Estimating Confidence Intervals around Relative Humidity Profiles from Satellite Observations: Application to the SAPHIR Sounder

Brogniez, Hélène; Fallourd, Renaud; Mallet, Cécile; Sivira, Ramses; Dufour, Christophe

doi:10.1175/jtech-d-15-0237.1

Cited by 20 publications

(35 citation statements)

References 82 publications

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“…We use water vapor retrievals from a multivariate regression scheme that provides the parameters of conditional distributions chosen a priori (Brogniez et al 2016). Compared to the relative humidity estimation scheme described by Brogniez et al (2016), which relied on a normal (Gaussian) distribution, here a Beta distribution is used as its compact support and allowance for asymmetries about the mean are more favorable for describing the relative humidity.…”

Section: Saphir and Megha-tropiquesmentioning

confidence: 99%

“…Compared to the relative humidity estimation scheme described by Brogniez et al (2016), which relied on a normal (Gaussian) distribution, here a Beta distribution is used as its compact support and allowance for asymmetries about the mean are more favorable for describing the relative humidity. The estimation of parameters also provides a characterization of the retrieval uncertainty for every observing pixel of SAPHIR.…”

Section: Saphir and Megha-tropiquesmentioning

confidence: 99%

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Structure and Dynamical Influence of Water Vapor in the Lower Tropical Troposphere

et al. 2017

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In situ, airborne and satellite measurements are used to characterize the structure of water vapor in the lower tropical troposphere-below the height, z Ã ; of the triple-point isotherm, T Ã : The measurements are evaluated in light of understanding of how lowertropospheric water vapor influences clouds, convection and circulation, through both radiative and thermodynamic effects. Lower-tropospheric water vapor, which concentrates in the first few kilometers above the boundary layer, controls the radiative cooling profile of the boundary layer and lower troposphere. Elevated moist layers originating from a preferred level of convective detrainment induce a profile of radiative cooling that drives circulations which reinforce such features. A theory for this preferred level of cumulus termination is advanced, whereby the difference between T Ã and the temperature at which primary ice forms gives a 'first-mover advantage' to glaciating cumulus convection, thereby concentrating the regions of the deepest convection and leading to more clouds and moisture near the triple point. A preferred level of convective detrainment near T Ã implies relative humidity reversals below zÃ which are difficult to identify using retrievals from satellite-borne microwave and infrared sounders. Isotopologues retrievals provide a hint of such features and their ability to constrain the structure of the vertical humidity profile merits further study. Nonetheless, it will likely remain challenging to resolve dynamically -017-9420-8 important aspects of the vertical structure of water vapor from space using only passive sensors.

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Section: Saphir and Megha-tropiquesmentioning

confidence: 99%

Section: Saphir and Megha-tropiquesmentioning

confidence: 99%

Structure and Dynamical Influence of Water Vapor in the Lower Tropical Troposphere

et al. 2017

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“…Over the past decades, development of satellite sensors has resulted in multiple sources of meteorological datasets, such as precipitation [23,24], land surface temperature [25,26], relative humidity [27,28] etc., that provide more reliable estimations over un-gauged areas compared with other interpolation methods. However, their spatial resolutions (i.e., 0.25-0.5 • ) are still too coarse for hydrological simulation and environmental modeling when applied to local basins and regions.…”

Section: Downscaling Methodsmentioning

confidence: 99%

Evaluation of All-for-One Tourism in Mountain Areas Using Multi-Source Data

2018

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All-for-one tourism is a new viewpoint of tourism development involving overall planning and cooperative mechanisms. Over the past few years, the researchers have put forward many conceptual models to guide the top-level design and specific practice of all-for-one tourism. However, these studies mainly focus on social, economic and cultural effect in mature tourism areas, lacking comprehensive analysis from geographical perspective and neglecting the underdeveloped regions. In this paper, we attempt to apply geographic information system technology to tourism evaluation, exploring the approach of all-for-one tourism development in mountain regions. Zunyi city is selected as the research region and evaluated on the abundance, quality and spatial pattern of tourism resources, climate comfort, natural disaster possibility, and convenience of infrastructure or social service. Multi-source datasets collected from websites, reanalysis data, remote sensing products and observation stations are used. Based on data analysis, some recommendations including enriching cultural tourism products through cultural creativity, ensuring regional coordinated development through spatial optimization, respecting the spatiotemporal characteristics of climate and the laws of nature, and strengthening construction of infrastructure, are discussed to promote the healthy development of all-for-one tourism. attention of governments, enterprises and social problem researchers, as it is regarded as an effective and reliable approach to achieve rural revitalization and promote the coordinated and sustainable development of urban and rural areas [6].Recently, various conceptual models have been presented to explain the connotation of all-for-one tourism. Li et al. [7] summed up all-for-one tourism as "four new ideas" (resources, products, industries and markets) and "eight constructive aspects" (all tourism elements, all professions, all processes, all levels, the entire space and time, the whole society, all participant departments and all latent tourists). They argued that all-for-one tourism should aim at providing tourists with sufficient product experiences by integrating various industries, cooperating different departments, uniting all participants in the region, and taking full use of tourism destinations. Li [8] pointed out that all-for-one tourism is a new regional coordinated development mode, where tourism is the dominant industry and promotes the development of the economy and society in the chosen region. The ultimate goal of all-for-one tourism is to achieve the scientific and reasonable integration of resources, industries and developments, as well as social co-construction and sharing through optimizing and upgrading the complex systematic structure within a specific region. Zhang et al. [9] emphasized the domain perspective of all-for-one tourism, including temporal-spatial domain, industry domain, element domain and management domain. Feng [5] unscrambled the necessity of all-for-one tourism development from the five charact...

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“…In this work, we used the layer-averaged RH (six layers distributed between 100 and 950 hPa) derived by Brogniez et al (2016), which is available for the period October 2011-present. In this study, the authors adopted a purely statistical technique to retrieve for each atmospheric layer the full distribution of RH from the space-borne observations of the upwelling radiation and training RH data derived from radiosonde profiles.…”

Section: Saphirmentioning

confidence: 99%

“…the surface emissivity, temperature profile, and a prior for RH profiles for brightness temperature simulations). Figure 1a shows an example for each atmospheric layer of the mean of the retrieved RH distribution, derived as detailed in Brogniez et al (2016).…”

Section: Saphirmentioning

confidence: 99%

Statistical downscaling of water vapour satellite measurements from profiles of tropical ice clouds

Carella

Vrac

Brogniez

et al. 2020

Earth Syst. Sci. Data

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Abstract. Multi-scale interactions between the main players of the atmospheric water cycle are poorly understood, even in the present-day climate, and represent one of the main sources of uncertainty among future climate projections. Here, we present a method to downscale observations of relative humidity available from the Sondeur Atmosphérique du Profil d'Humidité Intertropical par Radiométrie (SAPHIR) passive microwave sounder at a nominal horizontal resolution of 10 km to the finer resolution of 90 m using scattering ratio profiles from the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) lidar. With the scattering ratio profiles as covariates, an iterative approach applied to a non-parametric regression model based on a quantile random forest is used. This allows us to effectively incorporate into the predicted relative humidity structure the high-resolution variability from cloud profiles. The finer-scale water vapour structure is hereby deduced from the indirect physical correlation between relative humidity and the lidar observations. Results are presented for tropical ice clouds over the ocean: based on the coefficient of determination (with respect to the observed relative humidity) and the continuous rank probability skill score (with respect to the climatology), we conclude that we are able to successfully predict, at the resolution of cloud measurements, the relative humidity along the whole troposphere, yet ensure the best possible coherence with the values observed by SAPHIR. By providing a method to generate pseudo-observations of relative humidity (at high spatial resolution) from simultaneous co-located cloud profiles, this work will help revisit some of the current key barriers in atmospheric science. A sample dataset of simultaneous co-located scattering ratio profiles of tropical ice clouds and observations of relative humidity downscaled at the resolution of cloud measurements is available at https://doi.org/10.14768/20181022001.1 (Carella et al., 2019).

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Estimating Confidence Intervals around Relative Humidity Profiles from Satellite Observations: Application to the SAPHIR Sounder

Cited by 20 publications

References 82 publications

Structure and Dynamical Influence of Water Vapor in the Lower Tropical Troposphere

Structure and Dynamical Influence of Water Vapor in the Lower Tropical Troposphere

Evaluation of All-for-One Tourism in Mountain Areas Using Multi-Source Data

Statistical downscaling of water vapour satellite measurements from profiles of tropical ice clouds

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