scholarly journals High-Resolution Surface Observations for Climate Monitoring

10.5772/56044 ◽  
2013 ◽  
Author(s):  
Renee A.
Keyword(s):  
High Resolution ◽  
Climate Monitoring ◽  
Surface Observations

scholarly journals Analyzing Gaps in Hurricane Rain Coverage to Inform Future Satellite Proposals

2020 ◽  
Vol 12 (17) ◽  
pp. 2673
Author(s):  
Justin P. Stow ◽  
Mark A. Bourassa ◽  
Heather M. Holbach
Keyword(s):  
High Resolution ◽  
Tropical Cyclone ◽  
Drop Size ◽  
Low Pressure ◽  
Surface Winds ◽  
Pressure Center ◽  
Rain Drop ◽  
The Cost ◽  
Aircraft Data ◽  
Surface Observations

This study assesses where tropical cyclone (TC) surface winds can be measured as a function of footprint sizes and wavelengths (Ka- Ku- and C-band). During TCs, most high-resolution surface observations are impeded by considerable ‘rain contamination.’ Under these conditions, high-resolution surface observations typically come from operational aircraft. Other techniques that provide high-resolution surface observations through rain are also hindered somewhat by rain contamination and are very sparse in space and time. The impacts of rain are functions of the remotely sensed wavelength and rain–drop size. Therefore, relative long wavelengths have been used to observe the surface, but at the cost of a larger footprint. We examine how smaller footprint sizes could be used to observe through gaps between moderate to heavy rainbands that circulate around the main low-pressure center of a TC. Aircraft data from the National Oceanic and Atmospheric Administration’s (NOAA’s) WP-3D turboprop aircraft will be used to create realistic maps of rain. Our results provide information on the satellite instrument characteristics needed to see the surface through these gaps. This information is expected to aid in developing hurricane-related applications of new higher-resolution satellites.

Developing High-resolution Air Quality Reanalysis Dataset over China for Years 2013-2018 Based on Ensemble Kalman Filter and Surface Observations from CNEMC

2020 ◽  
Author(s):  
Lei Kong ◽  
Xiao Tang ◽  
Jiang Zhu ◽  
Zifa Wang ◽  
Huangjian Wu ◽  
...  
Keyword(s):  
Kalman Filter ◽  
Air Quality ◽  
High Resolution ◽  
Ensemble Kalman Filter ◽  
Air Pollutants ◽  
Reanalysis Data ◽  
Training Data ◽  
Reanalysis Dataset ◽  
Air Quality Prediction ◽  
Surface Observations

<p>A six-year long high-resolution Chinese air quality reanalysis datasets (CAQRA) covering the period 2013-2018 has been developed in this study by assimilating over 1000 surface air quality monitoring sites from China National Environmental Monitoring Centre (CNEMC) based on the ensemble Kalman filter (EnKF) and the Nested Air Quality Prediction Modeling System (NAQPMS). This reanalysis provides the surface fields of six conventional air pollutants in China, namely PM<sub>2.5</sub>, PM<sub>10</sub>, SO<sub>2</sub>, NO<sub>2</sub>, CO and O<sub>3</sub>, at high spatial (15km×15km) and temporal (1 hour) resolutions. This paper aims to document this dataset by providing the detailed descriptions of the assimilation system and presenting the first validation results for the reanalysis fields of air pollutants in China. A twenty-fold cross validation (CV) method was used to assess the quality of CAQRA. The CV results show that the CAQRA has excellent performances in reproducing the magnitude and variability of the air pollutants in China with the biases (normalized mean bias) of the reanalysis data about -2.6 (-4.9%) μg/m<sup>3</sup> for PM<sub>2.5</sub>, -6.8 (-7.6%) μg/m<sup>3</sup> for PM<sub>10</sub>, -2.0 (-8.5%) μg/m<sup>3</sup> for SO<sub>2</sub>, -2.3 (-6.9%) μg/m<sup>3</sup> for NO<sub>2</sub>, -0.06 (-6.1%) mg/m<sup>3</sup> for CO and -2.3 (-4.0%) μg/m<sup>3</sup> for O<sub>3</sub>. The interannual changes of the air quality in China were also well represented by the CAQRA in terms of the six air pollutants. Comparisons with previous datasets of daily PM<sub>2.5</sub>, SO<sub>2</sub> and NO<sub>2</sub> concentrations indicate that the CAQRA is more accurate with smaller RMSE values. We also compared our reanalysis dataset to the CAMSRA (The Copernicus Atmosphere Monitoring Service reanalysis) produced by ECMWF (European Centre for Medium-Range Weather Forecasts), which suggests that the CAQRA has higher accuracy in representing the surface air pollutants in China due to the assimilation of surface observations. This reanalysis dataset can provide us comprehensive pictures of the air quality in China from 2013 to 2018 with a complete spatial and temporal coverage, which can be used in the assessment of health impacts of air pollution, validation of model simulations and providing training data for the statistical or AI (Artificial Intelligence) based forecast.</p>

scholarly journals Expanding the Depth of Field for Imaging with Low keV Electrons: High Resolution Surface Observations of Nanostructured LaB6 Using Low keV Secondary and Backscattered Electrons

2017 ◽  
Vol 23 (S1) ◽  
pp. 1830-1831
Author(s):  
Takeshi Sunaoshi ◽  
Satoshi Okada ◽  
Kazutoshi Kaji ◽  
Edgar Voelkl ◽  
Roshini Ramachandran ◽  
...  
Keyword(s):  
High Resolution ◽  
Depth Of Field ◽  
Backscattered Electrons ◽  
Surface Observations

scholarly journals Analysis of the diurnal development of the <i>Ora del Garda</i> wind in the Alps from airborne and surface measurements

2013 ◽  
Vol 13 (7) ◽  
pp. 19121-19171 ◽  
Author(s):  
L. Laiti ◽  
D. Zardi ◽  
M. de Franceschi ◽  
G. Rampanelli
Keyword(s):  
High Resolution ◽  
Potential Temperature ◽  
Lake Breeze ◽  
Pollution Transport ◽  
Valley Wind ◽  
Combined Analysis ◽  
Airborne Measurements ◽  
Early Afternoon ◽  
Thermally Driven ◽  
Surface Observations

Abstract. A lake-breeze and valley-wind coupled circulation system, known as Ora del Garda, typically arises in the late morning from the northern shorelines of Lake Garda (southeastern Italian Alps), and then channels into the Sarca and Lakes valleys to the north. After flowing over an elevated saddle, in the early afternoon this wind breaks out from the west into the nearby Adige Valley, hindering the regular development of the local up-valley wind by producing a strong and gusty anomalous flow in the area. Two targeted flights of an equipped motorglider were performed in the morning and afternoon of 23 August 2001 in the above valleys, exploring selected vertical slices of the atmosphere, from the lake's shore to the area where the two local airflows interact. At the same time, surface observations were collected during an intensive field measurement campaign held in the interaction area, as well as from routinely-operated weather stations disseminated along the whole study area, allowing the analysis of the different stages of the Ora del Garda development. From airborne measurements, an atmospheric boundary-layer (ABL) vertical structure, typical of deep Alpine valleys, was detected in connection with the wind flow, with rather shallow (∼500 m) convective mixed layers surmounted by deeper, weakly stable layers. On the other hand, close to the lake's shoreline the ABL was found to be stabilized down to very low heights, as an effect of the onshore advection of cold air by the lake breeze. Airborne potential temperature observations were mapped over high-resolution 3-D grids for each valley section explored by the flights, using a geostatistical technique called residual kriging (RK). RK-regridded fields revealed fine-scale features and inhomogeneities of ABL thermal structures associated with the complex thermally-driven wind field developing in the valleys. The combined analysis of surface observations and RK-interpolated fields revealed an irregular propagation of the lake-breeze front in the lower part of the valley, and cross-valley thermal asymmetries amenable both to the differential solar heating of the valley slopes and to the valley curvature in its upper part. The overflowing of the potentially cooler Ora del Garda air from the Lakes Valley in the afternoon produces a strong katabatic wind at the bottom of the underlying Adige Valley, which blows in cross-valley (i.e. westerly) direction and impinges on the opposite eastern valley sidewall. RK-regridded potential temperature field highlighted that this phenomenon gives origin to a "hydraulic jump" flow structure in the urban area north of the city of Trento, leading to the down-stream formation of a ∼1300 m deep well-mixed layer. The improved knowledge of the typical Ora del Garda flow patterns and associated ABL structures, deriving from the combined analysis of surface and airborne observations, has practical application in air quality forecasting for the study area, for it helps in the understanding of pollution transport and dispersion processes by thermally-driven winds in the region. Moreover, 3-D meteorological fields produced by RK are likely to be an excellent basis for comparison with results from high-resolution numerical simulations, as they provide a degree of spatial detail that is fully comparable to the spatial scales resolved by large-eddy simulations.

scholarly journals Spatio-Temporal Variations of Atmospheric NH3 over East Asia by Comparison of Chemical Transport Model Results, Satellite Retrievals and Surface Observations

Atmosphere ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 900 ◽  
Author(s):  
Zhe Wang ◽  
Itsushi Uno ◽  
Kazuo Osada ◽  
Syuichi Itahashi ◽  
Keiya Yumimoto ◽  
...  
Keyword(s):  
High Resolution ◽  
East Asia ◽  
Temporal Variations ◽  
Central China ◽  
Model Simulations ◽  
Satellite Retrievals ◽  
In Situ Observations ◽  
Spatio Temporal ◽  
Surface Observations

Atmospheric ammonia (NH3) plays an important role in the formation of secondary inorganic aerosols, the neutralization of acid rain, and the deposition to ecosystems, but has not been well understood yet, especially over East Asia. Based on the GEOS-Chem model results, the IASI satellite retrievals, the in-site surface observations of a nationwide filter pack (FP) network over Japan and the long-term high resolution online NH3 measurements at Fukuoka of western Japan, the spatio-temporal distributions of atmospheric NH3 over East Asia was analyzed comprehensively. A significant seasonal variation with a summer peak was found in all datasets. Comparison between the satellite retrievals and model simulations indicated that the IASI NH3 vertical column density (VCD) showed good consistency with GEOS-Chem results over North and central China, but had large differences over South China due to the effect of clouds. Over the Japan area, GEOS-Chem simulated NH3 concentrations successfully reproduced the spatio-temporal variations compared with in-situ observations, while IASI NH3 VCD retrievals were below or near the detection limit and difficult to obtain a reasonable correlation for with model results. The comprehensive analysis indicated that there were still some differences among different datasets, and more in-situ observations, improved satellite retrievals, and high-resolution model simulations with more accurate emissions are necessary for better understanding the atmospheric NH3 over East Asia.

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