TOYODA Eizi's blog

2014-06-28

"jmd" metadata tools updated for WCMP1.3

A few years ago I made an experimental generator tool of WIS Discovery Metadata, called "jmd". It is found at http://www.gisc.kishou.go.jp/xsd/jmd0.1/.

During the work of writing guideline for WCMP 1.3, I need to create many metadata records as example. It was painful to write raw XML and correct it by modify-validate-fix cycle, so I remembered the "jmd" tool. So I've updated the tool to generate modern style of ISO19139 according to the new WMO profile.

2014-06-25

default CRS for meteorological data

There is an argument (again) that all coordinates in CF should have CRS specification.
http://mailman.cgd.ucar.edu/pipermail/cf-metadata/2014/057478.html

My thought:

- I agree Jim says default CRS is needed for backward compatibility.

- The default should be WGS84 http://epsg.io/4326

- For NWP model data, even if the modeller says the coordinates are spherical, that means only the equations are spherical. I've never seen surface elevation and observations are injected *after* coordinate conversion.

- For observational data, I hope the data source is migrated well to WGS84. Archived data is an issue, but that can't be an excuse to continue to create the issue.

Similar argument should exist for vertical CRS. I think it is convenient to use "MSL height" http://epsg.io/5714 which has no clear definition as an default.

2014-06-12

Asperatus and WMO International Cloud Atlas

Around 2011 and 2012, there appeared a movement to create a new cloud classification called Undulatus Asperatus and work with WMO to give it official recognition.
http://cloudappreciationsociety.org/asperatus-update/comment-page-2/

http://online.wsj.com/news/articles/SB10001424127887324251504578579204045089848

It was pretty impressive that the Royal Met Soc was supporting the idea:
http://www.rmets.org/asperatus-new-cloud-variety

Recently I learned that CIMO (Commission for Instrument and Methods of Observation) took responsibility of revising the International Cloud Atlas (ICA), and established a task team. The team had a meeting in 2013 and the report is available:
http://www.wmo.int/pages/prog/www/IMOP/reports/2013/CIMO-TT-ICA_FinalRep.pdf#page=20

Their recommendation is that the Asperatus cloud would be added not as a new Genera to existing ten (such as Cumulus or Altostratus), but as a new supplementary feature.

That should be a feasible compromise, since it has little impact of realtime synoptic meteorology, while skywatchers will have autholized terminology to describe the cloud with distinct appearance.

Recent document submitted to coming CIMO session says the task team is expected to finalize the revision of ICA by the end of 2015, and then it has to be authorized by some upper bodies, at least by the Executive Council of WMO which was held June every year. So the new ICA will be available in the latter half of 2016, if everything goes perfectly.

2014-06-06

ICSU WDS "replaced" WDCs

I had a question "is it still good to say ICSU WDC?"

I guess not. The decision 16.2 of the 29th General Assembly of ICSU says
WDS was established to *replace* WDCs.
http://www.icsu.org/publications/general-assembly/29GA/Decisions_29_GA_with_Annexes.pdf

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:
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