diff --git a/NAMESPACE b/NAMESPACE
index 0298434..9c78e66 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -15,6 +15,8 @@ export(k.crusius)
 export(k.crusius.base)
 export(k.heiskanen)
 export(k.heiskanen.base)
+export(k.klaus)
+export(k.klaus.base)
 export(k.macIntyre)
 export(k.macIntyre.base)
 export(k.read)
diff --git a/R/k.klaus.R b/R/k.klaus.R
new file mode 100644
index 0000000..0a6aa46
--- /dev/null
+++ b/R/k.klaus.R
@@ -0,0 +1,64 @@
+# ---Author: Bennett McAfee, 2026-06-08 --- 
+# Last update: 2026-06-08 
+
+#'@export
+k.klaus = function(ts.data, wnd.z, lake.area, spatial.int, method = c("linear", "power")){
+  
+  if(!has.vars(ts.data, 'wnd')){
+    stop('k.klaus requires a "wnd" (wind speed) column in the supplied data')
+  }
+  
+  wind = get.vars(ts.data, 'wnd')
+  
+  k600 = k.klaus.base(wind[,2], wnd.z, lake.area, spatial.int, method = method)
+  
+  return(data.frame(datetime=ts.data$datetime, k600=k600))
+}
+
+
+#'@export
+k.klaus.base <- function(wnd, wnd.z, lake.area, spatial.int, method = c("linear", "power")) {
+  
+  method <- match.arg(method)
+  
+  # converting m2 to km2
+  lake.area <- lake.area / 1e6 
+  
+  # Converting uz to u10
+  if (wnd.z != 10){
+    wnd <- wind.scale.base(wnd = wnd, wnd.z = wnd.z)
+  }
+  
+  # helper logit function
+  logit.custom <- function(x){
+    return(log(x / (1 - x)))
+  }
+  
+  # sanity checks
+  if (any(spatial.int <= 0 | spatial.int >= 1)) {
+    stop("spatial.int must be between 0 and 1 (exclusive)")
+  }
+  
+  if (method == "linear") {
+    k600 <- (0.328 * log10(lake.area) + 1.581) * wnd - 0.066 * logit.custom(spatial.int) + 1.266
+  } else if (method == "power") {
+    k600 <- (0.281 * log10(lake.area) + 1.361) * (wnd ^ 1.097) - 0.072 * logit.custom(spatial.int) + 1.401
+  } else if (method == "exp") {
+    # if (is.null(sdi)) {
+    #   stop("sdi must be provided for exponential model")
+    # }
+    # k600 <- (-0.057 * logit.custom(spatial.int) + 2.366) * exp(wnd * (0.144 * log10(sdi) + 0.156))
+    stop('The exponential model was removed per Klaus and Vachon (2020): "...[We] do not recommend using our
+models that include SDI."')
+  }
+  
+  k600 <- k600 * (24/100) # convert cm/hr to m/day
+  
+  return(k600)
+}
+
+
+# -- References
+# Klaus, Marcus, and Dominic Vachon. 2020. 
+# Challenges of Predicting Gas Transfer Velocity from Wind Measurements over Global Lakes. 
+# Aquatic Sciences 82 (3): 53. https://doi.org/10.1007/s00027-020-00729-9
diff --git a/R/k.read.R b/R/k.read.R
index 49a1cb1..8fc0371 100644
--- a/R/k.read.R
+++ b/R/k.read.R
@@ -7,6 +7,7 @@
 #'k.crusius
 #'k.vachon
 #'k.heiskanen
+#'k.klaus
 #'@title Returns a timeseries of gas exchange velocity
 #'@description
 #'Returns the gas exchange velocity based on the chosen model in units of m/day
@@ -24,13 +25,19 @@
 #'k.vachon(ts.data, lake.area, params=c(2.51,1.48,0.39))
 #'
 #'k.heiskanen(ts.data, wnd.z, Kd, atm.press)
+#'
+#'k.klaus(ts.data, wnd.z, lake.area, spatial.int, method = c("linear", "power"))
 #'@param ts.data vector of datetime in POSIXct format
-#'@param method Only for \link{k.crusius}. String of valid method . Either "linear", "bilinear", or "power"
+#'@param method Only for \link{k.crusius} and \link{k.klaus}. String of valid method. For k.crusius either "linear", "bilinear", or "power". For k.klaus either "linear" or "power"
 #'@param wnd.z height of wind measurement, m
 #'@param Kd Light attenuation coefficient (Units:m^-1)
 #'@param atm.press atmospheric pressure in mb
 #'@param lat Latitude, degrees north
 #'@param lake.area Lake area, m^2
+#'@param spatial.int Only for \link{k.klaus}. Numeric scale of spatial integration, expressed relative
+#'to total lake surface area: from near 0 (a point-scale measurement, e.g. 1 m^2 / lake.area)
+#'up to but not including 1 (whole-lake integration). Must satisfy 0 < spatial.int < 1; the value 1 is
+#'not supported because the model uses logit(spatial.int).
 #'@param params Only for \link{k.vachon.base} and \link{k.macIntyre}. See details.
 #'
 #'@details Can change default parameters of MacIntyre and Vachon models. Default for Vachon is
@@ -70,14 +77,18 @@
 #'\emph{An approach to estimation of near-surface turbulence and CO2 transfer
 #'velocity from remote sensing data}. Journal of Marine Systems 66, (2007): 182-194.
 #'
+#'Marcus Klaus and Dominic Vachon. \emph{Challenges of Predicting Gas Transfer Velocity from Wind Measurements over Global Lakes}. 
+#'Aquatic Sciences 82 (3): 53. (2020).
+#'
 #'@author
-#'Hilary Dugan, Jake Zwart, Luke Winslow, R. Iestyn. Woolway, Jordan S. Read
+#'Hilary Dugan, Jake Zwart, Luke Winslow, R. Iestyn. Woolway, Jordan S. Read, Bennett McAfee
 #'@seealso
 #'\link{k.cole}
 #'\link{k.crusius}
 #'\link{k.macIntyre}
 #'\link{k.vachon}
 #'\link{k.heiskanen}
+#'\link{k.klaus}
 #'@examples
 #'data.path = system.file('extdata', package="LakeMetabolizer")
 #'
@@ -101,6 +112,7 @@
 #'atm.press  = 1018
 #'lat       = tb.data$metadata$latitude
 #'lake.area = tb.data$metadata$lakearea
+#'spatial.int        = 1/lake.area
 #'
 #'#for k.read and k.macIntyre, we need LW_net.
 #'#Calculate from the observations we have available.
@@ -116,6 +128,8 @@
 #'
 #'k600_macIntyre = k.macIntyre(ts.data, wnd.z=wnd.z, Kd=kd, atm.press=atm.press)
 #'
+#'k600_klaus = k.klaus(ts.data, wnd.z=wnd.z, lake.area=lake.area, spatial.int=spatial.int)
+#'
 #'@export
 k.read = function(ts.data, wnd.z, Kd, atm.press, lat, lake.area){
 
@@ -178,6 +192,7 @@ k.read = function(ts.data, wnd.z, Kd, atm.press, lat, lake.area){
 #'k.crusius.base
 #'k.vachon.base
 #'k.heiskanen.base
+#'k.klaus.base
 #'@title Returns a timeseries of gas exchange velocity
 #'@description
 #'Returns the gas exchange velocity based on the chosen model in units of m/day
@@ -199,8 +214,9 @@ k.read = function(ts.data, wnd.z, Kd, atm.press, lat, lake.area){
 #'
 #'k.heiskanen.base(wnd.z, Kd, atm.press, dateTime, Ts, z.aml, airT, wnd, RH, sw, lwnet)
 #'
+#'k.klaus.base(wnd, wnd.z, lake.area, spatial.int, method = c("linear", "power"))
 #'@param wnd Numeric value of wind speed, (Units:m/s)
-#'@param method Only for \link{k.crusius.base}. String of valid method . Either "constant", "bilinear", or "power"
+#'@param method Only for \link{k.crusius.base} and \link{k.klaus.base}. String of valid method. For k.crusius.base either "constant", "bilinear", or "power". For k.klaus.base either "linear" or "power"
 #'@param wnd.z Height of wind measurement, (Units: m)
 #'@param Kd Light attenuation coefficient (Units: m^-1)
 #'@param lat Latitude, degrees north
@@ -213,10 +229,15 @@ k.read = function(ts.data, wnd.z, Kd, atm.press, lat, lake.area){
 #'@param RH Numeric value of relative humidity, \%
 #'@param sw Numeric value of short wave radiation, W m^-2
 #'@param lwnet Numeric value net long wave radiation, W m^-2
+#'@param spatial.int Only for \link{k.klaus}. Numeric scale of spatial integration, expressed relative
+#'to total lake surface area: from near 0 (a point-scale measurement, e.g. 1 m^2 / lake.area)
+#'up to but not including 1 (whole-lake integration). Must satisfy 0 < spatial.int < 1; the value 1 is
+#'not supported because the model uses logit(spatial.int).
 #'@param params Optional parameter input, only for \link{k.vachon.base} and \link{k.macIntyre.base}. See details.
 #'@details Can change default parameters of MacIntyre and Vachon models. Default for Vachon is
 #'c(2.51,1.48,0.39). Default for MacIntyre is c(1.2,0.4872,1.4784). Heiskanen et al. (2014) uses MacIntyre
 #'model with c(0.5,0.77,0.3) and z.aml constant at 0.15.
+#'
 #'@return Numeric value of gas exchange velocity (k600) in units of m/day. Before use,
 #'should be converted to appropriate gas using \link{k600.2.kGAS}.
 #'@keywords methods math
@@ -248,8 +269,11 @@ k.read = function(ts.data, wnd.z, Kd, atm.press, lat, lake.area){
 #'\emph{An approach to estimation of near-surface turbulence and CO2 transfer
 #'velocity from remote sensing data}. Journal of Marine Systems 66, (2007): 182-194.
 #'
+#'Marcus Klaus and Dominic Vachon. \emph{Challenges of Predicting Gas Transfer Velocity from Wind Measurements over Global Lakes}. 
+#'Aquatic Sciences 82 (3): 53. (2020).
+#'
 #'@author
-#'R. Iestyn. Woolway, Hilary Dugan, Luke Winslow, Jordan S Read, GLEON fellows
+#'R. Iestyn. Woolway, Hilary Dugan, Luke Winslow, Jordan S Read, Bennett McAfee, GLEON fellows
 #'@seealso
 #'\link{k.cole}
 #'\link{k.read}
@@ -257,6 +281,7 @@ k.read = function(ts.data, wnd.z, Kd, atm.press, lat, lake.area){
 #'\link{k.macIntyre}
 #'\link{k.vachon}
 #'\link{k.heiskanen}
+#'\link{k.klaus}
 #'@examples
 #'wnd.z <- 2
 #'Kd <- 2
@@ -271,6 +296,7 @@ k.read = function(ts.data, wnd.z, Kd, atm.press, lat, lake.area){
 #'RH <- 90
 #'sw <- 800
 #'lwnet <- -55
+#'spatial.int <- 1/lake.area
 #'timeStep <- 30
 #'
 #'U10 <- wind.scale.base(wnd, wnd.z)
@@ -288,6 +314,8 @@ k.read = function(ts.data, wnd.z, Kd, atm.press, lat, lake.area){
 #'k600_macInytre <- k.macIntyre.base(wnd.z, Kd, atm.press,
 #'dateTime, Ts, z.aml, airT, wnd, RH, sw, lwnet)
 #'
+#'k600_klaus <- k.klaus.base(wnd, wnd.z, lake.area, spatial.int)
+#'
 #'@export
 k.read.base <- function(wnd.z, Kd, lat, lake.area, atm.press, dateTime, Ts, z.aml, airT, wnd, RH, sw, lwnet){
 
diff --git a/man/k.read.Rd b/man/k.read.Rd
index 5ec6ba1..8bf9b84 100644
--- a/man/k.read.Rd
+++ b/man/k.read.Rd
@@ -8,6 +8,7 @@
 \alias{k.crusius}
 \alias{k.vachon}
 \alias{k.heiskanen}
+\alias{k.klaus}
 \title{Returns a timeseries of gas exchange velocity}
 \usage{
 k.cole(ts.data)
@@ -23,6 +24,8 @@ k.macIntyre(ts.data, wnd.z, Kd, atm.press,params=c(1.2,0.4872,1.4784))
 k.vachon(ts.data, lake.area, params=c(2.51,1.48,0.39))
 
 k.heiskanen(ts.data, wnd.z, Kd, atm.press)
+
+k.klaus(ts.data, wnd.z, lake.area, spatial.int, method = c("linear", "power"))
 }
 \arguments{
 \item{ts.data}{vector of datetime in POSIXct format}
@@ -37,7 +40,12 @@ k.heiskanen(ts.data, wnd.z, Kd, atm.press)
 
 \item{lake.area}{Lake area, m^2}
 
-\item{method}{Only for \link{k.crusius}. String of valid method . Either "linear", "bilinear", or "power"}
+\item{method}{Only for \link{k.crusius} and \link{k.klaus}. String of valid method. For k.crusius either "linear", "bilinear", or "power". For k.klaus either "linear" or "power"}
+
+\item{spatial.int}{Only for \link{k.klaus}. Numeric scale of spatial integration, expressed relative
+to total lake surface area: from near 0 (a point-scale measurement, e.g. 1 m^2 / lake.area)
+up to but not including 1 (whole-lake integration). Must satisfy 0 < spatial.int < 1; the value 1 is
+not supported because the model uses logit(spatial.int).}
 
 \item{params}{Only for \link{k.vachon.base} and \link{k.macIntyre}. See details.}
 }
@@ -75,6 +83,7 @@ wnd.z      = 10   #because we converted to u10
 atm.press  = 1018
 lat       = tb.data$metadata$latitude
 lake.area = tb.data$metadata$lakearea
+spatial.int        = 1/lake.area
 
 #for k.read and k.macIntyre, we need LW_net.
 #Calculate from the observations we have available.
@@ -90,6 +99,8 @@ atm.press=atm.press, lat=lat, lake.area=lake.area)
 
 k600_macIntyre = k.macIntyre(ts.data, wnd.z=wnd.z, Kd=kd, atm.press=atm.press)
 
+k600_klaus = k.klaus(ts.data, wnd.z=wnd.z, lake.area=lake.area, spatial.int=spatial.int)
+
 }
 \references{
 Cole, J., J. Nina, and F. Caraco. \emph{Atmospheric exchange of carbon dioxide
@@ -118,6 +129,9 @@ transfer coefficients in a boreal lake}. Tellus B 66, no.22827 (2014)
 Alexander Soloviev, Mark Donelan, Hans Graber, Brian Haus, Peter Schlussel.
 \emph{An approach to estimation of near-surface turbulence and CO2 transfer
 velocity from remote sensing data}. Journal of Marine Systems 66, (2007): 182-194.
+
+Marcus Klaus and Dominic Vachon. \emph{Challenges of Predicting Gas Transfer Velocity from Wind Measurements over Global Lakes}. 
+Aquatic Sciences 82 (3): 53. (2020).
 }
 \seealso{
 \link{k.cole}
@@ -125,9 +139,10 @@ velocity from remote sensing data}. Journal of Marine Systems 66, (2007): 182-19
 \link{k.macIntyre}
 \link{k.vachon}
 \link{k.heiskanen}
+\link{k.klaus}
 }
 \author{
-Hilary Dugan, Jake Zwart, Luke Winslow, R. Iestyn. Woolway, Jordan S. Read
+Hilary Dugan, Jake Zwart, Luke Winslow, R. Iestyn. Woolway, Jordan S. Read, Bennett McAfee
 }
 \keyword{math}
 \keyword{methods}
diff --git a/man/k.read.base.Rd b/man/k.read.base.Rd
index d0ec805..7af7312 100644
--- a/man/k.read.base.Rd
+++ b/man/k.read.base.Rd
@@ -8,6 +8,7 @@
 \alias{k.crusius.base}
 \alias{k.vachon.base}
 \alias{k.heiskanen.base}
+\alias{k.klaus.base}
 \title{Returns a timeseries of gas exchange velocity}
 \usage{
 k.cole.base(wnd)
@@ -26,6 +27,8 @@ lwnet, params=c(1.2,0.4872,1.4784))
 k.vachon.base(wnd, lake.area, params=c(2.51,1.48,0.39))
 
 k.heiskanen.base(wnd.z, Kd, atm.press, dateTime, Ts, z.aml, airT, wnd, RH, sw, lwnet)
+
+k.klaus.base(wnd, wnd.z, lake.area, spatial.int, method = c("linear", "power"))
 }
 \arguments{
 \item{wnd.z}{Height of wind measurement, (Units: m)}
@@ -54,7 +57,12 @@ k.heiskanen.base(wnd.z, Kd, atm.press, dateTime, Ts, z.aml, airT, wnd, RH, sw, l
 
 \item{lwnet}{Numeric value net long wave radiation, W m^-2}
 
-\item{method}{Only for \link{k.crusius.base}. String of valid method . Either "constant", "bilinear", or "power"}
+\item{method}{Only for \link{k.crusius.base} and \link{k.klaus.base}. String of valid method. For k.crusius.base either "constant", "bilinear", or "power". For k.klaus.base either "linear" or "power"}
+
+\item{spatial.int}{Only for \link{k.klaus}. Numeric scale of spatial integration, expressed relative
+to total lake surface area: from near 0 (a point-scale measurement, e.g. 1 m^2 / lake.area)
+up to but not including 1 (whole-lake integration). Must satisfy 0 < spatial.int < 1; the value 1 is
+not supported because the model uses logit(spatial.int).}
 
 \item{params}{Optional parameter input, only for \link{k.vachon.base} and \link{k.macIntyre.base}. See details.}
 }
@@ -84,6 +92,7 @@ wnd <- 6
 RH <- 90
 sw <- 800
 lwnet <- -55
+spatial.int <- 1/lake.area
 timeStep <- 30
 
 U10 <- wind.scale.base(wnd, wnd.z)
@@ -101,6 +110,8 @@ atm.press, dateTime, Ts, z.aml, airT, wnd, RH, sw, lwnet)
 k600_macInytre <- k.macIntyre.base(wnd.z, Kd, atm.press,
 dateTime, Ts, z.aml, airT, wnd, RH, sw, lwnet)
 
+k600_klaus <- k.klaus.base(wnd, wnd.z, lake.area, spatial.int)
+
 }
 \references{
 Cole, J., J. Nina, and F. Caraco. \emph{Atmospheric exchange of carbon dioxide
@@ -129,6 +140,9 @@ transfer coefficients in a boreal lake}. Tellus B 66, no.22827 (2014)
 Alexander Soloviev, Mark Donelan, Hans Graber, Brian Haus, Peter Schlussel.
 \emph{An approach to estimation of near-surface turbulence and CO2 transfer
 velocity from remote sensing data}. Journal of Marine Systems 66, (2007): 182-194.
+
+Marcus Klaus and Dominic Vachon. \emph{Challenges of Predicting Gas Transfer Velocity from Wind Measurements over Global Lakes}. 
+Aquatic Sciences 82 (3): 53. (2020).
 }
 \seealso{
 \link{k.cole}
@@ -137,9 +151,10 @@ velocity from remote sensing data}. Journal of Marine Systems 66, (2007): 182-19
 \link{k.macIntyre}
 \link{k.vachon}
 \link{k.heiskanen}
+\link{k.klaus}
 }
 \author{
-R. Iestyn. Woolway, Hilary Dugan, Luke Winslow, Jordan S Read, GLEON fellows
+R. Iestyn. Woolway, Hilary Dugan, Luke Winslow, Jordan S Read, Bennett McAfee, GLEON fellows
 }
 \keyword{math}
 \keyword{methods}