Evaluation of Satellite-Derived SST Products in Identifying the Rapid Temperature Drop on the West Florida Shelf Associated With Hurricane Irma

2018 ◽  
Vol 52 (3) ◽  
pp. 43-50 ◽  
Author(s):  
Yonggang Liu ◽  
Robert H. Weisberg ◽  
Jason Law ◽  
Boyin Huang
Keyword(s):  
Temperature Drop ◽  
Coastal Ocean ◽  
Sea Surface ◽  
West Florida Shelf ◽  
The West ◽  
Florida Shelf ◽  
Time Period ◽  
Rapid Temperature ◽  
Ocean Observations ◽  
Hurricane Irma

AbstractSatellite-derived daily sea surface temperature (SST) products are compared with moored SST observations on the West Florida Shelf during the time period of Hurricane Irma. Most of the SST products compare reasonably well with the moored data at the location of 25-m depth, where SST dropped by about 1°C after the hurricane passage. However, most of the SST products did not show the rapid SST drop at the location of 50-m depth where the surface water was cooled by about 4°C within 1 day in response to the hurricane passage. This finding has important implications to air-sea interaction studies and hurricane simulations, in which SST data play an important role. The limitations of the popular satellite products call for additional coastal ocean observations as well as proper inclusion of the real-time observations in satellite-derived products.

scholarly journals Ocean Currents and Sea Surface Heights Estimated across the West Florida Shelf

2007 ◽  
Vol 37 (6) ◽  
pp. 1697-1713 ◽  
Author(s):  
Yonggang Liu ◽  
Robert H. Weisberg
Keyword(s):  
Sea Level ◽  
Time Scales ◽  
Satellite Altimetry ◽  
Sea Surface ◽  
West Florida Shelf ◽  
The West ◽  
Inner Shelf ◽  
Florida Shelf ◽  
Synoptic Weather ◽  
Coastal Sea

Abstract The across-shelf structures of the ocean circulation and the associated sea surface height (SSH) variability are examined on the west Florida shelf (WFS) for the 3-yr interval from September 1998 to December 2001. Five sets of characteristic circulation patterns are extracted from 2-day, low-pass-filtered data using the self-organizing map: extreme upwelling and downwelling structures with strong currents, asymmetric upwelling and downwelling structures with moderate currents, and a set of transitional structures with weak currents. The temporal variations of these structures are coherent with the local winds on synoptic weather time scales. On seasonal time scales they are related to both the local winds and the water density variations. The circulation is predominantly upwelling during autumn to spring months (October–April) and downwelling during summer months (June–September). Coastal sea level fluctuations are related to both the dynamical responses of the inner shelf circulation to meteorological forcing and the offshore SSH. On long time scales, the offshore SSH variations appear to dominate, whereas on synoptic weather time scales, the inner shelf wind-driven circulation responses are largest. The across-shelf distribution of SSH is estimated from the velocity, hydrography, wind, and coastal sea level data, and the results are compared with satellite altimetry data, thereby providing a means for calibrating satellite altimetry on the shelf.

A coastal ocean observing system and modeling program for the West Florida Shelf

2003 ◽  
Author(s):  
R. Weisberg ◽  
Ruoying He ◽  
M. Luther ◽  
J. Walsh ◽  
R. Cole ◽  
...  
Keyword(s):  
Coastal Ocean ◽  
West Florida Shelf ◽  
The West ◽  
Florida Shelf ◽  
Ocean Observing

scholarly journals HF Radar Performance in a Low-Energy Environment: CODAR SeaSonde Experience on the West Florida Shelf*

2010 ◽  
Vol 27 (10) ◽  
pp. 1689-1710 ◽  
Author(s):  
Yonggang Liu ◽  
Robert H. Weisberg ◽  
Clifford R. Merz ◽  
Sage Lichtenwalner ◽  
Gary J. Kirkpatrick
Keyword(s):  
Coastal Ocean ◽  
Low Energy ◽  
Ocean Dynamics ◽  
Hf Radar ◽  
Limiting Factors ◽  
West Florida Shelf ◽  
The West ◽  
Florida Shelf ◽  
Significant Wave ◽  
Energy Environment

Abstract Three long-range (5 MHz) Coastal Ocean Dynamics Application Radar (CODAR) SeaSonde HF radars overlooking an array of as many as eight moored acoustic Doppler current profilers (ADCPs) have operated on the West Florida Shelf since September 2003 for the purpose of observing the coastal ocean currents. HF radar performance on this low-energy (currents and waves) continental shelf is evaluated with respect to data returns, the rms differences between the HF radar and the ADCP radial currents, bearing offsets, and radial velocity uncertainties. Possible environmental factors affecting the HF radar performance are discussed, with the findings that both the low-energy sea state and the unfavorable surface wave directions are the main limiting factors for these HF radar observations of currents on the WFS. Despite the challenge of achieving continuous backscatter from this low-energy environment, when acquired the data quality is good in comparison with the ADCP measurements. The rms differences range from 6 to 10 cm s−1 for hourly and from 3 to 6 cm s−1 for 36-h low-pass-filtered radial currents, respectively. Bearing offsets are in the range from −15° to +9°. Coherent variations of the HF radar and ADCP radial currents are seen across both tidal and subtidal frequency bands. By examining the HF radar radial velocities at low wave energy, it is found that the data returns decrease rapidly for significant wave heights smaller than 1 m, and that the rms differences between the HF radar and ADCP radials are degraded when the significant wave height is smaller than 0.3 m.

scholarly journals A cloud-free, satellite-derived, sea surface temperature analysis for the West Florida Shelf

2003 ◽  
Vol 30 (15) ◽  
Author(s):  
Ruoying He ◽  
Robert H. Weisberg ◽  
Haiying Zhang ◽  
Frank E. Muller-Karger ◽  
Robert W. Helber
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Sea Surface ◽  
Temperature Analysis ◽  
West Florida Shelf ◽  
The West ◽  
Florida Shelf

High Frequency Radar Observing Systems in SEACOOS: 2002-2007 Lessons Learned

2008 ◽  
Vol 42 (3) ◽  
pp. 55-67 ◽  
Author(s):  
Lynn K. Shay ◽  
Harvey E. Seim ◽  
Dana Savidge ◽  
Richard Styles ◽  
Robert H. Weisberg
Keyword(s):  
North Carolina ◽  
High Frequency ◽  
Surface Current ◽  
Coastal Ocean ◽  
Quality Data ◽  
West Florida Shelf ◽  
The West ◽  
Florida Shelf ◽  
The North ◽  
Wave Measurements

From 2002-2007, the Southeast Coastal Ocean Observing System (SEACOOS) deployed high frequency (HF) radars to overlook several venues stretching from the West Florida Shelf to the North Carolina Shelf. Based on extensive deliberations within SEACOOS, we decided to assess the two differing types of coastal ocean current radars within the southeast that were on the commercial market. The long-range SeaSondes (SS) were deployed to sense surface currents at hourly intervals and a 6 km resolution along the West Florida Shelf and the North Carolina Shelf. The medium and long-range Wellen Radars (WERA) were deployed along the Florida Straits and along the South Atlantic Bight with spatial resolutions of 1.2 to 3 km sampling at time scales of minutes. A common theme in these deployments was to sense the Loop Current, Florida Current and the Gulf Stream, which transport heat poleward as part of the gyre circulation.Several lessons were learned as part of these deployments, such as the need to protect against lightening strikes and the challenge of providing robust communication links between the remote sites and a central hub to make the data available in near real-time. Since states in the southeast and surrounding the Gulf of Mexico are prone to the passage of hurricanes, surface current and wave measurements during hurricanes are invaluable for improving storm surge and inundation models that are now being coupled to surface waves. In addition, significant wave heights (and directional surface wave spectra) are critical in the model assessment. Data quality and accuracy of the surface current and wave fields remain a central issue to search and rescue and safe maritime operations and to understanding the limitations of these radar systems. As more phased array systems (i.e., WERAs) are deployed for surface current and wave measurements, more attention needs to be placed on the interoperability between the two types of systems to insure the highest quality data possible is available to meet applied and operational goals. To insure the highest quality data possible, a full-time technician and a half-time IT specialist are needed for each installation as well as access to spares to keep these systems running consistently and to make quality observations available in near real-time.

scholarly journals Sea Surface Temperature Patterns on the West Florida Shelf Using Growing Hierarchical Self-Organizing Maps

2006 ◽  
Vol 23 (2) ◽  
pp. 325-338 ◽  
Author(s):  
Yonggang Liu ◽  
Robert H. Weisberg ◽  
Ruoying He
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Sea Surface ◽  
Self Organizing Map ◽  
West Florida Shelf ◽  
The West ◽  
Florida Shelf ◽  
Network Analyses ◽  
Sst Anomaly ◽  
Self Organizing

Abstract Neural network analyses based on the self-organizing map (SOM) and the growing hierarchical self-organizing map (GHSOM) are used to examine patterns of the sea surface temperature (SST) variability on the West Florida Shelf from time series of daily SST maps from 1998 to 2002. Four characteristic SST patterns are extracted in the first-layer GHSOM array: winter and summer season patterns, and two transitional patterns. Three of them are further expanded in the second layer, yielding more detailed structures in these seasons. The winter pattern is one of low SST, with isotherms aligned approximately along isobaths. The summer pattern is one of high SST distributed in a horizontally uniform manner. The spring transition includes a midshelf cold tongue. Similar analyses performed on SST anomaly data provide further details of these seasonally varying patterns. It is demonstrated that the GHSOM analysis is more effective in extracting the inherent SST patterns than the widely used EOF method. The underlying patterns in a dataset can be visualized in the SOM array in the same form as the original data, while they can only be expressed in anomaly form in the EOF analysis. Some important features, such as asymmetric SST anomaly patterns of winter/summer and cold/warm tongues, can be revealed by the SOM array but cannot be identified in the lowest mode EOF patterns. Also, unlike the EOF or SOM techniques, the hierarchical structure in the input data can be extracted by the GHSOM analysis.

From rivers to the coastal ocean: A model for integrating observing systems on the west Florida shelf

2012 Oceans ◽  
2012 ◽  
Author(s):  
R. L. Mullins Perry ◽  
C. Simoniello ◽  
A. E. Jochens ◽  
M. K. Howard ◽  
S. Wolfe
Keyword(s):  
Coastal Ocean ◽  
West Florida Shelf ◽  
The West ◽  
Florida Shelf ◽  
Observing Systems

USGS field activity 09FSH02 on the west Florida shelf, Gulf of Mexico, in August 2009

Data Series ◽  
2009 ◽  
Author(s):  
Lisa L. Robbins ◽  
Paul O. Knorr ◽  
Xuewu Liu ◽  
Robert H. Byrne ◽  
Ellen A. Raabe
Keyword(s):  
Gulf Of Mexico ◽  
West Florida Shelf ◽  
The West ◽  
Florida Shelf ◽  
Field Activity
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