Characteristics, home ranges and population estimates of narwhals (Monodon monoceros) around Baffin Island

Twenty-one narwhals tagged in 2003 and 2004 in Admiralty Inlet showed a different summer distributional pattern than previous narwhal-tracking studies from Somerset Island, Eclipse Sound and Melville Bay. The migration of the narwhals tracked from Admiralty Inlet moved out through Lancaster Sound 15 days earlier (P <0.0001) than the narwhals summering around Eclipse Sound, whereas the Admiralty Inlet narwhals reached the mouths of Eclipse Sound 18 days later (P <0.0001) than the Eclipse Sound summering population. The winter range of the Admiralty Inlet narwhals overlapped with the winter range of narwhals from Melville Bay and Eclipse Sound in central southern Baffin Bay and Northern Davis Strait, but not with the winter range of narwhals from Somerset Island that wintered further north. Distribution size of range, and population size did not appear to be related. An example of considerable year to year variation between area of summer and winter distribution in the 2 years was believed to be related to the sample size and number of pods of whales tagged, rather than to differences in sex or age classes.

At surface behaviour of emperor penguins from Pointe Géologie, Adélie Land, Antarctica, from expedition DDU 2005

The foraging distributions of 20 breeding emperor penguins were investigated at Pointe Géologie, Terre Adélie, Antarctica by using satellite telemetry in 2005 and 2006 during early and late winter, as well as during late spring and summer, corresponding to incubation, early chick-brooding, late chick-rearing and the adult pre-moult period, respectively. Dive depth records of three post-egg-laying females, two post-incubating males and four late chick-rearing adults were examined, as well as the horizontal space use by these birds. Foraging ranges of chick-provisioning penguins extended over the Antarctic shelf and were constricted by winter pack-ice. During spring ice break-up, the foraging ranges rarely exceeded the shelf slope, although seawater access was apparently almost unlimited. Winter females appeared constrained in their access to open water but used fissures in the sea ice and expanded their prey search effort by expanding the horizontal search component underwater. Birds in spring however, showed higher area-restricted-search than did birds in winter. Despite different seasonal foraging strategies, chick-rearing penguins exploited similar areas as indicated by both a high 'Area-Restricted-Search Index' and high 'Catch Per Unit Effort'. During pre-moult trips, emperor penguins ranged much farther offshore than breeding birds, which argues for particularly profitable oceanic feeding areas which can be exploited when the time constraints imposed by having to return to a central place to provision the chick no longer apply.

Travel time and speed of gray whales and amphipod abundance along Chukotka Peninsula in 2006

The purpose of this study was to evaluate summer and fall residency and habitat selection by gray whales, Eschrichtius robustus, together with the biomass of benthic amphipod prey on the coastal feeding grounds along the Chukotka Peninsula. Thirteen gray whales were instrumented with satellite transmitters in September 2006 near the Chukotka Peninsula, Russia. Nine transmitters provided positions from whales for up to 81 days. The whales travelled within 5 km of the Chukotka coast for most of the period they were tracked with only occasional movements offshore. The average daily travel speeds were 23 km/day (range 9-53 km/day). Four of the whales had daily average travel speeds <1 km/day suggesting strong fidelity to the study area. The area containing 95% of the locations for individual whales during biweekly periods was on average 13,027 km**2 (range 7,097-15,896 km**2). More than 65% of all locations were in water <30 m, and between 45 and 70% of biweekly kernel home ranges were located in depths between 31 and 50 m. Benthic density of amphipods within the Bering Strait at depths <50 m was on average ~54 g wet wt/m**2 in 2006. It is likely that the abundant benthic biomass is more than sufficient forage to support the current gray whale population. The use of satellite telemetry in this study quantifies space use and movement patterns of gray whales along the Chukotka coast and identifies key feeding areas.

The SPARC Data Initiative CFC-11, CFC-12, HF and SF6 climatologies from international satellite limb sounders

CFC-11 (CCl3F), CFC-12 (CCl2F2), HF, and SF6 products from limb-viewing satellite instruments are provided in the form of monthly zonal mean time series obtained from HALOE, MIPAS, ACE-FTS, and HIRDLS within the time period 1991-2010. The data products are made available as part of the Stratosphere-troposphere Processes And their Role in Climate (SPARC) Data Initiative. The trace gas time series extend from the mid-troposphere to as high as the mesosphere. The zonal monthly mean time series are calculated on the SPARC Data Initiative climatology grid using 5° latitude bins and 28 pressure levels. The zonal monthly mean volume mixing ratio (VMR) and the standard deviation along with the number of averaged data values are given for each month, latitude bin, and pressure level. Furthermore, the mean, minimum, and maximum local solar time, the average latitude, and the average day of the month within each bin for one selected pressure level are provided. The time series of all variables are saved in a consistent netcdf format.

Mean dynamic topography and oceanographic parameters estimated from an inverse model and satellite geodesy, with link to model result in one single NetCDF file (392 MB), including the inverse data error covariance

Geostrophic surface velocities can be derived from the gradients of the mean dynamic topography-the difference between the mean sea surface and the geoid. Therefore, independently observed mean dynamic topography data are valuable input parameters and constraints for ocean circulation models. For a successful fit to observational dynamic topography data, not only the mean dynamic topography on the particular ocean model grid is required, but also information about its inverse covariance matrix. The calculation of the mean dynamic topography from satellite-based gravity field models and altimetric sea surface height measurements, however, is not straightforward. For this purpose, we previously developed an integrated approach to combining these two different observation groups in a consistent way without using the common filter approaches (Becker et al. in J Geodyn 59(60):99-110, 2012, doi:10.1016/j.jog.2011.07.0069; Becker in Konsistente Kombination von Schwerefeld, Altimetrie und hydrographischen Daten zur Modellierung der dynamischen Ozeantopographie, 2012, http://nbn-resolving.de/nbn:de:hbz:5n-29199). Within this combination method, the full spectral range of the observations is considered. Further, it allows the direct determination of the normal equations (i.e., the inverse of the error covariance matrix) of the mean dynamic topography on arbitrary grids, which is one of the requirements for ocean data assimilation. In this paper, we report progress through selection and improved processing of altimetric data sets. We focus on the preprocessing steps of along-track altimetry data from Jason-1 and Envisat to obtain a mean sea surface profile. During this procedure, a rigorous variance propagation is accomplished, so that, for the first time, the full covariance matrix of the mean sea surface is available. The combination of the mean profile and a combined GRACE/GOCE gravity field model yields a mean dynamic topography model for the North Atlantic Ocean that is characterized by a defined set of assumptions. We show that including the geodetically derived mean dynamic topography with the full error structure in a 3D stationary inverse ocean model improves modeled oceanographic features over previous estimates.

EOT11a - Global Empirical Ocean Tide model from multi-mission satellite altimetry, with links to model results

EOT11a is a global (E)mpirical (O)cean (T)ide model derived in 2011 by residual analysis of multi-mission satellite (a)ltimeter data. EOT11a includes amplitudes and phases of the main astronomical tides M2, S2, N2, K2, 2N2, O1, K1, P2, and Q1, the non-linear constituent M4, the long period tides Mm and Mf, and the radiational tide S1. Ocean tides as well as loading tides are provided. EOT11a was computed by means of residual tidal analysis of multi-mission altimeter data from TOPEX/Poseidon, ERS-2, ENVISAT, and Jason-1/2, as far as acquired between September 1992 and April 2010. The resolution of 7.5'x7.5' is identical with FES2004 which was used as reference model for the residual tide analysis. The development of EOT11a was funded by the Deutsche Forschungsgemeinschaft (DFG) under grant BO1228/6-2.