A Freshwater Budget of the Gulf of Boothia, Northwest Territories

A freshwater budget for the Gulf of Boothia (here considered to include Prince Regent Inlet) was estimated from oceanographic data available for the Canadian Arctic using a formula derived by Tully: integral of S(z) dz between limits L and 0 divided by S*L where C is the fraction of freshwater to the depth L, L is the depth at which the salinity attained S* or the depth to the bottom if the salinity there was less than S*, S(z) is the salinity at depth z and S* is the base salinity, in this budget taken to be 33.8 per mil. For each station occupied in 1961 and 1962 the amount of freshwater in metres, CL, was obtained. The result for 1962 is shown in Fig. 1. Sources of freshwater include direct precipitation, runoff, advection of less saline water and of ice, and condensation at the surface. It may be removed by evaporation and advection. We assumed that condensation is so small it may be neglected and that the rates of precipitation and evaporation are the same over the land as over the water. The mean precipitation in the region of the Gulf of Boothia is usually less than 20 cm/year and in nearby Barrow Strait it was estimated that the evaporation was about 8 cm/year in 1962. If the latter value is representative of the Gulf of Boothia and its drainage basin, the excess of precipitation over evaporation is about 12 cm/year. The estimate is supported by 1965 streamflow measurements of the Back River; for this basin the excess of precipitation over evaporation is about 17 cm/year. It seems that the water surplus for the Gulf of Boothia drainage basin is somewhat less so the estimate of 12 cm/year appears reasonable. As the area of the drainage basin is one and one quarter that of the gulf, runoff would add 15 cm/year to the freshwater of the gulf. Combining the gains and losses we estimate the net annual input at the surface to be 27 cm/year. If the 8 metres of freshwater estimated to occur in the gulf (Fig. 1) were due to the annual gain, it would represent an accumulation of close to 30 years. As free exchange with Lancaster Sound and beyond is possible, such a long period of accumulation seems unrealistic. There is no reason to believe that the accumulation is related to an excess of imported over exported ice, indeed export may exceed import, but data which would permit a quantitative assessment are not available. Examination of ice reconnaissance data in each year, for example that for 1967, indicates that, while movement of ice occurs from northern parts of the gulf to the south, the ice conditions observed within the system could be due entirely to ice formed there. It seems likely therefore that the accumulation is due to advection of low salinity water and that a direct relation exists between the depth of freshwater in the gulf and that calculated to occur in the archipelago to the west and in the Arctic Ocean (Fig. 1). It is generally considered that a net surface movement from west to east occurs through the archipelago; the freshwater budget provides support for this view

Supporting women farmers in a changing climate: five policy lessons

Policies, institutions and services to help farmers develop new approaches to deal with climate change will need to produce results for women farmers as well as men. This brief provides five policy lessons to support this process, based on evidence from research in low- and middle- income countries and offers guidelines for crafting gender-responsive climate policies at global and national levels. This research was presented in March 2015 at a seminar in Paris on ‘Closing the gender gap in farming under climate change’, co-organized by the CGIAR Research Program on Climate Change, Agriculture and Food Security (CCAFS), the International Social Science Council (ISSC) and Future Earth

Apoyo a las mujeres agricultoras en un clima cambiante: cinco lecciones de políticas

Recientes investigaciones presentadas en un seminario en París, coorganizado por el Programa de Investigación de CGIAR en Cambio Climático, Agricultura y Seguridad Alimentaria (CCAFS), el Consejo Internacional de Ciencias Sociales (CICS) y Future Earth, dieron lugar a cinco recomendaciones de políticas clave para apoyar a las mujeres agricultoras en un clima cambiante. Los conocimientos y competencias técnicas únicos de las mujeres en materia de gestión ambiental pueden contribuir a hallar soluciones innovadoras que hagan frente a los problemas causados por el cambio climático. English version: https://cgspace.cgiar.org/bitstream/handle/10568/68533/CCAFS%20PB10.pdf?sequence=

Stakeholder engagement in gender and climate change policy processes: Lessons from CCAFS

With the rapid increase in the dynamics caused by climate change, policies governing climate change have proliferated while the integration of gender considerations to address the gender-differentiated needs and impacts has remained a challenge. Stakeholder engagement is touted as a critical ingredient in climate change decisions and governance at different levels. However, detailed methods and outcomes of gender-responsive stakeholder engagement processes for climate change policy development are rarely published. This paper uses a CCAFS-developed framework of 10 stakeholder engagement principles to examine the stakeholder engagement processes in the gender and climate change policy arena in the context of CGIAR’s Research Program on Climate Change, Agriculture and Food Security (CCAFS). We analyze both primary and secondary data to understand the categories of stakeholders engaged, methods of engagement, and the outcomes and lessons learned across five regions. Our results show that analysis of the existing policies and programs is a very critical entry point for identifying the points of leverage, the type of stakeholders to engage and how to engage them in the processes that focus on integrating gender in climate policies. Working with influential stakeholders, with the capacity and interest to address gender considerations yields more positive results. Mechanisms to address power relations need to be in place for gender considerations to be voiced and integrated and include women in decision-making processes. Co-learning and co-development of knowledge products cultivate interest and commitment among stakeholders to address gender issues, although systematic monitoring and evaluation remains a challenge. This has implications for effective stakeholder engagement in mainstreaming gender in climate policies and evidence-based policy formualation

Statistical properties of near‐surface flow in the California coastal transition zone

The article of record as published may be found at https://doi.org/10.1029/91JC01072During the summers of 1987 and 1988, 77 near-surface satellite-tracked drifters were deployed in or near cold filaments near Point Arena, California (39°N), and tracked for up to 6 months as part of the Coastal Transition Zone (CTZ) program. The drifters had large drogues centered at 15 m, and the resulting drifter trajectory data set has been analyzed in terms of its Eulerian and Lagrangian statistics. The CTZ drifter results show that the California Current can be characterized in summer and fall as a meandering coherent jet which on average flows southward to at least 30°N, the southern end of the study domain. From 39°N south to about 33°N, the typical core velocities are of O(50 cm s−1) and the current meanders have alongshore wavelengths of O (300 km) and onshore-offshore amplitude of O(100–200 km). The lateral movement of this jet leads to large eddy kinetic energies and large eddy diffusivities, especially north of 36°N. The initial onshore-offshore component of diffusivity is always greater than the alongshore component in the study domain, but at the southern end, the eddy diffusivity is more isotropic, with scalar single particle diffusivity (Kxx + Kyy) of O(8 × 107 cm2 s−1). The eddy diffusivity increases with increasing eddy energy. Finally, a simple volume budget for the 1988 filament observed near 37°N off Point Arena suggests that subduction can occur in a filament at an average rate of O (10 m d−1) some 200 km offshore, thus allowing the cold water initially in the filament core to sink below the warmer ambient water by the time the surface velocity core has turned back onshore. This process explains why satellite temperature and color imagery tend to “see” only flow proceeding offshore

The Effect of Rainfall on the Surface Layer during a Westerly Wind Burst in the Western Equatorial Pacific

Measurements of a fresh surface anomaly (fresh lens) produced by rainfall during a westerly wind burst have been analyzed. The measurements were made in December 1992 as part of the Coupled Ocean–Atmosphere Response Experiment in the western equatorial Pacific (2°S, 156°E). Measurements included radar estimates of rainfall, upper-ocean temperature (T), salinity (S), horizontal velocity, and microstructure. In situ observations of the fresh lens were made 5 to 7 hours after its formation. In the 5 hours after formation, the lens deepened to a depth of 40 m as indicated by its salinity anomaly. Salinity and temperature were highly correlated within the lens, consistent with its initial formation by cold rainfall. The T–S relation exhibited curvature, which can be explained by surface cooling and upper-ocean mixing subsequent to formation of the lens. The lens exhibited a horizontal velocity anomaly in the direction of wind, which extended down to a depth of 40 m. The horizontal velocity anomaly is consistent with momentum being trapped near the surface due to rain-induced stratification. Vertical velocity, estimated from the divergence of zonal velocity, showed downwelling at the leading edge of the lens and upwelling at the trailing edge. The magnitude of vertical velocity at a depth of 20 m is 20 m day⁻¹. Richardson numbers within the lens were low (0.25 to 0.5), suggesting that turbulent mixing was governed by critical-Ri instability. Wavenumber spectra of T and S in the upper 20 m exhibit a −5/3 range, which extends to wavenumbers below the range of local isotropy. Spectral levels were used to estimate turbulent dissipation rates of T and S, which were in turn used to estimate turbulent fluxes of heat and salt. Turbulent fluxes were also estimated from microstructure observations between depths of 10 and 60 m. Fluxes within the fresh lens were nearly uniform from 2 m to 35 m depth, then decreased to near zero at 45 m. The lifetime of fresh lenses during westerly wind bursts appears to be less than one day

Two coastal upwelling domains in the northern California Current system

A pair of hydrographic sections, one north and one south of Cape Blanco at 42.9N, was sampled in five summers (1998–2000 and 2002–2003). The NH line at 44.6N lies about 130 km south of the Columbia River, and spans a relatively wide shelf off Newport, Oregon. The CR line at 41.9N off Crescent City, California, lies 300 km farther south and spans a narrower shelf. Summer winds are predominantly southward in both locations but the southward winds are stronger on the CR line. Sampling included CTD/rosette casts (to measure temperature, salinity, dissolved oxygen, nutrients, chlorophyll), zooplankton net tows and continuous operation of an Acoustic Doppler Current Profiler. We summarize and compare July-August observations from the two locations. We find significant summer-season differences in the coastal upwelling domains north and south of Cape Blanco. Compared to the domain off Newport, the domain off Crescent City has a more saline, cooler, denser and thicker surface mixed layer, a wider coastal zone inshore of the upwelling front and jet, higher nutrient concentrations in the photic zone and higher phytoplankton biomass. The southward coastal jet lies near the coast (about 20–30 km offshore, over the shelf) on the NH line, but far from shore (about 120 km) on the CR line; a weak secondary jet lies near the shelf-break (35 km from shore) off Crescent City. Phytoplankton tend to be light-limited on the CR line and nutrient-limited on the NH line. Copepod biomass is high (15 mg C m−3) inshore of the mid-shelf on both NH and CR lines, and is also high in the core of the coastal jet off Crescent City. The CR line shows evidence of deep chlorophyll pockets that have been subducted from the surface layer. We attribute these significant differences to stronger mean southward wind stress over the southern domain, to strong small-scale wind stress curl in the lee of Cape Blanco, and to the reduced influence of the Columbia River discharge in this region