Construction of Stratospheric Temperature Data Records from Stratospheric Sounding Units

Abstract In recognizing the importance of Stratospheric Sounding Unit (SSU) onboard historical NOAA polar-orbiting satellites in assessment of long-term stratospheric temperature changes and limitations in previous available SSU datasets, this study constructs a fully documented, publicly accessible, and well-merged SSU time series for climate change investigations. Focusing on methodologies, this study describes the details of data processing and bias corrections in the SSU observations for generating consistent stratospheric temperature data records, including 1) removal of the instrument gas leak effect in its CO2 cell; 2) correction of the atmospheric CO2 increase effect; 3) adjustment for different observation viewing angles; 4) removal of diurnal sampling biases due to satellite orbital drift; and 5) statistical merging of SSU observations from different satellites. After reprocessing, the stratospheric temperature records are composed of nadirlike, gridded brightness temperatures that correspond to identical weighting functions and a fixed local observation time. The 27-yr reprocessed SSU data record comprises global monthly and pentad layer temperatures, with grid resolution of 2.5° latitude by 2.5° longitude, of the midstratosphere (TMS), upper stratosphere (TUS), and top stratosphere (TTS), which correspond to the three SSU channel observations. For 1979–2006, the global mean trends for TMS, TUS, and TTS, are respectively −1.236 ± 0.131, −0.926 ± 0.139, and −1.006 ± 0.194 K decade−1. Spatial trend pattern analyses indicated that this cooling occurred globally with larger cooling over the tropical stratosphere.

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Intercalibrating Microwave Satellite Observations for Monitoring Long-Term Variations in Upper- and Midtropospheric Water Vapor*

Journal of Atmospheric and Oceanic Technology ◽

10.1175/jtech-d-13-00001.1 ◽

2013 ◽

Vol 30 (10) ◽

pp. 2303-2319 ◽

Cited By ~ 13

Author(s):

Eui-Seok Chung ◽

Brian J. Soden ◽

Viju O. John

Keyword(s):

Water Vapor ◽

Relative Humidity ◽

Sampling Bias ◽

Quantitative Agreement ◽

Observation Time ◽

Satellite Observations ◽

Water Vapor Absorption ◽

Infrared Measurements ◽

Orbital Drift

Abstract This paper analyzes the growing archive of 183-GHz water vapor absorption band measurements from the Advanced Microwave Sounding Unit B (AMSU-B) and Microwave Humidity Sounder (MHS) on board polar-orbiting satellites and document adjustments necessary to use the data for long-term climate monitoring. The water vapor channels located at 183.31 ± 1 GHz and 183.31 ± 3 GHz are sensitive to upper- and midtropospheric relative humidity and less prone to the clear-sky sampling bias than infrared measurements, making them a valuable but underutilized source of information on free-tropospheric water vapor. A method for the limb correction of the satellite viewing angle based upon a simplified model of radiative transfer is introduced to remove the scan angle dependence of the radiances. Biases due to the difference in local observation time between satellites and spurious trends associated with satellite orbital drift are then diagnosed and adjusted for using synthetic radiative simulations based on the Interim European Centre for Medium-Range Weather Forecasts Re-Analysis (ERA-Interim). The adjusted, cloud-filtered, and limb-corrected brightness temperatures are then intercalibrated using zonal-mean brightness temperature differences. It is found that these correction procedures significantly improve consistency and quantitative agreement between microwave radiometric satellite observations that can be used to monitor upper- and midtropospheric water vapor. The resulting radiances are converted to estimates of the deep-layer-mean upper- and midtropospheric relative humidity, and can be used to evaluate trends in upper-tropospheric relative humidity from reanalysis datasets and coupled ocean–atmosphere models.

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Detection and Correction of Diurnal Sampling Bias in HIRS/2 Brightness Temperatures

Journal of Atmospheric and Oceanic Technology ◽

10.1175/jtech2062.1 ◽

2007 ◽

Vol 24 (8) ◽

pp. 1425-1438 ◽

Cited By ~ 19

Author(s):

Darren L. Jackson ◽

Brian J. Soden

Keyword(s):

Climate Model ◽

Sampling Bias ◽

Observation Time ◽

Geophysical Fluid Dynamics Laboratory ◽

Tropospheric Temperature ◽

Brightness Temperatures ◽

Channel Surface ◽

Local Observation ◽

Radiance Data ◽

Climate Studies

Abstract Diurnal sampling biases arise in the High-Resolution Infrared Radiation Sounder (HIRS) satellite observations because some of the NOAA polar-orbiting satellites drift significantly from their original local observation time. Such bias adversely affects interpretation of these data for climate studies. Twenty-six years of HIRS/2 radiance satellite data (1979–2004) were examined by creating monthly mean gridded data that categorize the observations by local observing time through averaging ascending and descending orbits separately. Corresponding HIRS/2 simulated radiance data from the Geophysical Fluid Dynamics Laboratory (GFDL) climate model were constructed using HIRS/2 satellite sampling and were found to accurately represent the diurnal sampling bias. Correction of the HIRS/2 observations from the observed diurnal sampling bias was using the model simulations of HIRS brightness temperatures to adjust the observed brightness temperatures to the model daily mean. The diurnal bias was found to vary with channel, surface type, latitude, satellite, and cloud cover, but showed little dependence on satellite scan angle. Diurnal bias is most pronounced for ascending orbit observations of the afternoon [1400 local solar time (LST)] satellites with 60°N to 60°S domain averaged brightness temperatures variations up to 0.78 K yr−1. Lower tropospheric temperature and water vapor channels contained the largest bias, and biases over land were more than twice as large as those over the ocean. Brightness temperature adjustments of up to 10 K were needed in the most extreme situations.

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Technical Note: On the intercalibration of HIRS channel 12 brightness temperatures following the transition from HIRS 2 to HIRS 3/4 for ice saturation studies

10.5194/amt-2016-289 ◽

2016 ◽

Cited By ~ 1

Author(s):

Klaus Gierens ◽

Kostas Eleftheratos

Keyword(s):

Time Series ◽

Technical Note ◽

Temperature Data ◽

Distribution Functions ◽

Cumulative Distribution ◽

Central Wavelength ◽

Upper Troposphere ◽

Cumulative Distribution Functions ◽

Brightness Temperatures

Abstract. In the present study we explore the capability of the intercalibrated HIRS brightness temperature data at channel 12 (the HIRS water vapour channel; T12) to reproduce ice supersaturation in the upper troposphere during the period 1979–2014. Focus is given on the transition from the HIRS 2 to the HIRS 3 instrument in the year 1999, which involved a shift of the central wavelength in channel 12 from 6.7 µm to 6.5 µm. It is shown that this shift produced a discontinuity in the time series of low T12 values ( 70 %) in the year 1999 which prevented us from maintaining a continuous, long term time series of ice saturation throughout the whole record (1979–2014). We present that additional corrections are required to the low T12 values in order to bring HIRS 3 levels down to HIRS 2 levels. The new corrections are based on the cumulative distribution functions of T12 from NOAA 14 and 15 satellites (that is, when the transition from HIRS 2 to HIRS 3 occurred). By applying these corrections to the low T12 values we show that the discontinuity in the time series caused by the transition of HIRS 2 to HIRS 3 is not apparent anymore when it comes to calculate extreme UTHi cases. We come up with a new time series for values found at the low tail of the T12 distribution, which can be further exploited for analyses of ice saturation and supersaturation cases. The validity of the new method with respect to typical intercalibration methods such as regression-based methods is presented and discussed.

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Technical note: On the intercalibration of HIRS channel 12 brightness temperatures following the transition from HIRS 2 to HIRS 3/4 for ice saturation studies

Atmospheric Measurement Techniques ◽

10.5194/amt-10-681-2017 ◽

2017 ◽

Vol 10 (2) ◽

pp. 681-693 ◽

Cited By ~ 1

Author(s):

Klaus Gierens ◽

Kostas Eleftheratos

Keyword(s):

Time Series ◽

Technical Note ◽

Temperature Data ◽

Distribution Functions ◽

Cumulative Distribution ◽

Central Wavelength ◽

Upper Troposphere ◽

Brightness Temperatures ◽

Upper Tropospheric Humidity

Abstract. In the present study we explore the capability of the intercalibrated HIRS brightness temperature data at channel 12 (the HIRS water vapour channel; T12) to reproduce ice supersaturation in the upper troposphere during the period 1979–2014. Focus is given on the transition from the HIRS 2 to the HIRS 3 instrument in the year 1999, which involved a shift of the central wavelength in channel 12 from 6.7 to 6.5 µm. It is shown that this shift produced a discontinuity in the time series of low T12 values ( < 235 K) and associated cases of high upper-tropospheric humidity with respect to ice (UTHi  > 70 %) in the year 1999 which prevented us from maintaining a continuous, long-term time series of ice saturation throughout the whole record (1979–2014). We show that additional corrections are required to the low T12 values in order to bring HIRS 3 levels down to HIRS 2 levels. The new corrections are based on the cumulative distribution functions of T12 from NOAA 14 and 15 satellites (that is, when the transition from HIRS 2 to HIRS 3 occurred). By applying these corrections to the low T12 values we show that the discontinuity in the time series caused by the transition of HIRS 2 to HIRS 3 is not apparent anymore when it comes to calculating extreme UTHi cases. We come up with a new time series for values found at the low tail of the T12 distribution, which can be further exploited for analyses of ice saturation and supersaturation cases. The validity of the new method with respect to typical intercalibration methods such as regression-based methods is presented and discussed.

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Development of Device for Detecting Helium Leak From Canister: Part 1 — Experiment on Temperature Behavior During Gas Leak From Canister of 1/4.5 Scale Cask Model

Volume 6A: Thermal-Hydraulics and Safety Analyses ◽

10.1115/icone26-81477 ◽

2018 ◽

Author(s):

Hirofumi Takeda ◽

Masanori Goto

Keyword(s):

Performance Monitoring ◽

Temperature Data ◽

Detection Methods ◽

Helium Pressure ◽

Leak Detector ◽

Long Term Storage ◽

Sealing Performance ◽

Gas Leak ◽

Term Storage

A concrete cask has an advantage in cost and period of manufacturing compared with a metal cask. In the metal cask, monitoring of helium pressure between a primary lid and a secondary lid of the cask is required by regulation. On the other hand, in the concrete cask, the lids of a canister are welded and have high sealing performance, so that the monitoring of helium leak from the canister is not required. However, a loss of the sealing performance of the secondary lid, which is caused by stress corrosion cracking (SCC), is concerned in the case of long-term storage by the concrete cask. In the view of this situation, it would be useful to install a helium leak detector in the concrete cask in order to improve the safety of the long-term storage. Thus, we have been developing the detector. The phenomenon that the temperature at the bottom of the canister (TB) increases and the temperature at the top of the canister (TT) decreases during the helium leak from the canister has been confirmed by the experiments in the previous study. We have proposed the performance monitoring by monitoring the temperature difference ΔTBT (= TB-TT) instead of pressure monitoring. This time, to make the installation and maintenance of the helium leak detector easier in consideration of practical use, we proposed a new detection technique using only the temperature of either the lid or the bottom of the canister. We performed leak tests by using a 1/4.5 scale cask model based on a similarity law of thermal hydraulics. In the experiments, air was used for an inner gas of a canister of the model, and a heat flux of a canister surface had the same value as that of the actual canister surface. In this model, Ra* number can be made to coincide with that of the actual canister. Besides, Gr* number and Bo* number are almost equal to those of the actual canister. Temperature data at respective canister parts were obtained under condition of canister internal pressure from 6 atm to 1 atm (atmosphere pressure). Also, the new and old leak detection methods were evaluated by using the obtained temperature data.

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How well do stratospheric reanalyses reproduce high-resolution satellite temperature measurements?

10.5194/acp-2018-515 ◽

2018 ◽

Author(s):

Corwin J. Wright ◽

Neil P. Hindley

Keyword(s):

Recovery Phase ◽

Wave Activity ◽

Temperature Data ◽

High Gravity ◽

Recent Past ◽

Sudden Stratospheric Warming ◽

Brightness Temperatures ◽

Stratospheric Temperature ◽

True State ◽

Mean Differences

Abstract. Atmospheric reanalyses are data-assimilating weather models which are widely used as proxies for the true state of the atmosphere in the recent past, particularly for the stratosphere, where historical observations are sparse. But how realistic are these stratospheric reanalyses? Here, we resample stratospheric temperature data from six modern reanalyses (CFSR, ERA-5, ERA-Interim, JRA-55, JRA-55C and MERRA-2) to produce synthetic satellite observations, which we directly compare to retrieved temperatures from the COSMIC, HIRDLS and SABER instruments and to brightness temperatures from the AIRS instrument for the ten-year period 2003–2012. We explicitly sample standard public-release products in order to best assess their suitability for typical use cases. We find that all-time all-latitude correlations between limb sounder observations and synthetic observations from full-input reanalyses are 0.97–0.99 at 30 km altitude, falling to 0.84–0.94 at 50 km. The highest correlations are seen at high latitudes and the lowest in the sub-tropics, but root-mean-square (RMS) differences are highest (10 K or greater) in high-latitude winter. At all latitudes, differences increase with increasing height. High-altitude differences become especially large during disrupted periods such as the post-sudden stratospheric warming recovery phase, where zonal-mean differences can be as high as 18 K between different datasets. We further show that, for the current generation of reanalysis products, a full-3D sampling approach is always required to produce realistic synthetic AIRS observations, but is almost never required to produce realistic synthetic HIRDLS observations. For synthetic SABER and COSMIC observations full-3D sampling is required in equatorial regions and regions of high gravity-wave activity but not otherwise. Finally, we use cluster-analyses to show that full-input reanalyses are more tightly correlated with each other than with observations, even observations which they assimilate. This may suggest that these reanalyses are over-tuned to match their comparators. If so, this could have significant implications for future reanalysis development.

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Interannual variability and long term changes in planetary wave activity in the middle atmosphere observed by lidar

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-6-11299-2006 ◽

2006 ◽

Vol 6 (6) ◽

pp. 11299-11316 ◽

Cited By ~ 4

Author(s):

A. Hauchecorne ◽

P. Keckhut ◽

M. L. Chanin

Keyword(s):

Interannual Variability ◽

Planetary Wave ◽

Middle Atmosphere ◽

Stratospheric Ozone ◽

Wave Activity ◽

Temperature Data ◽

Positive Trend ◽

Stratospheric Temperature ◽

Rayleigh Lidar

Abstract. The upwelling planetary wave activity (PW) from the troposphere controls the intensity of the equator to pole transport of stratospheric ozone by the Brewer-Dobson circulation and thereby modulates the total ozone content at mid- and high-latitudes. Rayleigh lidar temperature data obtained from 1981 to 2001 at mid-latitude were used to study the interannual variability of PW activity in winter (October to April). The spectrum of stratospheric temperature fluctuations exhibits 2 peaks corresponding to 2 dominant modes of free travelling Rossby waves known as 16 day- and 12 day-waves. The 12 day-wave activity is shown to be anticorrelated with the equatorial QBO wind at 40 hPa. During the period 1981–2000 the global PW activity shows a negative trend for months October to January and a positive trend in March and April.

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Anomalous Long Term Trends in USHCN Temperature Data

SSRN Electronic Journal ◽

10.2139/ssrn.2939569 ◽

2017 ◽

Cited By ~ 6

Author(s):

Jamal Munshi

Keyword(s):

Temperature Data ◽

Long Term Trends

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Modeling of unforced demand response programs

International Journal of Emerging Electric Power Systems ◽

10.1515/ijeeps-2020-0208 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Hassan Jalili ◽

Pierluigi Siano

Keyword(s):

Demand Response ◽

Load Shifting ◽

Response Models ◽

Temperature Changes ◽

Proposed Model ◽

Equipment Failures ◽

Demand Response Programs ◽

Simultaneous Implementation ◽

Long Term Studies

Abstract Demand response programs are useful options in reducing electricity price, congestion relief, load shifting, peak clipping, valley filling and resource adequacy from the system operator’s viewpoint. For this purpose, many models of these programs have been developed. However, the availability of these resources has not been properly modeled in demand response models making them not practical for long-term studies such as in the resource adequacy problem where considering the providers’ responding uncertainties is necessary for long-term studies. In this paper, a model considering providers’ unavailability for unforced demand response programs has been developed. Temperature changes, equipment failures, simultaneous implementation of demand side management resources, popular TV programs and family visits are the main reasons that may affect the availability of the demand response providers to fulfill their commitments. The effectiveness of the proposed model has been demonstrated by numerical simulation.

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