Evaluation of Arctic broadband surface radiation measurements

Abstract

Abstract. The Arctic is a challenging environment for making in-situ surface radiation measurements. A standard suite of radiation sensors is typically designed to measure incoming and outgoing shortwave (SW) and thermal infrared, or longwave (LW), radiation. Enhancements may include various sensors for measuring irradiance in narrower bandwidths. Many solar radiation/thermal infrared flux sensors utilize protective glass domes and some are mounted on complex mechanical platforms (solar trackers) that keep sensors and shading devices trained on the sun along its diurnal path. High quality measurements require striking a balance between locating stations in a pristine undisturbed setting free of artificial blockage (such as from buildings and towers) and providing accessibility to allow operators to clean and maintain the instruments. Three significant sources of erroneous data in the Arctic include solar tracker malfunctions, rime/frost/snow deposition on the protective glass domes of the radiometers and operational problems due to limited operator access in extreme weather conditions. In this study, comparisons are made between the global and component sum (direct [vertical component] + diffuse) SW measurements. The difference between these two quantities (that theoretically should be zero) is used to illustrate the magnitude and seasonality of arctic radiation flux measurement problems. The problem of rime/frost/snow deposition is investigated in more detail for one case study utilizing both SW and LW measurements. Solutions to these operational problems that utilize measurement redundancy, more sophisticated heating and ventilation strategies and a more systematic program of operational support and subsequent data quality protocols are proposed.

On the Increasing Importance of Air-Sea Exchanges in a Thawing Arctic: A Review

“…One of the important challenges to in situ measurements is riming on instruments [64,93]. Riming negatively affects measurements from instruments such as anemometers measuring wind speed and radiometers measuring longwave fluxes [94]. This issue is especially prevalent in winter when solar radiation, which can warm the instruments, is absent.…”

Global atmospheric downward longwave radiation at the surface from ground‐based observations, satellite retrievals, and reanalyses

“…The spectral response function of a pyrgeometer normally covers a wavelength from 3.5 µm to 50 µm, while its reading is calibrated to the total range of terrestrial longwave emission (~4 µm to 200 µm). A dome protects this instrument from impacts of weather events, such as dew, snow [ Matsui et al ., ], and rainfall (Figure ). Solar heating of this dome may introduce errors in L d measurements [ Enz et al ., ; Meloni et al ., ; Udo , ] as also other phenomena (such as frost riming and deposition of aerosols).…”

“…The measurements of L d are also affected by the environment. For example, they are especially difficult in Arctic winter due to low water vapor content and extreme meteorological conditions [ Marty et al ., ; Matsui et al ., ; Ruckstuhl and Philipona , ]. According to a laboratory study, when the instrument body temperature is lowered to −60°C, the pyrgeometer's sensitivity increases by 13% from the factory‐default specification [ Su et al ., ].…”

The Role of Springtime Arctic Clouds in Determining Autumn Sea Ice Extent

“…Cloud anomalies have also been found to affect the sea ice melt season during the 149 summer months (e.g., Kay et al 2008 Observations are quality controlled first by visual inspection and then processed by 213 an automated procedure described by Long and Shi (2008). The resulting quality controlled Barrow radiation data sets for LW↓, 217 LW↑, SW↓, SW↑ are each 93% complete or better for the period 1993-2014, though it is 218 important to note that frost and rime problems are common in the Arctic and difficult to 219 screen out (e.g., Matsui et al 2012). The resulting quality controlled Barrow radiation data sets for LW↓, 217 LW↑, SW↓, SW↑ are each 93% complete or better for the period 1993-2014, though it is 218 important to note that frost and rime problems are common in the Arctic and difficult to 219 screen out (e.g., Matsui et al 2012).…”