Analysis of upper tropospheric humidity measurements by microwave sounders and radiosondes by Viju Oommen John Download PDF EPUB FB2
This thesis describes results of several analyses of humidity measurements by microwave humidity sounders and radiosondes. The goal of this work is to pave the way for fully utilizing these. Analysis of upper tropospheric humidity measurements by microwave sounders and radiosondes [Oommen John Viju] on *FREE* shipping on qualifying offers.
Analysis of upper tropospheric humidity measurements by microwave sounders and radiosondesCited by: 2. Analysis of upper tropospheric humidity measurements by microwave sounders and radiosondes John, V.
Universität Bremen, Institute of Environmental by: 2. In this study, we compare upper tropospheric humidity (UTH) retrieved from the Advanced Microwave Sounding Unit and the Microwave Humidity Sounder against radiosonde data measured at four of the.
Analysis of upper tropospheric humidity measurements by. Upper Tropospheric Humidity data set from operational microwave sounders Viju John, ITSC, 08 May This paper compares upper-tropospheric humidity from the Microwave Limb Sounder (MLS) on theUpper Atmosphere Research Satellite with European Centre for Medium-Range Weather Forecasts (ECMWF) data.
MLS measurements are not included in the ECMWF analyses, and so a comparison of two independent datasets is possible. Radiosonde humidity sensors are unreliable in the upper troposphere (Elliot and Gaffen ; Miloshevich et al.
) and spotty coverage can lead to biases in regions not well covered by radiosondes, especially in the Tropics and subtropics (Soden and Lazante ). Several previous efforts have been made to use satellite datasets to understand UTH.
The accuracy of the upper tropospheric H 2 O measurement is strongly sensor‐dependent and often poor. The best currently available humidity sensors for the upper troposphere are the Vaisala RS90 (discontinued) and RS92 radiosondes.
Paper I – Comparing upper tropospheric humidity data from microwave satellite instruments and tropical radiosondes 77 Paper II – Correcting geolocation errors for microwave instruments aboard NOAA satellites 79 Paper III – Assessing the quality of humidity measurements from global operational radiosonde sensors carrying out a time series analysis on a uniform database of corrected radiosonde vertical profiles gathered at Uccle, Belgium, and covering the – time period.
The most remarkable finding of this trend analysis is a significant drop in upper tropospheric humidity (UTH) around autumnwhich marks an end to the upper tropospheric. An Analysis of Tropospheric Humidity Trends from Radiosondes MARK P.
MCCARTHY, AND H. TITCHNER Hadley Centre for Climate Change, Met Ofﬁce, Exeter, United Kingdom (Manuscript received 6 Octoberin ﬁnal form 27 May ) ABSTRACT A new analysis of historical radiosonde humidity observations is described.
An assessment of. The upper tropospheric humidity dataset generated from microwave limb sounder measurements was used by Eriksson et al.
 to evaluate UTH in climate models. A recent study by Chung et al.  used UTH from microwave measurements to evaluate diurnal cycle in reanalysis data. Using six. Atmos. Chem. Phys., 5, –, © Author(s) This work is licensed under the Creative Commons Attribution.
A study has been carried out to assess the importance of radiosonde corrections in improving the agreement between satellite and radiosonde measurements of upper-tropospheric humidity.
Infrared [High Resolution Infrared Radiation Sounder (HIRS)] and microwave [Advanced Microwave Sounding Unit (AMSU)] measurements from the NOAA satellite were used for this purpose.  Satellite‐borne measurements provide valuable information on the global distribution of upper tropospheric humidity (UTH), which represents the mean relative humidity in a layer approximately enclosed by the atmospheric pressure levels and hPa.
Monthly mean distributions of microwave observations of UTH obtained from the Advanced Microwave Sounding Unit‐B (AMSU‐B) and the Humidity Sounder.
Infrared Sounder (AIRS) instrument on the Aqua sat-ellite (Aumann et al. ) and the Microwave Limb Sounder (MLS) instruments on the Upper Atmospheric Research Satellite (UARS) (Read et al.
) and Aura satellite (Read et al. We examine how the PDFs vary between regions and between measurements. We also examine whether the observed. upper-tropospheric humidity (UTH) could contribute as much as W m 2 of direct radiative forcing.
UTH is especially critical in the dry subtropics (Hartmann and Larson ) where the radiative forcing of humid-ity at upper levels above a dry troposphere can be even larger (Jensen et al. Understanding the distribution and variability of. The present study deals with using long-term database for upper tropospheric water vapour (UTWV) variability studies over three tropical stations (Gadanki, Singapore and Truk), where different climatic conditions prevail.
Over Gadanki (°N, °E) strong seasonal variation in UTWV is revealed but not over Singapore (°N, °E) and Truk (°N, °E) except at hPa.
Abstract. The Advanced Microwave Sounding Unit-B (AMSU-B) and Microwave Humidity Sounder (MHS) are total power microwave radiometers operating at frequencies near the water vapor absorption line at GHz. The measurements of these instruments are crucial for deriving a variety of climate and hydrological products such as water vapor, precipitation, and ice cloud parameters.
In this work, we evaluate the upper tropospherichumidity (UTH) in a regional atmospheric model in conjunction with remote sensing observations and reanalysis products during the Indian summer monsoon (ISM). We performed continuous Weather Research and Forecast (WRF) model simulations from 1st May to 1st October for every year during to at 45 km spatial resolution.
between satellite and radiosonde measurements of upper-tropospheric humidity. Infrared [High Resolution Infrared Radiation Sounder (HIRS)] and microwave [Advanced Microwave Sounding Unit (AMSU)] measurements from the NOAA satellite were used for.
The validation of version (v) H2O measurements from the Earth Observing System (EOS) Microwave Limb Sounder (Aura MLS) on the Aura satellite are presented. Results from comparisons made with Aqua Atmospheric Infrared Sounder (AIRS), Vaisala radiosondes, frost point hygrometer, and WB57 aircraft hygrometers are presented.
The need for global measurements of ClO motivated initial development of a satellite microwave instrument for stratospheric chemistry. The Microwave Limb Sounder (MLS), operating unchopped in bands aroand GHz, was developed to measure ClO, O 3, and H 2 O from NASA’s Upper Atmosphere Research Satellite (UARS) launched in A somewhat similar.
effect as well as the dry bias, the radiosondes were flown on relatively wet nights and the upper tropospheric data were not used for the calibration of the lidar. The most recent calibration flight is shown in Figure 1. The radiosonde’s relative humidity and temperature have been used to calcu.
Raman lidar. The lidar measurements were taken by RALMO in Payerne, Switzerland ( ∘ N, ∘ E, m a.s.l.).RALMO is a fully automated operational water vapour lidar capable of reaching into the upper troposphere at nighttime and has been designed to run autonomously with minimal downtime, high accuracy, and temporal measurement stability (Dinoev et al., ; Brocard et al.
Conventional radiosondes can be used to measure the relative humidity over liquid (RHL) by assuming a saturated vapor pressure over the liquid.
However, this assumption results in significant errors with respect to measurements in the upper troposphere, where the effect of ice is dominant. Therefore, this study presents a novel method that considers the effects of ice to determine the relative.
VIZ differed from RSA radiosondes by about 20% relative to an average PWV of cm. Similar conclusions have been made by Wang et al. () and by Ferrare et al.
() for upper-tropospheric and lower-stratospheric measurements at midlati-tudes. 2) In using the MWRP, the use of all five channels in the water vapor band provided very good.
Layer-2, 4 and 6 represent the lower, middle and upper tropospheric humidity, respectively. In the present analysis, layer-1 data is not considered the bias involved is high (Ratnam et al., ). Fig. 2a shows the anomaly of the diurnal variability at three hourly intervals in the lower tropospheric humidity (LTH) for August The Indian.
currently made on the use of microwave sounders, infra-red sounders and radio-occultations, in the long term, a significant advance can be expected from advanced infra-red sounders onboard geostationary satellites (mainly because of its good time coverage on the area viewed by the satellite).
3D humidity field Tropospheric humidity profiles are available from radiosondes over populated land. hPa as other instruments such as Microwave Limb Sounder (MLS), which is specially designed for the accurate measurements of the atmospheric humidity profiles in the upper troposphere and lower stratosphere.
The MLS measurements for levels above hPa are provided as a separate dataset.passive microwave technique to observe atmospheric structure (Waters et al. ). It is distinguished from conventional satellite measurements by its ability to ob-serve humidity in cloudy as well as clear-sky regions.
Unlike nadir-viewing microwave measurements, MLS recovers humidity over continental regions as well as maritime regions.Atmospheric Science Letters. Open access.