Initial release based on merra1 september 2016 download publicationspecific datasets. In the first level, the longterm reanalysis meteorological data of wind speed, solar irradiation and ambient temperature are acquired from merra, processed via virtual generation systems, and corrected by insitu measured data. It was introduced to replace the original merra dataset because of the advances made in the assimilation system that enable assimilation of modern hyperspectral radiance and microwave observations, along with gps. Over land, merra2 does not seem to show a clear tendency for higher or lower errors when compared to cfsr and merra. Nasas earth observing system data and information system eosdis is a key core capability in nasas earth science data systems program for archiving and distributing earth science data from multiple missions to users. Wind resource data for wind farm developments vortex fdc. This conclusion has been verified in many other studies achberger et al. Wind speed and direction are not directly provided by merra, but computed. Well have it back up and running as soon as possible. To obtain hubheight wind vectors, vertical interpolation was performed on 3hourly vrcesm, 3hourly merra2, 6hourly cfsr, and 3hourly narr products from 1980 to 2000.
Dozens of internal and thirdparty validations prove the higher accuracy of vortex modeled wind resource data. Measurements and reanalysis data on wind speed and solar. Calculated from cfsr specific humidity, maximum temperature, and surface pressure and then linearly interpolated to 0. Quantitative synergy assessment of regional windsolar. Datasets on hubheight wind speed comparisons for wind farms. Online visualization and value added services of merra2. The modernera retrospective analysis for research and applications, version 2 merra 2 provides data beginning in 1980. Includes weather data from 19801984, 2015 and 2016, updated wind fleets, now based on merra 2 june 2017 v1. Initial release based on merra 1 september 2016 download publicationspecific datasets. Sep 24, 2018 calculated from merra specific humidity, maximum temperature, and surface pressure and then linearly interpolated to 0. The definition of speed is valid for the merra data, but has changed in subsequent versions of the geos5 data assimilation system.
However, the uscrn data do not include the wind speed and cloud cover data required for the mepdg models. It is based on a version of the geos5 atmospheric data assimilation system that was frozen in 2008. Cfdda to a lower resolution when made available to the users. Toolbox for wind and site data analysis the global wind atlas is a free, webbased application developed to help policymakers and investors identify potential high wind areas for wind power generation virtually anywhere in the world, and perform preliminary calculations. Specifically, the geosdas version 5 implements incremental analysis updates iau to slowly adjust the model states toward the observed state. A high proportionality among the wind speed and correlation coefficient was found i. Demonstrates the use of the data downloader module of windographer professional edition, which lets you download longterm hourly wind speed, temperature, and pressure data from the merra data set.
Reanalysis and observational datasets and variables available. Questions regarding merra 2 science, modeling and data assimilation should be sent to. There is still ocean surface vector wind data from the european ascat system which provides a partial mitigation for quikscat. The modernera retrospective analysis for research and applications, version 2 merra2 provides data beginning in.
Jun 24, 2010 the modern era retrospectiveanalysis for research and applications was developed to support nasas earth science objectives, by applying the stateoftheart gmao data assimilation system that includes many modern observing systems such as eos in a climate framework. This meant the datasets need to both be of high quality, but also high enough resolution that the downscaling process would not be missing large amounts of information. Yes, it allows free download of merra and merra 2 data, which is often suitable for longterm reference data. To describe the broader wind conditions four of the tools use data from reanalysis models to show the temporal variability in the data as well as the predominant wind directions. The data assimilation is based on a 12hourly fourdimensional variational analysis 4dvar with adaptive estimation of biases in satellite radiance data varbc. How to obtainplotanalyze data advancing reanalysis. The average eastwest zonal wind speed for 45s to 75s. The original data and models used can be downloaded freely on request here, though wed.
The global wind atlas is a product of the world bank and the technical university of denmark. Uncertainty in recent nearsurface wind speed trends. The modernera retrospective analysis for research and applications, version 2 merra2 web service, available worldwide, delivers time series of temperature at 2 m, relative humidity at 2 m, pressure at 2 m, wind speed and direction at 10 m, rainfall, snowfall and snow depth time steps range from 1 min up to 1 month original data are hourly. What is the best data center to download world climatic data. Merra data is availible on a 12 degree latitude by 23 degree longitude grid every 6 hours from 1979 20.
Calculated from merra specific humidity, maximum temperature, and surface pressure and then linearly interpolated to 0. Quikscat was launched in 1999 and was already operating 7 years beyond its design life. The result data frame is used as the parameter to the functions below. There is a good site where you can download up to date climate data such as precipitation, average minimum maximum temperature, relative humidity, wind. Also, the merra 2 budget equations are outlined there. Correlation analysis of ncar, merra and cfsr reanalysis wind data with wind measurements wind speed measurements from 24 masts met masts and 11 colocations on telecommunication masts distributed rather uniformly over sweden have been used in. Online visualization and value added services of merra2 data. We are both a research institute and a 247 operational service, producing global numerical weather predictions and other data for our member and cooperating states and the broader community. Examples of hourly wind speed at 50m ms above surface over europe for a 1985 annual mean, b 1985 maximum, c time series at location marked as x in a x a b c mean7. Also, the merra2 budget equations are outlined there.
This tool facilitates online queries and provides freely downloadable datasets based on the latest input data and modeling methodologies. If youre interested in using this for simulating wind generation, then i highly recommend the paper by cannon et al on analysing the merra data for wind energy simulation. The longterm wind speed estimates using annual data periods have quite a large range, from a low of 7. Latitudepressure cross section of mean zonal wind at 210e for january 2010.
Many of the models described in table 1v were run at a high spatial resolution but the data was truncated e. Global land data assimilation system clm2, mosaic, noah 1979 2005. The trends of wind speed at 850 hpa for jra55 and merra2 figures s4 and s5 show that the jra55 trends at 850 hpa are similar in magnitude to those of both erai and merra2, supporting the hypothesis that the overestimation of the jra55 trends is a feature due to the treatment of the winds near the surface. Exporting data does windographer let me export graphs for my reports. It is currently being produced with the gmaogeos5 data assimilation system version 5. Image is shown for 1 april31 december on the 100hpa surface. Histogram of wind speed for point 25, latitude, longitude. Jul 17, 2019 the wind speed is a phenomena with a much more variable characteristic on a spatial scale and therefore the fit between ground measurements and reanalysis data merra and era5,which are rather spatially coarse, was relatively poor. It was introduced to replace the original merra dataset because of the advances made in the assimilation system that enable assimilation of modern hyperspectral radiance and microwave observations, along with gpsradio occultation datasets. At that point, they provisionally release it for download.
An atrain and merra view of cloud, thermodynamic, and. This is due to the processing time of the data at nasa and the subsetprocessing at emd. Windographer data downloader is a part of the windographer software that lets you download merra data for free for any location on earth. The centre has one of the largest supercomputer facilities and meteorological data archives in the world. Its purpose is to provide quick and easy access to wind resource data globally. Merra 2 data are available at mdisc, managed by the nasa goddard earth sciences ges data and information services center disc. All three series are shown in the graph moving annual and cumulative longterm wind speed estimates. Hi, i downloaded merra 6hourly data of specific humidity, temperature and wind and i cannot read them. If you are looking for the horizontal wind speed at the surface you will likely be better served by downloading the two meter wind speeds u2m and v2m. An assessment of nasas gmao merra2 reanalysis surface. There is a good site where you can download up to date climate data such as precipitation, average minimum maximum temperature, relative humidity, wind speed, global radiationetc.
Merra data containing wind speed data at 2m, 10m and 50m. To obtain hubheight wind vectors, vertical interpolation was performed on 3hourly vrcesm, 3hourly merra 2, 6hourly cfsr, and 3hourly narr products from 1980 to 2000. Time series for nasa merra wind speed and direction are. Apr 10, 2017 the modernera retrospective analysis for research and applications merra dataset was released in 2009. The next section of the tutorial shows the use cases of eda exploratory data analysis that is possible with wind speed and direction time series for a single point location.
How to obtainplotanalyze data by anonymous not verified unfortunately, it is not straight forward to automate the download of erainterim and era40 fields. Windographer data downloader free era5 and merra2 data. Wind speed and direction are not directly provided by merra, but computed from the u and v. Plot is shown for 1 octoberl30 june on the 100hpa surface. No altitude correction applied to the meteorological parameters retrieved by using this service. Includes weather data from 19801984, 2015 and 2016, updated wind fleets, now based on merra2 june 2017 v1. Cfsr wind speed ms mast wind speed ms mast wind speed ms y0. The average eastwest zonal wind speed for 45n to 75n. Exploring the suitability of merra2 reanalysis data for. At any stage of the project lifecycle and for anywhere around the world. Merra2 notes, questions, and discussion advancing reanalysis. I do have automated routines for the conversion of era40 and erainterim to goat format but you need to download the nc files yourself.
Merra 2 is intended to replace the merra reanalysis product which was created with geos5. Exploring the suitability of merra2 reanalysis data for wind. Here details of the reanalysis data used in the global wind atlas are given and. Over land, merra 2 does not seem to show a clear tendency for higher or lower errors when compared to cfsr and merra. Jan 30, 2014 demonstrates the use of the data downloader module of windographer professional edition, which lets you download longterm hourly wind speed, temperature, and pressure data from the merra data set. I was just looking into the wind speed profiles provided by merra 2. The modernera retrospective analysis for research and applications, version 2 merra 2 web service, available worldwide, delivers time series of temperature at 2 m, relative humidity at 2 m, pressure at 2 m, wind speed and direction at 10 m, rainfall, snowfall and snow depth time steps range from 1 min up to 1 month original data are hourly. Nasas merra2 reanalysis is a widely used dataset in renewable energy resource modelling. Reanalyses blend the continuity and breadth of output data of a numerical model with the constraint of vast quantities of observational data. The method using the combined atrain and merra data set has demonstrated that an increase in re within shallow cumulus is strongly related to higher mbl wind speeds that further correspond to increased precipitation occurrence according to cloudsat, previously demonstrated with surface observations.
Datasets on hubheight wind speed comparisons for wind. When the data have been processed at emd, then the following parameters are available from within the online data services within windpro. Retrospectiveanalyses or reanalyses have been a critical tool in studying weather and climate variability for the last 15 years. Yes, you can right click on any graph or wind rose to copy it to the clipboard or export it to a. Where can i freely download global climate data sets. The nasajpl press release and a blog that jeff masters wrote contain some additional information. Merra wind speed and direction dataset has 1 hour time step. Time series for each 4 variables are available since 1 january 1979 up to 31 july 2014 35. When the data have been processed at emd, then the following parameters are available from within the onlinedata services within windpro. The 35 year merra2 data sets that you download using this tool contain hourly time series values of the following four variables. The trends of wind speed at 850 hpa for jra55 and merra 2 figures s4 and s5 show that the jra55 trends at 850 hpa are similar in magnitude to those of both erai and merra 2, supporting the hypothesis that the overestimation of the jra55 trends is a feature due to the treatment of the winds near the surface. There is, however, a lack of an analysis of the performance of merra2 with bias correction from gwa on different spatial levels and for regions outside of europe, china or the united states.
Wind speed at 50m above ground ms wind direction at 50m above ground temperature at ground level c pressure at ground level kpa the merra data sets are no longer being updated and include data through. The modernera retrospective analysis for research and applications, version 2 merra2 provides data beginning in 1980. Merra data is commonly available within windpro with a timelag of 12 months. With some exceptions, erainterim uses input observations prepared for era40 until 2002, and data from ecmwfs operational archive thereafter.
An assessment of nasas gmao merra2 reanalysis surface winds. You might also be interested in the cfsr data, which runs 19792010. Sep 25, 2015 merra 2 is a reanalysis data product from nasagmao. The modernera retrospective analysis for research and applications, version 2 merra 2 web service, available worldwide, delivers time series of temperature at 2 m, relative humidity at 2 m, pressure at 2 m, wind speed and direction at 10 m, rainfall, snowfall and snow depth. Ecmwf is the european centre for mediumrange weather forecasts.
Other sites may also have the data ncar, for example and those methods would be different than those below. The merra time period covers the modern era of remotely sensed data, from. Merra data span the period 1979 through february 2016 and were produced on a 0. Questions regarding merra2 science, modeling and data assimilation should be sent to. The lowest level 3d wind speed is given at an height of about 65m. The wind speed is a phenomena with a much more variable characteristic on a spatial scale and therefore the fit between ground measurements and reanalysis data merra and era5,which are rather spatially coarse, was relatively poor. Where can i get archived hourly wind speed data for germany. Webbased reanalysis intercomparison tools writ allows users to quick analyze and intercompare multiple contemporary reanalyses data. It would have been ideal to evaluate mepdg performance predictions using the uscrn ground truth data in addition to the medpg and merra weather time series. Wind speed and direction tutorial climate wikience.
I was just looking into the wind speed profiles provided by merra2. After data is produced, the gmao examines the data files in several ways to test the. Information on merra 2 data files can be found in bosilovich et al. Time series for nasa merra wind speed and direction are now. Apr 28, 2009 quikscat was launched in 1999 and was already operating 7 years beyond its design life. Reanalysis and observational datasets and variables. I need the surface wind speed in merra, and the file specification document. Stilling and recovery of the surface wind speed based on. The data used in the global wind atlas was chosen from the best availible global datasets for each required category.
Yes, it allows free download of merra and merra2 data, which is often suitable for longterm reference data. Information on merra2 data files can be found in bosilovich et al. However, these validations do not capture errors and uncertainties introduced when wind speeds are extrapolated from 10m to typical wind turbine hub heights using assumed vertical wind speed pro. For the wind speed and direction merra2 shows lower rmse values than cfsr and merra over practically all the world oceans, but higher than the jra55 and erai in the tropics particularly for the wind speed. Unified user interface at nasa, uui, data, ges disc, datasets.
The modernera retrospective analysis for research and applications merra dataset was released in 2009. Acronym full name time period grid resolution variables used. I use era interim monthly means of daily means data for. The global wind atlas is a free, webbased application developed to help policymakers and investors identify potential highwind areas for wind power generation virtually anywhere in the world, and perform preliminary calculations. Surprisingly, i found the 50m wind speed being exactly the same value as the lowest level 3d wind speed. To improve forecasts, data are assimilated in the numerical model. The global wind atlas gwa has been used to biascorrect merra2 data before.
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