scholarly journals CALIPSO lidar level 3 aerosol profile product: version 3 algorithm design

2018 ◽  
Author(s):  
Jason L. Tackett ◽  
David M. Winker ◽  
Brian J. Getzewich ◽  
Mark A. Vaughan ◽  
Stuart A. Young ◽  
...  
Keyword(s):  
Algorithm Design ◽  
Global Ocean ◽  
Orthogonal Polarization ◽  
Aerosol Extinction ◽  
Averaging Methods ◽  
Global Land ◽  
Level 3 ◽  
Classification Information ◽  
The Impact ◽  
Level 2

Abstract. The Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) level 3 aerosol profile product reports globally-gridded, quality-screened monthly mean aerosol extinction profiles retrieved by the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP). This paper describes the quality screening and averaging methods used to generate the version 3 product. The fundamental input data are CALIOP level 2 aerosol extinction profiles and layer classification information (aerosol, cloud, and clear-air). Prior to aggregation, the extinction profiles are quality-screened by a series of filters to reduce the impact of layer detection errors, layer classification errors, extinction retrieval errors, and biases due to an intermittent signal anomaly at the surface. The relative influence of these filters are compared in terms of sample rejection frequency, mean extinction, and mean AOD. The extinction QC flag filter is the most influential in preventing high-biases in level 3 mean extinction, while the misclassified cirrus fringe filter is most aggressive at rejecting cirrus misclassified as aerosol. The impact of quality screening on monthly mean aerosol extinction is investigated globally and regionally. After applying quality filters, monthly mean AOD is reduced by −24 and −31 % for global ocean and global land, respectively, thus indicating the importance of quality screening.

scholarly journals CALIPSO lidar level 3 aerosol profile product: version 3 algorithm design

2018 ◽  
Vol 11 (7) ◽  
pp. 4129-4152 ◽  
Author(s):  
Jason L. Tackett ◽  
David M. Winker ◽  
Brian J. Getzewich ◽  
Mark A. Vaughan ◽  
Stuart A. Young ◽  
...  
Keyword(s):  
Algorithm Design ◽  
Global Ocean ◽  
Orthogonal Polarization ◽  
Aerosol Extinction ◽  
Averaging Methods ◽  
Global Land ◽  
Level 3 ◽  
Classification Information ◽  
The Impact ◽  
Level 2

Abstract. The CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations) level 3 aerosol profile product reports globally gridded, quality-screened, monthly mean aerosol extinction profiles retrieved by CALIOP (the Cloud-Aerosol Lidar with Orthogonal Polarization). This paper describes the quality screening and averaging methods used to generate the version 3 product. The fundamental input data are CALIOP level 2 aerosol extinction profiles and layer classification information (aerosol, cloud, and clear-air). Prior to aggregation, the extinction profiles are quality-screened by a series of filters to reduce the impact of layer detection errors, layer classification errors, extinction retrieval errors, and biases due to an intermittent signal anomaly at the surface. The relative influence of these filters are compared in terms of sample rejection frequency, mean extinction, and mean aerosol optical depth (AOD). The “extinction QC flag” filter is the most influential in preventing high-biases in level 3 mean extinction, while the “misclassified cirrus fringe” filter is most aggressive at rejecting cirrus misclassified as aerosol. The impact of quality screening on monthly mean aerosol extinction is investigated globally and regionally. After applying quality filters, the level 3 algorithm calculates monthly mean AOD by vertically integrating the monthly mean quality-screened aerosol extinction profile. Calculating monthly mean AOD by integrating the monthly mean extinction profile prevents a low bias that would result from alternately integrating the set of extinction profiles first and then averaging the resultant AOD values together. Ultimately, the quality filters reduce level 3 mean AOD by −24 and −31 % for global ocean and global land, respectively, indicating the importance of quality screening.

scholarly journals Minimum aerosol layer detection sensitivities and their subsequent impacts on aerosol optical thickness retrievals in CALIPSO level 2 data products

2018 ◽  
Vol 11 (1) ◽  
pp. 499-514 ◽  
Author(s):  
Travis D. Toth ◽  
James R. Campbell ◽  
Jeffrey S. Reid ◽  
Jason L. Tackett ◽  
Mark A. Vaughan ◽  
...  
Keyword(s):  
Optical Thickness ◽  
Aerosol Optical Thickness ◽  
Orthogonal Polarization ◽  
Aerosol Layer ◽  
Aerosol Extinction ◽  
Noise Floor ◽  
Data Products ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
Level 2 ◽  
Global Mean

Abstract. Due to instrument sensitivities and algorithm detection limits, level 2 (L2) Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) 532 nm aerosol extinction profile retrievals are often populated with retrieval fill values (RFVs), which indicate the absence of detectable levels of aerosol within the profile. In this study, using 4 years (2007–2008 and 2010–2011) of CALIOP version 3 L2 aerosol data, the occurrence frequency of daytime CALIOP profiles containing all RFVs (all-RFV profiles) is studied. In the CALIOP data products, the aerosol optical thickness (AOT) of any all-RFV profile is reported as being zero, which may introduce a bias in CALIOP-based AOT climatologies. For this study, we derive revised estimates of AOT for all-RFV profiles using collocated Moderate Resolution Imaging Spectroradiometer (MODIS) Dark Target (DT) and, where available, AErosol RObotic NEtwork (AERONET) data. Globally, all-RFV profiles comprise roughly 71 % of all daytime CALIOP L2 aerosol profiles (i.e., including completely attenuated profiles), accounting for nearly half (45 %) of all daytime cloud-free L2 aerosol profiles. The mean collocated MODIS DT (AERONET) 550 nm AOT is found to be near 0.06 (0.08) for CALIOP all-RFV profiles. We further estimate a global mean aerosol extinction profile, a so-called “noise floor”, for CALIOP all-RFV profiles. The global mean CALIOP AOT is then recomputed by replacing RFV values with the derived noise-floor values for both all-RFV and non-all-RFV profiles. This process yields an improvement in the agreement of CALIOP and MODIS over-ocean AOT.

Evaluating and Assessing the Quality and Impact of Coaching Services

2019 ◽  
pp. 133-142
Keyword(s):  
Student Learning ◽  
Assessment Model ◽  
Transfer Of Knowledge ◽  
Knowledge And Skills ◽  
Annual Basis ◽  
Level 3 ◽  
Four Levels ◽  
Student Reactions ◽  
The Impact ◽  
Level 2

This chapter offers best practices, methods, and strategies for evaluating and assessing coaching services once they have been implemented. In order to determine the extent to which the coaching services that have been implemented are impacting retention, a comprehensive assessment combined with thoughtful analysis of the assessment data must be undertaken on a regular and continuous cycle. The Kirkpatrick and Kirkpatrick (2006) four-level assessment model to evaluate the impact and effectiveness of the selected coaching program on an annual basis, for either an outsourced coaching service or an internal coaching unit or department, is the recommended approach detailed in this chapter. The four levels of the assessment are as follows: Level 1 of the assessment will measure student reactions to the coaching services; Level 2 will assess student learning through the use of pre- and post-coaching assessments; Level 3 will assess transfer of knowledge and skills; and Level 4 will assess the impact and results as a result of the coaching program. The chapter provides advice and discussion about when to conduct each level of the four-part assessment model and a comprehensive sample assessment that can be modified to fit the needs of a wide variety of programs and institutions.

scholarly journals Investigation of CATS aerosol products and application toward global diurnal variation of aerosols

2019 ◽  
Vol 19 (19) ◽  
pp. 12687-12707 ◽  
Author(s):  
Logan Lee ◽  
Jianglong Zhang ◽  
Jeffrey S. Reid ◽  
John E. Yorks
Keyword(s):  
Middle East ◽  
North Africa ◽  
Orthogonal Polarization ◽  
Aerosol Extinction ◽  
Extinction Data ◽  
Time Variations ◽  
First Time ◽  
Global Oceans ◽  
Level 2 ◽  
Global Mean

Abstract. We present a comparison of 1064 nm aerosol optical depth (AOD) and aerosol extinction profiles from the Cloud-Aerosol Transport System (CATS) level 2 aerosol product with collocated Aerosol Robotic Network (AERONET) AOD, Moderate Imaging Spectroradiometer (MODIS) Aqua and Terra Dark Target AOD and Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) AOD and extinction data for the period of March 2015–October 2017. Upon quality-assurance checks of CATS data, reasonable agreement is found between aerosol data from CATS and other sensors. Using quality-assured CATS aerosol data, for the first time, variations in AODs and aerosol extinction profiles are evaluated at 00:00, 06:00, 12:00 and 18:00 UTC (and/or 00:00, 06:00, 12:00 and 18:00 local time or LT) on both regional and global scales. This study suggests that marginal variations are found in AOD from a global mean perspective, with the minimum aerosol extinction values found at 18:00 LT near the surface layer for global oceans, for both the June–November and December–May seasons. Over land, below 500 m, the daily minimum and maximum aerosol extinction values are found at 12:00 and 00:00/06:00 LT, respectively. Strong diurnal variations are also found over north Africa, the Middle East and India for the December–May season, and over north Africa, south Africa, the Middle East and India for the June–November season.

scholarly journals Long-term (1999–2019) variability of stratospheric aerosol over Mauna Loa, Hawaii, as seen by two co-located lidars and satellite measurements

2020 ◽  
Vol 20 (11) ◽  
pp. 6821-6839 ◽  
Author(s):  
Fernando Chouza ◽  
Thierry Leblanc ◽  
John Barnes ◽  
Mark Brewer ◽  
Patrick Wang ◽  
...  
Keyword(s):  
Stratospheric Ozone ◽  
Volcanic Eruptions ◽  
Stratospheric Aerosol ◽  
Atmospheric Composition ◽  
Orthogonal Polarization ◽  
Mauna Loa ◽  
Quiescent Period ◽  
Level 3 ◽  
The Impact ◽  
Good Agreement

Abstract. As part of the Network for the Detection of Atmospheric Composition Change (NDACC), ground-based measurements obtained from the Jet Propulsion Laboratory (JPL) stratospheric ozone lidar and the NOAA stratospheric aerosol lidar at Mauna Loa, Hawaii, over the past 2 decades were used to investigate the impact of volcanic eruptions and pyrocumulonimbus (PyroCb) smoke plumes on the stratospheric aerosol load above Hawaii since 1999. Measurements at 355 and 532 nm conducted by these two lidars revealed a color ratio of 0.5 for background aerosols and small volcanic plumes and 0.8 for a PyroCb plume recorded on September 2017. Measurements of the Nabro plume by the JPL lidar in 2011–2012 showed a lidar ratio of (64±12.7) sr at 355 nm around the center of the plume. The new Global Space-based Stratospheric Aerosol Climatology (GloSSAC), Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) Level 3 and Stratospheric Aerosol and Gas Experiment III on the International Space Station (SAGE III-ISS) stratospheric aerosol datasets were compared to the ground-based lidar datasets. The intercomparison revealed a generally good agreement, with vertical profiles of extinction coefficient within 50 % discrepancy between 17 and 23 km above sea level (a.s.l.) and 25 % above 23 km a.s.l. The stratospheric aerosol depth derived from all of these datasets shows good agreement, with the largest discrepancy (20 %) being observed between the new CALIOP Level 3 and the other datasets. All datasets consistently reveal a relatively quiescent period between 1999 and 2006, followed by an active period of multiple eruptions (e.g., Nabro) until early 2012. Another quiescent period, with slightly higher aerosol background, lasted until mid-2017, when a combination of extensive wildfires and multiple volcanic eruptions caused a significant increase in stratospheric aerosol loading. This loading maximized at the very end of the time period considered (fall 2019) as a result of the Raikoke eruption, the plume of which ascended to 26 km altitude in less than 3 months.

Fair value's effects on closed-end funds' discounts and premia: is level 3 the sole perpetrator?

2020 ◽  
Vol 46 (8) ◽  
pp. 1001-1022 ◽  
Author(s):  
Steve Fortin ◽  
Ahmad Hammami ◽  
Michel Magnan
Keyword(s):  
Relevant Information ◽  
Fair Value ◽  
Content Type ◽  
Level 3 ◽  
Closed End Funds ◽  
Level 1 ◽  
Value Hierarchy ◽  
Valuation Uncertainty ◽  
The Impact ◽  
Level 2

PurposeThis study examines the long-term link between fair valuation uncertainty and discounts/premia in closed-end funds. This study argues that, in exploring the close-end funds puzzle, prior research generally omits to consider the uncertainty surrounding the measurement of funds' financial disclosure, as reflected in the fair value hierarchy, when investment specialty differs across funds.Design/methodology/approachRegressions were employed to explore how the fair value hierarchy affects closed-end funds' discounts/premia when investment specialty differs. The authors also examine the effects pre- and post-2012 to explore if that relationship changes due to the additional disclosure requirements enacted at the end of 2011.FindingsThe authors find that the three levels of the fair value hierarchy have effects that vary according to a fund's specialty. For equity specialized funds, Level 3 significantly increases discounts and decreases premia, suggesting the impact of valuation uncertainty that underlies Level 3 estimates; this relationship disappears (decreases in severity) for premia (discount) experiencing funds post-2012. In contrast, Level 1 and Level 2 do not have any significant effect on discounts or premia except that post-2012, Level 2 begins to display discount decreasing effects. For bond specialized funds, no significant association was noted between premia and any of the fair value levels except that post-2012, Level 3 begins to display premium increasing effects. However, results are different for discounts. The authors note that Level 1 valuations significantly increase discounts, but only post-2012; Level 2 valuations significantly decrease discounts (pre- and post-2012), consistent with such estimates incorporating unique and relevant information; and Level 3 valuations do not have a significant effect on discounts.Originality/valueThe results of this study revisit prior evidence and indicate that results about the effects of fair value measurement and the closed-end funds' puzzle are sensitive to the period length being considered and the investment specialty of the fund. The authors also note that additional disclosure regarding Level 3 valuation inputs decreases market concern for valuation uncertainty and increases the liquidity benefits of investing in Level 3 carrying funds.

CONTINUOUS INTENTION CRITERIA OF SNS APPROPRIATION PROCESS IN FAMILY CONTEXT: A SYSTEMATIC LITERATURE REVIEW

2015 ◽  
Vol 75 (1) ◽  
Author(s):  
Yuzi Mahmud ◽  
Nor Zairah Ab. Rahim ◽  
Suraya Miskon ◽  
Nazean Jomhari
Keyword(s):  
Social Network ◽  
Family Environment ◽  
Family Relationships ◽  
Communication Technologies ◽  
Family Context ◽  
Research Attention ◽  
The Family ◽  
Level 3 ◽  
The Impact ◽  
Level 2

Communication technologies such as Social Network Sites (SNSs) are increasingly being used within family settings to support and extend the family relationships. Although many previous researchers have highlighted the impact of SNSs in family environment, criteria of SNS adoption and use in family context have received little research attention. This paper highlights selected SNS appropriation process criteria in family, individual and technical perspectives in order to understand why and how the SNS is being used in family context. Using the procedure of Bandara et al. (2011), NVivo 9.0 was employed to conduct content analysis of 284 articles published between the year of 2006 until 2014. As a result, the adoption and use criteria of SNS appropriation process were identified, and has been categorized in family, individual and technical perspectives using the Family Appropriation Process of Social Network Site (FAPSNS) framework. The understanding of the criteria could assist in effective and healthy adoption and use of SNSs among family members. However, this paper is merely focusing on level 2 and level 3 of SNS appropriation process in family, individual and technical perspectives. 

scholarly journals Synergy between CALIOP and MODIS instruments for aerosol monitoring: application to the Po Valley

2010 ◽  
Vol 3 (2) ◽  
pp. 1323-1359 ◽  
Author(s):  
P. Royer ◽  
J.-C. Raut ◽  
G. Ajello ◽  
S. Berthier ◽  
P. Chazette
Keyword(s):  
Signal To Noise Ratio ◽  
Extinction Ratio ◽  
Orthogonal Polarization ◽  
Aerosol Extinction ◽  
Large Area ◽  
Total Uncertainty ◽  
Aerosol Model ◽  
Po Valley ◽  
The Mean ◽  
Level 2

Abstract. We propose here a synergy between Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations/Cloud-Aerosol LIdar with Orthogonal Polarization (CALIPSO/CALIOP) and Moderate Resolution Imaging Spectroradiometer (MODIS) onboard Aqua and Terra in order to retrieve aerosol optical properties over the Po Valley from June 2006 to February 2009. Such an approach gives simultaneously access to the aerosol extinction vertical profile and to the equivalent backscatter-to-extinction ratio at 532 nm (BER, inverse of the lidar ratio). The choice of the Po valley has been driven by the great occurrences of pollutant events leading to a mean MODIS-derived aerosol optical thickness of 0.27(±0.17) at 550 nm over a large area of ~120 000 km2. In such area, a significant number of CALIOP level-1 vertical profiles can be averaged (~200 individual laser shots) leading to a signal-to-noise ratio greater than 10 in the planetary boundary layer (PBL) sufficient to perform a homemade inversion of the mean lidar profiles. The mean BER (together with the associated variabilities) over the Po Valley retrieved from the coupling between CALIOP/MODIS-Aqua and CALIOP/MODIS-Terra are ~0.014(±0.003) sr−1 and ~0.013(±0.004) sr−1, respectively. The total uncertainty on BER retrieval has been assessed to be ~0.003 sr−1 using a Monte Carlo approach. These mean BER values retrieved have been compared with those given by the level-2 operational products of CALIOP ~0.016(±0.003) sr−1. The values we assessed appear close to what is expected above urban area. A seasonal cycle has been observed with higher BER values in spring, summer and fall, which can be associated to dust event occurring during this period. In most of cases, the mean aerosol extinction coefficient in the PBL diverges significantly between the level-2 operational products and the result of our own inversion procedure. Indeed, mean differences of 0.10 km−1 (~50%) and 0.13 km−1 (~60%) have been calculated using MODIS-Aqua/CALIOP and MODIS-Terra/CALIOP synergies, respectively. Such differences may be due to the identification of the aerosol model by the operational algorithm and thus to the choice of the BER.

scholarly journals Minimum Aerosol Layer Detection Sensitivities and their Subsequent Impacts on Aerosol Optical Thickness Retrievals in CALIPSO Level 2 Data Products

2017 ◽  
Author(s):  
Travis D. Toth ◽  
James R. Campbell ◽  
Jeffrey S. Reid ◽  
Jason L. Tackett ◽  
Mark A. Vaughan ◽  
...  
Keyword(s):  
Optical Thickness ◽  
Aerosol Optical Thickness ◽  
Orthogonal Polarization ◽  
Aerosol Layer ◽  
Aerosol Extinction ◽  
Noise Floor ◽  
Data Products ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
Level 2 ◽  
Global Mean

Abstract. Due to instrument sensitivities and algorithm detection limits, Level 2 (L2) Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) 532 nm aerosol extinction profile retrievals are often populated with retrieval fill values (RFVs), which indicate the absence of detectable levels of aerosol within the profile. In this study, using four years (2007–2008 and 2010–2011) of CALIOP Version 3 L2 aerosol data, the occurrence frequency of daytime CALIOP profiles containing all RFVs (all-RFV profiles) is studied. In the CALIOP data products, the aerosol optical thickness (AOT) of any all-RFV profile is reported as being zero, which may introduce a bias in CALIOP-based AOT climatologies. For this study, we derive revised estimates of AOT for all-RFV profiles using collocated Moderate Resolution Imaging Spectroradiometer (MODIS) Dark Target (DT) and, where available, Aerosol Robotic Network (AERONET) data. Globally, all-RFV profiles comprise roughly 71 % of all daytime CALIOP L2 aerosol profiles (i.e., including completely attenuated profiles), accounting for nearly half (45 %) of all daytime cloud-free L2 aerosol profiles. The mean collocated MODIS DT (AERONET) 550 nm AOT is found to be near 0.06 (0.08) for CALIOP all-RFV profiles. We further estimate a global mean aerosol extinction profile, a so-called noise floor, for CALIOP all-RFV profiles. The global mean CALIOP AOT is then recomputed by replacing RFV values with the derived noise floor values for both all-RFV and non-all-RFV profiles. This process yields an improvement in the agreement of CALIOP and MODIS over-ocean AOT.

Managerial ability and fair value accounting: evidence from nonfinancial firms

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Wray Bradley ◽  
Li Sun
Keyword(s):  
Design Methodology ◽  
Fair Value ◽  
Managerial Ability ◽  
Fair Value Accounting ◽  
Content Type ◽  
Level 3 ◽  
Level 1 ◽  
The Impact ◽  
Nonfinancial Firms ◽  
Level 2

Purpose The purpose of this study is to examine the relation between managerial ability and fair value inputs (measured as fair value intensity) for nonfinancial firms. Design/methodology/approach This study uses regression analysis to investigate the impact of managerial ability on the level of fair value inputs. Findings This study finds significant and positive relations between managerial ability and use of Level 1 and Level 2 fair value inputs. On the other hand, this study finds an insignificant relation between managerial ability and Level 3 inputs. Originality/value The findings contribute to two research streams. To the best of the author’s knowledge, this is perhaps the first study that directly examines the link between managerial ability and fair value inputs.

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