Quantification of methane bubbles in shallow freshwaters using horizontal hydroacoustical observations

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985858%3A_____%2F15%3A00443155" target="_blank" >RIV/67985858:_____/15:00443155 - isvavai.cz</a>

Alternative codes found

RIV/60077344:_____/15:00443155

Result on the web

<a href="http://dx.doi.org/10.1002/lom3.10051" target="_blank" >http://dx.doi.org/10.1002/lom3.10051</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1002/lom3.10051" target="_blank" >10.1002/lom3.10051</a>

Result language

angličtina

Original language name

Quantification of methane bubbles in shallow freshwaters using horizontal hydroacoustical observations

Original language description

Methane represents an important greenhouse gas, and its ebullition is a significant method of releasing the gas from bottom sediments of shallow waters to the atmosphere. Detecting methane bubbles is complicated because of high spatiotemporal variability; however, hydroacoustical surveys represent an effective method for quantifying ebullitive emissions. Vertical and horizontal hydroacoustical observations performed in shallow waters are presented in this work, with an emphasis on horizontal observations. Bubbles of various sizes, ranging from 2.5 to 907.2 μl, were artificially prepared using a bubble generator and released from a depth of 6 m in a freshwater lake. The acoustic target strength (TS) of these bubbles was observed using both the vertical and horizontal beams of 120-kHz frequency sonar. The recorded TS of the bubbles in vertical mode varied from -61 dB to -43 dB. These values were significantly stronger than those of the bubbles observed in horizontal mode, which ranged from 62 dB to -48 dB. The TS obtained in both the vertical and horizontal modes increased with increasing bubble size. Additionally, the TS of the smallest sizes in vertical mode increased as the bubbles rose to the surface. For other sizes of bubbles and in horizontal mode, the bubble TS either decreased or did not change significantly when the bubbles traveled upwards. Based on these results, we suggest elimination of the depth correction for volume in studying methane bubbles in shallow waters. Furthermore, we developed equations that can determine bubble volume from bubble TS in both the vertical and horizontal planes.

Czech name

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Czech description

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Type

J_x - Unclassified - Peer-reviewed scientific article (Jimp, Jsc and Jost)

CEP classification

DA - Hydrology and limnology

OECD FORD branch

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Project

<a href="/en/project/GAP504%2F12%2F1186" target="_blank" >GAP504/12/1186: Hydroacoustical distinguishing between fish and bubbles, and quantification of methane bubble ebullition in freshwater reservoirs of temperate zone</a><br>

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2015

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

LIMNOLOGY AND OCEANOGRAPHY-METHODS

ISSN

1541-5856

e-ISSN

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Volume of the periodical

13

Issue of the periodical within the volume

11

Country of publishing house

US - UNITED STATES

Number of pages

8

Pages from-to

609-616

UT code for WoS article

000367227000002

EID of the result in the Scopus database

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