R/V Blue Heron
The Welp lab participated in two cruises during summer 2016.

Leaf gas exchange measurements
Student uses the LiCor 6400 to measure photosynthesis, transpiration, and stomatal conductance of different crops in the field.

Atmospheric CO2 seasonal cycle increases
The peak-to-trough amplitude of the CO2 seasonal cycle at Barrow, Alaska has increased by about 50% over the last 50 years. Indicates wide-spread ecological changes have occurred.

Stable isotopes from the Kolyma River in Siberia
Oxygen isotope analysis suggests that summer evapotranspiration in this northeastern Siberian ecosystem is fueled by as much as 40% snowmelt.

Water vapor exchange between crops and the atmosphere
Measuring the isotopic composition of evapotranspiration and the sites of leaf water evaporation in a soybean canopy.

Artic zone and boreal zone
Artic zone and boreal zone

El Nino signature discovered in oxygen isotopes of atmospheric CO2
This El Nino signal was used to estimate the global rate of terrestrial photosynthesis.