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Black Rock Forest

Intensive measurements over Complex Terrain

Xu, X., C. Yi, the influence of geometry on recirculation and co2 transport over forested hills, Meteorology and Atmospheric Physics, 2012, DOI: 10.1007/s00703-012-0224-6 . PDF

Chen, H., and C. Yi, Optimal control of katabatic flows within canopies, Quarterly Journal of the Royal Meteorological Society, DOI:10.1002/qj.1904, 2012. PDF

Wang, W. and C. Yi, A new nonlinear analytical model for canopy flow over a forested hill, Theoretical and Applied Climatology, DOI 10.1007/s00704-012-0599-9, 2012. PDF


Yi, C., R. K. Monson, Z. Zhai, D. E. Anderson, B. Lamb, G. Allwine, A. A. Turnipseed, and S. P. Burns, Modeling and measuring the nocturnal drainage flow in a high-elevation, subalpine forest with complex terrain, Journal of Geographical Research, 110, D22303, doi:10.1029/2005JD006282, 2005. PDF


April 19 - 21, 2013

We mounted instruments on two towers in Black Rock Forest with helps from many people!

From left to right: Rahul Singh, Tim Eaton, Yunping Chen, Fung Liew, Qianyu Zhang, Bobby Stratakos, Nadia Berry, Tree Yi, Nicole Migliove, Max Trukhin, Eric Kutter, Cody Bachu, Satwika Reddy, George Hendry.


The eddy covariance technique has become the most useful method to quantify ecosystem carbon sequestration. Complex terrain and complicated canopy structure create difficult conditions that can induce non-ignorable advection errors during calm nights. Both advection experiments and model simulations have demonstrated that the signs/magnitudes of advection flux components are related to the tower-location over complex terrain. We intend to use a seven tower setup to examine simultaneously several typical advection problems on a single forested hill in the Black Rock Forest (BRF).

Our analytical model predicts the recirculation on the leeward side of a forested hill (Wang and Yi, 2012)

Wang, W. and C. Yi, A new nonlinear analytical model for canopy flow over a forested hill, Theoretical and Applied Climatology, DOI 10.1007/s00704-012-0599-9, 2012.



Our CFD numerical model predicts that these recirculation bubbles have huge influence on CO2 exchanges between forests and atmosphere.

Xu, X., C. Yi, the influence of geometry on recirculation and co2 transport over forested hills, Meteorology and Atmospheric Physics, DOI: 10.1007/s00703-012-0224-6, 2012.


Yi-Hendrey group wants to measure these bubbles by setting up a two-tower system at Black Rock Forest

April 16 (Tuesday) before going to the BRF, 2013

Eric had a meeting with students (Geol. 216) for preparation of BRF project


George emphasized on safety issues

April 19 (Friday), 2013

At 6:00 AM students arrived on the campus

Bobby, Cody, Nicole, Max, Nadia, Tree, and Fung

We arrived at the BRF


Rahul and Nadia

Cody and Eric



George said " Get'em up, and mov'em out!"

Qianyu started working with her slope-tower team: Nicole, Max, Yunping and Tree


George's generator team: Fung, Rahul, and Nadia

Eric was going to the top-tower with his team: Cody, Bobby, Nocole



Tree moved poles to the top-tower

Eric mounted Li-cor and Net Radiation sensors on the top level of the top-tower


3D-Sonic, Li-Cor, and net radiation sensors were setup on the top level of the top-tower

Eric and Cody were working on the data logger


Cody was working on the data logger

Bobby was working on generator


Eric's team was busy

Eric's team was transport instruments on different levels





The top tower

The top tower


Lunch time

Lunch time


Qianyu and Yunping were working on top level of the slope-tower

Max was transporting something to Qianyu and Yunping


Nicole, Max, and George

Max and Tree


Yunping and Qianyu

George was working on generator


George was teaching Max how to do it.

Max and George


Rahul was delivering temperature sensor up to the tower

Max, George, and Rahul


Max was working on the connnection



Tree kept eyes on Yunping and Qianyu on the tower

Qianyu and Yunping


George and Max

Nicole and Max worked together


George and Rahul

George and Rahul


Rahul was thinking of a problem

Eric was working on the data logger



Bobby, Cody, Nadia, and Satwika


Satwika and Nadia

Bobby, Cody, and Eric


Eric's team was working on the top-tower

Bobby, Cody, and Eric


Eric, Bobby, Cody, and Satwika




Satwika and Nadia

Friday Evening, April 19, 2013

Kitchen in the BRF

Matt, Qianyu, and George


Qianyu, Li (Chief cook), Tree

George bought beers and wine, while Tree bought the Chinese liquor




Fung was checking emails


Rahul was downloading pictures

Dinner time


Qianyu, Matt, Bobby, Nicole

Fung, Rahul, Cody



Matt and Tree were playing a Chinese liquor game


Fung, Nadia, Satwika, and Cody

Tree was playing the game with Bobby


Rahul was studying

Li, Cody, and Satwika were cooking breakfast

Saturday Morning, April 20, 2013

They were preparing breakfast

George was making pancakes


Bobby, Nadia, Max, Nicole, and Qianyu

Moving to the field, Nadia opened the door

Saturday, April 20, 2013

George was driving

Arrived field, Eric, Cody, Nadia, Satwika, Bobby


Bobby, Nadia, and Tree

Started working


Max was cranking the tower up

Tree was cranking the tower up


Max's turn

Fung found a new way to cranking up



Rahul's turn

The cables were broken and Qianyu was going up to check


Qianyu found that three were broken

Qianyu was fixing the problems


Bobby, Cody, and Eric were working on the top-tower

The top-view from the top-tower


Bobby, Cody, and Satwika

The top tower


Fung was workinh on the generator

Rahul was working on the generator


Nadia and Bobby setup a sensor to measure ground heat flux

The slope-tower must be cranked down and cranked up again


Tim was watching and conducting the cables when we were cranking up the tower

Tree was cranking the tower up


Yunping was cranking the tower up

Fung was checking emails from the top of the top tower


To fix the guy-wire tangled problem, Max was cutting the branches of the tree.


George said: " A giant on the shoulders of two giants"


Max jumped up

Max jumped down


George and Tree were working on the guy wires

George and Tree


George and Tree

George and Tree


Lunch time

Lunch time


Yunping and Tim

Rahul found something very interesting



Fung, Nadia, and Cody


Yunping and Tim were working on the fourth level on the slope-tower

Tim and Yunping 


Qianyu and Kat were moving sothing up to Tim and Yunping

All four up levels were finished



To fix the guy-wire tangled problem, the branches of trees must be cut off at very high level.

John brought a very high latter and his son Ben Brady and his son's friend to help.


Ben was on the top of very tall latter

Ben was sawing the branches.


Ben was sawing the branches on the other tree

John and Ben's friend


Ben was too tired and came down

Ben wanted to use the harness


Ben was equipped with harness

George and Qianyu were working on the fifth level of the slope tower



Ben climbed the very tall latter again


Ben held him on the tree by the harness


Ben cut off one big branch

Tree is moving it away.


We are working on solving the guy-wires tangled problem.

Yunping, Tree, and George



Qianyu was working on the data logger

So far both tower systems started collecting data

Saturday Evening, April 20, 2013

Nicole and Max were making food

Dinner time


Dinner time

They were playing the game: Nadia drew a picture and the rest gussed


George explained  the game to Li

George drew a picture

Sunday Morning, April 21, 2013

George came with Eric, Qianyu, and Tree worked on generators after his class. Qianyu was working on data logger






Ready to go the field

They are ready to go the field. George, Eric, Tim, and Tree were talking with Bill (director of the BRF)



Tree was talking about recirculation formation in the BRF


Qianyu, Max, John, Tree, and Kevin

They were measuring the heights of sensors on the slope-tower by triangle methods: Bobby, Nadia, Cody, Eric, and Satwika.


Tree was explaining to John: what is the main point of the tower systems

John, Max, Nicole, Tree, and Kevin (Professor from Columbia who conducts measurements of soil respiration)


John, Max, Nicole, Kevin, Tree


Rahul and John's dog


 June 8-9, 2013

From left to right:Tim Eaton, Bobby Stratakos, Rahul Singh, Jim Rice, Lili Ye, Saidan Qi, Sue Wei, Qianyu Zhang, Eric Kutter, Tree Yi, Li Guan

They arrived in afternoon of June 18, 2013. They will dismantel all the instruments from the towers aand move them back to Queens College on June19, 2013. In the mid-night of June 18, they will do smoke experiments (watch drainge flow) and generator-turn on/off experiments. Before doing that, they will make dumplings to celebrate the end of the experiments.

Saturday Evening, June 8, 2013

They started making dumplings.

They were making dumplings.



Jim was showing magic (something through glasses)




Jim and Tree were playing Chinese Liquor Game.




Sunday, June 9, 2013

We are ready to take all instruments down.



Rahul and Bobby were working on generators

Lili and Jim were working on the slope tower


3D sonic and Li-Cor at the top-level on the top-tower.

Gaurav Singh is a professional photographor


Rahul and Bobby were moving the instruments from the top of the hill to the bottom


Rahul and Eric

Tree was climbing the tower


Tim was ready to climb the tower

Tim and Tree



The top-tower (also called fire tower)


Jim, Sue, Saidan, and Lili were working on the wires

This is our professional photographer, Gaurav Singh


Typically vegetated complex terrain

Lunch time


All the photos were taken by this gentleman, Gaurav Singh.





360 degree view from top tower of the black rock forest