scholarly journals Comparison of AIRS and IASI Radiances Using GOES Imagers as Transfer Radiometers toward Climate Data Records

2010 ◽  
Vol 49 (3) ◽  
pp. 478-492 ◽  
Author(s):  
Likun Wang ◽  
Xiangqian Wu ◽  
Mitch Goldberg ◽  
Changyong Cao ◽  
Yaping Li ◽  
...  
Keyword(s):  
Brightness Temperature ◽  
Climate Data ◽  
Atmospheric Infrared Sounder ◽  
Mean Values ◽  
Tropical Regions ◽  
Time Period ◽  
Double Differences ◽  
Cross Track ◽  
Spectral Channels

Abstract The Atmospheric Infrared Sounder (AIRS) and the Infrared Atmospheric Sounding Interferometer (IASI), together with the future Cross-track Infrared Sounder, will provide long-term hyperspectral measurements of the earth and its atmosphere at ∼10 km spatial resolution. Quantifying the radiometric difference between AIRS and IASI is crucial for creating fundamental climate data records and establishing the space-based infrared calibration standard. Since AIRS and IASI have different local equator crossing times, a direct comparison of these two instruments over the tropical regions is not feasible. Using the Geostationary Operational Environmental Satellite (GOES) imagers as transfer radiometers, this study compares AIRS and IASI over warm scenes in the tropical regions for a time period of 16 months. The double differences between AIRS and IASI radiance biases relative to the GOES-11 and -12 imagers are used to quantify the radiance differences between AIRS and IASI within the GOES imager spectral channels. The results indicate that, at the 95% confidence level, the mean values of the IASI − AIRS brightness temperature differences for warm scenes are very small, that is, −0.0641 ± 0.0074 K, −0.0432 ± 0.0114 K, and −0.0095 ± 0.0151 K for the GOES-11 6.7-, 10.7-, and 12.0-μm channels, respectively, and −0.0490 ± 0.0100 K, −0.0419 ± 0.0224 K, and −0.0884 ± 0.0160 K for the GOES-12 6.5-, 10.7-, and 13.3-μm channels, respectively. The brightness temperature biases between AIRS and IASI within the GOES imager spectral range are less than 0.1 K although the AIRS measurements are slightly warmer than those of IASI.

scholarly journals Radiometric consistency assessment of hyperspectral infrared sounders

2015 ◽  
Vol 8 (7) ◽  
pp. 7161-7199 ◽  
Author(s):  
L. Wang ◽  
Y. Han ◽  
X. Jin ◽  
Y. Chen ◽  
D. A. Tremblay
Keyword(s):  
Brightness Temperature ◽  
Infrared Imaging ◽  
Atmospheric Infrared Sounder ◽  
Atmospheric Sounding ◽  
Benchmark Datasets ◽  
Spectral Scale ◽  
One Year ◽  
Cross Track ◽  
Spectral Channels

Abstract. The radiometric and spectral consistency among the Atmospheric Infrared Sounder (AIRS), the Infrared Atmospheric Sounding Interferometer (IASI), and the Cross-track Infrared Sounder (CrIS) is fundamental for the creation of long-term infrared (IR) hyperspectral radiance benchmark datasets for both inter-calibration and climate-related studies. In this study, the CrIS radiance measurements on Suomi National Polar-orbiting Partnership (SNPP) satellite are directly compared with IASI on MetOp-A and -B at the finest spectral scale and with AIRS on Aqua in 25 selected spectral regions through one year of simultaneous nadir overpass (SNO) observations to evaluate radiometric consistency of these four hyperspectral IR sounders. The spectra from different sounders are paired together through strict spatial and temporal collocation. The uniform scenes are selected by examining the collocated Visible Infrared Imaging Radiometer Suite (VIIRS) pixels. Their brightness temperature (BT) differences are then calculated by converting the spectra onto common spectral grids. The results indicate that CrIS agrees well with IASI on MetOp-A and IASI on MetOp-B at the longwave IR (LWIR) and middle-wave IR (MWIR) bands with 0.1–0.2 K differences. There are no apparent scene-dependent patterns for BT differences between CrIS and IASI for individual spectral channels. CrIS and AIRS are compared at the 25 spectral regions for both Polar and Tropical SNOs. The combined global SNO datasets indicate that, the CrIS-AIRS BT differences are less than or around 0.1 K among 21 of 25 comparison spectral regions and they range from 0.15 to 0.21 K in the remaining 4 spectral regions. CrIS-AIRS BT differences in some comparison spectral regions show weak scene-dependent features.

scholarly journals Radiometric consistency assessment of hyperspectral infrared sounders

2015 ◽  
Vol 8 (11) ◽  
pp. 4831-4844 ◽  
Author(s):  
L. Wang ◽  
Y. Han ◽  
X. Jin ◽  
Y. Chen ◽  
D. A. Tremblay
Keyword(s):  
Infrared Imaging ◽  
Data Sets ◽  
Atmospheric Infrared Sounder ◽  
Benchmark Data ◽  
Long Wave ◽  
Atmospheric Sounding ◽  
Spectral Scale ◽  
Cross Track ◽  
Spectral Channels

Abstract. The radiometric and spectral consistency among the Atmospheric Infrared Sounder (AIRS), the Infrared Atmospheric Sounding Interferometer (IASI), and the Cross-track Infrared Sounder (CrIS) is fundamental for the creation of long-term infrared (IR) hyperspectral radiance benchmark data sets for both intercalibration and climate-related studies. In this study, the CrIS radiance measurements on Suomi National Polar-orbiting Partnership (SNPP) satellite are directly compared with IASI on MetOp-A and MetOp-B at the finest spectral scale and with AIRS on Aqua in 25 selected spectral regions through simultaneous nadir overpass (SNO) observations in 2013, to evaluate radiometric consistency of these four hyperspectral IR sounders. The spectra from different sounders are paired together through strict spatial and temporal collocation. The uniform scenes are selected by examining the collocated Visible Infrared Imaging Radiometer Suite (VIIRS) pixels. Their brightness temperature (BT) differences are then calculated by converting the spectra onto common spectral grids. The results indicate that CrIS agrees well with IASI on MetOp-A and IASI on MetOp-B at the long-wave IR (LWIR) and middle-wave IR (MWIR) bands with 0.1–0.2 K differences. There are no apparent scene-dependent patterns for BT differences between CrIS and IASI for individual spectral channels. CrIS and AIRS are compared at the 25 spectral regions for both polar and tropical SNOs. The combined global SNO data sets indicate that the CrIS–AIRS BT differences are less than or around 0.1 K among 21 of 25 spectral regions and they range from 0.15 to 0.21 K in the remaining four spectral regions. CrIS–AIRS BT differences in some comparison spectral regions show weak scene-dependent features.

scholarly journals Uncertainty Characterization and Propagation in the Community Long-Term Infrared Microwave Combined Atmospheric Product System (CLIMCAPS)

2019 ◽  
Vol 11 (10) ◽  
pp. 1227 ◽  
Author(s):  
Nadia Smith ◽  
Christopher D. Barnet
Keyword(s):  
Uncertainty Propagation ◽  
State Variables ◽  
Product System ◽  
Atmospheric Infrared Sounder ◽  
Cloud Properties ◽  
Infrared Measurements ◽  
Highly Correlated ◽  
Cross Track ◽  
Correlated Signals

The Community Long-term Infrared Microwave Combined Atmospheric Product System (CLIMCAPS) retrieves multiple Essential Climate Variables (ECV) about the vertical atmosphere from hyperspectral infrared measurements made by the Atmospheric InfraRed Sounder (AIRS, 2002–present) and its successor, the Cross-track Infrared Sounder (CrIS, 2011–present). CLIMCAPS ECVs are profiles of temperature and water vapor, column amounts of greenhouse gases (CO2, CH4), ozone (O3) and precursor gases (CO, SO2) as well as cloud properties. AIRS (and CrIS) spectral measurements are highly correlated signals of many atmospheric state variables. CLIMCAPS inverts an AIRS (and CrIS) measurement into a set of discrete ECVs by employing a sequential Bayesian approach in which scene-dependent uncertainty is rigorously propagated. This not only linearizes the inversion problem but explicitly accounts for spectral interference from other state variables so that the correlation among ECVs (and their uncertainty) may be minimized. Here, we outline the CLIMCAPS retrieval methodology with specific focus given to its sequential scene-dependent uncertainty propagation system. We conclude by demonstrating continuity in two CLIMCAPS ECVs across AIRS and CrIS so that a long-term data record may be generated to study the feedback cycles characterizing our climate system.

scholarly journals An Uncertainty Quantified Fundamental Climate Data Record for Microwave Humidity Sounders

2019 ◽  
Vol 11 (5) ◽  
pp. 548 ◽  
Author(s):  
Imke Hans ◽  
Martin Burgdorf ◽  
Stefan Buehler ◽  
Marc Prange ◽  
Theresa Lang ◽  
...  
Keyword(s):  
Brightness Temperature ◽  
Uncertainty Propagation ◽  
Uncertainty Budget ◽  
Intermediate Step ◽  
Climate Data ◽  
Data Record ◽  
Upper Tropospheric Humidity ◽  
Uncertainty Information ◽  
Climate Data Record

To date, there is no long-term, stable, and uncertainty-quantified dataset of upper tropospheric humidity (UTH) that can be used for climate research. As intermediate step towards the overall goal of constructing such a climate data record (CDR) of UTH, we produced a new fundamental climate data record (FCDR) on the level of brightness temperature for microwave humidity sounders that will serve as basis for the CDR of UTH. Based on metrological principles, we constructed and implemented the measurement equation and the uncertainty propagation in the processing chain for the microwave humidity sounders. We reprocessed the level 1b data to obtain newly calibrated uncertainty quantified level 1c data in brightness temperature. Three aspects set apart this FCDR from previous attempts: (1) the data come in a ready-to-use NetCDF format; (2) the dataset provides extensive uncertainty information taking into account the different correlation behaviour of the underlying errors; and (3) inter-satellite biases have been understood and reduced by an improved calibration. Providing a detailed uncertainty budget on these data, this new FCDR provides valuable information for a climate scientist and also for the construction of the CDR.

scholarly journals Validation and Error Estimation of AIRS MUSES CO Profiles with HIPPO, ATom and NOAA GML Aircraft Observations

2021 ◽  
Author(s):  
Jennifer D. Hegarty ◽  
Karen E. Cady-Pereira ◽  
Vivienne H. Payne ◽  
Susan S. Kulawik ◽  
John R. Worden ◽  
...  
Keyword(s):  
Lower Troposphere ◽  
Optimal Estimation ◽  
Reference Network ◽  
Atmospheric Infrared Sounder ◽  
Tropical Regions ◽  
Mixing Ratios ◽  
Bias Drift ◽  
Time Period ◽  
Aircraft Observations ◽  
Standard Deviations

Abstract. Single footprint retrievals of carbon monoxide from the Atmospheric Infrared Sounder (AIRS) are evaluated using aircraft in situ observations. The aircraft data are from the HIAPER Pole-to-Pole (HIPPO, 2009–2011), the first three Atmospheric Tomography Mission (ATom, 2016–2017) campaigns and the National Oceanic and Atmospheric Administration (NOAA) Global Monitoring Laboratory (GML) Global Greenhouse Gas Reference Network Aircraft Program from 2006–2017. The retrievals are obtained using an optimal estimation approach within the MUlti-SpEctra, MUlti-SpEcies, MUlti-Sensors (MUSES) algorithm. Retrieval biases and estimated errors are evaluated across a range of latitudes from the sub-polar to tropical regions over both ocean and land points. AIRS MUSES CO profiles were compared with HIPPO, ATom, and NOAA GML aircraft observations with a coincidence of 9 hours and 50 km to estimate retrieval biases and standard deviations. Comparisons were done for different pressure levels and column averages, latitudes, day, night, land, and ocean observations. We find mean biases of +6.6 % +/− 4.6 %, +0.6 % +/− 3.2 %, −6.1 % +/− 3.0 %, and 1.4 % +/− 3.6 %, for 750 hPa, 510 hPa, 287 hPa, and the column averages, respectively. The mean standard deviation is 15 %, 11 %, 12 %, and 9 % at these same pressure levels, respectively. Observation errors (theoretical errors) from the retrievals were found to be broadly consistent in magnitude with those estimated empirically from ensembles of satellite aircraft comparisons. The GML Aircraft Program comparisons generally had higher standard deviations and biases than the HIPPO and ATom comparisons. Since the GML aircraft flights do not go as high as the HIPPO and ATom flights, results from these GML comparisons are more sensitive to the choice of method for extrapolation of the aircraft profile above the uppermost measurement altitude. The AIRS retrieval performance shows little sensitivity to surface type (land or ocean) or day or night but some sensitivity to latitude. Comparisons to the NOAA GML set spanning the years 2006–2017 show that the AIRS retrievals are able to capture the distinct seasonal cycles but show a high bias of ~20 % in the lower troposphere during the summer when observed CO mixing ratios are at annual minimum values. The retrieval bias drift was examined over the same period and found to be small at < 0.5 % over the 2006–2017 time period.

Monitoring precipitation convective clouds with collocated hyperspectral infrared sounder and imager measurements

2020 ◽  
Author(s):  
Xinya Gong ◽  
Jun Li ◽  
Zhenglong Li ◽  
Christopher C. Moeller
Keyword(s):  
Brightness Temperature ◽  
Infrared Imaging ◽  
Water Vapor Absorption ◽  
Mean Values ◽  
Convective Clouds ◽  
Vapor Absorption ◽  
Absorption Channel ◽  
Cross Track ◽  
High Clouds ◽  
Meteorological Satellite

&lt;p&gt;Typically, DCCs are identified by 11 &amp;#181;m band brightness temperature (BT11) lower than a fixed BT threshold. Another method of combining the brightness temperature difference (BTD) between a water vapor absorption channel and a window channel to its measurement noise ratio (BNR) is adopted and applied to DCC identification. This BNR method improves the DCC detections over the legacy method because it is less contaminated with high clouds not thick and bright enough. BNR detects fewer DCCs than BT11, but with more confidence.&amp;#160;&lt;/p&gt;&lt;p&gt;Using observations of the collocated Cross-track Infrared Sounder (CrIS) and the Visible Infrared Imaging Radiometer Suite (VIIRS) onboard the Suomi National Polar-orbiting Partnership (SNPP) from 2017 to 2018, the results show BNR has better performances than BT11 for identifying the DCC and monitoring reflective solar bands. When comparing to BT11, BNR has more robust and invariant time series of monthly reflectance for all RSBs. Because BNR affects more on the left tails (less reflective) of the histograms than the mode reflectance, the improvement is more significant on the mean values than the modes. This method can be applied to other imagers with collocated advanced infrared sounders for detecting DCCs and monitoring the calibration stabilities of RSBs.&amp;#160;&lt;/p&gt;&lt;p&gt;Recently, the hyperspectral infrared atmospheric sounders onboard China&amp;#8217;s next-generation FengYun satellites, i.e. the Geosynchronous Interferometric InfraRed Sounder (GIIRS) on the FengYun-4 geostationary satellite series and the Hyperspectral Infrared Atmospheric Sounder (HIRAS) on the FengYun-3 polar orbiting meteorological satellite series, are in operation. Flown onboard the same platforms, the collocated (consistent in time and space) infrared sounders and imagers, provide mount of match-up measurements for the study of methodology and process for synergistic use of both infrared sounder and imager for multiple applications. The findings will provide scientific evidences for further enhancements and applications of future FengYun satellites and its observing system.&lt;/p&gt;

Island in the Stream: Oceanography and Fisheries of the Charleston Bump

2001 ◽  
Keyword(s):  
Yellowfin Tuna ◽  
Small Range ◽  
Catch Per Unit Effort ◽  
Size Frequency Distribution ◽  
Mean Values ◽  
Time Period ◽  
Migratory Routes ◽  
Resident Populations ◽  
Charleston Bump

<em>Abstract</em>.—Commercial landings of yellowfin tuna <em> Thunnus albacares </em>for the period 1975–1998 showed an overall increasing trend while blackfin tuna <em> T. atlanticus </em>landings did not. The landings of yellowfin tuna from 1992 to 1998 were significantly higher (mean = 51.7 mt) than in the previous five year period when there was apparently less directed effort. Maximum landings (67.3 mt) were recorded in 1996. Blackfin tuna landings over this same time period were generally less than 10 mt with a peak of 16 mt in 1986. The seasonality of commercial landings by quarter is presented for a 12 year period (1987–1998). For yellowfin tuna, the second and third quarters consistently had the highest landings while the first quarter was lowest. The second and third quarters combined accounted for greater than 70% of annual landings in every year. The seasonality in landings of blackfin tuna was more pronounced with the third quarter predominating in every year but one. Third quarter landings comprised 42–72% of the annual values while the first quarter was typically less than 5%. An analysis of catch per unit effort for both species over the same period (1987–1998) was conducted using an index developed from the detailed catch records of ten commercial fishers who target pelagic species. Mean values for yellowfin tuna increased significantly from 1992 onward and have oscillated in a small range (2.0–3.0 Kg per hour fishing) through 1998. The values for blackfin tuna were uniformly low and showed little variation. A long term recreational tagging program has resulted in high recapture rates for both species (yellowfin tuna 17.3%, blackfin tuna 10.8%) which may be associated with stable migratory routes or resident populations. An analysis of days at liberty for tag-recaptured fish indicated that 52.6% of all recaptured yellowfin tuna (<EM> N </EM>= 78) were taken within 30 days of release. The corresponding figure for all recaptured blackfin tuna (<EM> N </EM>= 46) was 13%. There is a significantly higher proportion of long term recaptures (up to four years) in blackfin tuna. An examination of the size-frequency distribution for yellowfin tuna indicates that a broad size range is caught in Bermuda waters, however, the catch is dominated by relatively small size classes (modal size = 79 cm FL).

The Hydrological Cycle in Three State-of-the-Art Reanalyses: Intercomparison and Performance Analysis

2012 ◽  
Vol 13 (5) ◽  
pp. 1397-1420 ◽  
Author(s):  
Christof Lorenz ◽  
Harald Kunstmann
Keyword(s):  
Hydrological Cycle ◽  
Water Cycle ◽  
State Of The Art ◽  
Geographic Location ◽  
Moisture Flux ◽  
Flux Divergence ◽  
Climate Trend ◽  
Mean Values ◽  
Tropical Regions

Abstract The three state-of-the-art global atmospheric reanalysis models—namely, ECMWF Interim Re-Analysis (ERA-Interim), Modern-Era Retrospective Analysis for Research and Applications (MERRA; NASA), and Climate Forecast System Reanalysis (CFSR; NCEP)—are analyzed and compared with independent observations in the period between 1989 and 2006. Comparison of precipitation and temperature estimates from the three models with gridded observations reveals large differences between the reanalyses and also of the observation datasets. A major source of uncertainty in the observations is the spatial distribution and change of the number of gauges over time. In South America, active measuring stations were reduced from 4267 to 390. The quality of precipitation estimates from the reanalyses strongly depends on the geographic location, as there are significant differences especially in tropical regions. The closure of the water cycle in the three reanalyses is analyzed by estimating long-term mean values for precipitation, evapotranspiration, surface runoff, and moisture flux divergence. Major shortcomings in the moisture budgets of the datasets are mainly due to inconsistencies of the net precipitation minus evaporation and evapotranspiration, respectively, (P − E) estimates over the oceans and landmasses. This imbalance largely originates from the assimilation of radiance sounding data from the NOAA-15 satellite, which results in an unrealistic increase of oceanic P − E in the MERRA and CFSR budgets. Overall, ERA-Interim shows both a comparatively reasonable closure of the terrestrial and atmospheric water balance and a reasonable agreement with the observation datasets. The limited performance of the three state-of-the-art reanalyses in reproducing the hydrological cycle, however, puts the use of these models for climate trend analyses and long-term water budget studies into question.

Stability and Change in Emotional Intelligence: Exploring the Transition to Young Adulthood

2005 ◽  
Vol 26 (2) ◽  
pp. 100-106 ◽  
Author(s):  
James D.A. Parker ◽  
Donald H. Saklofske ◽  
Laura M. Wood ◽  
Jennifer M. Eastabrook ◽  
Robyn N. Taylor
Keyword(s):  
High School ◽  
Emotional Intelligence ◽  
Postsecondary Education ◽  
Life Transition ◽  
Full Time ◽  
Major Life ◽  
Long Term Stability ◽  
Time Period ◽  
Transition From High School

Abstract. The concept of emotional intelligence (EI) has attracted growing interest from researchers working in various fields. The present study examined the long-term stability (32 months) of EI-related abilities over the course of a major life transition (the transition from high school to university). During the first week of full-time study, a large group of undergraduates completed the EQ-i:Short; 32 months later a random subset of these students (N = 238), who had started their postsecondary education within 24 months of graduating from high school, completed the measures for a second time. The study found EI scores to be relatively stable over the 32-month time period. EI scores were also found to be significantly higher at Time 2; the overall pattern of change in EI-levels was more than can be attributed to the increased age of the participants.

Comparative Study of effectiveness of mobilization with movement (MWM) and End range mobilization (ERM) techniques in frozen shoulder

2018 ◽  
Vol 4 (4) ◽  
pp. 519-522
Author(s):  
Jeyakumar S ◽  
Jagatheesan Alagesan ◽  
T.S. Muthukumar
Keyword(s):  
Range Of Motion ◽  
Frozen Shoulder ◽  
Type I ◽  
Mean Values ◽  
Functional Activities ◽  
Group A ◽  
The Mean ◽  
Group B

Background: Frozen shoulder is disorder of the connective tissue that limits the normal Range of motion of the shoulder in diabetes, frozen shoulder is thought to be caused by changes to the collagen in the shoulder joint as a result of long term Hypoglycemia. Mobilization is a therapeutic movement of the joint. The goal is to restore normal joint motion and rhythm. The use of mobilization with movement for peripheral joints was developed by mulligan. This technique combines a sustained application of manual technique “gliding” force to the joint with concurrent physiologic motion of joint, either actively or passively. This study aims to find out the effects of mobilization with movement and end range mobilization in frozen shoulder in Type I diabetics. Materials and Methods: 30 subjects both male and female, suffering with shoulder pain and clinically diagnosed with frozen shoulder was recruited for the study and divided into two groups with 15 patients each based on convenient sampling method. Group A patients received mobilization with movement and Group B patients received end range mobilization for three weeks. The outcome measurements were SPADI, Functional hand to back scale, abduction range of motion using goniometer and VAS. Results: The mean values of all parameters showed significant differences in group A as compared to group B in terms of decreased pain, increased abduction range and other outcome measures. Conclusion: Based on the results it has been concluded that treating the type 1 diabetic patient with frozen shoulder, mobilization with movement exercise shows better results than end range mobilization in reducing pain and increase functional activities and mobility in frozen shoulder.

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