User Guide for the WegenerNet Data Portal (v9/18feb2010) The WegenerNet Data Portal provides access to measurement data from the climate stations as well as detailed information about the project. Quality-checked measurements can be visualized and downloaded on various temporal scales (from 5-minutes data to annually averaged climate data). The datasets are the first version (v1.0) of data products based on quality-controlled and gap-interpolated data, all with transparent flags classifying their quality. Work on updates and enhancements are continually on-going. The data portal can either be accessed directly via the web link http://www.wegenernet.org or via http://www.wegcenter.at/wegenernet (WegenerNet Homepage with detailed information on the project and with a link to the data portal).
System Requirements In order to allow all graphical elements to be displayed the Java plug-in and Java script are required. More information regarding the system requirements can be found in the appendix of this user guide (pages 13 and 14). 1) Signing-in (see Fig. 1) Fig. 1: Sign-in window of the WegenerNet data portal If you are a new user: A registration is required to obtain access to the data portal. Click not yet registered? (Fig. 1) and enter your data in the registration window (Fig. 2). As soon as your data has been verified you will receive your access data to the WegenerNet data portal by e-mail (user name and password). If you are an already registered user: Enter your user name and password und and click the Login button. Via the link What is the WegenerNet? you will get to the WegenerNet Homepage. Under the link User Guide WegenerNet Data Portal you will find this document. Abb. 2: WegenerNet data portal registration window Page 1 of 15
2) WegenerNet Data Portal Main Window (see Fig. 3) In the upper right hand corner your user name is displayed. With the two links underneath you can change your password (link Change Password ) and leave the data portal (link Logout ), respectively. We ask you to always properly log out this way. On the right side of the window you can find information about people and organizations, who are involved in the project (buttons Team, Partners and StationSp ). Further interesting links (button Links ) as well as information about the used software and further sources of information regarding the creation of the homepage (button powered by ) can also be found there. The Help button takes you to this User Guide. Map Control, Map Display, Station Selection The navigation within the map is done by activating the respective button at the upper right corner of the map window (a: overview of the analyzed area, b: zoom in, c: zoom out, d: pan). A station is selected by clicking the button (e) which is also the default active button. Then click the desired station within the map or draw a rectangle over several stations with the mouse. Selected stations are highlighted in yellow. Stations can be selected prior to or after the data selection (regarding the point Data Selection, see below; Fig. 4). Via the button Default Settings the default settings are restored (all settings are reset to default). Under Map Selection various background maps as well as several theme maps can be selected ; confirm your selection by clicking the button (,f). The buttons Station Data, Data Download and Grid data lead to sub-windows, which are described in sections 3 to 5 below. Right next to the Data Download button (in the field Station Types) the link Data Fact Sheet can be found. This Data Fact Sheet provides a concise overview of the station network, the sensors and the WegenerNet status (1-page file in pdf-format). a b c d e f Fig. 3: Main window of the WegenerNet data portal Page 2 of 15
Data Selection (see Fig. 4; select via in Fig. 3) By means of the Data Selection button (in Fig. 4; in Fig. 3) the Data selection window is opened (Fig. 4). Under Data type you can choose the desired data type. Apart from basis data there are the following weather and climate data available (your selection is highlighted blue): Data type Temporal resolution basis data 5 minutes half hourly data 30 minutes hourly data 1 hour daily data 1 day* monthly data 1 month seasonal data 1 season (3 months) - spring: Mar, Apr, May - summer: Jun, Jul, Aug - autumn: Sep, Oct., Nov - winter: Dec (previous year), Jan, Feb annual data 1 year (Jan Dec) meteo. annual data 1 year (Dec of previous year Nov) * Precipitation amount from 06:00 to 06:00 (UTC) of the next day Fig. 4: Data selection window The time period is defined by direct input via keyboard or via a calendar tool (exit the calendar tool by pressing Enter or click the desired day). In the case of basis data you can choose if you would like the data to be displayed in Central European Time (CET), Universal Time (UTC) or Local Time (Vienna/Europe) via Time Zone. Derived (non-basis) data types are processed and provided in UTC. The desired measurement parameters are selected by checking the respective boxes (checkmark appears). Selected parameters, which are not measured by the selected stations, are not displayed subsequently. Wind speed and wind gusts can be displayed in [km/h] or [m/s]. Finally, confirm your selection by clicking the OK button. Page 3 of 15
3) Displaying the Station Data and Information Station Data Window A window with a graphical display of your selection and further information is opened by clicking Station data ( in Fig. 3). On the left side you see the data visualized whereas on the lower right hand side the selected stations are listed. When clicking on one of the stations this station is highlighted in green and in the upper right hand part of the window station details are displayed. If no selection is made, information about Station No. 77 (Reference station) and the time series of the basis data of temperature over the last two weeks is shown by default. This default setting will also be restored when clicking the Default Settings button in the Main window ( in Fig. 3). Fig. 5: Station data window of the WegenerNet data portal Visualization of the measurement data basis data half hourly data hourly data daily data monthly data Data type seasonal data, annual data, meteo. annual data Selected Period [Sel. Period] <= 1 hour 1 hour < Sel. Period < 3 days >= 3 days <= 1 day 1 day < Sel. Period < 2 weeks >= 2 weeks <= 1 day 1 day < Sel. Period < 1 month >= 1 month <= 1 week 1 week < Sel. Period < 3 months >= 3 months <= 1 year 1 year < Sel. Period < 3 years >= 3 years <= 2 years 2 years< Sel. Period < 10 years >= 10 years Displayed Period 1 hour Sel. Period 3 days 1 day Sel. Period 2 weeks 1 day Sel. Period 1 month 1 week Sel. Period 3 months 1 year Sel. Period 3 years 2 years Sel. Period 10 years Page 4 of 15
Precipitation data are presented in a histogram of two types as shown in Fig. 6 (left type for basis data, half hourly data, and hourly data only). Example: Fig. 6 shows hourly sums of precipitation for one day (left) and daily sums for a period of one week (right). Fig. 6: Examples of precipitation data visualization hourly and daily sums 4) Downloading Station Data and Information Data Download Window By clicking Data Download ( in Fig.3) the corresponding window is opened (see Fig. 7). In this window the data and station selection is listed again. At all times the current selection of data is available (for instance the data, which has been displayed graphically in the Station data window previously). By clicking Download the data is downloaded to your computer. The downloaded data are saved in compressed format as.zip -files (archive file), which contains a file in csv -format for every selected station. Further information on station coordinates and altitude is available by clicking Geographical data of stations ( in Fig.7). Fig. 7: Data download window Example: After downloading the.zip archive file (according to the selection in Fig. 7) one receives the three station files contained in the selection: WN_L2_V1_BD_St045_2009-08-01d00h00m_2009-08-04d00h00m_CET.csv WN_L2_V1_BD_St046_2009-08-01d00h00m_2009-08-04d00h00m_CET.csv WN_L2_V1_BD_St047_2009-08-01d00h00m_2009-08-04d00h00m_CET.csv The respective file name contains besides the data product identifiers the station number and the period, which allows for unique identification. For instance WN_L2_V1_BD_St045_2009-08-01d00h00m_2009-08-04d00h00m_CET.csv stands for: WegenerNet_Level2_Version1_BasisData of Station045 for the period 2009-08-01 00:00 hours to 2009-08-04 00:00 hours in Central European Time The file type.csv" (comma-separated-values) is a standardized, easily manageable spread sheet file, which contains data separated by commas and line breaks. Semicolons ; are used as data separator so that the files can be opened and further processed with spread sheet programs such as for instance Open Office Calc (www.openoffice.org) or Microsoft Excel. Alternatively, the files can be viewed with any text editor (pure ASCII format) and can also easily be imported into self-written computer programs. Page 5 of 15
Example: The excerpt from a.csv file "from (CET)";"to (CET)";" Air temperature [ C] (2m)";"QC" 2009-07-31 23:55";"2009-08-01 00:00";"16.360000";"0" "2009-08-01 00:00";"2009-08-01 00:05";"16.410000";"0" "2009-08-01 00:05";"2009-08-01 00:10";"16.390000";"0" is written automatically into the cells A1 through D4 of a spread sheet program when opening the file (if you see ### in individual cells simple increase the column width). In case of Microsoft Excel one needs to note that various (older) Excel versions can behave differently. The following two problems may occur in particular: 1) The correct value 16.36 (from the example above) is displayed as 16.360.000. This means that the decimal point is not recognized and thus not interpreted correctly (as the comma of the number). 2) All data is inserted into column A of the Excel file. This means that the semicolon is not recognized and thus not interpreted as the cell separator. Tips and guides how to resolve such problems can be found in the appendix of this User Guide (pages 8 10). Besides station data, also graphics (like for instance in Fig. 5) are available for easy download: Put the mouse pointer on the image and click the right mouse button; the appearing context menu allows storing the image (.png files with file naming convention corresponding to the.csv files). Structure of the Station Data Files The station data file contains a list of the selected measurement values (incl. quality control flags = QC, see and in Fig.8) for all measurement times from the selected period for the selected data type. In the case of basis data the 5 minutes precipitation amount is assigned to the end date/time of each 5-min period. Example: the precipitation data at 01.08.2009 00:05:00 stand for the precipitation amount accumulated between 01.08.2009 00:00:00 and 01.08.2009 00:05:00. Fig. 8: Structure of a WegenerNet station data file Page 6 of 15
5) Displaying the Grid Data Grid Data Window A window with a graphical display of grid data products is opened by clicking Grid data in Fig. 3 (). The window is arranged referring to the main window of the WegenerNet data portal and consequently only a short overview is given subsequently. You get back to the main window by clicking the link Station data ( in Fig. 9). a b c d Fig. 9: Grid data window of displayed grid data products 11 The navigation within the map is done by activating the respective button at the upper left corner of the map window (a: pan, b: zoom in, c: overview of the analyzed area, d: zoom out). The functionality of a is also given by moving the mouse and hitting the left button at once. The sub-windows (visualization of several elements in the map) and (general map) are activated and deactivated with the sign plus and minus, respectively. Under Parameter you can choose the desired parameter and under Product the data product out of the listed available ones with various time scales (see data types in Fig. 4). Page 7 of 15
The quality of displayed grid data is shown as follows (more information is given in section 7): QC-Flag 0: very good quality data QC-Flag 1: good quality data QC-Flag 2: medium quality data QC-Flag 3: poor quality data QC-Flag 4: bad data Right next () there are some basic statistics of the displayed grid data calculated (arithmetic mean, standard deviation, maximum, minimum). The date is shown below () and it could be changed for one time step by clicking the buttons and. Furthermore the calendar tool is opened by clicking at (). Fig. 10: Calendar tool 6) Downloading Grid Data The grid data products are provided in NetCDF format (Network Common Data Form) which requires appropriate software tools or programming languages. By clicking the button Download NetCDF Files in Fig. 9 ( 11 ) the available data is listed as shown in Fig. 11. The download starts by clicking the desired product. Fig. 11: List of available grid data products, compressed data files (tar.bz2) in UTM (1 km x 1 km) and GEO (0.01 x 0.01 ) More details of containing data could be taken from the descriptions of variables. Page 8 of 15
7) Data Quality and Data Preparation All measurement values are run through an automated Quality Control System (QCS), which checks the fundamental correctness and plausibility of the data. This takes place in near real time immediately following the hourly GPRS/mobile transfer of the data to the Wegener Center. The following table gives a brief explanation of the individual layers: Check Layer Explanation of QCS layers 0 Check regarding station operation: pre-check if QCS layers 1-7 have to be run 1 Check of data availability: check if data is available due to sensor operating 2 3 4 5 6 7 Check of sensor function: check if measurement value exceeds permitted range of technical sensor specifications Check of climatological plausibility: check if measurement value exceeds climatic limits (available from long-term ZAMG measurements) Check of temporal variability: check if measurement value shows too high or too little temporal variability (either unnaturally high jumps or constant values over unnaturally long periods) Check of intra-station consistency: check if measurement value does not properly correlate with other physically interdependent parameters (e.g., correlation between precipitation and humidity) Check of inter-station consistency: check if measurement value shows too much deviation relative to neighboring stations Check against external reference: check if measurement value deviates too much from external reference values (ZAMG stations Feldbach, Bad Gleichenberg) (checked for air pressure, which is only measured by the Reference station) The subsequent Data Product Generator (DPG) is utilizing only measurement values that have passed all QCS station quality checks without errors. If there are gaps in the basis data series, from missing or corrupt values, they get interpolated by several methods depending on the length of missing data. Shorter periods are linearly interpolated in time and, in the case of the basic parameters (temperature, humidity and precipitation), longer periods are spatially interpolated by closest neighboring stations or the closest grid points (of derived grid point data, provided as well in future), respectively. A quality control check flag (QC Flag) is assigned to each measurement value. These QC Flags are stored right next to the respective measurement parameter column in the station data file (see and in Fig. 8). The nature of derivation of the basis data is made transparent this way, but also for the derived data types (time-averaged, etc.) the QC flags have a reasonable qualitative meaning; the QC Flags can be understood as follows: QC Flag 0 Legend and Explanation of DPG QC Flags for basis data derived data types Measurement value has passed all quality checks without errors Very good quality data 1 Temporal interpolation of data point Good quality data 2 3 Spatial interpolation of data point based on data from defined neighboring stations Spatial interpolation of data point based on closest grid points from derived grid data Medium quality data Poor quality data 4 Missing value Bad data or missing value Enhancements are continually in progress and will be implemented in future versions. Page 9 of 15
FINALLY AN IMPORTANT NOTICE The information of the WegenerNet Data Portal is created at the highest scientific and technical standards and improved continually. Despite the applied diligence errors may occur. Therefore, all liability is disclaimed: Please read the Disclaimer in any case (link in the main and registration window, lower right). The WegenerNet Team wishes fun and an informative use of the data portal! Page 10 of 15
Appendix Tips regarding Import of Station Data Files (.csv) into Microsoft Excel When using Microsoft Excel the following settings are useful if the two problems stated in section 4 occur when importing.csv files. Problem 1: The decimal point is not interpreted as the decimal separator/comma of the number Start Excel (with empty workbook) and carry out the steps according to Fig. A.1 and A.2 (note: these changes are maintained and will also be active when working with other Excel files. However, the default setting can be restored very easily): Start Excel with a new empty workbook (or create one with File > New ) and select Tools and Options Fig. A.1: Start of the settings change when working with Microsoft Excel in case of Problem 1 Change in the now opening Options.. window, in the International tab, the settings under Number handling to Decimal separator. and Thousands separator,, as shown in Fig. A.2. Confirm your input by clicking the OK button. (Reset to the original settings, if needed, also in this window) Fig. A.2: Adjustment of settings when using Microsoft Excel in case of Problem 1 Page 11 of 15
Problem 2: The semicolon is not recognized and interpreted as a cell separator If all data are shown in column A (see Fig. A3) then proceed as follows: a Mark the first column (column A) and click Data and Text to Columns Fig. A.3: Start of the settings change when using Microsoft Excel in case of Problem 2 In the subsequently opening window Convert Text to Columns Wizard Step 1 of 3 select Delimited (see Fig. A.4). Fig. A.4: Continuation of the settings adjustment when using Microsoft Excel in case of Problem 2 Page 12 of 15
By clicking the Next > button you get to Convert Text to Columns Wizard Step 2 of 3, where you activate under Delimiters the Semicolon as delimiter (checkmark appears; see Fig. A.5). Fig. A.5: Finalization of the settings adjustment when using Microsoft Excel in case of Problem 2 Finally, confirm the settings by clicking the Complete button (Step 3 of the Text Conversion Assistant is not required). Also these settings can easily be reset back to the original settings using the same windows. Page 13 of 15
Guide to the Display of Graphical Elements If graphics display problems occur like for instance in Fig. A.6 below, the Java plug-in may not be installed or Java Script may not be active. Fig. A.6: Erroneous display of graphical elements Java Plug-In not installed The download is available for your operating system under http://www.java.com. Java script not active The Java script can be activated via the settings of your internet browser. The example given in Fig. A.7 below (next page) illustrates the procedure for Internet Explorer 5.x and 6.x: 1. Click Tools in the Menu Bar and select Internet Options 2. Click the Security tab 3. Select the Internet zone and click "Custom Level " 4. Under Scripting enable the options "Active scripting" and "Scripting of Java applets" 5. Finally, restart your browser. Page 14 of 15
Fig. A.7: Activation of Java script in the Internet Explorer end of document Page 15 of 15