Stable isotopic signature of Australian monsoon controlled by regional convection

C. Zwart, N. C. Munksgaard, N. Kurita, M. I. Bird

    Research output: Contribution to journalArticleResearchpeer-review

    Abstract

    The aim of this study was to identify the main meteorological drivers of rainfall isotopic variation in north Australia in order to improve the interpretation of isotopic proxy records in this region. An intense monitoring program was conducted during two monsoonal events that showed significant and systematic isotopic change over time. The results showed a close link between isotopic variation in precipitation and variability in monsoon conditions, associated with the presence of large convective envelopes propagating through the study site. The largest negative amplitudes in the isotopic signal were observed when eastward and westward moving precipitation systems within the convective envelope merged over the measurement site. This suggests that the amplitude of the isotopic signal is related to the size and activity of the convective envelope. The strong correlation between rainfall isotopic variation, regional outgoing longwave radiation and regional rainfall amount supports this conclusion. This is further strengthened by the strong relationship between isotopic variation and the integrated rainfall history of air masses prior to arriving at the measurement locations. A local amount effect was not significant and these findings support the interpretation of δ18O as proxy for regional climatic conditions rather than local rainfall amount. Meteorological parameters that characterize intra-seasonal variability of monsoon conditions were also found to be strongly linked to inter-seasonal variability of the monthly based δ18O values in the Global Network of Isotopes in Precipitation (GNIP) database. This leads to the conclusion that information about the Australian monsoon variability can likely be inferred from the isotopic proxy record in North Australia on short (intra seasonal) and long (inter seasonal or longer) timescales.

    Original languageEnglish
    Pages (from-to)228-235
    Number of pages8
    JournalQuaternary Science Reviews
    Volume151
    DOIs
    Publication statusPublished - 1 Nov 2016

    Fingerprint

    monsoon
    convection
    rain
    rainfall
    interpretation
    seasonal variation
    regional difference
    meteorological parameters
    longwave radiation
    air mass
    driver
    air
    monitoring
    isotopes
    Signature
    Rainfall
    Controlled
    event
    isotope
    timescale

    Cite this

    Zwart, C. ; Munksgaard, N. C. ; Kurita, N. ; Bird, M. I. / Stable isotopic signature of Australian monsoon controlled by regional convection. In: Quaternary Science Reviews. 2016 ; Vol. 151. pp. 228-235.
    @article{7b93a0cd32864973a654413ae2f10208,
    title = "Stable isotopic signature of Australian monsoon controlled by regional convection",
    abstract = "The aim of this study was to identify the main meteorological drivers of rainfall isotopic variation in north Australia in order to improve the interpretation of isotopic proxy records in this region. An intense monitoring program was conducted during two monsoonal events that showed significant and systematic isotopic change over time. The results showed a close link between isotopic variation in precipitation and variability in monsoon conditions, associated with the presence of large convective envelopes propagating through the study site. The largest negative amplitudes in the isotopic signal were observed when eastward and westward moving precipitation systems within the convective envelope merged over the measurement site. This suggests that the amplitude of the isotopic signal is related to the size and activity of the convective envelope. The strong correlation between rainfall isotopic variation, regional outgoing longwave radiation and regional rainfall amount supports this conclusion. This is further strengthened by the strong relationship between isotopic variation and the integrated rainfall history of air masses prior to arriving at the measurement locations. A local amount effect was not significant and these findings support the interpretation of δ18O as proxy for regional climatic conditions rather than local rainfall amount. Meteorological parameters that characterize intra-seasonal variability of monsoon conditions were also found to be strongly linked to inter-seasonal variability of the monthly based δ18O values in the Global Network of Isotopes in Precipitation (GNIP) database. This leads to the conclusion that information about the Australian monsoon variability can likely be inferred from the isotopic proxy record in North Australia on short (intra seasonal) and long (inter seasonal or longer) timescales.",
    keywords = "Climate proxy records Australia, Convection, MJO, Monsoon variability, Palaeoclimatology, Precipitation, Stable isotopes, Tropics",
    author = "C. Zwart and Munksgaard, {N. C.} and N. Kurita and Bird, {M. I.}",
    year = "2016",
    month = "11",
    day = "1",
    doi = "10.1016/j.quascirev.2016.09.010",
    language = "English",
    volume = "151",
    pages = "228--235",
    journal = "Quaternary Science Reviews",
    issn = "0277-3791",
    publisher = "Elsevier",

    }

    Stable isotopic signature of Australian monsoon controlled by regional convection. / Zwart, C.; Munksgaard, N. C.; Kurita, N.; Bird, M. I.

    In: Quaternary Science Reviews, Vol. 151, 01.11.2016, p. 228-235.

    Research output: Contribution to journalArticleResearchpeer-review

    TY - JOUR

    T1 - Stable isotopic signature of Australian monsoon controlled by regional convection

    AU - Zwart, C.

    AU - Munksgaard, N. C.

    AU - Kurita, N.

    AU - Bird, M. I.

    PY - 2016/11/1

    Y1 - 2016/11/1

    N2 - The aim of this study was to identify the main meteorological drivers of rainfall isotopic variation in north Australia in order to improve the interpretation of isotopic proxy records in this region. An intense monitoring program was conducted during two monsoonal events that showed significant and systematic isotopic change over time. The results showed a close link between isotopic variation in precipitation and variability in monsoon conditions, associated with the presence of large convective envelopes propagating through the study site. The largest negative amplitudes in the isotopic signal were observed when eastward and westward moving precipitation systems within the convective envelope merged over the measurement site. This suggests that the amplitude of the isotopic signal is related to the size and activity of the convective envelope. The strong correlation between rainfall isotopic variation, regional outgoing longwave radiation and regional rainfall amount supports this conclusion. This is further strengthened by the strong relationship between isotopic variation and the integrated rainfall history of air masses prior to arriving at the measurement locations. A local amount effect was not significant and these findings support the interpretation of δ18O as proxy for regional climatic conditions rather than local rainfall amount. Meteorological parameters that characterize intra-seasonal variability of monsoon conditions were also found to be strongly linked to inter-seasonal variability of the monthly based δ18O values in the Global Network of Isotopes in Precipitation (GNIP) database. This leads to the conclusion that information about the Australian monsoon variability can likely be inferred from the isotopic proxy record in North Australia on short (intra seasonal) and long (inter seasonal or longer) timescales.

    AB - The aim of this study was to identify the main meteorological drivers of rainfall isotopic variation in north Australia in order to improve the interpretation of isotopic proxy records in this region. An intense monitoring program was conducted during two monsoonal events that showed significant and systematic isotopic change over time. The results showed a close link between isotopic variation in precipitation and variability in monsoon conditions, associated with the presence of large convective envelopes propagating through the study site. The largest negative amplitudes in the isotopic signal were observed when eastward and westward moving precipitation systems within the convective envelope merged over the measurement site. This suggests that the amplitude of the isotopic signal is related to the size and activity of the convective envelope. The strong correlation between rainfall isotopic variation, regional outgoing longwave radiation and regional rainfall amount supports this conclusion. This is further strengthened by the strong relationship between isotopic variation and the integrated rainfall history of air masses prior to arriving at the measurement locations. A local amount effect was not significant and these findings support the interpretation of δ18O as proxy for regional climatic conditions rather than local rainfall amount. Meteorological parameters that characterize intra-seasonal variability of monsoon conditions were also found to be strongly linked to inter-seasonal variability of the monthly based δ18O values in the Global Network of Isotopes in Precipitation (GNIP) database. This leads to the conclusion that information about the Australian monsoon variability can likely be inferred from the isotopic proxy record in North Australia on short (intra seasonal) and long (inter seasonal or longer) timescales.

    KW - Climate proxy records Australia

    KW - Convection

    KW - MJO

    KW - Monsoon variability

    KW - Palaeoclimatology

    KW - Precipitation

    KW - Stable isotopes

    KW - Tropics

    UR - http://www.scopus.com/inward/record.url?scp=84988487460&partnerID=8YFLogxK

    U2 - 10.1016/j.quascirev.2016.09.010

    DO - 10.1016/j.quascirev.2016.09.010

    M3 - Article

    VL - 151

    SP - 228

    EP - 235

    JO - Quaternary Science Reviews

    JF - Quaternary Science Reviews

    SN - 0277-3791

    ER -