Validation of near-real-time sea surface temperature from MODIS in the ocean around Japan

Author(s):  
K. Hosoda ◽  
H. Murakami
Author(s):  
F. Bayat ◽  
M. Hasanlou

Sea surface temperature (SST) is one of the critical parameters in marine meteorology and oceanography. The SST datasets are incorporated as conditions for ocean and atmosphere models. The SST needs to be investigated for various scientific phenomenon such as salinity, potential fishing zone, sea level rise, upwelling, eddies, cyclone predictions. On the other hands, high spatial resolution SST maps can illustrate eddies and sea surface currents. Also, near real time producing of SST map is suitable for weather forecasting and fishery applications. Therefore satellite remote sensing with wide coverage of data acquisition capability can use as real time tools for producing SST dataset. Satellite sensor such as AVHRR, MODIS and SeaWIFS are capable of extracting brightness values at different thermal spectral bands. These brightness temperatures are the sole input for the SST retrieval algorithms. Recently, Landsat-8 successfully launched and accessible with two instruments on-board: (1) the Operational Land Imager (OLI) with nine spectral bands in the visual, near infrared, and the shortwave infrared spectral regions; and (2) the Thermal Infrared Sensor (TIRS) with two spectral bands in the long wavelength infrared. The two TIRS bands were selected to enable the atmospheric correction of the thermal data using a split window algorithm (SWA). The TIRS instrument is one of the major payloads aboard this satellite which can observe the sea surface by using the split-window thermal infrared channels (CH10: 10.6 μm to 11.2 μm; CH11: 11.5 μm to 12.5 μm) at a resolution of 30 m. The TIRS sensors have three main advantages comparing with other previous sensors. First, the TIRS has two thermal bands in the atmospheric window that provide a new SST retrieval opportunity using the widely used split-window (SW) algorithm rather than the single channel method. Second, the spectral filters of TIRS two bands present narrower bandwidth than that of the thermal band on board on previous Landsat sensors. Third, TIRS is one of the best space born and high spatial resolution with 30&thinsp;m. in this regards, Landsat-8 can use the Split-Window (SW) algorithm for retrieving SST dataset. Although several SWs have been developed to use with other sensors, some adaptations are required in order to implement them for the TIRS spectral bands. Therefore, the objective of this paper is to develop a SW, adapted for use with Landsat-8 TIRS data, along with its accuracy assessment. In this research, that has been done for modelling SST using thermal Landsat 8-imagery of the Persian Gulf. Therefore, by incorporating contemporary in situ data and SST map estimated from other sensors like MODIS, we examine our proposed method with coefficient of determination (R2) and root mean square error (RMSE) on check point to model SST retrieval for Landsat-8 imagery. Extracted results for implementing different SW's clearly shows superiority of utilized method by R<sup>2</sup>&thinsp;=&thinsp;0.95 and RMSE&thinsp;=&thinsp;0.24.


2010 ◽  
Vol 49 (11) ◽  
pp. 2267-2284 ◽  
Author(s):  
Jason C. Knievel ◽  
Daran L. Rife ◽  
Joseph A. Grim ◽  
Andrea N. Hahmann ◽  
Joshua P. Hacker ◽  
...  

Abstract This paper describes a simple technique for creating regional, high-resolution, daytime and nighttime composites of sea surface temperature (SST) for use in operational numerical weather prediction (NWP). The composites are based on observations from NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS) aboard Aqua and Terra. The data used typically are available nearly in real time, are applicable anywhere on the globe, and are capable of roughly representing the diurnal cycle in SST. The composites’ resolution is much higher than that of many other standard SST products used for operational NWP, including the low- and high-resolution Real-Time Global (RTG) analyses. The difference in resolution is key because several studies have shown that highly resolved SSTs are important for driving the air–sea interactions that shape patterns of static stability, vertical and horizontal wind shear, and divergence in the planetary boundary layer. The MODIS-based composites are compared to in situ observations from buoys and other platforms operated by the National Data Buoy Center (NDBC) off the coasts of New England, the mid-Atlantic, and Florida. Mean differences, mean absolute differences, and root-mean-square differences between the composites and the NDBC observations are all within tenths of a degree of those calculated between RTG analyses and the NDBC observations. This is true whether or not one accounts for the mean offset between the skin temperatures of the MODIS dataset and the bulk temperatures of the NDBC observations and RTG analyses. Near the coast, the MODIS-based composites tend to agree more with NDBC observations than do the RTG analyses. The opposite is true away from the coast. All of these differences in point-wise comparisons among the SST datasets are small compared to the ±1.0°C accuracy of the NDBC SST sensors. Because skin-temperature variations from land to water so strongly affect the development and life cycle of the sea breeze, this phenomenon was chosen for demonstrating the use of the MODIS-based composite in an NWP model. A simulated sea breeze in the vicinity of New York City and Long Island shows a small, net, but far from universal improvement when MODIS-based composites are used in place of RTG analyses. The timing of the sea breeze’s arrival is more accurate at some stations, and the near-surface temperature, wind, and humidity within the breeze are more realistic.


2016 ◽  
Vol 8 (1) ◽  
Author(s):  
Rizqi Rizaldi Hidayat ◽  
Indra Jaya ◽  
Totok Hestirianoto

<p><em>The availability of data in real time and continuous is important to monitor in environmental change as early as possible. Wireless sensor networks (WSN) offer a new paradigm in the field of oceanography that can measure the parameters of complex marine environment using a moored buoy. This paper described design of a data transmission system with a moored buoy and tested the performance of WSN instrument based on ZigBee protocol radio module for monitoring coastal water environment in real time. Instruments were divided into two i.e., (1) five sensors served to measure sea surface temperature, stored the data, and transmitted the data to the base station, and (2) a coordinating instrument that placed on the bases station served to receive and record all measurement results of each sensor. The testing was done by deploying the instrument sensors in waters with depths of 2 to 5 meters and a coordinating instrument was located on the ground as a base station. Each instrument's sensor measure sea surface temperature, store, and transmit it to other nearby sensors and forward data to the next sensor and then to the next sensor send it to the base station. </em><em>The </em><em>Packet Delivery Ratio (PDR)</em><em> value </em><em>wa</em><em> used as an indicator to determine the instrument performance</em><em> </em><em>and the values were from 89.69% up to 100% with transmission range up to 430 meter and battery endurance was up to 26 hours. The result showed that a buoy moored instrument based on WSN ZigBee radio module protocol has the potential for monitoring coastal water environment in a real time. </em></p><strong><em>Keywords: </em></strong><em>mooring buoy, wsn, zigbee</em>


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