After that, the magnetic field data showed a negative excursion of approximately 300 nT, which is a typical signature of the expansion phase of auroral substorms.
Interval D is a negative excursion, where δ13Ccarb values decrease rapidly in the upper part of the Lianglitag Formation and fluctuate up to 2.1 ‰.
Interval B is a negative excursion, where the fluctuation range of δ13Ccarb values in the middle of the Qiaerbak Formation is at least −0.3 ‰.
The correlation among these areas is supported by a positive excursion of organic carbon isotope after a sharp negative excursion (Ward et al., 2001, 2004, 2007; Hesselbo et al., 2002; Guex et al., 2004; Williford et al., 2007).
On CEJ days, PC-2(H) shows a large negative excursion at equatorial stations (KAN to BAN).
Although the differences are large at 119 and 130.9 mbsf, we still see a clear negative excursion.
However, two b* minima are present at ~ 30 m and ~ 70 m that are not associated with a negative δ18O excursion (Fig. 5b).
Pressure relief valves are designed to protect a pressure system against excessive normal or subnormal pressure in the event of positive or negative excursion of the system pressure.
The exercise gains significance through a Bombay magnetogram that Tsurutani et al. (2003) recently published showing a negative H excursion of ∼1600 nT, which is unprecedented for the latitude of the station, and which presents difficulties of interpretation if the negative excursion is taken to be equivalent to Dst.
