Temporal Studies of Biogeochemical Processes Determined from Ocean Time-Series Observations During the JGOFS Era

Interpretations of biogeochemical processes from the US JGOFS Bermuda and Hawaii time-series sites

Deep Sea Research Part II Topical Studies in Oceanography ◽

10.1016/s0967-0645(00)00147-8 ◽

2001 ◽

Vol 48 (8-9) ◽

pp. 1403-1404 ◽

Cited By ~ 11

Author(s):

D.A. Siegel ◽

D.M. Karl ◽

A.F. Michaels

Keyword(s):

Time Series ◽

Biogeochemical Processes ◽

The Us

Download Full-text

Temporal variations of mixed-layer oceanic CO2 at JGOFS-KERFIX time-series station: Physical versus biogeochemical processes

Journal of Marine Research ◽

10.1357/002224099765038607 ◽

1999 ◽

Vol 57 (1) ◽

pp. 165-187 ◽

Cited By ~ 15

Author(s):

Ferial Louanchi ◽

Diana P. Ruiz-Pino ◽

Alain Poisson

Keyword(s):

Time Series ◽

Mixed Layer ◽

Temporal Variations ◽

Biogeochemical Processes

Download Full-text

Climate change and Northern Hemisphere lake and river ice phenology from 1931–2005

The Cryosphere ◽

10.5194/tc-15-2211-2021 ◽

2021 ◽

Vol 15 (5) ◽

pp. 2211-2234

Author(s):

Andrew M. W. Newton ◽

Donal J. Mullan

Keyword(s):

Time Series ◽

Northern Hemisphere ◽

Regional Variation ◽

Open Water ◽

River Ice ◽

Biogeochemical Processes ◽

Short Term ◽

Show Evidence ◽

Time Periods ◽

Ice Phenology

Abstract. At high latitudes and altitudes one of the main controls on hydrological and biogeochemical processes is the breakup and freeze-up of lake and river ice. This study uses 3510 time series from across 678 Northern Hemisphere lakes and rivers to explore historical patterns in lake and river ice phenology across five overlapping time periods (1931–1960, 1946–1975, 1961–1990, 1976–2005, and 1931–2005). These time series show that the number of annual open-water days increased by 0.63 d per decade from 1931–2005 across the Northern Hemisphere, with trends for breakup and, to a lesser extent, freeze-up closely correlating with regionally averaged temperature. Breakup and freeze-up trends display a spatiotemporally complex evolution and reveal considerable caveats with interpreting the implications of ice phenology changes at lake and river sites that may only have breakup or freeze-up data, rather than both. These results provide an important contribution by showing regional variation in ice phenology trends through time that can be hidden by longer-term trends. The overlapping 30-year time periods also show evidence for an acceleration in warming trends through time. Understanding the changes on both long- and short-term timescales will be important for determining the causes of this change, the underlying biogeochemical processes associated with it, and the wider climatological significance as global temperatures rise.

Download Full-text

The LDE-Type Flare Occurrence (1969-1993)

International Astronomical Union Colloquium ◽

10.1017/s0252921100025458 ◽

1994 ◽

Vol 144 ◽

pp. 279-282

Author(s):

A. Antalová

Keyword(s):

Time Series ◽

Fourier Analysis ◽

Sunspot Cycle ◽

List Type ◽

Type Number ◽

Solar Cycles ◽

Type Iv ◽

Long Duration ◽

Cycle Maximum ◽

Flare Index

AbstractThe occurrence of LDE-type flares in the last three cycles has been investigated. The Fourier analysis spectrum was calculated for the time series of the LDE-type flare occurrence during the 20-th, the 21-st and the rising part of the 22-nd cycle. LDE-type flares (Long Duration Events in SXR) are associated with the interplanetary protons (SEP and STIP as well), energized coronal archs and radio type IV emission. Generally, in all the cycles considered, LDE-type flares mainly originated during a 6-year interval of the respective cycle (2 years before and 4 years after the sunspot cycle maximum). The following significant periodicities were found:• in the 20-th cycle: 1.4, 2.1, 2.9, 4.0, 10.7 and 54.2 of month,• in the 21-st cycle: 1.2, 1.6, 2.8, 4.9, 7.8 and 44.5 of month,• in the 22-nd cycle, till March 1992: 1.4, 1.8, 2.4, 7.2, 8.7, 11.8 and 29.1 of month,• in all interval (1969-1992):a)the longer periodicities: 232.1, 121.1 (the dominant at 10.1 of year), 80.7, 61.9 and 25.6 of month,b)the shorter periodicities: 4.7, 5.0, 6.8, 7.9, 9.1, 15.8 and 20.4 of month.Fourier analysis of the LDE-type flare index (FI) yields significant peaks at 2.3 - 2.9 months and 4.2 - 4.9 months. These short periodicities correspond remarkably in the all three last solar cycles. The larger periodicities are different in respective cycles.

Download Full-text