Stability analysis of geomagnetic baseline data obtained at Cheongyang observatory in Korea

The stability of baselines produced by Cheongyang (CYG) observatory from the period of 2014 to 2016 is analysed. Step heights of higher than 5 nT were found in H and Z components in 2014 and 2015 due to magnetic noise in the absolute-measurement hut. In addition, a periodic modulation behaviour observed in the H and Z baseline curves was related to annual temperature variation of about 20 °C in the fluxgate magnetometer hut. Improvement in data quality was evidenced by a small dispersion between successive measurements from June 2015 to the end of 2016. Moreover, the baseline was also improved by correcting the discontinuity in the H and Z baselines.

OBSERVATIONS-BASED COMPUTATIONAL ANALYTICS ON LOCAL CLIMATE DYNAMICS: CHANGE-POINTS

The paper concerns the problem on the computational decision making on evolution of local climate dynamics taking into account inevitable nonlinear nature of such systems and deficiency of reliable data on climate dynamics. With this purpose we consider annual temperature variation in the context of the bifurcation phenomena under the hysteresis regulation with double synchronization. The corresponding conceptual model (HDS-model) provides the homogeniety of the analysed states as well as the ability to derive some constituent of regional (external) impacts on a local climate system. In accordance with the peculiarities of HDS-model dynamics, we formalize three mechanisms of local temperature changes and introduce the corresponding indicators of change-points. It allows to substitute, at least partly, expert analytics concerning identification of qualitative changes in local climate dynamics. Examples of applications of the indicators are presented on the basis of processing the time series of temperature observations on daily mean surface air temperature made over last century. We believe that the results could be applied in order to increase the confidence of estimations about local climate changes.

Proximate constraints on reproductive output in a northern population of painted turtles: an empirical test of the bet-hedging paradigm

For long-lived, iteroparous organisms whose annual reproductive success is low and unpredictable, the “bet-hedging” life-history paradigm predicts that an increase in resource acquisition should result in an increase in stored lipids and not an increase in reproductive output. We tested whether reproductive patterns in a population of midland painted turtles ( Chrysemys picta marginata Agassiz, 1857) are consistent with this prediction. Assuming that annual temperature variation is a proxy for variation in resource acquisition, we hypothesized that if harvested resources are generally sequestered for future reproduction, then there should be no relationship between clutch frequency (the number of clutches laid per season) and the temperature experienced when no follicular growth occurred. We hypothesized further that if temperature constrains clutch frequency by limiting the amount of energy that can be allocated to reproduction, then clutch frequency would be related only to the temperature experienced during the period in which follicular growth occurred (fall temperature). We found that clutch frequency was primarily related to fall temperature, which suggests that the amount of thermal energy experienced during periods of follicular development limits the amount of stored energy that can be allocated to developing follicles. This pattern of reproductive allocation is consistent with the bet-hedging paradigm.