Airborne measurements of the total heat flux from the sea during Bomex

McAlister, E. D.; McLeish, William; Corduan, Ernst A.

doi:10.1029/jc076i018p04172

Cited by 21 publications

(11 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Water has different absorption coefficients in the two wavelength bands chosen so that the effective depths from which the emission comes are 25 and 75 km, respectively, in the latest version of this instrument (McAlister and McLeish, 1970). Data on the slope of the temperature profile gave heat fluxes in general agreement with other measurements of heat flux during BOMEX (McAlister et al, 1971). However, corrections for incidence angle and slope of the sea surface complicate interpretation of the data (Katsaros and Businger, 1973).…”

Section: Field Observations and Measurement Techniquessupporting

confidence: 61%

The aqueous thermal boundary layer

Katsaros

1980

Boundary-Layer Meteorol

113

View full text Add to dashboard Cite

This article reviews the available data, measurement techniques, and present understanding of the millimeter thick aqueous thermal boundary layer. A temperature difference between the surface and lower strata, AT, of the order of a few tenths to -1 "C have been observed. Techniques ranging from miniature mercury thermometers and electrical point sensors to optical interferometry and infrared radiometry have been employed. Many processes influence the temperature structure in this thin boundary layer. Among them are: the net upward heat flux due to evaporation and sensible heat transfer; infrared and solar radiation; and the turbulence near the interface due to wind mixing, wave breaking and current shear. Presence of solute and surface-active materials stimulate or dampen these mixing processes thereby influencing boundary-layer thickness and temperature structure.

show abstract

Section: Field Observations and Measurement Techniquessupporting

confidence: 61%

The aqueous thermal boundary layer

Katsaros

1980

Boundary-Layer Meteorol

113

View full text Add to dashboard Cite

show abstract

“…been described in a series of papers [McAlister, 1964[McAlister, , 1969McAlister andMcLeish, 1969, 1970;McAlister et al, 1971].…”

mentioning

confidence: 76%

“…The more recent field experiments with this improved version, which obtains the temperature gradient between 25-and 75-t•m depths, have not had adequate control measurements of heat flux available to give a dependable value for the error. However, from comparison with other observations near in space or time [McAtister and McLeish, 1970;McAlister et al, 1971] the accuracy seems to lie between 10 and 33%. This sophisticated technique should certainly aim at an accuracy of 10% or better.…”

mentioning

confidence: 99%

Comments on the determination of the total heat flux from the sea with a two-wavelength radiometer system as developed by McAlister

Katsaros¹,

Businger²

1973

J. Geophys. Res.

View full text Add to dashboard Cite

Two‐wavelength radiometric measurements of heat flux as developed by McAlister require corrections under rough sea conditions. One correction stems from the increase in sea surface area compared with a horizontal plane. Another correction due to sea surface roughness and nadir angle of viewing is required to obtain the temperature gradient normal to the interface. For example, these errors combined amount to 8% for 10‐m/sec wind and 20° nadir angle. Vertical advection associated with convergence and divergence due to wave motion and turbulence generally have negligible effect on the two‐wavelength radiometric measurement of heat flux but can possibly become significant for capillary waves and strong convection.

show abstract

“…In fact, in situ sensors can be placed only a few centimeters below the sea surface, and they usually perturb the media by generating mixing and destroying small-scale gradients. The first attempt of using radiometric measurements for SST retrievals was by Ewing and McAlister [1960] and McAlister et al [1971] introduced the idea of using two infrared channels with different skin penetration depths to study surface gradients. Trokhimovski et al [1998] pointed out that increasing the penetration depth difference between the two channels would lead to better chances to estimate sea-surface gradients; they also suggested coupling microwave and infrared channels.…”

Section: Introductionmentioning

confidence: 99%

“…As anticipated, coupling measurements from the two radiometers could lead to sea surface gradient estimates, but only if the absolute accuracy of each instrument is within 0.1 K [McAlister et al, 1971;Trokhimovski et al, 1998;Shaw et al, 2001]. Experimental data were collected in June and July 1999 during the Nauru99 ship-based experiment, which brought the National Oceanic and Atmospheric Administration's (NOAA) R/V Ronald H. Brown (RHB) in the vicinity of Nauru Island (Lat.…”

Section: Introductionmentioning

confidence: 99%

Air temperature profile and air/sea temperature difference measurements by infrared and microwave scanning radiometers

Cimini¹,

Shaw²,

Westwater

et al. 2003

Radio Science

View full text Add to dashboard Cite

[1] A system of two scanning radiometers has been developed by the National Oceanic and Atmospheric Administration/Environmental Technology Laboratory and deployed on the NOAA R/V Ronald H. Brown during the Nauru99 cruise in the tropical western Pacific in June and July 1999. The system is composed of a high-quality temperature sensor and two independent, vertically scanning radiometers, measuring atmospheric and oceanic emission in the microwave (MW), and infrared (IR) regions. Both radiometers measure emission from a uniformly mixed atmospheric gas: oxygen for MW (60 GHz) and carbon dioxide for IR (14.2 mm). The high atmospheric absorption at these frequencies allows one calibration point from the horizontal atmospheric view using the in situ temperature sensor measurements as a reference. The signal at all other scan angles is scaled relative to that at the horizontal, resulting in a differential technique that is independent of calibration offset. This technique provides continuous and accurate estimates of boundary layer air temperature profile and air/sea temperature difference. The main advantage of this technique is that the water skin temperature can be measured at different optical depths without disturbing the skin layer (magnitude order of microns). We first compare radiometric data collected during the experiment with simulations obtained by atmospheric and oceanic radiative transfer models. We then use statistical inversion techniques to estimate air temperature profiles from upward looking measurements, based on an a priori data set of about 1500 ship-based radiosonde observations. For the ''well-posed'' problem of air/sea temperature difference estimation, we apply a physical retrieval algorithm to the downward looking measurements, accounting for air attenuation and sea surface roughness. Then we show retrieval results and evaluate the achieved accuracy. Finally, we compare radiometric estimates with in situ measurements, discussing similarities and discrepancies.

show abstract

Airborne measurements of the total heat flux from the sea during Bomex

Cited by 21 publications

References 2 publications

The aqueous thermal boundary layer

The aqueous thermal boundary layer

Comments on the determination of the total heat flux from the sea with a two-wavelength radiometer system as developed by McAlister

Air temperature profile and air/sea temperature difference measurements by infrared and microwave scanning radiometers

Contact Info

Product

Resources

About