The sensitivity of tree growth to air mass variability and the Pacific Decadal Oscillation in coastal Alabama

Abstract

This study investigates the relationship between tree growth and air mass type variability, using the spatial synoptic classification (SSC) in a bottomland slash pine forest in coastal Alabama (USA). The use of an air mass approach in dendroclimatology is somewhat unconventional and has not been fully explored. However, we believe that it may be useful because the air mass approach represents a holistic and comprehensive measure of surface conditions. Cores from 36 slash pines (Pinus elliotti) were extracted and ring widths were measured to the nearest 0.01 mm. The cores were then cross-dated and a standardized ring index series was established. Relationships were explored between the index series and several climate variables and teleconnections. The index series showed significant relationships with SSC air mass types and SSC air mass ratios, but insignificant results with teleconnections. Specifically the Dry Tropical air mass type was negatively correlated with tree growth while Moist Moderate was positively correlated. Concomitantly, Dry Tropical : Moist Moderate, Dry Tropical : Moist Tropical, and Dry Moderate : Moist Moderate air mass ratios also showed negative correlations. Positive Pacific Decadal Oscillation (PDO) sea surface temperatures were also associated with significant moisture and air mass variability in the region, although the PDO did not have a significant relationship with tree growth. The significance between SSC air mass variability and tree growth in the humid subtropical climate of coastal Alabama has favorable implications for dendroclimatological research in drier environments where trees are more sensitive to climatic variables.

Frequencies of Multivariate Air Masses Drive Tree Growth

“…Using a similar air mass classification (the Spatial Synoptic Classification; Sheridan, 2002), Senkbeil et al. (2007) found similar correlations with a hot and dry air mass (significantly negative) and a humid and mild air mass (significantly positive) and tree rings along the Gulf coast of the United States. We note, however, that many of the sites in the ITRDB were developed for climate reconstruction (Klesse et al., 2018; Zhao et al., 2018), resulting in a geographically biased sample with disproportionate representation of sites with strong climatic limitations to growth.…”

“…Due to the typical size of AMs (synoptic‐scale) and the remoteness of many tree‐ring sites, a tree‐ring based reconstruction of AMs would be particularly beneficial at filling in spatial gaps in the historical record. Such reconstructions would allow quantification and contextualization of recent trends in AM frequencies (e.g., Lee, 2020b; Lee & Sheridan, 2018; Petrou et al., 2022) that are not achievable from instrumental records alone, and—considering the known relationships between AMs and internal climate oscillations (Lee, 2020b; Senkbeil et al., 2007; Sheridan, 2002)—could facilitate a more‐robust (and longer‐term) estimate of these key drivers of interannual climate variability. Moreover, an AM reconstruction would allow for a longer period of study for the multitude of various applied climate projects for which AMs have historically been used.…”

“…While much work in dendroclimatology has focused on temperature or precipitation/drought, recent work in “synoptic dendroclimatology” (Hirschboeck et al., 1996) examines growth responses to synoptic‐scale atmospheric circulation (Dannenberg & Wise, 2017; Hudson et al., 2019) and reconstructs those circulation patterns in the pre‐instrumental period (Trouet et al., 2018; Wise & Dannenberg, 2014, 2017). While some studies have examined connections between synoptic‐scale air masses and tree growth at regional scales (Schultz & Neuwirth, 2012; Seim et al., 2017; Woodhouse & Kay, 1990), along with connections to known climate oscillations (Senkbeil et al., 2007), recent developments in air mass classification systems and further development of a large international tree‐ring database now allow a robust, large‐scale assessment of the impacts of AM frequencies (and their lagged effects) on tree growth across many more species and regions. Hence, a bioclimatological investigation relating tree rings and AM variability could yield not only new information on how AMs impact ecological systems but could also lay the groundwork for reconstructing past AM frequencies, allowing the comparison of recent trends in AM frequencies to pre‐instrumental variability.…”

A Study of Lean Behavior in Business Development and IT Department

“…The second analysis of correlation is to measure how each main variable is related to each other. Before calculating a correlation coefficient, a few assumptions for correlation analysis, namely the normality and linearity [9] were taken into consideration. Pearson's correlation coefficient is a measure of linear association with the score for each variable is normally distributed.…”

Perspectives on the Synoptic Climate Classification and its Role in Interdisciplinary Research

“…Further growth was seen as climatologists began to use SSC as a way to define “synoptically weak” or “benign” days, which is important when studying convection, lightning, and other meteorological phenomena that are driven by thermal instability rather than dynamic forcing (Ashley et al ; Bentley et al , ; Haberlie et al ; Mote et al ; Owen and Dixon ; Shem and Shepherd ; Stallins et al ). Similarly, some researchers have discovered the utility of the SSC to efficiently analyze weather conditions as they relate to tree growth (Huang et al ; Senkbeil et al ) and wildlife behavior (Esslinger et al ; Palumbo et al ). Our discussion of articles using the SSC is not exhaustive, but it is clear that SSC is continuing to grow in popularity among researchers studying weather–health interactions as well as several other applications, mostly within applied climatology.…”