© 2011 Pearson Education, Inc. CHAPTER 5 Water and Seawater

© 2011 Pearson Education, Inc. Earth’s Water 97.2% in the world ocean 2.15% frozen in glaciers and ice caps 0.62% in groundwater and soil moisture 0.02% in streams and lakes 0.001% as water vapor in the atmosphere

© 2011 Pearson Education, Inc. Seawater Components Water Dissolved material Suspended (sediment) material

© 2011 Pearson Education, Inc. The Water Molecule Polar material Hydrogen Bonds

© 2011 Pearson Education, Inc. Polar Material Loves other polar molecules. What happens when all + and – are taken????

© 2011 Pearson Education, Inc. Hydrogen Bonding Hydrogen bonds (between water) and polarity result in unique properties See Coursenotes……

© 2011 Pearson Education, Inc. pH –Fresh water is 7 (Neutral) –Seawater is around 8 (Slightly Basic) –Buffered……it changes little

© 2011 Pearson Education, Inc. Freezing and Boiling Points Freezing point = melting point: 32°F Boiling point = condensation point: 212°F

© 2011 Pearson Education, Inc. Water’s Three States of Matter

© 2011 Pearson Education, Inc. Latent Heat High latent heats: energy released from –Condensation –Freezing

© 2011 Pearson Education, Inc. Water’s Heat Capacity High heat capacity Can take in or lose much heat without changing temperature

© 2011 Pearson Education, Inc. Differential heat capacities of land and water. Summer day –From ocean to land Winter Day –From land to ocean Sea and Land Breezes

© 2011 Pearson Education, Inc. Water In The Ocean Moderates temperatures on Earth Moderates temperatures in the Ocean

© 2011 Pearson Education, Inc. Salinity Dissolved solids/Water Expressed in parts per thousand (ppt) Typical ocean salinity is 35 ppt ( o / oo ) (33-37 o / oo )

© 2011 Pearson Education, Inc. Earth’s Hydrologic Cycle

© 2011 Pearson Education, Inc. Processes Affecting Salinity All Occur on Surface!!!

© 2011 Pearson Education, Inc. Surface Salinity Variation by Latitude

© 2011 Pearson Education, Inc. Global Salinity

© 2011 Pearson Education, Inc. Salinity Variation with Depth Low latitudes – salinity decreases with depth High latitudes – salinity increases with depth Deep ocean salinity fairly consistent globally Halocline – change in salinity

© 2011 Pearson Education, Inc. Seawater Density Freshwater density = g/cm 3 Ocean surface water =1.022 to g/cm 3 Ocean layered according to density

© 2011 Pearson Education, Inc. Seawater Density Density increases with decreasing temperature Density increases with increasing salinity

© 2011 Pearson Education, Inc. Temperature/Density Variation With Depth Pycnocline – abrupt change of density with depth Thermocline – abrupt change of temperature with depth

© 2011 Pearson Education, Inc. Layered Ocean Three distinct water masses based on density: Mixed surface layer – above thermocline Upper water – thermocline and pycnocline Deep water – below thermocline to ocean floor High latitude oceans – thermocline and pycnocline rarely develop

© 2011 Pearson Education, Inc. Thermocline Curves Deepwater is Always Cold Surfacewater is Polar: Cold Tropical: Warm Temperate: Both!!!! Warm Summer, Cold Winter