Baseline radon detectors for shipboard use: Development and deployment in the First Aerosol Characterization Experiment (ACE 1)

Whittlestone, S.; Zahorowski, W.

doi:10.1029/98jd00687

Cited by 145 publications

(111 citation statements)

References 22 publications

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“…5). Observations of radon-222 at the MLO (17,18) are consistent with these findings and suggest a reduction in continental (Eurasian-originating) airflow at the beginning of the growing season from the early to the mid-1990s (Fig. 5).…”

Section: Mlosupporting

confidence: 77%

The changing carbon cycle at Mauna Loa Observatory

Buermann¹,

Lintner

Koven³

et al. 2007

Proc. Natl. Acad. Sci. U.S.A.

113

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The amplitude of the CO2 seasonal cycle at the Mauna Loa Observatory (MLO) increased from the early 1970s to the early 1990s but decreased thereafter despite continued warming over northern continents. Because of its location relative to the large-scale atmospheric circulation, the MLO receives mainly Eurasian air masses in the northern hemisphere ( atmospheric circulation ͉ atmospheric CO2 seasonal cycle ͉ terrestrial carbon sinks ͉ continental droughts T he time series of CO 2 at Mauna Loa Observatory (MLO) located on the Island of Hawaii is unique not only because of its accuracy and length but also because it was designed and has been repeatedly demonstrated to capture the globally averaged secular trend in atmospheric CO 2 . The seasonal cycle of atmospheric CO 2 at the MLO, with a maximum at the beginning of the growing season (May) and a minimum at the end of the growing season (September/October), records the ''breathing'' of the northern hemisphere (NH) biosphere, that is, the seasonal asynchrony between photosynthetic drawdown and respiratory release of CO 2 by terrestrial ecosystems (e.g., refs. 1-3).During the course of a year, the MLO experiences marked shifts in large-scale atmospheric circulation. In the NH cold season, air masses from Eurasia dominate transport to the MLO as a result of a deepening of the Aleutian Low and intensified midlatitude westerly flow (4). In the NH warm season, the dominant subtropical North Pacific high-pressure system located to the northeast of the MLO leads to short-range transport of air masses to the MLO that originate over or near the North American continent (4). During this season, the MLO receives an approximately equal mix of air masses from both continents with relatively more North American contributions at the peak of the NH growing season (July/August). The MLO is also located in the vicinity of the subsiding branch of the Hadley circulation, rendering it sensitive to interhemispheric mixing.Several studies have analyzed variability in the MLO CO 2 seasonal cycle to infer the sensitivity of ecosystem dynamics to climate perturbations. The increasing trends in the seasonal amplitude of CO 2 at the MLO and Point Barrow, AK, from the early 1970s to the early 1990s are postulated to be evidence of a temperature-related lengthening of the boreal growing season (1

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Section: Mlosupporting

confidence: 77%

The changing carbon cycle at Mauna Loa Observatory

Buermann¹,

Lintner

Koven³

et al. 2007

Proc. Natl. Acad. Sci. U.S.A.

113

View full text Add to dashboard Cite

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“…Here we use two full years of data from 2011 and 2012. The instruments are of the twofilter dual flow loop design, with a delay chamber of 400 L to remove thoron and a radon detection chamber of 750 L (Whittlestone and Zahorowski, 1998). This design eliminates an uncertainty inherent to progeny detectors (Xia et al, 2010) but means that the detectors are large and have a relatively slow response time.…”

Section: Radon Observations At Jungfraujoch and Bernmentioning

confidence: 99%

Surface-to-mountaintop transport characterised by radon observations at the Jungfraujoch

et al. 2014

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Abstract. Atmospheric composition measurements at Jungfraujoch are affected intermittently by boundary-layer air which is brought to the station by processes including thermally driven (anabatic) mountain winds. Using observations of radon-222, and a new objective analysis method, we quantify the land-surface influence at Jungfraujoch hour by hour and detect the presence of anabatic winds on a daily basis. During 2010-2011, anabatic winds occurred on 40 % of days, but only from April to September. Anabatic wind days were associated with warmer air temperatures over a large fraction of Europe and with a shift in air-mass properties, even when comparing days with a similar mean radon concentration. Excluding days with anabatic winds, however, did not lead to a better definition of the unperturbed aerosol background than a definition based on radon alone. This implies that a radon threshold reliably excludes local influences from both anabatic and non-anabatic vertical-transport processes.

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“…At a site with lower nocturnal peak radon concentrations, or for a longer-term deployment, a more sensitive detector would be preferred (e.g. Whittlestone and Zahorowski, 1998), despite being less portable. The radon detector measured air sampled from 2 m a.g.l.…”

Section: Site and Instrumentationmentioning

confidence: 99%

Improved mixing height monitoring through a combination of lidar and radon measurements

et al. 2013

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Surface-based radon (<sup>222</sup>Rn) measurements can be combined with lidar backscatter to obtain a higher quality time series of mixing height within the planetary boundary layer (PBL) than is possible from lidar alone, and a more quantitative measure of mixing height than is possible from only radon. The reason why lidar measurements are improved is that there are times when lidar signals are ambiguous, and reliably attributing the mixing height to the correct aerosol layer presents a challenge. By combining lidar with a mixing length scale derived from a time series of radon concentration, automated and robust attribution is possible during the morning transition. <br><br> Radon measurements provide mixing information during the night, but concentrations also depend on the strength of surface emissions. After processing radon in combination with lidar, we obtain nightly measurements of radon emissions and are able to normalise the mixing length scale for changing emissions. After calibration with lidar, the radon-derived equivalent mixing height agrees with other measures of mixing on daily and hourly timescales and is a potential method for studying intermittent mixing in nocturnal boundary layers

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Baseline radon detectors for shipboard use: Development and deployment in the First Aerosol Characterization Experiment (ACE 1)

Cited by 145 publications

References 22 publications

The changing carbon cycle at Mauna Loa Observatory

The changing carbon cycle at Mauna Loa Observatory

Surface-to-mountaintop transport characterised by radon observations at the Jungfraujoch

Improved mixing height monitoring through a combination of lidar and radon measurements

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