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Zeitliche Variabilität von internen Wellen und vertikaler Vermischung im Nordatlantik

Das Ziel dieses Projektes ist die Untersuchung der zeitlichen Variabilität in der Energie von internen Wellen und der Stärke von vertikaler Vermischung in Abhängigkeit des Nordatlantikstroms und dem damit verbundenen Wirbelfeld. Hierfür werden 5-6 Jahre von Strömungsmesserdaten und Temperatur/Leitfähigkeitsmessungen von drei Verankerungen entlang eines Schnittes westlich des Mittelatlantischen Rückens (MAR) sowie LADCP/CTD Daten von fünf Schifffahrten genutzt. Konkrete wissenschaftliche Ziele dabei sind:- Erstellung von Zeitserien der Energie in internen Wellen unter Benutzung der Verankerungszeitreihen von Strömung und Schichtung- Untersuchung der Zeitskalen auf denen Veränderungen in der Energie interner Wellen stattfinden. Mögliche Ursachen für Variabilität sind der Windeintrag, Position des Nordatlantikstroms und Wirbel- Identifizierung von Prozessen, welche die beobachteten internen Wellen generieren, wie z.B. Gezeiten, Stürme, Jahresgang, Wirbel, die Arme des Nordatlanikstroms (Verhältnis von lokalen zu großräumigen Erzeugungsmechanismen)- Bestimmung der Vermischungsraten (Temperaturinversionen, Thorpe Skalen, Feinstrukturparameterisierung) in Abhängigkeit der variablen Hintergrundbedingungen Hierfür werden zunächst Spektren potentieller und kinetischer Energy der internen Wellen auf ihre Abhängigkeit von veränderlichen Hintergrundbedingungen wie z.B. Wind, Gezeiten, Wirbel, Schichtung und Variabilität im Nordatlantikstrom sowieso des Einflusses der Topographie untersucht. Die instrumentelle Ausstattung der Verankerungen seit Sommer 2012 erlaubt zusätzlich die Approximation der internen Wellen durch vertikale Moden und damit verbunden die Berechnung von Energieflüssen, welche wichtige Informationen über die Menge und die Variabilität in der Energie, die in internen Wellen im Nordatlantik transportiert wird, liefern. Außerdem geben diese so gewonnenen Energieflüsse in Kombination mit der Berechnung von Ausbreitungspfaden von internen Wellen, welche am mittelatlantischen Rücken erzeugt wurden, Aufschluss über die relative Bedeutung der Topographie des MAR für die Erzeugung von internen Wellen. Beginnend vom Sommer 2015 werden die Analysen erweitert, indem Temperatur- und Druckdaten mit hoher Tiefenauflösung für die Berechnung von Thorpe Skalen und Dissipationsraten und deren zeitlichen Variabilität genutzt werden. Weitere Informationen über die zeitliche und räumliche Variabilität der Vermischungsraten im Nordatlantik werden durch die Analyse von Diffusionsraten, die anhand von LADCP/CTD Daten und einer Feinstrukturparameterisierung berechnet werden, erlangt. Dies liefert weitere Aufschlüsse über die dominanten Prozesse in der Erzeugung von internen Wellen und vertikaler Vermischung im Nordatlantik, sowie deren zeitlicher und räumlicher Variabilität.

Trajectories of roach downstream of a vertical slot under low- and high-fluctuating flow

This dataset contains fish trajectory data recorded downstream of a single vertical slot in a true to scale hydraulic flume. The dataset was generated for a spatio-temporal analysis of jet approach, jet entry, exposure time, and swimming velocities of fish under two hydraulic conditions, a low-fluctuating flow (LFF) and a high-fluctuating flow (HFF) representative of vertical-slot fishway hydraulics. Fish positions were obtained from synchronized video recordings using a semi-automatic tracking workflow. The dataset is provided as two separate files, one for LFF and one for HFF. Each file contains two-dimensional fish trajectory data (x–y positions) of juvenile roach (Rutilus rutilus; mean length = 0.13 m) recorded with a framerate of 19 Hz in a restricted area downstream of the vertical slot.

WarmWorld - Modul 1 Better, Teilprojekt 2: Wissenschaftliche Koordination und Modelltests und -tuning

Vorwärtstrajektorie (Klimaanalyse)

Vorwärtstrajektorien der regionalen Kaltluftströmungssysteme. Die Daten sind Teil der landesweiten Planungshinweiskarte und zeigen gemeinsam mit den regionalen Kaltluftströmungssystemen die Bedeutung der überregionalen Betrachtung von Kaltluft. Die Trajektorien beschreiben den Pfad bestimmter kühler Luftpakete im Laufe der modellierten Nacht vom Entstehungsort bis hin zum Siedlungsraum.

Stable Water Isotopologue data collected during HCCT-2010

Cloud samples for the isotopic analysis were collected in the framework of the Hill Cap Cloud Thuringia 2010 (HCCT-2010) campaign on Schmücke (50° 39'N/ 10° 46'E, 937 m a.s.l.; Germany) in September and October 2010 with a three-stage Caltech Active Strand Cloudwater Collector (CASCC) during 13 different cloud events with a temporal resolution of 1 to 3 hours. In a first step, we ensured that no additional fractionation occurred during sampling with the CASCC. The d values of the three sizes classes of the CASCC (4 µm to 16 µm, 16 µm to 22 µm and >22 µm) did not differ significantly, revealing that the cloud droplets of different sizes quickly equilibrate their delta value with the one of the surrounding vapor. delta values in the cloud droplets varied from -77 per mil to -15 per mil in d2H and from -12.1 per mil to -3.9 per mil in d18O and were fitted by d2H =7.8*d18O +13*10**-3. delta values decreased with temperature as well as towards the end of the campaign, representing a seasonal trend which is known from d values in precipitation. The deuterium excess of the cloud samples was generally higher than the Local Meteoric Water Line of the closest GNIP (Global Network of Isotopes in Precipitation) station. Rain decreases its deuterium excess during falling through an unsaturated air column, while the cloud droplets conserve the deuterium excess of the initial evaporation and thus have been found to be a good indicator for the airmass source region: higher deuterium excess was measured for polar air masses and lower deuterium excess for Mediterranean air masses. Changes in d values during one cloud event were up to 3.6 per mil (d2H) and 0.23 per mil (d18O), except for frontal passages, which were associated with increases of ~6 per mil per hour (d2H) and ~0.6 per mil per hour (d18O). Using a box model, we showed that the influence of condensation only was able to explain the variation in the isotope signal of two cloud passages. Consequently, we deduced that the water vapor "feeding" the cloud advected the measured changes. A trajectory analysis and moisture source diagnostic revealed that it is very likely that the variations were either related to rain out along the trajectories or to meteorological changes in the moisture source region. This was the first study using stable water isotopologues in cloud water manifesting their potential in the context of atmospheric water vapor circulation.

Trajectories and sensor data from drifter deployment number 10 during MS FRITZ REUTER and RV HEINCKE cruise HE644

During cruise HE644 (joint campaign of MS FRITZ REUTER and RV HEINCKE), Lagrangian surface drifters (Meyerjürgens et al., 2019; Deyle et al., 2024) were deployed from MS FRITZ REUTER, following the near-surface water motion, therefore allowing for observations within a moving water mass over extended periods with minimal disturbance to the surrounding water. Coordinates of the drifter position were transmitted by a GPS satellite tracker (inReach® Messenger from Garmin Ltd.) at two-minute intervals. Position data was processed after Deyle et al. (2024) and is available on minutely resolution in this dataset. For original trajectories see "<DOI>". In addition, the drifters were equipped with (down to 1.75 m depth) instrument chains including temperature and lightweight CTD (conductivity, temperature, depth) sensors. Depth in water was only recorded by RBRbrevio³ sensors, for others the depth was measured during sensor chain preparation and saved in the data array as fixed depth. The in situ temperature was recorded at up to six different depths using RBRsolo³, RBRbrevio³ (both sample frequency 1-2 Hz) and Aqua TROLL® 100 sensors (sample frequency 1 min-1). Conductivity was measured at up to three different depths, using RBRbrevio³ and Aqua TROLL® 100 sensors. RBR sensors were calibrated to a measurement uncertainty of ± 0.002 °C and ± 0.003 mS cm-1, whereas the TROLL sensors have a measurement uncertainty of ± 0.1 °C and ± 0.5%. For details on the sensor data processing see the appropriate processing report.

Trajectories and sensor data from drifter deployment number 06 during MS FRITZ REUTER and RV HEINCKE cruise HE644

During cruise HE644 (joint campaign of MS FRITZ REUTER and RV HEINCKE), Lagrangian surface drifters (Meyerjürgens et al., 2019; Deyle et al., 2024) were deployed from MS FRITZ REUTER, following the near-surface water motion, therefore allowing for observations within a moving water mass over extended periods with minimal disturbance to the surrounding water. Coordinates of the drifter position were transmitted by a GPS satellite tracker (inReach® Messenger from Garmin Ltd.) at two-minute intervals. Position data was processed after Deyle et al. (2024) and is available on minutely resolution in this dataset. For original trajectories see "<DOI>". In addition, the drifters were equipped with (down to 1.75 m depth) instrument chains including temperature and lightweight CTD (conductivity, temperature, depth) sensors. Depth in water was only recorded by RBRbrevio³ sensors, for others the depth was measured during sensor chain preparation and saved in the data array as fixed depth. The in situ temperature was recorded at up to six different depths using RBRsolo³, RBRbrevio³ (both sample frequency 1-2 Hz) and Aqua TROLL® 100 sensors (sample frequency 1 min-1). Conductivity was measured at up to three different depths, using RBRbrevio³ and Aqua TROLL® 100 sensors. RBR sensors were calibrated to a measurement uncertainty of ± 0.002 °C and ± 0.003 mS cm-1, whereas the TROLL sensors have a measurement uncertainty of ± 0.1 °C and ± 0.5%. For details on the sensor data processing see the appropriate processing report.

Trajectories and sensor data from drifter deployment number 07 during MS FRITZ REUTER and RV HEINCKE cruise HE644

During cruise HE644 (joint campaign of MS FRITZ REUTER and RV HEINCKE), Lagrangian surface drifters (Meyerjürgens et al., 2019; Deyle et al., 2024) were deployed from MS FRITZ REUTER, following the near-surface water motion, therefore allowing for observations within a moving water mass over extended periods with minimal disturbance to the surrounding water. Coordinates of the drifter position were transmitted by a GPS satellite tracker (inReach® Messenger from Garmin Ltd.) at two-minute intervals. Position data was processed after Deyle et al. (2024) and is available on minutely resolution in this dataset. For original trajectories see "<DOI>". In addition, the drifters were equipped with (down to 1.75 m depth) instrument chains including temperature and lightweight CTD (conductivity, temperature, depth) sensors. Depth in water was only recorded by RBRbrevio³ sensors, for others the depth was measured during sensor chain preparation and saved in the data array as fixed depth. The in situ temperature was recorded at up to six different depths using RBRsolo³, RBRbrevio³ (both sample frequency 1-2 Hz) and Aqua TROLL® 100 sensors (sample frequency 1 min-1). Conductivity was measured at up to three different depths, using RBRbrevio³ and Aqua TROLL® 100 sensors. RBR sensors were calibrated to a measurement uncertainty of ± 0.002 °C and ± 0.003 mS cm-1, whereas the TROLL sensors have a measurement uncertainty of ± 0.1 °C and ± 0.5%. For details on the sensor data processing see the appropriate processing report.

Trajectories and sensor data from drifter deployment number 03 during MS FRITZ REUTER and RV HEINCKE cruise HE644

During cruise HE644 (joint campaign of MS FRITZ REUTER and RV HEINCKE), Lagrangian surface drifters (Meyerjürgens et al., 2019; Deyle et al., 2024) were deployed from MS FRITZ REUTER, following the near-surface water motion, therefore allowing for observations within a moving water mass over extended periods with minimal disturbance to the surrounding water. Coordinates of the drifter position were transmitted by a GPS satellite tracker (inReach® Messenger from Garmin Ltd.) at two-minute intervals. Position data was processed after Deyle et al. (2024) and is available on minutely resolution in this dataset. For original trajectories see "<DOI>". In addition, the drifters were equipped with (down to 1.75 m depth) instrument chains including temperature and lightweight CTD (conductivity, temperature, depth) sensors. Depth in water was only recorded by RBRbrevio³ sensors, for others the depth was measured during sensor chain preparation and saved in the data array as fixed depth. The in situ temperature was recorded at up to six different depths using RBRsolo³, RBRbrevio³ (both sample frequency 1-2 Hz) and Aqua TROLL® 100 sensors (sample frequency 1 min-1). Conductivity was measured at up to three different depths, using RBRbrevio³ and Aqua TROLL® 100 sensors. RBR sensors were calibrated to a measurement uncertainty of ± 0.002 °C and ± 0.003 mS cm-1, whereas the TROLL sensors have a measurement uncertainty of ± 0.1 °C and ± 0.5%. For details on the sensor data processing see the appropriate processing report.

Trajectories and sensor data from drifter deployment number 02 during MS FRITZ REUTER and RV HEINCKE cruise HE644

During cruise HE644 (joint campaign of MS FRITZ REUTER and RV HEINCKE), Lagrangian surface drifters (Meyerjürgens et al., 2019; Deyle et al., 2024) were deployed from MS FRITZ REUTER, following the near-surface water motion, therefore allowing for observations within a moving water mass over extended periods with minimal disturbance to the surrounding water. Coordinates of the drifter position were transmitted by a GPS satellite tracker (inReach® Messenger from Garmin Ltd.) at two-minute intervals. Position data was processed after Deyle et al. (2024) and is available on minutely resolution in this dataset. For original trajectories see "<DOI>". In addition, the drifters were equipped with (down to 1.75 m depth) instrument chains including temperature and lightweight CTD (conductivity, temperature, depth) sensors. Depth in water was only recorded by RBRbrevio³ sensors, for others the depth was measured during sensor chain preparation and saved in the data array as fixed depth. The in situ temperature was recorded at up to six different depths using RBRsolo³, RBRbrevio³ (both sample frequency 1-2 Hz) and Aqua TROLL® 100 sensors (sample frequency 1 min-1). Conductivity was measured at up to three different depths, using RBRbrevio³ and Aqua TROLL® 100 sensors. RBR sensors were calibrated to a measurement uncertainty of ± 0.002 °C and ± 0.003 mS cm-1, whereas the TROLL sensors have a measurement uncertainty of ± 0.1 °C and ± 0.5%. For details on the sensor data processing see the appropriate processing report.

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