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Author
Steffen, J. ; Bourassa, M.
Title
Barrier Layer Development Local to Tropical Cyclones based on Argo Float Observations
Type
$loc['typeJournal Article']
Year
2018
Publication
Journal of Physical Oceanography
Abbreviated Journal
J. Phys. Oceanogr.
Volume
48
Issue
9
Pages
1951-1968
Keywords
SEA-SURFACE TEMPERATURE ; UPPER-OCEAN RESPONSE ; NINO SOUTHERN-OSCILLATION ; MIXED-LAYER ; INDIAN-OCEAN ; HEAT-BUDGET ; NUMERICAL SIMULATIONS ; HURRICANES ; VARIABILITY ; PACIFIC
Abstract
The objective of this study is to quantify barrier layer development due to tropical cyclone (TC) passage using Argo float observations of temperature and salinity. To accomplish this objective, a climatology of Argo float measurements is developed from 2001 to 2014 for the Atlantic, eastern Pacific, and central Pacific basins. Each Argo float sample consists of a prestorm and poststorm temperature and salinity profile pair. In addition, a no-TC Argo pair dataset is derived for comparison to account for natural ocean state variability and instrument sensitivity. The Atlantic basin shows a statistically significant increase in barrier layer thickness (BLT) and barrier layer potential energy (BLPE) that is largely attributable to an increase of 2.6 m in the post-TC isothermal layer depth (ITLD). The eastern Pacific basin shows no significant changes to any barrier layer characteristic, likely due to a shallow and highly stratified pycnocline. However, the near-surface layer freshens in the upper 30 m after TC passage, which increases static stability. Finally, the central Pacific has a statistically significant freshening in the upper 20-30 m that increases upper-ocean stratification by similar to 35%. The mechanisms responsible for increases in BLPE vary between the Atlantic and both Pacific basins; the Atlantic is sensitive to ITLD deepening, while the Pacific basins show near-surface freshening to be more important in barrier layer development. In addition, Argo data subsets are used to investigate the physical relationships between the barrier layer and TC intensity, TC translation speed, radial distance from TC center, and time after TC passage.
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Publisher
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Language
Summary Language
Original Title
Series Editor
Series Title
Abbreviated Series Title
Series Volume
Series Issue
Edition
ISSN
0022-3670
ISBN
Medium
Area
Expedition
Conference
Funding
Approved
$loc['no']
Call Number
COAPS @ user @
Serial
970
Permanent link to this record
Author
Smith, S.R. ; Briggs, K. ; Lopez, N. ; Kourafalou, V.
Title
Applying Automated Underway Ship Observations to Numerical Model Evaluation
Type
$loc['typeJournal Article']
Year
2016
Publication
Journal of Atmospheric and Oceanic Technology
Abbreviated Journal
J. Atmos. Oceanic Technol.
Volume
33
Issue
3
Pages
409-428
Keywords
Ship observations ; Automatic weather stations ; Ocean models ; Model evaluation/performance ; In situ atmospheric observations ; Observational techniques and algorithms ; Models and modeling ; In situ oceanic observations
Abstract
Address
Corporate Author
Thesis
Publisher
Place of Publication
Editor
Language
Summary Language
Original Title
Series Editor
Series Title
Abbreviated Series Title
Series Volume
Series Issue
Edition
ISSN
0739-0572
ISBN
Medium
Area
Expedition
Conference
Funding
Approved
$loc['no']
Call Number
COAPS @ mfield @
Serial
53
Permanent link to this record
Author
Holbach, H.M. ; Uhlhorn, E.W. ; Bourassa, M.A.
Title
Off-Nadir SFMR Brightness Temperature Measurements in High-Wind Conditions
Type
$loc['typeJournal Article']
Year
2018
Publication
Journal of Atmospheric and Oceanic Technology
Abbreviated Journal
J. Atmos. Oceanic Technol.
Volume
35
Issue
9
Pages
1865-1879
Keywords
Tropical cyclones ; Wind ; Air-sea interaction ; Microwave observations ; Remote sensing ; Surface observations
Abstract
Wind and wave-breaking directions are investigated as potential sources of an asymmetry identified in off-nadir remotely sensed measurements of ocean surface brightness temperatures obtained by the Stepped Frequency Microwave Radiometer (SFMR) in high-wind conditions, including in tropical cyclones. Surface wind speed, which dynamically couples the atmosphere and ocean, can be inferred from SFMR ocean surface brightness temperature measurements using a radiative transfer model and an inversion algorithm. The accuracy of the ocean surface brightness temperature to wind speed calibration relies on accurate knowledge of the surface variables that are influencing the ocean surface brightness temperature. Previous studies have identified wind direction signals in horizontally polarized radiometer measurements in low to moderate (0�20 m s−1) wind conditions over a wide range of incidence angles. This study finds that the azimuthal asymmetry in the off-nadir SFMR brightness temperature measurements is also likely a function of wind direction and extends the results of these previous studies to high-wind conditions. The off-nadir measurements from the SFMR provide critical data for improving the understanding of the relationships between brightness temperature, surface wave�breaking direction, and surface wind vectors at various incidence angles, which is extremely useful for the development of geophysical model functions for instruments like the Hurricane Imaging Radiometer (HIRAD).
Address
Corporate Author
Thesis
Publisher
Place of Publication
Editor
Language
Summary Language
Original Title
Series Editor
Series Title
Abbreviated Series Title
Series Volume
Series Issue
Edition
ISSN
0739-0572
ISBN
Medium
Area
Expedition
Conference
Funding
Approved
$loc['no']
Call Number
COAPS @ rl18 @
Serial
980
Permanent link to this record
Author
Nielsen, E.R. ; Schumacher, R.S. ; Keclik, A.M.
Title
The Effect of the Balcones Escarpment on Three Cases of Extreme Precipitation in Central Texas
Type
$loc['typeJournal Article']
Year
2016
Publication
Monthly Weather Review
Abbreviated Journal
Mon. Wea. Rev.
Volume
144
Issue
1
Pages
119-138
Keywords
Circulation/ Dynamics ; Orographic effects ; Atm/Ocean Structure/ Phenomena ; Flood events ; Physical Meteorology and Climatology ; Hydrometeorology ; Forecasting ; Ensembles ; Numerical weather prediction/forecasting
Abstract
Address
Corporate Author
Thesis
Publisher
Place of Publication
Editor
Language
Summary Language
Original Title
Series Editor
Series Title
Abbreviated Series Title
Series Volume
Series Issue
Edition
ISSN
0027-0644
ISBN
Medium
Area
Expedition
Conference
Funding
Approved
$loc['no']
Call Number
COAPS @ mfield @
Serial
102
Permanent link to this record
Author
Zheng, Y. ; Ali, M.M. ; Bourassa, M.A.
Title
Contribution of Monthly and Regional Rainfall to the Strength of Indian Summer Monsoon
Type
$loc['typeJournal Article']
Year
2016
Publication
Monthly Weather Review
Abbreviated Journal
Mon. Wea. Rev.
Volume
144
Issue
9
Pages
3037-3055
Keywords
Abstract
Address
Corporate Author
Thesis
Publisher
Place of Publication
Editor
Language
Summary Language
Original Title
Series Editor
Series Title
Abbreviated Series Title
Series Volume
Series Issue
Edition
ISSN
0027-0644
ISBN
Medium
Area
Expedition
Conference
Funding
Approved
$loc['no']
Call Number
COAPS @ mfield @
Serial
60
Permanent link to this record
Author
Kozar, M.E. ; Misra, V. ; Powell, M.D.
Title
Hindcasts of Integrated Kinetic Energy in Atlantic Tropical Cyclones: A Neural Network Prediction Scheme
Type
$loc['typeJournal Article']
Year
2016
Publication
Monthly Weather Review
Abbreviated Journal
Mon. Wea. Rev.
Volume
144
Issue
12
Pages
4591-4603
Keywords
Abstract
Address
Corporate Author
Thesis
Publisher
Place of Publication
Editor
Language
Summary Language
Original Title
Series Editor
Series Title
Abbreviated Series Title
Series Volume
Series Issue
Edition
ISSN
0027-0644
ISBN
Medium
Area
Expedition
Conference
Funding
Approved
$loc['no']
Call Number
COAPS @ mfield @
Serial
38
Permanent link to this record
Author
Misra, V. ; Bhardwaj, A.
Title
Defining the Northeast Monsoon of India
Type
$loc['typeJournal Article']
Year
2019
Publication
Monthly Weather Review
Abbreviated Journal
Mon. Wea. Rev.
Volume
147
Issue
3
Pages
791-807
Keywords
Indian Summer Monsoon, intraseasonal,Climate models, variability, NEM, rainfall
Abstract
This study introduces an objective definition for onset and demise of the Northeast Indian Monsoon (NEM). The definition is based on the land surface temperature analysis over the Indian subcontinent. It is diagnosed from the inflection points in the daily anomaly cumulative curve of the area-averaged surface temperature over the provinces of Andhra Pradesh, Rayalseema, and Tamil Nadu located in the southeastern part of India. Per this definition, the climatological onset and demise dates of the NEM season are 6 November and 13 March, respectively. The composite evolution of the seasonal cycle of 850hPa winds, surface wind stress, surface ocean currents, and upper ocean heat content suggest a seasonal shift around the time of the diagnosed onset and demise dates of the NEM season. The interannual variations indicate onset date variations have a larger impact than demise date variations on the seasonal length, seasonal anomalies of rainfall, and surface temperature of the NEM. Furthermore, it is shown that warm El Niño�Southern Oscillation (ENSO) episodes are associated with excess seasonal rainfall, warm seasonal land surface temperature anomalies, and reduced lengths of the NEM season. Likewise, cold ENSO episodes are likely to be related to seasonal deficit rainfall anomalies, cold land surface temperature anomalies, and increased lengths of the NEM season.
Address
Corporate Author
Thesis
Publisher
Place of Publication
Editor
Language
English
Summary Language
Original Title
Series Editor
Series Title
Abbreviated Series Title
Series Volume
Series Issue
Edition
ISSN
0027-0644
ISBN
Medium
Area
Expedition
Conference
Funding
Approved
$loc['no']
Call Number
COAPS @ rl18 @
Serial
999
Permanent link to this record
Author
Ahern, K. ; Bourassa, M.A. ; Hart, R.E. ; Zhang, J.A. ; Rogers, R.F.
Title
Observed Kinematic and Thermodynamic Structure in the Hurricane Boundary Layer During Intensity Change
Type
$loc['typeJournal Article']
Year
2019
Publication
Monthly Weather Review
Abbreviated Journal
Mon. Wea. Rev.
Volume
Issue
Pages
Keywords
Abstract
The axisymmetric structure of the inner-core hurricane boundary layer (BL) during intensification [IN; intensity tendency ≥ 20 kt (24 h)−1], weakening [WE; intensity tendency < −10 kt (24 h)−1], and steady-state [SS; the remainder] periods are analyzed using composites of GPS dropwindsondes from reconnaissance missions between 1998 and 2015. A total of 3,091 dropsondes were composited for analysis below 2.5 km elevation—1,086 during IN, 1,042 during WE, and 963 during SS. In non-intensifying hurricanes, the lowlevel tangential wind is greater outside the radius of maximum wind (RMW) than for intensifying hurricanes, implying higher inertial stability (I) at those radii for non-intensifying hurricanes. Differences in tangential wind structure (and I) between the groups also imply differences in secondary circulation. The IN radial inflow layer is of nearly equal or greater thickness than nonintensifying groups, and all groups show an inflow maximum just outside the RMW. Non-intensifying hurricanes have stronger inflow outside the eyewall region, likely associated with frictionally forced ascent out of the BL and enhanced subsidence into the BL at radii outside the RMW. Equivalent potential temperatures (θe) and conditional stability are highest inside the RMW of non-intensifying storms, which is potentially related to TC intensity. At greater radii, inflow layer θe is lowest in WE hurricanes, suggesting greater subsidence or more convective downdrafts at those radii compared to IN and SS hurricanes. Comparisons of prior observational and theoretical studies are highlighted, especially those relating BL structure to large-scale vortex structure, convection, and intensity.
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Summary Language
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Series Editor
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Series Issue
Edition
ISSN
0027-0644
ISBN
Medium
Area
Expedition
Conference
Funding
Approved
$loc['no']
Call Number
COAPS @ user @
Serial
1031
Permanent link to this record
Author
Devanas, A. ; Stefanova, L.
Title
Statistical Prediction Of Waterspout Probability For The Florida Keys
Type
$loc['typeJournal Article']
Year
2018
Publication
Weather and Forecasting
Abbreviated Journal
Wea. Forecasting
Volume
33
Issue
Pages
389-410
Keywords
Regression analysis ; Forecast verification/skill ; Forecasting techniques ; Probability forecasts/models/distribution ; Statistical forecasting
Abstract
A statistical model of waterspout probability was developed for wet-season (June–September) days over the Florida Keys. An analysis was performed on over 200 separate variables derived from Key West 1200 UTC daily wet-season soundings during the period 2006–14. These variables were separated into two subsets: days on which a waterspout was reported anywhere in the Florida Keys coastal waters and days on which no waterspouts were reported. Days on which waterspouts were reported were determined from the National Weather Service (NWS) Key West local storm reports. The sounding at Key West was used for this analysis since it was assumed to be representative of the atmospheric environment over the area evaluated in this study. The probability of a waterspout report day was modeled using multiple logistic regression with selected predictors obtained from the sounding variables. The final model containing eight separate variables was validated using repeated fivefold cross validation, and its performance was compared to that of an existing waterspout index used as a benchmark. The performance of the model was further validated in forecast mode using an independent verification wet-season dataset from 2015–16 that was not used to define or train the model. The eight-predictor model was found to produce a probability forecast with robust skill relative to climatology and superior to the benchmark waterspout index in both the cross validation and in the independent verification.
Address
Corporate Author
Thesis
Publisher
Place of Publication
Editor
Language
Summary Language
Original Title
Series Editor
Series Title
Abbreviated Series Title
Series Volume
Series Issue
Edition
ISSN
0882-8156
ISBN
Medium
Area
Expedition
Conference
Funding
Approved
$loc['no']
Call Number
COAPS @ mfield @
Serial
553
Permanent link to this record
Author
Williford, C. E. ; Krishnamurti, T.N. ; Torres, R.C. ; Cocke, S. ; Christidis, Z. ; Vijaya Kumar, T.S.
Title
Real-Time Multimodel Superensemble Forecasts of Atlantic Tropical Systems of 1999
Type
$loc['typeJournal Article']
Year
2003
Publication
Monthly Weather Review
Abbreviated Journal
Mon. Wea. Rev.
Volume
131
Issue
8
Pages
1878-1894
Keywords
Abstract
Address
Corporate Author
Thesis
Publisher
Place of Publication
Editor
Language
Summary Language
Original Title
Series Editor
Series Title
Abbreviated Series Title
Series Volume
Series Issue
Edition
ISSN
0027-0644
ISBN
Medium
Area
Expedition
Conference
Funding
Approved
$loc['no']
Call Number
COAPS @ mfield @
Serial
839
Permanent link to this record