scholarly journals Comparison of assimilating all‐sky and clear‐sky infrared radiances from Himawari‐8 in a mesoscale system

2019 ◽  
Vol 145 (719) ◽  
pp. 745-766 ◽  
Author(s):  
Kozo Okamoto ◽  
Yohei Sawada ◽  
Masaru Kunii
Keyword(s):  
Clear Sky ◽  
Mesoscale System ◽  
Infrared Radiances

scholarly journals All-sky assimilation of infrared radiances sensitive to mid- and upper-tropospheric moisture and cloud

2019 ◽  
Vol 12 (9) ◽  
pp. 4903-4929 ◽  
Author(s):  
Alan J. Geer ◽  
Stefano Migliorini ◽  
Marco Matricardi
Keyword(s):  
Weather Forecasting ◽  
Deep Convection ◽  
Cloud Detection ◽  
Clear Sky ◽  
Atmospheric Sounding ◽  
Beneficial Impact ◽  
Infrared Radiances ◽  
The Tropics ◽  
The Impact ◽  
Better Than

Abstract. All-sky assimilation of infrared (IR) radiances has not yet become operational at any weather forecasting centre, but it promises to bring new observations in sensitive areas and avoid the need for cloud detection. A new all-sky IR configuration gives results comparable to (and in some areas better than) clear-sky assimilation of the same data, meaning that operational implementation is now feasible. The impact of seven upper-tropospheric water vapour (WV) sounding channels from the Infrared Atmospheric Sounding Interferometer (IASI) is evaluated in both all-sky and clear-sky approaches. All-sky radiative transfer simulations (and the forecast model's cloud fields) are now sufficiently accurate that systematic errors are comparable to those of clear-sky assimilation outside of a few difficult areas such as deep convection. All-sky assimilation brings 65 % more data than clear-sky assimilation globally, with the biggest increases in midlatitude storm tracks and tropical convective areas. However, all-sky gives slightly less weight to any one observation than in the clear-sky approach. In the midlatitudes, all-sky and clear-sky assimilation have similarly beneficial impact on mid- and upper-tropospheric dynamical forecast fields. Here the addition of data in cloudy areas is offset by the slightly lower weight given to the observations. But in the tropics, all-sky assimilation is significantly more beneficial than clear-sky assimilation, with improved dynamical short-range forecasts throughout the troposphere and stratosphere.

scholarly journals All-sky assimilation of infrared radiances sensitive to mid- and upper-tropospheric moisture and cloud

2019 ◽  
Author(s):  
Alan J. Geer ◽  
Stefano Migliorini ◽  
Marco Matricardi
Keyword(s):  
Weather Forecasting ◽  
Deep Convection ◽  
Cloud Detection ◽  
Clear Sky ◽  
Atmospheric Sounding ◽  
Beneficial Impact ◽  
Infrared Radiances ◽  
The Tropics ◽  
The Impact ◽  
Better Than

Abstract. All-sky assimilation of infrared (IR) radiances has not yet become operational at any weather forecasting centre but it promises to bring new observations in sensitive areas and it avoids the need for cloud detection. A new all-sky IR configuration gives results comparable to (and in some areas better than) clear-sky assimilation of the same data, meaning that operational implementation is now feasible. The impact of 7 upper-tropospheric water vapour (WV) sounding channels from the Infrared Atmospheric Sounding Interferometer (IASI) is evaluated in both all-sky and clear-sky approaches. All-sky radiative transfer simulations (and the forecast model’s cloud fields) are now sufficiently accurate that systematic errors are comparable to those of clear-sky assimilation outside of a few difficult areas such as deep-convection. All-sky assimilation brings 65 % more data than clear-sky assimilation globally, with the biggest increases in midlatitude storm tracks and tropical convective areas. However all-sky gives slightly less weight to any one observation than in the clear-sky approach. In the midlatitudes, all-sky and clear-sky assimilation have similarly beneficial impact on mid- and upper-tropospheric dynamical forecast fields. Here the addition of data in cloudy areas is offset by the slightly lower weight given to the observations. But in the tropics, all-sky assimilation is significantly more beneficial than clear-sky assimilation, with improved dynamical short-range forecasts throughout the troposphere and stratosphere.

Retrieving clear-sky atmospheric parameters from SEVIRI and ABI infrared radiances

2008 ◽  
Vol 113 (D15) ◽  
Author(s):  
Xin Jin ◽  
Jun Li ◽  
Timothy J. Schmit ◽  
Jinlong Li ◽  
Mitchell D. Goldberg ◽  
...  
Keyword(s):  
Atmospheric Parameters ◽  
Clear Sky ◽  
Infrared Radiances

scholarly journals Impact of updates to the HITRAN spectroscopic database on the modeling of clear-sky infrared radiances

2002 ◽  
Vol 29 (20) ◽  
pp. 18-1-18-4 ◽  
Author(s):  
Stuart M. Newman ◽  
Jonathan P. Taylor
Keyword(s):  
Clear Sky ◽  
Spectroscopic Database ◽  
Infrared Radiances

Evaluation of net shortwave radiation over China with a regional climate model

2020 ◽  
Vol 80 (2) ◽  
pp. 147-163
Author(s):  
X Liu ◽  
Y Kang ◽  
Q Liu ◽  
Z Guo ◽  
Y Chen ◽  
...  
Keyword(s):  
Regional Climate Model ◽  
Climate Model ◽  
Regional Climate ◽  
Radiant Energy ◽  
Energy System ◽  
Radiation Budget ◽  
Shortwave Radiation ◽  
Monsoon Region ◽  
Clear Sky ◽  
Sky Conditions

The regional climate model RegCM version 4.6, developed by the European Centre for Medium-Range Weather Forecasts Reanalysis, was used to simulate the radiation budget over China. Clouds and the Earth’s Radiant Energy System (CERES) satellite data were utilized to evaluate the simulation results based on 4 radiative components: net shortwave (NSW) radiation at the surface of the earth and top of the atmosphere (TOA) under all-sky and clear-sky conditions. The performance of the model for low-value areas of NSW was superior to that for high-value areas. NSW at the surface and TOA under all-sky conditions was significantly underestimated; the spatial distribution of the bias was negative in the north and positive in the south, bounded by 25°N for the annual and seasonal averaged difference maps. Compared with the all-sky condition, the simulation effect under clear-sky conditions was significantly better, which indicates that the cloud fraction is the key factor affecting the accuracy of the simulation. In particular, the bias of the TOA NSW under the clear-sky condition was <±10 W m-2 in the eastern areas. The performance of the model was better over the eastern monsoon region in winter and autumn for surface NSW under clear-sky conditions, which may be related to different levels of air pollution during each season. Among the 3 areas, the regional average biases overall were largest (negative) over the Qinghai-Tibet alpine region and smallest over the eastern monsoon region.

Radiative properties of snow for clear sky solar radiation

1981 ◽  
Vol 4 (2) ◽  
pp. 103-120 ◽  
Author(s):  
Bhaskar Choudhury
Keyword(s):  
Solar Radiation ◽  
Radiative Properties ◽  
Clear Sky

scholarly journals A Bi-Spectral Microbolometer Sensor for Wildfire Measurement

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3690
Author(s):  
Denis Dufour ◽  
Loïc Le Noc ◽  
Bruno Tremblay ◽  
Mathieu N. Tremblay ◽  
Francis Généreux ◽  
...  
Keyword(s):  
Low Resource ◽  
Long Wave ◽  
Radiative Power ◽  
Infrared Radiances ◽  
Moderate Scale ◽  
Long Wave Infrared ◽  
Detector Type ◽  
Experimental Burns ◽  
Fire Radiative Power

This study describes the development of a prototype bi-spectral microbolometer sensor system designed explicitly for radiometric measurement and characterization of wildfire mid- and long-wave infrared radiances. The system is tested experimentally over moderate-scale experimental burns coincident with FLIR reference imagery. Statistical comparison of the fire radiative power (FRP; W) retrievals suggest that this novel system is highly reliable for use in collecting radiometric measurements of biomass burning. As such, this study provides clear experimental evidence that mid-wave infrared microbolometers are capable of collecting FRP measurements. Furthermore, given the low resource nature of this detector type, it presents a suitable option for monitoring wildfire behaviour from low resource platforms such as unmanned aerial vehicles (UAVs) or nanosats.

Efficient downscaling of satellite oceanographic data with convolutional neural networks

2021 ◽  
Vol 12 (3) ◽  
pp. 46-47
Author(s):  
Nikita Saxena
Keyword(s):  
Neural Networks ◽  
Deep Learning ◽  
Convolutional Neural Networks ◽  
Super Resolution ◽  
Sea Surface ◽  
Clear Sky ◽  
Oceanographic Data ◽  
Computationally Expensive ◽  
Sky Conditions ◽  
Data Inference

Space-borne satellite radiometers measure Sea Surface Temperature (SST), which is pivotal to studies of air-sea interactions and ocean features. Under clear sky conditions, high resolution measurements are obtainable. But under cloudy conditions, data analysis is constrained to the available low resolution measurements. We assess the efficiency of Deep Learning (DL) architectures, particularly Convolutional Neural Networks (CNN) to downscale oceanographic data from low spatial resolution (SR) to high SR. With a focus on SST Fields of Bay of Bengal, this study proves that Very Deep Super Resolution CNN can successfully reconstruct SST observations from 15 km SR to 5km SR, and 5km SR to 1km SR. This outcome calls attention to the significance of DL models explicitly trained for the reconstruction of high SR SST fields by using low SR data. Inference on DL models can act as a substitute to the existing computationally expensive downscaling technique: Dynamical Downsampling. The complete code is available on this Github Repository.

A one-parameter family of clear-sky solar irradiance models adapted for different aerosol types

2021 ◽  
Vol 13 (2) ◽  
pp. 023701
Author(s):  
Robert Blaga ◽  
Delia Calinoiu ◽  
Marius Paulescu
Keyword(s):  
Solar Irradiance ◽  
Parameter Family ◽  
Clear Sky ◽  
Aerosol Types

A novel approach for quantifying high-frequency urban land cover changes at the block level with scarce clear-sky Landsat observations

2021 ◽  
Vol 255 ◽  
pp. 112293
Author(s):  
Chuanbao Jing ◽  
Weiqi Zhou ◽  
Yuguo Qian ◽  
Wenjuan Yu ◽  
Zhong Zheng
Keyword(s):  
Land Cover ◽  
High Frequency ◽  
Urban Land ◽  
Land Cover Changes ◽  
Clear Sky ◽  
Urban Land Cover ◽  
Novel Approach ◽  
Block Level
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