Editing Laptev Sea (section)

==Hydrology==
The sea is characterized by the low water temperatures, which ranges from {{convert|-1.8|C}} in the north to {{convert|-0.8|C}} in the south-eastern parts. The medium water layer is warmer, up to 1.5 °С because it is fed by the warm Atlantic waters. It takes them 2.5–3 years to reach the Laptev Sea from their formation near [[Spitsbergen]].<ref name=rev/> The deeper layer is colder at about −0.8 °С. In summer, the surface layer in the ice-free zones warms up by the sun up to 8–10 °С in the bays and 2–3 °С in the open sea, and remains close to 0 °С under ice. The water [[salinity]] is significantly affected by the thawing of ice and river runoff. The latter amounts to about 730&nbsp;km<sup>3</sup> and would form a 135&nbsp;cm freshwater layer over the entire sea; it is the second largest in the world after the [[Kara Sea]]. The salinity values vary in winter from 20 to 25‰ (parts per thousand) in the south-east to 34‰ in the northern parts of the sea; it decreases in summer to 5–10‰ and 30–32‰ respectively.<ref name=bse/><ref name=brit/>

Most of the river runoff (about 70% or 515&nbsp;km<sup>3</sup>/year) is contributed by the Lena River. Other major contributions are from Khatanga (more than 100&nbsp;km<sup>3</sup>), Olenyok (35&nbsp;km<sup>3</sup>), Yana (greater than 30&nbsp;km<sup>3</sup>) and Anabar (20&nbsp;km<sup>3</sup>), with other rivers contributing about 20&nbsp;km<sup>3</sup>. Owing to the ice melting season, about 90% of the annual runoff occurs between June and September with 35–40% in August alone, whereas January contributes only 5%.<ref name=rev/>

Sea currents form a cyclone consisting of the southward stream near Severnaya Zemlya which reaches the continental coast and flows along it from west to east. It is then amplified by the Lena River flow and diverts to the north and north-west toward the Arctic Ocean. A small part of the cyclone leaks through the [[Sannikov Strait]] to the East Siberian Sea. The cyclone has a speed of 2&nbsp;cm/s which decreases toward the center. The center of the cyclone drifts with time that slightly alters the flow character.<ref name=rev/>

The tides are mostly semi-diurnal (rise twice a day), with the average amplitude of {{convert|0.5|m|sp=us}}. In the [[Khatanga Gulf]] it may reach 2 m because of the funnel-like shape of the gulf.<ref name=bse/> This tidal wave is then noticeable up to the unusually long distance of 500&nbsp;km up to the [[Khatanga River]] – the tidal wave is damped at much shorter distance in other rivers of the Laptev Sea.<ref name=rev/>

The seasonal variations of the sea level are relatively small – the sea level rises up to {{convert|40|cm|abbr=on}} in summer near the river deltas and lowers in winter. Wind-induced changes are observed all through the year, but are more frequent in autumn when the winds are strong and steady. In general, the sea level rises with northern and lowers with southern winds, but depending on the area, the maximum amplitude is observed for a specific wind direction (e.g. western and north-western in the south-eastern part of the sea). They average amplitudes are 1–2 m and may exceed {{convert|2.5|m|sp=us}} near Tiksi.<ref name=bse/><ref name=rev/>

Owing to the weak winds and shallow waters, the sea is relatively calm with the waves typically within {{convert|1|m|sp=us}}. In July–August waves up to 4–5 m are observed near the sea center, and they may reach {{convert|6|m|sp=us}} in autumn.<ref name=rev/>