scholarly journals Can turbulence within the field of view cause significant biases in radiative transfer modelling at the 183 GHz band?

2018 ◽  
Author(s):  
Xavier Calbet ◽  
Niobe Peinado-Galan ◽  
Sergio DeSouza-Machado ◽  
Emil Robert Kursinski ◽  
Pedro Oria ◽  
...  
Keyword(s):  
Radiative Transfer ◽  
Water Vapour ◽  
Scale Up ◽  
Field Of View ◽  
Uniform Field ◽  
Upper Troposphere ◽  
Air Turbulence ◽  
Water Vapour Absorption ◽  
Novel Method ◽  
Transfer Modelling

Abstract. The hypothesis whether turbulence within the passive microwave sounders field of view can cause significant biases in radiative transfer modelling at the 183 GHz water vapour absorption band is tested. A novel method to calculate the effects of turbulence in radiative transfer modelling is presented. It is shown that the turbulent nature of water vapour in the atmosphere can be a critical component of radiative transfer modelling in this band. Radiative transfer simulations are performed comparing a uniform field with a turbulent one. These comparisons show frequency dependent biases which can scale up to several Kelvin in brightness temperature. These biases can match experimentally observed biases, such as the ones reported in Brogniez et al. (2016). Our simulations show that those biases could be explained as an effect of high intensity turbulence in the upper troposphere. This kind of turbulence is common in clear air turbulence, storm or cumulus cloud situations.

scholarly journals Can turbulence within the field of view cause significant biases in radiative transfer modeling at the 183 GHz band?

2018 ◽  
Vol 11 (12) ◽  
pp. 6409-6417 ◽  
Author(s):  
Xavier Calbet ◽  
Niobe Peinado-Galan ◽  
Sergio DeSouza-Machado ◽  
Emil Robert Kursinski ◽  
Pedro Oria ◽  
...  
Keyword(s):  
Water Vapor ◽  
Radiative Transfer ◽  
Field Of View ◽  
Uniform Field ◽  
Water Vapor Absorption ◽  
Air Turbulence ◽  
Vapor Absorption ◽  
High Turbulence ◽  
Novel Method ◽  
Radiative Transfer Modeling

Abstract. The hypothesis whether turbulence within the passive microwave sounders field of view can cause significant biases in radiative transfer modeling at the 183 GHz water vapor absorption band is tested. A novel method to calculate the effects of turbulence in radiative transfer modeling is presented. It is shown that the turbulent nature of water vapor in the atmosphere can be a critical component of radiative transfer modeling in this band. Radiative transfer simulations are performed comparing a uniform field with a turbulent one. These comparisons show frequency dependent biases which can be up to several kelvin in brightness temperature. These biases can match experimentally observed biases, such as the ones reported in Brogniez et al. (2016). Our simulations show that those biases could be explained as an effect of high-intensity turbulence in the upper troposphere. These high turbulence phenomena are common in clear air turbulence, storm or cumulus cloud situations.

On the structure of instantaneous radiative forcing kernels for greenhouse gases

2020 ◽  
Author(s):  
Amanda C. Maycock ◽  
Christopher J. Smith ◽  
Alexandru Rap ◽  
Owain Rutherford
Keyword(s):  
Greenhouse Gases ◽  
Water Vapour ◽  
Radiative Forcing ◽  
Small Amplitude ◽  
The Other ◽  
Background Concentration ◽  
Upper Troposphere ◽  
Water Vapour Absorption ◽  
Cloud Radiative Effects ◽  
Absorption Features

AbstractThe SOCRATES offline radiative transfer code is used to investigate the magnitude and structure of the instantaneous radiative forcing kernels (IRFKs) for five major greenhouse gases (GHGs; CO2, CH4, N2O, CFC-11, and O3). All gases produce IRFKs that peak in the tropical upper troposphere. In addition to differences in spectroscopic intensities and the position of absorption features relative to the peak of the Planck function for Earth’s temperature, the variation in current background concentration of gases substantially affects the IRFK magnitudes. When the background concentration of CO2 is reduced from parts per million to parts per trillion levels, the peak magnitude of the IRFK increases by a factor of 642. When all gases are set to parts per trillion concentrations in the troposphere, the peak IRFK magnitudes are 1.0, 3.0, 3.1, 58 and 75 Wm−2 ppmv−1 100 hPa−1 for CH4, CO2, N2O, O3 and CFC-11, respectively. The altitude of the IRFK maximum also differs, with the maximum for CFC-11 and water vapour occurring above 100 hPa while the other gases peak near 150-200 hPa. Overlap with water vapour absorption decreases the magnitude of the IRFKs for all the GHGs, particularly in the low-to-mid troposphere, but it does not strongly affect the peak IRFK altitude. Cloud radiative effects reduce the magnitude of the IRFK for CO2 by around 10-20% in the upper troposphere. The use of IRFKs to estimate IRF is found to be accurate for small amplitude perturbations, but becomes inaccurate for large amplitude changes (e.g. a doubling) for gases with a higher atmospheric optical depth.

scholarly journals Consistency between GRUAN sondes, LBLRTM and IASI

2017 ◽  
Vol 10 (6) ◽  
pp. 2323-2335 ◽  
Author(s):  
Xavier Calbet ◽  
Niobe Peinado-Galan ◽  
Pilar Rípodas ◽  
Tim Trent ◽  
Ruud Dirksen ◽  
...  
Keyword(s):  
Radiative Transfer ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
Climate Data ◽  
Night Time ◽  
Upper Troposphere ◽  
Atmospheric Sounding ◽  
Data Record ◽  
Water Vapour Absorption ◽  
Reference Measurements

Abstract. Radiosonde soundings from the GCOS Reference Upper-Air Network (GRUAN) data record are shown to be consistent with Infrared Atmospheric Sounding Instrument (IASI)-measured radiances via LBLRTM (Line-By-Line Radiative Transfer Model) in the part of the spectrum that is mostly affected by water vapour absorption in the upper troposphere (from 700 hPa up). This result is key for climate data records, since GRUAN, IASI and LBLRTM constitute reference measurements or a reference radiative transfer model in each of their fields. This is specially the case for night-time radiosonde measurements. Although the sample size is small (16 cases), daytime GRUAN radiosonde measurements seem to have a small dry bias of 2.5 % in absolute terms of relative humidity, located mainly in the upper troposphere, with respect to LBLRTM and IASI. Full metrological closure is not yet possible and will not be until collocation uncertainties are better characterized and a full uncertainty covariance matrix is clarified for GRUAN.

scholarly journals Ground-based FTIR water vapour profile analyses

2009 ◽  
Vol 2 (2) ◽  
pp. 609-619 ◽  
Author(s):  
M. Schneider ◽  
F. Hase
Keyword(s):  
Remote Sensing ◽  
Fourier Transform ◽  
Radiative Transfer ◽  
Water Vapour ◽  
Line Shape ◽  
Trace Gases ◽  
Vertical Gradient ◽  
Logarithmic Scale ◽  
Shape Model ◽  
Transfer Modelling

Abstract. Due to a large vertical gradient and strong variability of water vapour, algorithms that are effectively applied for ground-based remote sensing of many different atmospheric trace gases can be insufficient for the retrieval of tropospheric water vapour profiles. We review the most important features of the retrieval and of the radiative transfer modelling required for accurate monitoring of tropospheric water vapour profiles by ground-based FTIR (Fourier Transform Infrared) experiments. These are: a fit of a variety of different water vapour lines with different strength, a logarithmic scale inversion, a speed dependent Voigt line shape model, and a joint temperature profile retrieval. Furthermore, the introduction of an interspecies constraint allows for a monitoring of HDO/H2O ratio profiles.

Failure Analysis Case Study of a 1.5 Meter Space Flex Harness

2017 ◽  
Author(s):  
Erick Kim ◽  
Kamjou Mansour ◽  
Gil Garteiz ◽  
Javeck Verdugo ◽  
Ryan Ross ◽  
...  
Keyword(s):  
Failure Analysis ◽  
Failure Modes ◽  
Field Of View ◽  
Area Of Interest ◽  
Air Stream ◽  
Novel Method ◽  
Temperature Controlled ◽  
Non Destructive ◽  
Failure Site

Abstract This paper presents the failure analysis on a 1.5m flex harness for a space flight instrument that exhibited two failure modes: global isolation resistances between all adjacent traces measured tens of milliohm and lower resistance on the order of 1 kiloohm was observed on several pins. It shows a novel method using a temperature controlled air stream while monitoring isolation resistance to identify a general area of interest of a low isolation resistance failure. The paper explains how isolation resistance measurements were taken and details the steps taken in both destructive and non-destructive analyses. In theory, infrared hotspot could have been completed along the length of the flex harness to locate the failure site. However, with a field of view of approximately 5 x 5 cm, this technique would have been time prohibitive.

scholarly journals The Impact of Post-Manufacture Treatments on the Surface Characteristics Important for Finishing of OSB and Particleboard

Forests ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 975
Author(s):  
Antonio Copak ◽  
Vlatka Jirouš-Rajković ◽  
Nikola Španić ◽  
Josip Miklečić
Keyword(s):  
Water Vapour ◽  
Oriented Strand Board ◽  
Construction Material ◽  
Surface Characteristics ◽  
Surface Treatments ◽  
Factors Affecting ◽  
Treatment Conditions ◽  
Water Vapour Absorption ◽  
The Impact

Oriented strand board (OSB) is a commonly used structural wood-based panel for walls and roof siding, but recently the industry has become interested in OSB as a substrate for indoor and outdoor furniture. Particleboard is mainly used in furniture productions and has become popular as a construction material due to its numerous usage possibilities and inexpensive cost. Moisture is one of the most important factors affecting wood-based panel performance and the post-treatment conditions affected their affinity to water. When OSB and particleboard are used as substrates for coatings, their surface characteristics play an important role in determining the quality of the final product. Furthermore, roughness can significantly affect the interfacial phenomena such as adsorption, wetting, and adhesion which may have an impact on the coating performance. In this research particleboard and OSB panels were sanded, re-pressed and IR heated and the influence of surface treatments on hardness, roughness, wetting, water, and water vapour absorption was studied. Results showed that sanding improved the wetting of particleboard and OSB with water. Moreover, studied surface treatments increased water absorption and water penetration depth of OSB panels, and re-pressing had a positive effect on reducing the water vapour absorption of particleboard and OSB panels.

Sign in / Sign up

Export Citation Format

Share Document