This layer shows global ocean surface currents using magnitude and direction. Magnitude is represented in meters per second (m/s) and direction is represented in geographic degrees. Ocean currents are important for several reasons:Climate regulation: Ocean currents play a crucial role in regulating Earth's climate by distributing heat around the planet. For example, the Gulf Stream carries warm water from the tropics to the North Atlantic, which helps to moderate temperatures in Europe.Nutrient distribution: Ocean currents transport nutrients from deep waters to the surface, supporting the growth of phytoplankton and other marine organisms. These organisms form the base of the marine food web and are essential for the survival of many species, including fish and marine mammals.Oxygen production: Phytoplankton, which rely on nutrients brought to the surface by ocean currents, are responsible for producing a significant portion of the Earth's oxygen through photosynthesis.Marine ecosystems: Ocean currents influence the distribution of marine species and shape the structure of marine ecosystems. They can create habitats for specific organisms and affect the migration patterns of marine animals.Transportation and trade: Ocean currents have been used for centuries as natural highways for maritime transportation and trade. They can help ships travel more efficiently by taking advantage of favorable currents.This climatology was developed by Rick Lumpkin (NOAA/AOML) and Lucas Laurindo (Univ. Miami), in collaboration with Arthur Mariano (Univ. Miami), Mayra Pazos (NOAA/AOML), and Erik Valdes (CIMAS/AOML). Previous versions were developed with Gregory Johnson (NOAA/PMEL), Silvia Garzoli (NOAA/AOML), Jessica Redman (CIMAS), and Zulema Garraffo (Univ. Miami).More Information: https://www.aoml.noaa.gov/phod/gdp/mean_velocity.phpCitation: Laurindo, L., A. Mariano, and R. Lumpkin, 2017: An improved near-surface velocity climatology for the global ocean from drifter observations Deep-Sea Res. I, 124, pp.73-92, doi:10.1016/j.dsr.2017.04.009Dataset summaryVariable Mapped: ocean currents - magnitude (meters/second) and direction (geographic degrees).Data Projection: GCS WGS84Service Projection: GCS WGS84Extent: Global (73S to 85N)Cell Size: (~30km)Source Type: Vector-MagDirData Source: NOAA Atlantic Oceanographic and Meteorological Laboratory – Physical Oceanography Division (PhOD)Data Time Period: Data from 2005-2023 was compiled and used to generate this annual climatology layer.Accessed Date: July 24, 2023Version: 3.10, released 21 August 2023.What can you do with this layer?The layer can be used in analysis and visualization. This layer can be used to summarize the magnitude minimum, maximum, and mean values withing a polygon (using zonal statistics). In ArcGIS Online this layer can be used with the “Flow” renderer to visualize ocean currents with movement.

When precipitation falls on the surface of the Earth, much of it is captured in storage (e.g. lakes, aquifers, soil moisture, snowpack, and vegetation). Precipitation that exceeds the storage capacity of the landscape becomes runoff, which flows into river systems. Overland flow is the most visible form of runoff, causing erosion and flash floods, but subsurface flow is the larger contributor in many watersheds. Subsurface flow can emerge on the surface through springs, or more commonly, seep into rivers and lakes through their banks. In urban areas, impervious land cover drastically increases the amount of surface runoff generated, which sweeps trash and urban debris into waterways and increases the likelihood and severity of flash floods. In agricultural areas, surface or subsurface runoff can carry excess salts and nutrients, especially nitrogen and phosphorus. This map contains a historical record showing the amount of runoff generated each month from March 2000 to present. It is reported in millimeters, so multiply by a surface area to calculate the total volume of runoff.Dataset SummaryThe GLDAS Runoff layer is a time-enabled image service that shows average monthly runoff from 2000 to the present measured in millimeters. It is calculated by NASA using the Noah land surface model, run at 0.25 degree spatial resolution using satellite and ground-based observational data from the Global Land Data Assimilation System (GLDAS-1). The model is run with 3-hourly time steps and aggregated into monthly averages. Review the complete list of model inputs, explore the output data (in GRIB format), and see the full Hydrology Catalog for all related data and information!What can you do with this layer?This layer is suitable for both visualization and analysis. It can be used in ArcGIS Online in web maps and applications and can be used in ArcGIS Desktop. t is useful for scientific modeling, but only at global scales.Time: This is a time-enabled layer. It shows the total runoff generated during the map's time extent, or if time animation is disabled, a time range can be set using the layer's multidimensional filter. The map shows the sum of all months in the time extent. Minimum temporal resolution is one month; maximum is one year.Variables: This layer has two variables: surface flow and subsurface flow. By default the two are summed, but you can view either by itself using the multidimensional filter. You must disable time animation on the layer before using its multidimensional filter.Important: You must switch from the cartographic renderer to the analytic renderer in the processing template tab in the layer properties window before using this layer as an input to geoprocessing tools.This layer has query, identify, and export image services available. This layer is part of a larger collection of earth observation maps that you can use to perform a wide variety of mapping and analysis tasks.The Living Atlas of the World provides an easy way to explore the earth observation layers and many other beautiful and authoritative maps on hundreds of topics.Geonet is a good resource for learning more about earth observations layers and the Living Atlas of the World. Follow the Living Atlas on GeoNet.