Comparison Table

Last edited by gilbert.p.compo on Thu, 03/08/2012 - 11:13

Atmospheric Reanalyses Comparison Table

Name	Source	Time Range	Assimilation	Model Resolution	Model Output Resolution	Publicly Available Dataset Resolution
Arctic System Reanalysis (ASR)	Polar Met Group	2000-2010	WRF-Var	10-20km	10-30km	10-30km
ECMWF Interim Reanalysis (ERA Interim)	ECMWF	1979-present	4D-VAR	T_L255L60 and N128 reduced Gaussian	T_L255L60 and N128 reduced Gaussian (~79km globally)	User defined, down to 0.75x0.75
ECMWF 40 year Reanalysis (ERA-40)	ECMWF	1958-2001	3D-VAR	T_L159L60 and N80 reduced Gaussian	T_L159L60 and N80 reduced Gaussian (~125km globally)	2.5x2.5 / 1.125x1.125
Japanese Reanalysis (JRA-25) JMA Climate Data Assimilation System (JCDAS)	Japan Meteorological Agency	1979-2004 2005-present	3D-VAR	T106L40	1.125x1.125/2.5x2.5	1.125x1.125/2.5x2.5
NASA MERRA	NASA	1979-present	3D-VAR	2/3 lon x1/2 lat deg; 72 sigma levels	2/3 lon x1/2 lat deg 3d Analysis and 2d variables; 1.25 deg 3d Diagnostics; 72 model levels and 42 pressure levels	2/3 lon x1/2 lat deg 3d Analysis and 2d variables; 1.25 deg 3d Diagnostics; 72 model levels and 42 pressure levels
NCEP Climate Forecast System Reanalysis (CFSR)	NCEP	1979-?	3D-VAR	T382 L64	.5x.5 and 2.5x2.5	.5x.5 and 2.5x2.5
NCEP/DOE Reanalysis AMIP-II (R2)	NCEP/DOE	1979-present	3D-VAR	T62 L28	2.5x2.5	2.5x2.5
NCEP/NCAR Reanalysis I (R1)	NCEP/NCAR	1948-present	3D-VAR	T62 L28	2.5x2.5 and 2x2 gaussian	2.5x2.5 and 2x2 gaussian
NCEP North American Regional Reanalysis (NARR)	NCEP	1979-present	RDAS	32km	32km	32km
NOAA-CIRES 20th Century Reanalysis (20CR)	NOAA/ESRL PSD	1871-2008	Ensemble Kalman Filter	T62 L28	2x2	2x2

Quote in comment

Comments (7)

Reanalysis comparison

Submitted by David (not verified) on Thu, 05/05/2011 - 10:36.

Hello, first I would like to congratulate all that contribute to this excellent website, which is very helpful and full of valuable information! I believe that the "state of the art" in reanalysis are, nowadays, the ERA-Interim, NASA-MERR and NCEP-CFSR reanalysis. I consulted your Comparison Table for the Atmospheric reanalysis, but the "Publicly Available Dataset Resolution" presents datasets that are not freely available to public, like the ERA-Interim of 0.7º. On the other hand, I consulted the UCAR website and they seem to have available datasets for the NCEP-CFSR reanalysis with 0.313º of resolution! Is this true?? I have been spending huge time consulting what are the available reanalysis datasets, and what are the best to use, but I found several websites and articles about this subject with a lot of different reanalysis products and i must confess that i am a bit confused... I would like to ask if someone has an opinion of which reanalysis data set is better to use in my case: Near surface wind fields in Iberian Peninsula (inland and offshore) for the year of 2008 using WRF model, considering only freely public available data sets and preferable in GRIB format. Thank you all!!

reply
quote

Re: Reanalysis comparison

Submitted by Dick Dee (not verified) on Mon, 08/08/2011 - 12:25.

Admittedly the table entry for availability of ERA-Interim data is confusing.. Our public data server currently provides data for public download only at 1.5º resolution and on pressure levels. NCAR provides the full-resolution data (0.7º), but only to North-American users. And, of course, ECMWF member state users have access to all ECMWF data. The REALLY GOOD NEWS is that within the next few months we will open an expanded public data server, which will provide unrestricted access to all ERA-Interim data at full horizontal and vertical resolution, i.e. on all 60 model levels in addition to the 37 pressure levels currently provided. This is a major step for us. We are just fine-tuning the system to make sure that we can provide good quality of service - stay tuned... See our main web page at www.ecmwf.int/research/era for up-to-date information.

reply
quote

Re: Comparison Table

Submitted by Shaun (not verified) on Mon, 08/08/2011 - 11:03.

One suggestion for this table--add a "date updated" for the table. This would be helpful to know how recent the table was updated--I've found various tables like this, but it's difficult to know which is current. By the way, the ERA-Interim now goes back to 1979--this could be updated! Thank you!

reply
quote

Re: Comparison Table

Submitted by gilbert.p.compo on Mon, 11/14/2011 - 12:44.

Both the date updated and the ERA-Interim time extension have been added. Thanks for the suggestions.

reply
quote

Re: Comparison Table

Submitted by Warren Wiscombe (not verified) on Mon, 02/20/2012 - 12:53.

It would be helpful to have a table column for time resolution. I understand it is mostly either 3- or 6-hr but outsiders may not know this. Also, units are not specified for some resolution numbers. The unitless ones are obviously degrees but this should be stated.