Recalibration of the far-infrared brightness temperatures of the planets

1976 ◽  
Vol 210 ◽  
pp. 250 ◽  
Author(s):  
E. L. Wright
Keyword(s):  
Far Infrared ◽  
Brightness Temperatures ◽  
Infrared Brightness

Far-Infrared Brightness Temperatures of the Planets

1972 ◽  
Vol 178 ◽  
pp. L89 ◽  
Author(s):  
K. R. Armstrong ◽  
D. A., Jr. Harper ◽  
F. J. Low
Keyword(s):  
Far Infrared ◽  
Brightness Temperatures ◽  
Infrared Brightness

scholarly journals Barred Extreme IRAS Galaxies

1996 ◽  
Vol 157 ◽  
pp. 256-258
Author(s):  
Wim van Driel ◽  
Bert van den Broek
Keyword(s):  
Star Formation ◽  
Massive Star ◽  
Formation Rate ◽  
Far Infrared ◽  
Radio Continuum ◽  
Massive Star Formation ◽  
Barred Galaxies ◽  
Interacting Systems ◽  
Isolated Systems ◽  
Infrared Brightness

AbstractWe studied a statistically complete sample of 57 southern socalled extreme IRAS galaxies, i.e., objects with a high far-infrared/blue luminosity ratio, LFIR/LB>3, using optical (imaging and spectra), radio continuum, and CO(1–0) line observations. The sample can be divided into three distinct categories: dwarfs (20%), barred spirals (35%), and interacting systems (35%). The barred galaxies are generally morphologically undisturbed, isolated systems, with average star formation rates (4 M⊙ yr–1) and efficiencies (LFIR/MH2 = 16 L⊙/M⊙) for galaxies in our sample. An enhanced massive star formation rate is the cause of the infrared brightness in 93% of all galaxies in the sample. The nuclear region is the most important star formation locus, generally unresolved at 1" resolution, i.e., less than 0.2-0.6 kpc size (H0=75 km s–1 Mpc–1), though 2 kpc size in three cases. In about two-thirds of the extreme IRAS SB’s, fainter, diffuse (2.5-10 kpc size) massive star formation is seen in the bar as well.

How microphysical choices affect simulated infrared brightness temperatures

2015 ◽  
Vol 156 ◽  
pp. 67-79 ◽  
Author(s):  
S. Eikenberg ◽  
C. Köhler ◽  
A. Seifert ◽  
S. Crewell
Keyword(s):  
Brightness Temperatures ◽  
Infrared Brightness

scholarly journals Assessing the Accuracy of the Cloud and Water Vapor Fields in the Hurricane WRF (HWRF) Model Using Satellite Infrared Brightness Temperatures

2017 ◽  
Vol 145 (5) ◽  
pp. 2027-2046 ◽  
Author(s):  
Jason A. Otkin ◽  
William E. Lewis ◽  
Allen J. Lenzen ◽  
Brian D. McNoldy ◽  
Sharanya J. Majumdar
Keyword(s):  
Forecast Accuracy ◽  
Cloud Microphysics ◽  
Cumulus Parameterization ◽  
Upper Troposphere ◽  
Wind Speeds ◽  
Parameterization Schemes ◽  
Brightness Temperatures ◽  
Cumulus Parameterization Schemes ◽  
Hwrf Model ◽  
Infrared Brightness

Abstract In this study, cycled forecast experiments were performed to assess the ability of different cloud microphysics and cumulus parameterization schemes in the Hurricane Weather Research and Forecasting (HWRF) Model to accurately simulate the evolution of the cloud and moisture fields during the entire life cycle of Hurricane Edouard (2014). The forecast accuracy for each model configuration was evaluated through comparison of observed and simulated Geostationary Operational Environmental Satellite-13 (GOES-13) infrared brightness temperatures and satellite-derived tropical cyclone intensity estimates computed using the advanced Dvorak technique (ADT). Overall, the analysis revealed a large moist bias in the mid- and upper troposphere during the entire forecast period that was at least partially due to a moist bias in the initialization datasets but was also affected by the microphysics and cumulus parameterization schemes. Large differences occurred in the azimuthal brightness temperature distributions, with two of the microphysics schemes producing hurricane eyes that were much larger and clearer than observed, especially for later forecast hours. Comparisons to the forecast 10-m wind speeds showed reasonable agreement (correlations between 0.58 and 0.74) between the surface-based intensities and the ADT intensity estimates inferred via cloud patterns in the upper troposphere. It was also found that model configurations that had the smallest differences between the ADT and surface-based intensities had the most accurate track and intensity forecasts. Last, the cloud microphysics schemes had the largest impact on the forecast accuracy.

Assessing the Influence of Upper-Tropospheric Troughs on Tropical Cyclone Intensification Rates after Genesis

2017 ◽  
Vol 145 (4) ◽  
pp. 1295-1313 ◽  
Author(s):  
Michael S. Fischer ◽  
Brian H. Tang ◽  
Kristen L. Corbosiero
Keyword(s):  
Tropical Cyclones ◽  
North Atlantic ◽  
Temporal Evolution ◽  
Tropical Cyclogenesis ◽  
Brightness Temperatures ◽  
The North ◽  
The North Atlantic ◽  
Upper Level ◽  
Infrared Brightness

Abstract The role of upper-tropospheric troughs on the intensification rate of newly formed tropical cyclones (TCs) is analyzed. This study focuses on TCs forming in the presence of upper-tropospheric troughs in the North Atlantic basin between 1980 and 2014. TCs were binned into three groups based upon the 24-h intensification rate starting at the time of genesis: rapid TC genesis (RTCG), slow TC genesis (STCG), and neutral TC genesis (NTCG). Composite analysis shows RTCG events are characterized by amplified upper-tropospheric flow with the largest upshear displacement between the TC and trough of the three groups. RTCG events are associated with greater quasigeostrophic (QG) ascent in upshear quadrants of the TC, forced by differential vorticity advection by the thermal wind, especially around the time of genesis. This pattern of QG ascent closely matches the RTCG composite of infrared brightness temperatures. Conversely, NTCG events are associated with an upper-tropospheric trough that is closest to the TC center. The distribution of QG ascent in NTCG events becomes increasingly asymmetric around the time of genesis, with a maximum that shifts downshear of the TC center, consistent with infrared brightness temperatures. It is hypothesized that the TC intensification rate after tropical cyclogenesis, in environments of upper-tropospheric troughs, is closely linked to the structure and temporal evolution of the upper-level trough. The TC–trough configurations that provide greater QG ascent to the left of, and upshear of, the TC center feature more symmetric convection and faster TC intensification rates.

scholarly journals Climatology of Tropical Overshooting Tops in North Atlantic Tropical Cyclones

2017 ◽  
Vol 56 (6) ◽  
pp. 1783-1796 ◽  
Author(s):  
Sarah M. Griffin
Keyword(s):  
Tropical Cyclones ◽  
North Atlantic ◽  
North Atlantic Ocean ◽  
Vertical Wind Shear ◽  
Detection Algorithm ◽  
Exponential Relationship ◽  
Brightness Temperatures ◽  
Study Results ◽  
Infrared Brightness

AbstractOrganized tropical convection, often characterized by overshooting tops, is a distinguishing quality of tropical cyclones (TCs). In this study, the climatology of tropical overshooting tops (TOTs) in North Atlantic Ocean TCs from 2004 to 2015 is examined. Previous studies have investigated the distribution of convection in TCs based on lightning data. The purpose of this study is to examine the distribution of TC convection from geostationary satellites using an objective TOT detection algorithm based on infrared brightness temperatures and empirically dependent thresholds. It will be shown that TOTs can provide an additional metric for identifying the characteristics of TC convection. Based on the 12-yr (2004–15) climatology, a distinct semidiurnal cycle in TOT activity is detected within 500 km of the TC center. In agreement with lightning data from previous studies, a predawn maximum (local to the TC) in TOTs is observed within 300 km of the TC center. A second predusk maximum is associated with TOTs between 300 and 500 km of the TC center. TC intensity and intensity trend along with environmental factors can affect the number and distribution of TOTs. For example, an exponential relationship exists between the number of TOTs and increasing sea surface temperatures. Conversely, increasing vertical wind shear magnitude decreases the density of TOTs, with a higher percentage of TOTs observed downshear of the wind direction. Generally, within 100 km (100–300 km) of the TC center, the preferred quadrant for TOTs is downshear left (downshear right), and increased TOT activity is observed right of TC motion. The findings corroborate previous lightning study results while providing additional insights into TC convection.

scholarly journals Assessing the Impact of Stochastic Perturbations in Cloud Microphysics using GOES-16 Infrared Brightness Temperatures

2020 ◽  
Vol 148 (8) ◽  
pp. 3111-3137 ◽  
Author(s):  
Sarah M. Griffin ◽  
Jason A. Otkin ◽  
Gregory Thompson ◽  
Maria Frediani ◽  
Judith Berner ◽  
...  
Keyword(s):  
Potential Temperature ◽  
Control Object ◽  
Cloud Microphysics ◽  
Temperature Fields ◽  
Microphysics Scheme ◽  
Stochastic Perturbations ◽  
Brightness Temperatures ◽  
Object Based ◽  
The Impact ◽  
Infrared Brightness

Abstract In this study, infrared brightness temperatures (BTs) are used to examine how applying stochastic perturbed parameter (SPP) methodology to the widely used Thompson–Eidhammer cloud microphysics scheme impacts the cloud field in high-resolution forecasts. Modifications are made to add stochastic perturbations to three parameters controlling cloud generation and dissipation processes. Two five-member ensembles are generated, one using the microphysics parameter perturbations (SPP-MP) and another where white noise perturbations were added to potential temperature fields at initialization time (Control). The impact of the SPP method was assessed using simulated and observed GOES-16 BTs. This analysis uses pixel-based and object-based methods to assess the impact on the cloud field. Pixel-based methods revealed that the SPP-MP BTs are slightly more accurate than the Control BTs. However, too few pixels with a BT lower than 270 K result in a positive bias compared to the observations. A negative bias compared to the observations is observed when only analyzing lower BTs. The spread of the ensemble BTs was analyzed using the continuous ranked probability score differences, with the SPP-MP ensemble BTs having less (more) spread during May (January) compared to the Control. Object-based analysis using the Method for Object-Based Diagnostic Evaluation revealed the upper-level cloud objects are smaller in the SPP-MP ensemble than the Control but a lower bias exists in the SPP-MP BTs compared to the Control BTs when overlapping matching objects. However, there is no clear distinction between the SPP-MP and Control ensemble members during the evolution of objects, Overall, the SPP-MP perturbations result in lower BTs compared to the Control ensemble and more cloudy pixels.

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