Advances in Lake-Effect Process Prediction within NOAA’s Climate Forecast System for North America:

A Project Progress Report

Jiming Jin and Shaobo Zhang

Departments of Watershed Sciences and Plants, Soils, and Climate, Utah State University

Michael Ek and Yihua Wu

Environmental Modeling Center (EMC)National Centers for Environmental Prediction (NCEP)

Global Lake fractions for the Climate Forecast System model grids

The lake fraction data are from the Global Lake Database version 2 (GLDBv2)

Project Motivation

• The Climate Forecast System (CFS) version 2 does not include a lake scheme.

• For resolved lakes (i.e. the Great Lakes), the CFS model treats them as ocean; and unresolved small lakes are treated as land.

• Lake processes and their interactions with atmosphere are neglected.• Potentially degrading CFS climate forecasting skill.

Project Objective

To couple a physically based lake model with CFSv2 (and CFSv3) to improve the capacity of climate forecasting at NCEP

The FLake Model

• The Freshwater Lake (Flake) model developed by Mironov (2008): http://www.flake.igb-berlin.de

• FLake is a one dimensional, two-layer physically based lake model that simulates: • lake temperature• surface fluxes• lake ice thickness

• It is currently operational in climate system models in Europe and Canada.

Temperature simulations at a depth of 2m for an Arctic lake

Lake temperature profile simulations for the same Arctic lake

Surface Temperature Simulations for Lake Erie

The average depth of Lake Erie is 19 m with a maximum depth of 64 m

Surface Temperature Simulations for Lake Superior

The average depth of Lake Superior is 147 m with a maximum depth of 406 m.

Simulated temperature profile for Lake Superior

2 layer FLake model 10 layer CLM 4.5 lake model

if (flag_lake == 0) then ! Noah_MP call sfc_drv (…)else if (flag_lake == 1) then ! Noah_MP with FLake call sfc_drv_Flake(…)end if

subroutine sfc_drv_Flake(…)…if ( RFrLake (iix,iiy) .ge. lake_pct_min ) then ! RFrLake > lake_pct_min, FLake is activated call sfc_drv(…)

call flake(…)! Do flux average

End ifend subroutine sfc_drv_Flake

Currently, lake_pct_min is set to 10%

CFS subroutinesghphys.fsfc_drv.fFlake subroutinesfc_drv_Flake.f

Coupling between CFS and FLake

NoahMP and NoahMP_FLake runs

• We used CFSR data as forcing to drive both NoahMP and NoahMP_FLake models

• We performed simulations of six cycles for 2014 for the North America and used the first five cycle simulations as spin-up and analyzed the results for the last cycle.

• In NoahMP, there is no lake configured,and lake points are filled with the nearby land use types.

Simulated summer surface temperature biases

Simulated winter surface temperature biases

Simulated summer latend heat flux biases

Simulated winter latend heat flux biases

Simulated summer sensible heat flux biases

Simulated winter sensible heat flux biases

Simulated lake ice depth and observed ice fraction

Oberved and simulated surface albedo for August

Oberved and simulated surface albedo for February

Milestones of the project

Milestone Date StatusEMC provides data and model to this lake project to Build NCAR High Resolution LDAS (HRLDAS) for CFS land initialization

FY15Q4 done

Improve CFS land-cover and land-use (LULC) database by including lakes

FY16Q1 done

Implement latest FLake codes in CFS FY16Q2 on-going

Conduct CFS ensemble simulations at NCEP and assess the results with the NCEP metrics

FY16Q 2&3 Planned

Post-Project Review FY16Q4 Planned

• Transition Plan: R&D outputs to NOAA climate operations

• Demonstration Phase: NCEP performance metrics to assess readiness of the project results.

• Operational Deployment Phase:A smooth transfer of a new coupled CFS-FLake model into NCEP operations.

Transition Plan