JRA55 cyclones with incorrect sign

[aekiss]

Some tropical cyclones occurring over the Northeast Pacific and the North Atlantic from 1959 to 1987 were erroneously represented as anti-cyclonic vortices in the Japanese 55-year Reanalysis (JRA-55) dataset. A detailed report is available at the JRA-55 website:
https://jra.kishou.go.jp/JRA-55/index_en.html#quality
https://jra.kishou.go.jp/JRA-55/document/quality_issues_20200122_en.pdf

Presumably all versions of JRA55-do up to and including (at least) v1.4.0 inherit this issue.

[aekiss]

This problem afflicted two snapshots of one cyclone in 1959 in the Northeast Pacific but lots of storms from 1967 - 1987 in the North Atlantic.

[russfiedler]

Didn't Al Gore get pilloried by the "skeptics" for having a hurricane spinning the wrong way on the cover of a book or promo for his film?

[aekiss]

Tsujino email to omip-cmip@llnl.gov, 3 Feb:

Since the JRA-55 team does not have a plan to re-run the reanalysis, there does not seem to be no other options for us but to replace the surface atmospheric fields around the erroneous tropical cyclones of JRA55-do with those from another reanalysis. There would be various opinions regarding what reanalysis to be chosen, but I would like to use 20CRv3, considering a possible backward extension of the entire dataset in the future. We will report on the impact of these errors on long-term ocean-climate simulations and local SSTs as soon as an OMIP simulation is conducted with a corrected dataset.

So I guess we just wait and see when they produce an update that patches over this issue...

[aekiss]

RYF8485 (1 May 1984 - 30 April 1985) has four faulty North Atlantic storms

        	Time      	Position
Year/Storm#	YYYYMMDDHH	Lat 	Lon  
1984/01L	1984061400	30.2	278.2
1984/02L	1984062006	22.7	261.5
1984/09L	1984090806	23.2	261.9
1984/17L	1984102800	30.8	271.0

but RYF9091 and RYF0304 are OK.

[aekiss]

The upcoming JRA55-do v1.5 will correct this issue by replacing the erroneous cyclones with data from 20CRv3 : https://climate.mri-jma.go.jp/~htsujino/docs/JRA55-do/v1_5-manual/jra55do_v1_5_doc.html

[aekiss]

JRA55-do v1.5.0 is now available, which covers 01Jan1958 - 15Jul2020 and fixes this cyclone sign error https://climate.mri-jma.go.jp/pub/ocean/JRA55-do/

[access-hive-bot]

This issue has been mentioned on ACCESS Hive Community Forum. There might be relevant details there:

https://forum.access-hive.org.au/t/ryf-for-different-years/444/6