Investigating possible causal relations among physical, chemical and biological variables across regions in the Gulf of Maine

We examine potential causal relations between ecosystem variables in four regions of the Gulf of Maine under two major assumptions: (i) a causal cyclic variable will precede, or lead, its effect variable; e.g., a peak (through) in the causal variable will come before a peak (through) in the effect variable. (ii) If physical variables determine regional ecosystem properties, then independent clusters of observations of physical, biological and interaction variables from the same stations will show similar patterns. We use the leading–lagging-strength method to establish leading strength and potential causality, and we use principal component analysis, to establish if regions differ in their ecological characteristics. We found that several relationships for physical and chemical variables were significant, and consistent with ‘‘common knowledge’’ of causal relations. In contrast, relationships that included biological variables differed among regions. In spite of these findings, we found that physical and chemical characteristics of near shore and pelagic regions of the Gulf of Maine translate into unique biological assemblages and unique physical–biologi- cal interaction

Monetary policy and stability during six periods in US economic history: 1959–2008: a novel, nonlinear monetary policy rule

We investigate the monetary policy of the Federal Reserve Board during six periods in US economic history 1959–2008. In particular, we examine the Fed’s response to changes in three guiding variables: inflation, π, unemployment, U, and industrial production, y, during periods with low and high economic stability. We identify separate responses for the Fed’s change in interest rate depending upon (i) the current rate, FF, and the guiding variables’ level below or above their average values and (ii) recent movements in inflation and unemployment. The change in rate, FF, can then be calculated. We identify policies that both increased and decreased economic stability

An empirical study of mobile-device use at Norwegian oil and gas processing plants

publishedVersio

Pedagogisk Feilsøkingsmanual

HiO-rapport 2003 nr 32  av Knut Lehre Seip. ISBN 82-579-4294-4/ ISBN 978-82-579-4294-6 / ISSN 0807-1039Ny revidert utgave oktober 2021(Originaltittel 2003: ”Klar til start” – Pedagogis

A Review of Ocean Dynamics in the North Atlantic: Achievements and Challenges

I address 12 issues related to the study of ocean dynamics and its impact on global temperature change, regional and local climate change, and on the North Atlantic ecosystem. I outline present achievements and challenges that lie ahead. I start with observations and methods to extend observations of ocean oscillations back in time and end with challenges to find connections between ocean dynamics in the North Atlantic and dynamics in other parts of the globe

Correction: Seip and Zhang (2022). A High-Resolution Lead-Lag Analysis of US GDP, Employment, and Unemployment 1977–2021: Okun’s Law and the Puzzle of Jobless Recovery. Economies 10: 260

The authors would like to make the following correction to the published paper (Seip and Zhang 2022) [...

Temperature, growth season length and phytoplankton abundance in the Gulf of Maine

I show that the relation between annual average phytoplankton concentration (as mg Chl-a.m-3) and in situ sea surface temperature, SST, is positive (Chl-a â 0.5 Ã SST, r = 0.8, p 10oC). Tentative calculations suggest that the increased length matches the increase in annual phytoplankton concentration. For the second, negative relationship, I suggest that warmer water during late summer increases stratification and limits nutrient supply to the upper productive layer

A High-Resolution Lead-Lag Analysis of US GDP, Employment, and Unemployment 1977–2021: Okun’s Law and the Puzzle of Jobless Recovery

Okun’s law is formulated as the ratio between GDP and unemployment (UE): β = f(GDP/UE). It is used to investigate the relations between output and labor input across regions or across business cycles. Based on results by James D. Hamilton we replaced the United States UE with employment (EM) for the years 1977 to 2021 and examined how employment changed relative to output during recessions and recoveries. We found that (i) EM was leading GDP before and lagging GDP after all recessions, except the 2020 recession. (ii) The βE(9) = GDP/EM for rolling ordinary linear regression over 9 months decreases just after a recession and then recovers over 2- to 4-year periods. (iii) The two series showing that EM → GDP and βE(9) < 0.5 coincided in the 34 months that partly preceded and partly followed five of six NBER recession dates, providing a probability of ≈0.0002 to coincide with the recessions by chance. Thus, the two series may be used to support forecasts of coming recessions. Since EM precedes GDP and labor productivity declines before recessions, a policy recommendation for avoiding “jobless recovery” is that employment should not increase more rapidly than the real economy

The North Atlantic Oscillations: Lead–Lag Relations for the NAO, the AMO, and the AMOC—A High-Resolution Lead–lag Analysis

Several studies examine cycle periods and the interactions between the three major climate modes over the North Atlantic, namely the Atlantic meridional overturning circulation (AMOC), the Atlantic multidecadal oscillation (AMO), and the North Atlantic oscillation (NAO). Here, we use a relatively novel high-resolution Lead–lag (LL) method to identify short time windows with persistent LL relations in the three series during the period from 1947 to 2020. We find that there are roughly 20-year time windows where LL relations change direction at both interannual, high-frequency and multidecadal, low-frequency timescales. However, with varying LL strength, the AMO leads AMOC for the full period at the interannual timescale. During the period from 1980 to 2000, we had the sequence NAO→AMO→AMOC→NAO at the interannual timescale. For the full period in the decadal time scale, we obtain NAO→AMO→AMOC. The Ekman variability closely follows the NAO variability. Both single time series and the LL relation between pairs of series show pseudo-oscillating patterns with cycle periods of about 20 years. We list possible mechanisms that contribute to the cyclic behavior, but no conclusive evidence has yet been found