# IRISS-USV: Ocean Skin Temperature Sensor for Uncrewed Surface Vehicles and Buoys

> **NSF 01002526DB NSF RESEARCH & RELATED ACTIVIT** · University of Washington (WA) · $349,299

## Abstract

When the ocean loses heat to the atmosphere, a small but important difference in temperature occurs between the ocean surface and the water about 1 mm below the surface.  This temperature difference of 0.2 to 0.5 °C plays a significant role in how much carbon dioxide is absorbed by the ocean.  The only way to measure the temperature right at the surface, dubbed the “skin” temperature, is with an infrared radiometer that measures the ocean surface radiation.  Because the ocean surface reflects some infrared radiation, a correction for the sky radiation reflected from the ocean surface into the sensor is required.  Standard infrared measurements of the sea surface use a wavelength band for which the atmosphere is transparent in the infrared.  Using this waveband, an additional measurement of the downwelling radiation from the sky is necessary because of the large difference of sky temperature between clear and cloudy conditions.  This research implements a simplified technique using a special infrared wavelength band that significantly reduces the difference of sky temperature between clear and cloudy conditions and thus eliminates the need to make the sky measurement.  The waveband is in a semi-transparent region, which results in the sky radiance coming from the water vapor in the atmosphere from 3 km above the sensor.  The awardees have shown that the sky radiance in this band can be modeled using the air temperature and relative humidity in the vicinity of the sensor.  The 

## Key facts

- **NSF award ID:** 2524166
- **Awardee organization:** University of Washington (WA)
- **SAM.gov UEI:** HD1WMN6945W6
- **PI:** Andrew T Jessup
- **Primary program:** 01002526DB NSF RESEARCH & RELATED ACTIVIT
- **All programs:** —
- **Estimated total:** $349,299
- **Funds obligated:** $349,299
- **Transaction type:** Standard Grant
- **Period:** 09/01/2025 → 08/31/2026

## Primary source

NSF Award Search: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2524166

## Citation

> US National Science Foundation, Award 2524166, IRISS-USV: Ocean Skin Temperature Sensor for Uncrewed Surface Vehicles and Buoys. Retrieved via AI Analytics 2026-06-06 from https://api.ai-analytics.org/grant/nsf/2524166. Licensed CC0.

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