FAQ

FAQ (Frequently Asked Questions)

  Q1. Can I use APHRODITE for interannual variations and/or climate change?

  Q2. Can I use APHRODITE for extreme events analysis?

  Q3. What was improved in APHRODITE-2 products?

  Q4. What was the end of a day of APHRODITE (V1101, V1801) data?

  Q5. How can I access to the original data (point data)?

  Q6. I would like to see source codes.

  Q7. I think that APHRODITE precipitation is low (underestimated).

  Q8. Will you not make places other than Asia?

  Q9. Can I access to workshop materials?

  Q10. What will be the benefit if I provide original data?

  Q11. Can I request a workshop to be held?

  Q12. I would like to share products within our organization/research group once I download them.

  Q13. I would like to display the precipitation distribution on a specific day automatically, and to create a tool
      that can be downloaded or compared to other data.

  Q14. I want to release secondary product from APHRODITE data

  Q15. What is your next plan?

Q1. Can I use APHRODITE for interannual variations and/or climate change?
A: You can use it for limited areas. Please pay attention to “rstn.” (For “rstn”, please read Yatagai et al. (2009) or Yatagai et al. (2012).) You can use it for the areas where have no change in rstn during target period.

Q2. Can I use APHRODITE for extreme events analysis?
A:It depends on what kinds of extreme events. Basically, you cannot use V1101 and V1101EX. You may want to try events analysis for typhoon, for example; however, it is not easy to analyze its statistical property (nature) and its time-space change in extreme events cases. It is not limited to extreme events analysis, when you use APHRODITE, please pay attention to the indicator rstn that shows each day’s data distribution and make sure whether there is a rainfall gauge in the grid. The algorithm of V1801 and V1901 that are made in APHRODITE-2 have been improved, so they can be used to analyze extreme events. In V1801 and V1901, when interpolated value of 0.05 degree grid is calculated, it tries to preserve the value if there is a point at 0.05 degree grid.However, we can not release 0.05 degree product. We submitted papers on statistical analysis to show how APHRODITE products represent extreme rainfall characteristics. For details, please have a look at Readme of APHRO_V1901.

Q3. What was improved in APHRODITE-2 products?
A: APHRODITE-1 is for “assessment of global warming impact on water resources in Asia,” so we collected as much data as possible, devised the expression of mountain precipitation, and applied the same method throughout the analysis period. Here is our challenge. The objective of APHRODITE-2 is to improve the algorithm aiming at making datasets useful for extreme events analysis and forecast improvement. We will make the period of a day (end of the day (EOD) of 24-hr accumulated precipitation) correction products that make EOD clearly not tangling different EOD.

*EOD are different to various sources. Therefore, after the quality control, we use both datasets as input even if it is found that two datasets are off by one day. GTS’s data collected from Meteorological Agencies in the world is available at NOAA. However, we use both GTS’s prompt data and data with more stations that APHRODITE collected personally from each country.

*As a result of quality control, we sometimes find cases such as 10 times or 2.54 times differences (due to converting millimeters and inches) in unit between two datasets. We still use both datasets even these cases.

*In grid, we estimate “percentage” from daily climate value. We do so because we can get better results, even in years with less observations, the climate value distribution of the season will assist in expressing the mountain precipitation pattern. However, for example, when a minimal region and maximum region are close to each other in a climate value, if there is a strong rainfall event in a minimal region, a huge “percentage” is interpolated and extrapolated, and extraordinarily large values are calculated in places with high precipitation in climatic value. We have already devised measures to mitigate the effect, but it is necessary to pay attention to the extremely large value of the area without observation data.

* The basis of interpolation is to average the precipitation observation data included in a certain range that the precipitation observation points are close to each other against the grid (0.05 degree lattice) for which the value is to be obtained (We also devised considering terrain.) Thus, even if there is the observation value which is very close to the grid and there is extreme precipitation (large or no precipitation), the grid value is calculated using the values of the surrounding points. So, we do not save the value of the points. The public version is the result of 0.05 degree grid data obtained in this way to 0.25 degrees and 0.5 degrees.

* The large value removed by QC may include actual heavy rain (Extreme).

>> Please refer V1801_R1 Readme for an example of improvement in the 0.05 degree grid version.

Q4. What was the end of a day of APHRODITE(V1101, V1801) data?
A: We made the grid from data we got using their original dates in V1101 and V1801. For example, in India, we record 24 hour precipitation at 8:30 in the morning (= world time 03 UTC). The Indian area of APHRO (grid data) is the precipitation amount of the recorded dates. Therefore, in India, Nepal and Bhutan, APHRO's rainfall on December 25th will be 24 hours from the world time 03 UTC on December 24 to 03 UTC on December 25. Since APHRO_JP uses only AMeDAS observation data daily rainfall and it is 24 hours in Japan, the rainfall on December 25 will be 15 UTC on December 24 and 15 UC on 25 December. In APHRO_JP update released in July 2017, in order to avoid confusion, we released two kinds of time version of Japan and world time version, and also included the parameter EOD (end of the day). EOD is Japan time 24, world time 15.

Q5. How can I access to the original data (point data)?
A: Unfortunately, you cannot. In most cases, data providing agencies and projects etc. prohibit to distribute to third parties. APHRODITE makes data from GTS and unrestricted data in the same format. Data that have done quality control may be useful, and we think that we can give it to research collaborators and the community in the future. However, it is currently difficult because APHRODITE - 2 is executed with very few members.

Q6. I would like to see source codes.
A: Except for some, you are not allowed. We discussed and decided so with members of APHRODITE - 1 at the end of the project (the end of 2010). However, we can disclose if the developers at the time permitted the publication of the source, such as the QC code.

Q7. I think that APHRODITE precipitation is low (underestimated).
A: Exactly.It is true for V1101. First of all, we use it according to the "take in as much data as possible" policy which is answered in Q3 and the policy applying the same method in all areas for the entire period, even though we know that the GTS report value includes not reported as missing codes but as no precipitation. Second, there are many cases that the grid value is not necessarily given to the value of recordable heavy rain because the point is not saved. Moreover, in an objective QC applied by APHRO, data which was more than a certain statistical value is removed, and as a result of comparison with satellite data, we found out that there are quite a few cases which were truly Extreme. In addition, rain gauge observation values have losses when the wind is strong (especially in the case of snow). There are also evaporation losses. The current APHRODITE does not apply such losses (Only APHRO_V 0804 _ RU is partially applied.). These will work for undervaluation.

>> Please refer V1801_R1 Readme and V1901 Readme for an example of improvement in the 0.05 degree grid version.

Q8. Will you not make places other than Asia?
A: If someone requests and data is provided, it is possible to make. However, it is not easy to make immediately because we have limited human resources. If you would like to request, since it will be a reference for the development of APHRODITE in the future, please contact aphrodite.precinfo ”at” gmail.com specifying the data that can be provided. Also, you can make it if you attend APHRODITE-2 workshop. (We cannot provide source codes but will provide a file that you can calculate on linux.)

Q9. Can I access to workshop materials?
A: Unfortunately, no. For now, only workshop participants can get the materials. As we have announced before Chiba Workshop in September 2017, we will give workshop materials and grid data of a target country as a feedback to those who contributed data even though he/she could not attend the workshop.

Q10. What will be the benefit if I provide original data?
A: For daily precipitation data providers, we will give you workshop materials, publishable data creation tools and results (0.05 degree grid not open to the public).

Q11. Can I request a workshop to be held?
A: Possible. Under conditions: Original data to APHRODITE, linux machines are prepared and people who can use linux are gathered, travel expense of the instructors (APHRODITE-2 members), and workshop dates are flexible.

Q12. I would like to share products within our organization/research group once I download them.
A: APHRODITE team keeps a user's e-mail address to give errata, publish of reference paper and product updates. We highly recommend each person to register (It takes 10 SECONDS only.) at http://aphrodite.st.hirosaki-u.ac.jp/download/create/ because we are not able to reach all the users if a technician in charge is transferred and/or a student who registered graduated.
If it does not work for you, the registered person needs to provide all the e-mail addresses of people share the products at aphrodite.precinfo"at"gmail.com, so we can give necessary information to all of you.

Q13. I would like to display the precipitation distribution on a specific day automatically, and to create a tool
      that can be downloaded or compared to other data.
A: Unfortunately, we are not able to accept this request at this moment because of the following three reasons.
1. Except for APHRO_JP, boundary of a day (end of the day) is mixed in our products. If we allow daily basis data display and download, it is likely to cause a mis-use, so we want to avoid these problems happen.
2. Error is often found in the early stages after releasing a product. Also, it is inappropriate to publish if the reference paper has not been accepted.
3. We do need to have a user’s information (email address of the user) for informing errata, publish of reference paper and product updates.

Therefore, for data that satisfies condition 1 and 2 above, we have permitted secondary release (release of APHRODITE from other web-server) only if you agree to send your user’s information regularly (i.e. DIAS group does so).

Q14. I want to release secondary product from APHRODITE data
A: Please contact the PI of the APHRODITE project.

Q15. What is your next plan?
A: Unfortunately, at this moment, we do not have funding for hiring technical staffs, secretaries nor post doctors, so that it is not easy for us to make an enormous improvement for a while. However, during this fiscal year (April 2019 ? March 2020), we are going to make products where we have collaboration with funding such as JSPS. It is over Turkey and Thailand.
During APHRODITE-2 period (three years project from June 2016 to March 2018), we focused our target domain on monsoon Asia (MA) and only released products for the period of 1998-2015. However, as we did make APHRO_V1101 products over Russia and the Middle East during the APHRODITE-1 (five years project from 2006 to 2010), we want to create products over the Central Asia, Russia and the Middle East if there are cooperators.
We need to adopt the global warming and to manage water resources, especially over the mountain areas in Asia. Risk assessments of heavy precipitation and consequence of landslide disasters are inevitably important. As we have evaluated Nepali landslide risk by using APHRODITE, we believe APHRODITE is one of the most important products for scientifically and politically assess such issues. We are more than happy to cooperate and contribute to the societies which are suffering from rain induced disasters.
For the last three years, we, APHRODITE-2 team in Hirosaki University worked intensively on snow issue, since we have plenty of snow in winter and many students are interested in such an issue. In addition, we made hourly products for the West Japan heavy precipitation disasters in June/July 2018. We may release such products over Japan after acceptance of the relevant papers. In any cases, we welcome any kinds of cooperative studies. Please directly contact PI (yatagai”at”hirosaki-u.ac.jp), if you wish collaboration studies with us.