Robust Tropospheric Warming Revealed by Iteratively Homogenized Radiosonde Data

2008 ◽  
Vol 21 (20) ◽  
pp. 5336-5352 ◽  
Author(s):  
Steven C. Sherwood ◽  
Cathryn L. Meyer ◽  
Robert J. Allen ◽  
Holly A. Titchner
Keyword(s):  
Northern Hemisphere ◽  
Wind Shear ◽  
Goodness Of Fit ◽  
Lower Troposphere ◽  
Radiosonde Data ◽  
University Of Maryland ◽  
Chi Squared ◽  
Remote Sensing Systems ◽  
Stratospheric Cooling ◽  
The University

Abstract Results are presented from a new homogenization of data since 1959 from 527 radiosonde stations. This effort differs from previous ones by employing an approach specifically designed to minimize systematic errors in adjustment, by including wind shear as well as temperature, by seasonally resolving adjustments, and by using neither satellite information nor station metadata. Relatively few artifacts were detected in wind shear, and associated adjustments were indistinguishable from random adjustments. Temperature artifacts were detected most often in the late 1980s–early 1990s. Uncertainty was characterized from variations within an ensemble of homogenizations and used to test goodness of fit with satellite data using reduced chi squared. The meridional variations of zonally aggregated temperature trend since 1979 moved significantly closer to those of the Microwave Sounding Unit (MSU) after data adjustment. Adjusted data from 5°S to 20°N continue to show relatively weak warming, but the error is quite large, and the trends are inconsistent with those at other latitudes. Overall, the adjusted trends are close to those of MSU for the temperature of the lower troposphere (TLT). For channel 2, they are consistent with two analyses (Remote Sensing Systems, p = 0.54, and the University of Maryland, p = 0.32) showing the strongest warming but not with the University of Alabama dataset (p = 0.0001). The troposphere warms at least as strongly as the surface, with local warming maxima at 300 hPa in the tropics and in the boundary layer of the extratropical Northern Hemisphere (ENH). Tropospheric warming since 1959 is almost hemispherically symmetric, but since 1979 it is significantly stronger in ENH and weaker in the extratropical Southern Hemisphere (ESH). ESH trends are relatively uncertain because of poor sampling. Stratospheric cooling also remains stronger than indicated by MSU and likely excessive. While this effort appears not to have detected all artifacts, trends appear to be systematically improved. Stronger warming is shown in the Northern Hemisphere where sampling is best. Several suggestions are made for future attempts. These results support the hypothesis that trends in wind data are relatively uncorrupted by artifacts compared to temperature, and should be exploited in future homogenization efforts.

scholarly journals Evidence for an earlier greenhouse cooling effect in the stratosphere before 1980 over the Northern Hemisphere

2014 ◽  
Vol 14 (15) ◽  
pp. 7705-7720 ◽  
Author(s):  
C. S. Zerefos ◽  
K. Tourpali ◽  
P. Zanis ◽  
K. Eleftheratos ◽  
C. Repapis ◽  
...  
Keyword(s):  
Global Warming ◽  
Northern Hemisphere ◽  
Geopotential Height ◽  
Lower Stratosphere ◽  
Lower Troposphere ◽  
Radiosonde Data ◽  
Data Sets ◽  
Radiative Processes ◽  
Before And After

Abstract. This study provides a new look at the observed and calculated long-term temperature changes from the lower troposphere to the lower stratosphere since 1958 over the Northern Hemisphere. The data sets include the NCEP/NCAR reanalysis, the Free University of Berlin (FU-Berlin) and the RICH radiosonde data sets as well as historical simulations with the CESM1-WACCM global model participating in CMIP5. The analysis is mainly based on monthly layer mean temperatures derived from geopotential height thicknesses in order to take advantage of the use of the independent FU-Berlin stratospheric data set of geopotential height data since 1957. This approach was followed to extend the records for the investigation of the stratospheric temperature trends to the earliest possible time. After removing the natural variability with an autoregressive multiple regression model our analysis shows that the period 1958–2011 can be divided into two distinct sub-periods of long-term temperature variability and trends: before and after 1980. By calculating trends for the summer time to reduce interannual variability, the two periods are as follows. From 1958 until 1979, a non-significant trend (0.06 ± 0.06 °C decade−1 for NCEP) and slightly cooling trends (−0.12 ± 0.06 °C decade−1 for RICH) are found in the lower troposphere. The second period from 1980 to the end of the records shows significant warming (0.25 ± 0.05 °C decade−1 for both NCEP and RICH). Above the tropopause a significant cooling trend is clearly seen in the lower stratosphere both in the pre-1980 period (−0.58 ± 0.17 °C decade−1 for NCEP, −0.30 ± 0.16 °C decade−1 for RICH and −0.48 ± 0.20 °C decade−1 for FU-Berlin) and the post-1980 period (−0.79 ± 0.18 °C decade−1 for NCEP, −0.66 ± 0.16 °C decade−1 for RICH and −0.82 ± 0.19 °C decade−1 for FU-Berlin). The cooling in the lower stratosphere persists throughout the year from the tropics up to 60° N. At polar latitudes competing dynamical and radiative processes reduce the statistical significance of these trends. Model results are in line with reanalysis and the observations, indicating a persistent cooling (−0.33 °C decade−1) in the lower stratosphere during summer before and after 1980; a feature that is also seen throughout the year. However, the lower stratosphere CESM1-WACCM modelled trends are generally lower than reanalysis and the observations. The contrasting effects of ozone depletion at polar latitudes in winter/spring and the anticipated strengthening of the Brewer–Dobson circulation from man-made global warming at polar latitudes are discussed. Our results provide additional evidence for an early greenhouse cooling signal in the lower stratosphere before 1980, which appears well in advance relative to the tropospheric greenhouse warming signal. The suitability of early warning signals in the stratosphere relative to the troposphere is supported by the fact that the stratosphere is less sensitive to changes due to cloudiness, humidity and man-made aerosols. Our analysis also indicates that the relative contribution of the lower stratosphere versus the upper troposphere low-frequency variability is important for understanding the added value of the long-term tropopause variability related to human-induced global warming.

scholarly journals Observational description of the warp in our galaxy

1979 ◽  
Vol 84 ◽  
pp. 493-499 ◽  
Author(s):  
A. P. Henderson
Keyword(s):  
Southern Hemisphere ◽  
Northern Hemisphere ◽  
Outer Region ◽  
Neutral Hydrogen ◽  
Reduction Stage ◽  
University Of Maryland ◽  
The Galaxy ◽  
Region 10 ◽  
The University

In 1975 F. J. Kerr and P. F. Bowers of the University of Maryland made a full coverage survey of the neutral hydrogen in the southern hemisphere between ±10° latitude from 240° to 350° in longitude. This survey taken with the CSIRO 18 meter telescope is still in the reduction stage but when completed it will provide an ideal complement to the full ±10° coverage of the northern sky by H. Weaver and D. R. W. Williams (1973). The possibility of a unified analysis of the outer region of the Galaxy has inspired this present study. The plan here is to use the ±10° Weaver-Williams survey in the region 10° < ℓ < 130°; the ±30° extension to this survey (H. Weaver and D. R. W. Williams, 1974) in the region 115° < ℓ < 245° and finally the Kerr-Bowers survey, 240° < ℓ < 350°. Since the latter survey is incompletely reduced at this time we have only used profiles at 5° intervals in longitude and thereby have produced a preliminary determination of the plane in the southern hemisphere. The northern hemisphere determination is complete.

scholarly journals A Comparative Analysis of Data Derived from Orbiting MSU/AMSU Instruments

2017 ◽  
Vol 34 (1) ◽  
pp. 225-232
Author(s):  
R. Eric Swanson
Keyword(s):  
Lower Troposphere ◽  
Star Products ◽  
University Of Alabama ◽  
Sensing Systems ◽  
Merging Procedure ◽  
Satellite Applications ◽  
Remote Sensing Systems ◽  
North Polar ◽  
The University ◽  
Tropopause Temperature

AbstractSpencer and Christy of the University of Alabama in Huntsville (UAH) recently introduced a new method to process MSU/AMSU satellite brightness temperature data with their version 6 (v6) data. A comparison of UAH v6 north polar lower stratospheric (TLS) data with that from Remote Sensing Systems (RSS) is presented, indicating a possible bias between 1986 and 1988. Comparing UAH and NOAA Center for Satellite Applications and Research (NOAA) TLS data produces a similar result. An additional analysis utilizing midtropospheric (TMT) data also found a similar bias. Comparing the NOAA TMT data for the May 2016 release against UAH and RSS TMT evidenced another excursion, dated at the middle of 2005, that was corrected in later releases. These comparisons reinforce the concerns expressed by other analysts regarding the merging procedure for UAH v6, repeating similar concerns regarding the earlier UAH v5 products. Any biases in the UAH, RSS, or STAR products would impact the trends calculated for these products and could explain the differences between these trends. Biases in the UAH series would also impact the UAH TLTv6 lower-troposphere product, which is a linear combination of the UAH TMT, tropopause temperature (TTP), and TLS series.

scholarly journals Satellite and VIZ–Radiosonde Intercomparisons for Diagnosis of Nonclimatic Influences

2006 ◽  
Vol 23 (9) ◽  
pp. 1181-1194 ◽  
Author(s):  
John R. Christy ◽  
William B. Norris
Keyword(s):  
Remote Sensing ◽  
Time Series ◽  
Lower Troposphere ◽  
University Of Alabama ◽  
High Significance ◽  
Sensing Systems ◽  
Microwave Sounding Unit ◽  
Microwave Sounding ◽  
Remote Sensing Systems ◽  
The University

Abstract Radiosonde datasets of temperature often suffer from discontinuities due to changes in instrumentation, location, observing practices, and algorithms. To identify temporal discontinuities that affect the VIZ/Sippican family of radiosondes, the 1979–2004 time series of a composite of 31 VIZ stations are compared to composites of collocated values of layer temperatures from two microwave sounding unit datasets—the University of Alabama in Huntsville (UAH) and Remote Sensing Systems (RSS). Discontinuities in the radiosonde time series relative to the two satellite datasets were detected with high significance and with similar magnitudes; however, some instances occurred where only one satellite dataset differed from the radiosondes. For the products known as lower troposphere (LT; surface–300 hPa) and midtroposphere (MT; surface–75-hPa layer), significant discontinuities relative to both satellite datasets were found—two cases for LT and four for MT. These are likely associated with changes in the radiosonde system. Three apparent radiosonde discontinuities were also determined for the lower-stratospheric product (LS; 150–15 hPa). Because they cannot be definitely traced to changes in the radiosonde system, they could be the result of common errors in the satellite products. When adjustments are applied to the radiosondes based independently on each satellite dataset, 26-yr trends of UAH (RSS) are consistent with the radiosondes for LT, MT, and LS at the level of ±0.06, ±0.04, and ±0.07 (±0.12, ±0.10, and ±0.10) K decade−1. Also, simple statistical retrievals based on radiosonde-derived relationships of LT, MT, and LS indicate a higher level of consistency with UAH products than with those of RSS.

scholarly journals The Distribution of Service Time of Patients

2020 ◽  
Author(s):  
Ayotunde Samson Oladimeji ◽  
Olayemi Joshua Ibidoja
Keyword(s):  
Service Time ◽  
Goodness Of Fit ◽  
Waiting Times ◽  
Arrival Rate ◽  
Arrival Process ◽  
Service Process ◽  
Goodness Of Fit Test ◽  
Scale Parameters ◽  
Chi Squared ◽  
The University

The aim of this research was to study the distribution of service time of patients at the University of Ilorin Health Services Clinic. The distributions of patients’ arrival and their service time were studied. The system was treated as single, time-independent arrivals with multiple service points. Based on the histograms obtained on the arrival process and the service process, appropriate distributions were fitted and tested using Chi-squared goodness of fit test. It revealed that the arrival process follows a Poisson distribution with an arrival rate of 0.8 patient per 2 minutes while the service process follows a gamma distribution with shape and scale parameters equal to 6 and 0.1 respectively. The mean service time was also found to be around 63 minutes. The results of this study may be useful to understand the magnitude of the problem of queue, relationship between resources and waiting times and to find a solution for alleviating the problem.

scholarly journals Environmental Conditions for Nighttime Offshore Migration of Precipitation Area as Revealed by In Situ Observation off Sumatra Island

2019 ◽  
Vol 147 (9) ◽  
pp. 3391-3407 ◽  
Author(s):  
Satoru Yokoi ◽  
Shuichi Mori ◽  
Fadli Syamsudin ◽  
Urip Haryoko ◽  
Biao Geng
Keyword(s):  
Wind Shear ◽  
Lower Troposphere ◽  
Radiosonde Data ◽  
In Situ Observation ◽  
Western Coast ◽  
Field Campaign ◽  
Southwesterly Wind ◽  
Sumatra Island ◽  
Precipitation Area

Abstract The diurnal cycle over tropical coastal waters is characterized by offshore migration of precipitation area during nighttime. This study analyzes in situ observational data collected during the YMC-Sumatra 2017 field campaign around the western coast of Sumatra Island, Indonesia, to examine the offshore migration phenomenon during 5–31 December 2017, when the Research Vessel Mirai was deployed about 90 km off the coast to perform observation. The offshore migration is observed in only less than a half of the 27 days. A comparison of radiosonde data at the vessel between days with and without the offshore migration reveals that vertical wind shear in the lower troposphere is a key environmental condition. In late afternoon of the days with the offshore migration, offshore (northeasterly) wind shear with height with considerable magnitude is observed, which is due to weaker daily mean southwesterly wind in the lower free troposphere, stronger southwesterly wind in the boundary layer, and sea breeze. As this condition is considered favorable for regeneration of convective cells to the offshore side of old ones, these results support an idea that the regeneration process is critical for the offshore migration. The Madden–Julian oscillation and cold surges play some roles in the weakening of the free-tropospheric wind. The migration speed is estimated at 2–3 m s−1, which is lower than that observed in another field campaign conducted in 2015 (Pre-YMC 2015). This difference is partly due to the difference in the environmental wind in the lower to midtroposphere.

Discontinuity Issues with Radiosonde and Satellite Temperatures in the Australian Region 1979–2006

2009 ◽  
Vol 26 (3) ◽  
pp. 508-522 ◽  
Author(s):  
John R. Christy ◽  
William B. Norris
Keyword(s):  
Remote Sensing ◽  
Lower Stratosphere ◽  
Lower Troposphere ◽  
University Of Alabama ◽  
The Third ◽  
Sensing Systems ◽  
Air Temperatures ◽  
Remote Sensing Systems ◽  
Temperature Records ◽  
The University

Abstract The temperature records of 28 Australian radiosonde stations were compared with the bulk-layer temperatures of three satellite products of The University of Alabama in Huntsville (UAH) and Remote Sensing Systems (RSS) for the period 1979–2006. The purpose was to use the satellite data as “reference truth” to quantify the effect of changes in station equipment, software, and operations on the reported upper air temperatures and resulting trends. The products are lower troposphere (LT), midtroposphere (MT), and lower stratosphere (LS). Four periods of significant shifts in temperatures were found in the radiosondes relative to both satellite datasets. In the first two shifts—around 1982/83 and 1987/88—the radiosondes experienced an accumulated LT and MT warming shift of 0.5 K on average. These shifts coincided with equipment changes. If unadjusted for these shifts, the radiosondes report spurious tropospheric warming of almost 0.2 K decade−1. For LS in the first period, there is relative warming but in the second, cooling. If unadjusted, the radiosondes overstate LS cooling by about −0.15 K decade−1. The third (early 1990s) and fourth (1998 LT and MT and 2002 LS) shifts are less robustly connected to changes in the radiosondes. Errors in the construction methodology of the satellite products likely account for at least part of the discrepancies but cannot be attributed with confidence to a specific cause. Having opposite signs in the two periods, the last two discrepancies tend to cancel each other. The net effect of these last two shifts on the overall LT and MT trends of ±0.03 K decade−1 is small.

Structural Model of Service Quality Factors Affecting Loyalty Sustainability

2020 ◽  
Vol 11 (2) ◽  
Author(s):  
Eman Al-erqi ◽  
◽  
Mohd Lizam Mohd Diah ◽  
Najmaddin Abo Mosali ◽  
◽  
...  
Keyword(s):  
International Students ◽  
Service Quality ◽  
Goodness Of Fit ◽  
Structural Model ◽  
Quality Factors ◽  
Factors Affecting ◽  
Measurement Models ◽  
Confirmatory Factor ◽  
The University ◽  
The Impact

This study seeks to address the impact of service quality affecting international student's satisfaction towards loyalty tothe Universiti Tun Hussein Onn Malaysia(UTHM). The aim of thestudy is to develop relationship between service quality factor and loyalty to the university from the international students’ perspectives. The study adopted quantitative approach where data was collected through questionnaire survey and analysed statistically. A total of 246 responses were received and found to be valid. The model was developed and analysed using AMOS-SEM software. Confirmatory factor analysis (CFA) function of the software was to assessed the measurement models and found that all the models achieved goodness of fit. Then path analysis function was used to assessed structural model and found that service qualityfactors have a significant effect on the students’ satisfaction and thus affecting the loyaltyto the university. Hopefully the outcome form this study will benefit the university in providing services especially to the international students.

scholarly journals The McDonaldization of Academic Libraries?

2015 ◽  
Vol 76 (3) ◽  
pp. 339-352 ◽  
Author(s):  
Brian Quinn
Keyword(s):  
Academic Libraries ◽  
Fast Food ◽  
Food Industry ◽  
Fast Food Industry ◽  
University Of Maryland ◽  
The University

George Ritzer, a sociologist at the University of Maryland, has proposed an influential thesis that suggests that many aspects of the fast food industry are making their way into other areas of society. This article explores whether his thesis, known as the McDonaldization thesis, is applicable to academic libraries. Specifically, it seeks to determine to what extent academic libraries may be considered McDonaldized, and if so, what effect McDonaldization may be having on them. It also investigates some possible alternatives to McDonaldization, and their implications for academic libraries.

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