Moriya, H. Onoda, K. Onogi, H. Kamahori, C. Kobayashi, H. Endo, K. Miyaoka, and K. Takahashi , 2015: The JRA-55 Reanalysis: General Specifications and Basic Characteristics. J. Meteorol. Soc. Japan, 93, 5-48, doi: 10.2151/jmsj.2015-001

describes the details of this "separate" analysis:

The analysis of screen-level variables (2-m temperatures, 2-m relative humidities and 10-m winds) is performed separately from the atmospheric analysis component. These variables are analyzed with a univariate 2-dimensional optimal interpolation (2D-OI). In JRA-25, departures were estimated by comparing observations with the first guess at the analysis time. In JRA-55, observations are compared with the first guess at the actual observation time and the departures are applied at the analysis time (the so-called first guess at the appropriate time (FGAT) approach). Temperature and wind observations from islands are not used because they are not necessarily representative at the grid scale of JRA-55. Determining whether an observation is from an island is based on the 0.25-degree resolution land cover data; consequently, observations from the coast are also excluded. Screen-level analysis fields are not used as initial conditions for forecasts.

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