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December 9th, 2010

Bug fixed

Published at 9:40. Filed under English version; 9 Comments

APanel drawing bug for south hemisphere and regions between 179.75E-180.00E has been fixed. Thanks to Johnson Lau for pointing out.

December 8th, 2010

晴天钟重大更新

Published at 22:41. Filed under 中文版日志; no comment so far.

晴天钟刚刚顺利完成了自2005年运行以来最为重要的更新。更新的具体内容如下:

  1. 晴天钟成功由国家天文台宇宙驿站服务器成功迁移至上海天文台天之文项目2号服务器。自2005年来,晴天钟一直在宇宙驿站服务器运行,期间得到了管理员崔辰州博士以及宇宙驿站其他用户的大力协助与支持。但由于晴天钟运行需要的资源较大,本人一直竭力在发挥晴天钟运能以及不对服务器造成过大负担上寻求一个平衡点;不过最实际的解决方案还是将晴天钟迁移到一台专有服务器上。目前的服务器由上海天文台天之文项目提供,供晴天钟专门使用。除了可以让晴天钟发挥最大运能之外,还可以进行一些数值实验。
  2. 香港中文大学的Johnson Lau先生为晴天钟编写了非常棒的分布式数据处理系统,使得输出16天预报数据所需要的计算时间从1年前的5小时缩短到现在短短90分钟。这套系统还可以同时采集多个分辨率的数值预报,使得晴天钟最高分辨率由35公里提升到14公里。云量、气温、风向风速、雪深和致云因子的预报均有14公里的分辨率。同时,高分辨率预测由原来的180小时延长到192小时,9-16天预报的分辨率也从原来的175公里提升到40-70公里。
  3. 使用了新的视宁度模型。一篇有关云量及新视宁度模型预报效果的论文已被SCI收录的科研期刊接受,不日可发表。有兴趣者可参考 http://adsabs.harvard.edu/abs/2010arXiv1011.3863Y。
  4. 其他一些小修正,比如AP页面的日出日落问题等。

本人在此诚挚感谢:为晴天钟提供多年额外的网络资源,并数次耐心解决晴天钟运行故障导致服务器宕机的国家天文台崔辰州博士;提供专有服务器,帮助晴天钟实现长远发展蓝图的上海天文台林清博士和汤海明先生,以及花费许多日夜编写、调试程序,为晴天钟提供出色的分布式数据处理系统的香港中文大学Johnson Lau先生;当然,还有一直以来关注和支持晴天钟发展的各位。晴天钟虽然不算一个很大的计划,但要一直坚持做下来,没有各位的支持是不可能的。希望以后继续得到各位的关注和支持。

December 8th, 2010

Great changes today

Published at 21:59. Filed under English version; 2 Comments

Sorry for a five-month silence, as I have to work with papers and exams -- they are essential to my future so I hope you can understand. But after all, I manage to get a week on 7Timer. Today I am glad to announce that great changes are ready, and this may be the most important upgrade for 7Timer since it borned in 2005.

First of all, I am happy to let you know that 7Timer finds a new home at Shanghai! You may recall that 7Timer was placed at Cosmostation in Beijing since it borned in 2005. Cosmostation is a server that kindly provided by the National Astronomical Observatories of China and maintained by Dr. Chenzhou Cui, to provide a free and stable web host for amateur astronomers in China. To-date, it has operated for almost nine years and served hundreds of amateur astronomers to build their own tiny home over Internet. However, as 7Timer is a bold creature, it eats up a lot of resources on Cosmostation, and I did occasionary feel sorry for Dr. Cui as well as other Cosmostation users about this over these years. This summer, Dr. Qing Lin and Mr. Haiming Tang from Shanghai Astronomical Observatory, Chinese Academy of Sciences, agree to provide a new server for 7Timer. The server is for operation of 7Timer only, so it is able to provide resources to conduct normal operation as well as some numerical astro-meteorlogical experiment, so today the transfer from Beijing to Shanghai is completed. I would like to express my big thankness to Dr. Cui for his long-term support of the 7Timer project, which is essential to the project's grow; to all users of Cosmostation for their supports; and to Dr. Lin and Mr. Tang for providing an excellent new server.

On the very first runs today, you may notice that 7Timer is times faster: the time it requires to perform a normal 384-hour package extraction and figure production is reduced from ~5-hour about one year ago to approximately 90 minutes. Also you may notice that the resolution is times higher: the resolution can be as high as 14km now, over one time higher than the old one (35km). The major part of this fantastic change is contributed by Mr. Johnson Lau (will be Dr. soon ;-) from Hong Kong, who also credited my deepest thankness. He spent days on writing an excellent distributed data processing system for 7Timer that enable the latter to process different kind of products almost in real-time with the data release at NCEP with ease, also he saves pretty much of my time by helping me on bug searches. Without Mr. Lau's effort, this fantastic change will not be possible, or at least will require me a pretty long time to do it. It is very fair to say that 7Timer benefits A LOT from his wonderful design!

Okay, I will summarize the new changes here. Ah, I am sorry that there are no new products (yeh, it is my word that there will be new product this year, but probably we have to wait until next year!) But I believe the changes below are exciting enough!

  • Install a new data processing system, which significantly reduce data process time (from ~3h to ~1.5h).
  • July's GFS model upgrade effective in 7Timer products, some forecast fields have resolution as high as 14km, including cloud cover, CWF, temperature, snow depth, and wind. High resolution forecast is extent to 192h; for forecast posted 192h, higher resolution forecasts are available (0.6deg or 1.0deg, comparing to the 2.5deg before today).
  • New seeing model installed. The performance of the cloud cover forecast, as well as this new seeing model, is discussed on a paper that will be published on a scientific journal shortly (PASP, 123). For a preprint version, see http://adsabs.harvard.edu/abs/2010arXiv1011.3863Y.
  • ``Altitude correction'' function removed as study has shown that it does not have positive effect to improve the accuracy.
  • Some other misc changes (bug fixing, etc).


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