TOYODA Eizi's blog

2014-04-11

note on relative humidity in real nwp

1. ECMWF proposal to introduce new parameters for clarification.

https://groups.google.com/a/wmo.int/forum/#!topic/cbs-ipet-drmm/mjqgaFE3gSE

That proposes new parameters:

* 0-1-93 Relative humidity with respect to water
* 0-1-94 Relative humidity with respect to ice

There is already "0-1-1 Relative humidity" but ECMWF propses adding
*both* water and ice because 0-1-1 was used for RH computed using the
"virtual" saturation (not commonly-understood term) defined by water-ice
mixture.

2. JMA uses such RH, at least in the global model. Saturated vapor
pressure is linear combination of water and ice, and the mixing ratio
changes linearly from -15 C to 0 C.

Sources:

* Para 3.2.5 of NWP Outline 2013
http://www.jma.go.jp/jma/jma-eng/jma-center/nwp/outline2013-nwp/index.htm

* Para 3.5.2(4) of NWP text #43 (in Japanese)
http://www.jma.go.jp/jma/kishou/books/nwptext/43/chapter3.pdf#page=28

3. Large-scale condensation scheme

The reason to have such virtual saturation should be large-scale
condensation.
For example following article describes a formulation that leads to JMA
schme.

W.K. Tao, J. Simpson, and M. McCumber, 1989: An Ice-Water Saturation
Adjustment. MWR 117 231-235.
http://journals.ametsoc.org/doi/abs/10.1175/1520-0493%281989%29117%3C0231:AIWSA%3E2.0.CO%3B2

The minimum temperature of presence of water droplets was undefined in
Tao et al (1989). Smith (1990), cited by JMA Outline, reports -15 C was
a choice by tuning.

R.N.B. Smith, 1990: A scheme for predicting layer clouds and their water
content in a general circulation model. QJRMS 116 435-460.
http://onlinelibrary.wiley.com/doi/10.1002/qj.49711649210/abstract

2014-03-12

Review of changes to ISO 19115-1:2014 and 19115-3

This is a paper submitted to IPET-MDRD-1 meeting: http://wis.wmo.int/file=907

2014-02-28

Fwd: [IPET-MDRD] Updates to Manuals on GTS and WIS

There was an announcement from WMO Secretariat:
-----------------------------------------------------------

2014-02-13

reviewing TT-ApMD2 conclusion

I's only one month before the IPET-MDRD-1 meeting. Oh no.

I need to create input to the meeting by pushing actions identified in the TT-ApMD2 meeting last year. As as first step, I'm reviewing the final report of the meeting

Intermediate result: redmine tickets as my personal memoranda.

2014-01-30

when trouble receiving WMO Google Groups message

There is an member in having trouble receiving emails from TT-ApMD's Google Group. I think it is good to share the instruction for future re-use and reference for other members.

You can visit online archive to check (1) whether you are member and subscribing emails, and (2) any threads posted so far.

https://groups.google.com/a/wmo.int/forum/#!forum/cbs-tt-apmd

Maybe it is better to check the Atom Feed to verify every messages posted.

https://groups.google.com/a/wmo.int/forum/feed/cbs-tt-apmd/msgs/atom_v1_0.xml

If there's trouble in membership, I will ask the WMO Secretariat to address the issue.

2014-01-29

New mandatory regulations of WCMP 1.3 compared to version 1.2

The WMO Core Metadata Profile (WCMP) version 1.3 has more mandatory requirements compared to the previous version 1.2. The Manual on WIS (update 2013, see my previous post for text) has following mention on this matter:

Note: metadata created using profile version 1.2 is compatible with that created under version 1.3 other than that the records may have been completed inconsistently and therefore may fail the version 1.3 conformance checking rules.

So it is natural to ask "What are the checking rules newly introduced?" Please check following list.

6.1.2 Each WIS Discovery Metadata record shall validate without error against the rule-based constraints listed in ISO/TS 19139:2007 Annex A (Table A.1). [These constraints cannot be tested by XSD (W3C XML Schema), so it is highly likely to fail to meet this requirement even if your records pass XSD validation]
6.2.1 Each WIS Discovery Metadata record shall name explicitly all namespaces used within the record; use of default namespaces is prohibited. [the latter part is a kind of difficult to detect, as the XPath language cannot find where the namespace declaration is present.]
6.3.1 Each WIS Discovery Metadata record shall declare the following XML namespace for GML: http://www.opengis.net/gml/3.2. [WCMP1.2 preferred this namespace, but it was not in so strong language]
Intended scope of distribution
- [§9.1 ¶1] The scope of distribution for data within WIS shall be expressed using the following controlled vocabulary: "GlobalExchange", “RegionalExchange” and “OriginatingCentre” (if the scope of distribution is documented).
- Requirement 9.1.1: A WIS Discovery Metadata record describing data for global exchange via the WIS shall indicate the scope of distribution using the keyword “GlobalExchange” of type “dataCenterdataCentre” from thesaurus WMO_DistributionScopeCode.
Data policy
- Requirement 9.3.1: A WIS Discovery Metadata record describing data for global exchange via the WIS shall indicate the WMO Data License as Legal Constraint (type: “otherConstraints”) using one and only one term from the WMO_DataLicenseCode code list.
- [§9.3 ¶5] The presence of more than one WMO Data Policy statement in a single metadata record yields an ambiguous state; a WIS Discovery Metadata record describing data for global exchange shall declare only a single WMO Data Policy.
Requirement 9.3.2: A WIS Discovery Metadata record describing data for global exchange via the WIS shall indicate the GTS Priority as Legal Constraint (type: “otherConstraints”) using one and only one term from the WMO_GTSProductCategoryCode code list.
[§8.1 ¶9] WMO Core Metadata Profile mandates dateStamp in format YYYY-MM-DD or YYYY-MM-DDTHH:MM:SS. [WCMP 1.2 has similar words, but it didn't say "shall"].

For entire test set, my working draft of the Schematron rule set (pretty-printed by a stylesheet on PC browser) is available here.

2014-01-22

WIS Metadata todo's found during CAS/ET-WDC

todos new and gone:

people wanted to use the gmd:geographicelement tag with only xlink:href attribute with URL of Google Maps. I had to say so far there is no WCMP regulation against that. I hope this is not controversial for people demanding strong-typed XLink.
I heared GEO AQ CoP metadata discussion held in Dublin (Sep 2012) recommended the gmd:thesaurusName tag with only xlink:href attribute. That is different from WCMP's present use of gmd:thesaurusName/*/gmd:title string to identify the thesaurus.
some people wanted to use a bounding box for a country even though the data is for a single station. They say we don't know the boundary of a station in WIGOS sense. It's totally user unfriendly in the data discovery context. Metadata records with unnecessarily wide bounding box matches the search for other part of the country, and the user will be extremely frustrated when they cannot narrow down to remove the noise. I __strongly recommended__ to forget the word "bounding" and use point coords, i.e. using the same west == east and north == south. It was totally unexpected response of users and I felt it might be necessary to add a notice in WCMP.
don't know good Vertical CRS identifier for "metre above sea level" without clear datum definition. Meteorologists don't want precision for centimeter, but clear identification of "m asl" is necessary and to be __never__ confused with ellipsoid height. Some tried to use "WGS84" but I'm not sure whether it's geoid or ellipsoid height. If that's about EPSG:4326, that's only the 2d horizontal CRS and it's totally undefined. IPET-MDRD may take time to conclude, but the users need the answer today!!! I might have to propose something.

resolved todo:

The WMO category code "radiation" was proposed for measurements of infrared and visible electromagnetic waves. The ET incuding WRDC St Petersburg agreed to withdraw the proposal and use existing entry "actinometry". The term radiation has unclear meaning and may include nuclear radiation.

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