Radiation Explorer in the Far InfraRed - Prototype for Applications and Developments

REFIR-PAD results and available data

• PRANA campaign at Concordia Base, Dome C, Antartica, 2011-2013
  
• Test campaign at Testa Grigia, Plateau Rosa, Italy, March 2011
• RHUBC-II campaign at Cerro Toco , Atacama, Chile, August-October 2009
  
• ECOWAR-COBRA campaign at Testa Grigia, Plateau Rosa, Italy, March 2007
• First wideband spectral measurement of the Earth's upwelling emission, Teresina, Brazil, 30 June 2005
  
• NEWS - CNR (15/12/2005)( CNR web site or pdf file) (in Italian)

Measurements of the spectrum of DLR (Downward Longwave Radiation) were performed from ground at high-altitude sides and of OLR (Outgoing Longwave Radiation) from stratospheric balloon. Table here below reports available data.

REFIR-PAD at Concordia Station 75°S 123°E - Dome-C - Antarctica

Contact: Luca Palchetti luca.palchetti@ino.it, Giovanni Bianchini giovanni.bianchini@ino.it
Istituto Nazionale di Ottica, INO-CNR, Via Madonna del Piano 10, 50019 Sesto Fiorentino (I)
Tel. +39.055.522.6311, Fax. +39.055.522.6348

The instrument was installed at Concordia Station in December 2011, and since then, it has been performing automatic measurements all over the year with cycles of 5-6 hours of sky measurements and 1.5-3 hours of preliminary data analysis, whose results are sent to Italy in near real time, see plots below.

REFIR-PAD is operated under different projects supported by the Italian Programma Nazionale di Ricerche in Antartide (PNRA.).

PRANA - Radiative Properties of Atmospheric Water vapour and clouds in Antarctica
PNRA Project No. 2009/A4.03 - 2011-2013

The main objective of the PRANA (Proprieta' Radiative del vapore Acqueo e delle nubi in Antartide - Radiative Properties of Atmospheric Water vapour and clouds in Antarctica) research project is the monitoring and the spectral characterisation of the downwelling longwave radiation (DLR) from 100 to 1400 cm^-1 emitted by the atmosphere in different sky conditions. This measurement will allow to improve the knowledge in the under-explored far infrared (FIR) spectral region of the emission spectrum from 100 to 400 cm^-1. In particular, the modelling of the pure rotational water vapour band and the radiative properties of high altitude ice clouds, such as cirrus and polar stratospheric clouds (PSC), will be studied in depth. As the modelling capabilities is validated, the measurement can be used for the estimation of the total precipitable water vapour content (PWV) and the PSC coverage.
The spectral measurement of the downwelling radiance are performed by REFIR-PAD. Cloud characterisation are performed by a LIDAR system and ICECAMERA, which are operative on the site. Both instruments are installed in the Physics shelter devoted to atmospheric physics.
PRANA started in December 2011 with the XXVII scientific expedition (Italia in Antartide).

CoMPASs - Concordia Multi-Process Atmospheric Studies
PNRA Project No. 2013/AC3.01 - 2013-2014

The CoMPASs project has been developed in order to identify and characterize these feedbacks and interactions between processes, spanning across three different atmospheric regions: the boundary layer, the troposphere and the stratosphere. The main research themes follow the vertical structure of the atmosphere:
- Characterization of the atmospheric boundary layer (ABL) in terms of dynamics, turbulence and radiation, especially during the winter period, in which the ABL has peculiar properties in terms of reduced thickness and extreme sensitivity to external forcing.
- Study of the clouds in the free troposphere, which, in the region of Dome C, shows a remarkable variability, both daily and seasonal, and therefore requires continuous monitoring to quantify its interactions with the neighboring atmospheric layers.
- Study of the stratospheric processes within the Antarctic polar vortex, as ozone chemistry and polar stratospheric clouds, carried out throughout the year in order to constantly follow the evolution of the vortex itself.
CoMPASs makes use of a strong observational component, deploying an array of different instruments all characterized by the vertical remote sensing measurement technique: stratospheric and tropospheric lidars, UV and middle/far-infrared spectroradiometers, and a high-resolution mini-sodar. The study involves different spatial and temporal scales. The prevalent use of remote sensing instrumentation from the ground allows the characterization of a large part of the atmosphere. The instrumentation is expected to operate continuously, automatically or semi-automatically through the intervention of personnel present even during the winter season, thus obtaining a characterization of processes with temporal coverage on different scales (daily, seasonal, annual).

STRRAP-b - STudy of the Radiative Regimes over the Antarctic Plateau and beyond
PNRA Project No. 2013/AC3.06 - 2013-2014

The project aims to deepen the knowledge on the Antarctic Plateau radiative regime and its regulating processes, through in situ radiometric measurements coupled with remote sensing techniques, using broadband and hyperspectral instrumentation. Specifically, the project aims to define accurately the effects of cloud cover, ozone and water vapor, and surface reflectance properties on the radiative balance over the East antarctic Plateau. For the different conditions of cloud coverage, the downwelling and upwelling solar radiation will be spectrally and geometrically characterized. Information provided by the BSRN station and new instrument implementations will be exploited to calibrate/validate satellite retrieval products related to the surface reflectivity, and provide validated measures of the components of solar and infrared irradiance incident and reflected by the surface. The use of satellite information properly configured over the Antarctic in conjunction with the data provided by the other three BSRN stations operated in Antarctica (SPO, SYO, GVN), will allow researchers to expand definitions of the radiative regimes to a regional scale and possibly up along the coast. Atmospheric corrections will be taken into account by ground based remote sensing of columnar ozone, measurements of UV spectral radiation, while water vapor will be measured by various platforms including radiosonde, REFIR-PAD IR radiometer and HAMSTRAD MW radiometer.

REFIR-PAD products

REFIR-PAD supplies the following products:

• Raw measurement data (level 0)
• Non apodized calibrated spectra of the down-welling radiance (level 1). In the range of 100-400 cm^-1 these measurements are unique.
• Geophysical products (level 2): water vapour and temperature vertical profiles and total precipitable water vapour (PWV)

Expected uncertainties are for Brightness temperature error about 0.1K (@ 280K),and for PWV about 5%.

Real-time data from REFIR-PAD and auxiliary instruments at the Physics shelter

Downwelling emission spectrum

Sky views at beginning, middle and end of measurements
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Main housekeepings