Meteo Observations at IGMK

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mrr [2020/08/30 15:34] – [Measurement modes] bpospichmrr [2021/03/01 10:17] (current) – [Link to current observations] bpospich
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 ===== Principle ===== ===== Principle =====
  
-The **Micro Rain Radar (MRR)** is a vertical pointing FM-CW (frequency modulated –continuous wave) Doppler radar operating at 24.1 GHz (K-band, 12.4 mm wavelength). The emitted radar signal (only 50 mW transmitting power) is backscattered by falling hydrometeors (rain, graupel, snow). From the Doppler spectra the radar reflectivity factor (Ze) and the terminal fall velocity distribution can be derived. The range resolution can be varied from 10 to 200 m which determines together with the 30 range gates the system's maximum height range of 300 -6000 m. In case of rain the Doppler spectra can be used to derive vertical profiles of microphysical rain properties like drop size distribution and rain rate. The MRR system was also studied for its potential to observe snowfall ([[https://link.springer.com/article/10.1007/s00703-011-0142-z|Kneifel et al., 2011]]). Also, an improved MRR algorithm most suitable for snowfall observations has been developed at IGMK is freely available on [[https://github.com/maahn/IMProToo|Github]]+The **Micro Rain Radar (MRR)** is a vertical pointing FM-CW (frequency modulated –continuous wave) Doppler radar operating at 24.1 GHz (K-band, 12.4 mm wavelength). The emitted radar signal (only 50 mW transmitting power) is backscattered by falling hydrometeors (rain, graupel, snow). From the Doppler spectra the radar reflectivity factor (Ze) and the terminal fall velocity distribution can be derived.  
 + 
 +In case of rain the Doppler spectra can be used to derive vertical profiles of microphysical rain properties like drop size distribution and rain rate.  
 + 
 +The MRR system was also studied for its potential to observe snowfall ([[https://link.springer.com/article/10.1007/s00703-011-0142-z|Kneifel et al., 2011]]). Also, an improved MRR algorithm **IMProToo** most suitable for snowfall observations has been developed at IGMK ([[https://amt.copernicus.org/articles/5/2661/2012/amt-5-2661-2012.html|Maahn and Kollias, 2012]]). It is freely available on [[https://github.com/maahn/IMProToo|Github]].
 ===== Measurement modes ===== ===== Measurement modes =====
  
   * Vertically pointing observations with integration times from 10 to 3600 seconds.     * Vertically pointing observations with integration times from 10 to 3600 seconds.  
-  * 30 range gates with 10 to 200 meters distance (maximum range is 300 to 6000 meters)+  * The range resolution can be varied from 10 to 200 m which determines together with the 30 range gates the system's maximum height range of 300 to 6000 m. 
  
  
 ===== JOYCE-CF Standard Operation Procedures ===== ===== JOYCE-CF Standard Operation Procedures =====
  
-  * Standard measurement mode is vertically pointing, 2 second integration time  +  * Temporal resolution 10 seconds 
-  * Every 30 minutes one azimuth scan at 83° elevation angle with 6° azimuth resolution (duration ~2 minutes) for horizontal wind within clouds and the boundary layer (if sufficient insects are present)+  * Vertical resolution 35 meters (max. range = 1085 m)
  
 ===== Calibrations and data quality assurance procedures ===== ===== Calibrations and data quality assurance procedures =====
-  * Check with co-located disdrometer to find out reflectivity offsets +  * ImProToo features a noise removal based on recognition of the most significant peak and a dynamic dealiasing routine which allows observations even if the Nyquist velocity range is exceeded. 
-  * Consistency check with other cloud radars+
  
 ===== Data availability ===== ===== Data availability =====
  
-Some of the following data products are provided via Cloudnet [[https://cloudnet.fmi.fi/|ACTRIS cloudnet website]] with a temporal resolution of 30 seconds. If you would like to have additional data with better resolution or raw Doppler spectra please fill the {{ :joyce_data_request_form.pdf |data request sheet}} and send it to [[mailto:info@joyce.cloud|info@joyce.cloud]] +Data are available on request, please fill the {{ :joyce_data_request_form.pdf |data request sheet}} and send it to [[mailto:info@joyce.cloud|info@joyce.cloud]]. 
- + 
 ^ Dataset     ^ Temporal resolution       ^ File size          ^ Filename   ^ Remarks   ^  ^ Dataset     ^ Temporal resolution       ^ File size          ^ Filename   ^ Remarks   ^ 
-| Radar reflectivity factor   | 30 seconds    | 1 file per day (30-50 MB)     | //YYYYMMDD_juelich_categorize.nc//  | available via Cloudnet   | +| Raw data (ASCII)   | 10 seconds    | 1 file per day (~15 MB)     | //YYYYMMDD_jue_mrr_raw_txt.gz//  | METEK format (zipped)   | 
-| Doppler velocity   | 30 seconds    | 1 file per day (30-50 MB)     | //YYYYMMDD_juelich_categorize.nc//  | available via Cloudnet   | +| IMProToo (NetCDF)   | 1 minute    | 1 file per day (20-30 MB)     | //YYYYMMDD_jue_mrr_improtoo_0-101.nc.gz//  | [[https://github.com/maahn/IMProToo|IMProToo]] product (zipped) |
-| Spectral width   | 30 seconds    | 1 file per day (30-50 MB)     | //YYYYMMDD_juelich_categorize.nc//  | available via Cloudnet    | +
-| Linear depolarization ratio   | 30 seconds    | 1 file per day (30-50 MB)     | //YYYYMMDD_juelich_categorize.nc//  | available via Cloudnet    | +
-| Profiles of horizontal wind | 30 minutes | 1 file per day (30-50 MB)     | //YYYYMMDD_joyrad35_wind_profile.nc//  |  |  +
-| Radar moments  | 2 seconds   | variable size (up to 30 MB/hour in case of thick clouds)  | //YYYYMMDD_HHMM.mmclx.gz//  | zipped NetCDF file  | +
-| Doppler spectra, Radar moments  | 2 seconds   | variable size (up to 2 GB/hour in case of thick clouds)  | //YYYYMMDD_HHMM.znc//  | NetCDF file  | +
-| Doppler spectra  | 2 seconds   | variable size (up to 1 GB/hour in case of thick clouds)  | //YYYYMMDD_HHMM.zspc//  | Binary file  |+
  
 +Both available datasets include Doppler spectra, drop spectra, radar reflectivity, rain rate, and fall velocity.
  
  
-  * **Dual-wavelength ratio** Ka/X-Band and Ka/W-Band [[http://gop.meteo.uni-koeln.de/~Hatpro/dataBrowser/dataBrowser2.html?site=TRIPEX-pol&date=-1&UpperLeft=3radar_Ze&UpperRight=3radar_DWR|Link to Quicklooks]]   
-  * **Cloudnet target classification** uses Radar moments data from JOYRAD-35. Combined with microwave radiometer and ceilometer observation, clouds are characterized by their geometrical extent as well as their microphysical properties.  
  
 ===== Link to current observations ===== ===== Link to current observations =====
  
-Data quicklooks can be found in the [[http://gop.meteo.uni-koeln.de/~hatpro/dataBrowser/dataBrowser2.html?site=JOYCE&date=-1&UpperLeft=Joyrad35_Overview&UpperRight=Joyrad35_wind_ppi|JOYCE quicklook archive]] and in the [[https://guest.metek.de/skripts/animate_hourly_xcrl_skew.html?nic=juel|METEK archive]]+Data quicklooks can be found in the [[http://atmos.meteo.uni-koeln.de/~hatpro/dataBrowser/dataBrowser3.html?site=JOYCE&date=-1&UpperLeft=MRR_IMProToo&UpperRight=MRR_AveData&LowerRight=Parsivel-Pluvio-MRR_precipitation-rate|JOYCE quicklook browser]].
  
 ===== Measurement examples ===== ===== Measurement examples =====
  
-{{wiki:examples:200704_jue_l2_radar.png?direct&400|JOYRAD-35_obs}} +{{wiki:examples:20200617_jue_mrr_improtoo.png?direct&400|MRR_IMProToo}} 
-{{wiki:examples:20200704_joyrad35_wind_profile.png?direct&400|JOYRAD-35_wind}} \\ +{{wiki:examples:rr_pars_plu_mrr_20200617.png?direct&400|Rain_rate}} \\ 
-//Example time series of JOYRAD-35 observations (radar moments / horizontal wind)// +//Example time series of MRR observations (left: IMProToo radar reflectivity, spectral width, rain rate and mean spectral noise / right: rain rates from MRR (bottom), compared to Parsivel and Pluvio)//
- +
  
-{{wiki:examples:20200704_juelich_classification.png?direct&800|Cloudnet_target_classification}} \\ 
-//Example time series of Cloudnet target classification// 
  
  
  
-===== JOYRAD-35 History =====+===== MRR History =====
 ^  Period  ^  Place  ^  Project  ^ ^  Period  ^  Place  ^  Project  ^
-| 2017 |  |  Instrument upgrade | +| 03/2012 - today | Research Centre Jülich | [[http://www.tr32.de|TR32]] | 
-| 09/03/2012 - today | [[http://www.fz-juelich.de/|Research Center Jülich]], Germany | JOYCE | +| 04/2008 - 10/2011 | [[http://www.fz-juelich.de/icg/icg-4/index.php?index=500|Selhausen]], Germany | [[http://www.tr32.de|TR32]] | 
-| 08/11/2011 - 08/03/2012 | Munich Airport, Germany| iPort campaign | +| 05 - 12/2007 | Heselbach, Blackforest, Germany | COPS | 
-| 03/2011 - 07/11/2011 | [[http://www.fz-juelich.de/|Research Center Jülich]], Germany | JOYCE |+| 2006 - 2007 | Nangatchori, Benin | [[http://amma-international.org/|AMMA]] |
  
  
-{{:wiki:instruments:joyrad35_07.jpg?direct&600|JOYRAD-35 ©B. Pospichal}} \\ 
-//Cloud radar JOYRAD-35 installed at Jülich// 
  
  
mrr.1598801661.txt.gz · Last modified: 2020/08/30 15:34 by bpospich