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Table of Contents
Atmospheric Emitted Radiance Interferometer (AERI)
Principle
The AERI is an operational infrared spectrometer that measures the downwelling infrared radiance from 3.3-19 µm at 1 cm-1 resolution. Like the microwave spectrum, the infrared spectrum also contains information on the vertical profile of temperature and humidity. Spectral observations from 612-713 cm-1 and 2223-2260 cm-1 (i.e., measurements from the 15 µm and 4.3 µm CO2 bands, respectively) are used for temperature profiling, and observations from 538-588 cm-1 and 1250-1350 cm-1 (i.e., measurements from the wings of the rotational and 6.3 µm water vapor bands, respectively) for water vapor profiling. Additionally, selected window channels provide information on low-LWP (< 50 gm-2) liquid water cloud effective radius and cloud optical depth as well as ice clouds and aerosol. Currently, our AERI is also used for columnar trace gas retrieval (CO2, CH4, N2O).
Measurement modes
- Vertically pointing observations with integration times from 10 to 3600 seconds.
- 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
- Temporal resolution 10 seconds
- Vertical resolution 35 meters (max. range = 1085 m)
Calibrations and data quality assurance procedures
- 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.
Data availability
Data are available on request, please fill the data request sheet and send it to info@joyce.cloud. Both datasets include Doppler spectra, drop spectra, radar reflectivity, rain rate, and fall velocity.
Dataset | Temporal resolution | File size | Filename | Remarks |
---|---|---|---|---|
Raw data (ASCII) | 10 seconds | 1 file per day (~15 MB) | YYYYMMDD_jue_mrr_raw_txt.gz | METEK format (zipped) |
IMProToo (NetCDF) | 1 minute | 1 file per day (20-30 MB) | YYYYMMDD_jue_mrr_improtoo_0-101.nc.gz | IMProTpo product (zipped) |
- AERI on webmads link: This link shows the current observation of AERI instruments around the world
- Current observations:
Link to current observations
Data quicklooks can be found in the http://gop.meteo.uni-koeln.de/~Hatpro/dataBrowser/dataBrowser3.html?site=JOYCE&date=-1&UpperLeft=MRR_IMProToo&UpperRight=MRR_AveData&LowerRight=Parsivel-Pluvio-MRR_precipitation-rate.
Measurement examples
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)
AERI History
Period | Place | Project |
---|---|---|
May 13, 2011 - today | Forschungszentrum Jülich | JOYCE |
Technical Specifications
Parameter | Specification | Remark |
---|---|---|
Spectral range receiver 1 | 5-19 µm | corresponds to 2000 to 520 cm-1 |
Spectral range receiver 2 | 3.3-5 µm | corresponds to 3000 to 1800 cm-1 |
Spectral resolution | 1 cm-1 | |
Number of channels | ~2500 per receiver | |
Front end | gold-coated mirror, optical paths redirect radiation into back end | |
Calibration targets | 2 black bodies (ambient and hot load) | 3rd target optional |
Back end | FT-IR (Fourier Transform Infrared) spectrometer (ABB) | |
Temporal resolution | ~1 min for one spectrum | 142 interferometer sweeps / min. |
Manufacturer | ABB Analytical Business, Québec, CANADA |