function [a_phi] = phyto_avg_abs(wavelength) 
%averaged spectrum from Roesler et al. 1989
%scaled to specific absorption coefficient 0.0145 m2/mg at 676nm
wl=310:1:850;,wl=wl';
a_f = [    0.0148
    0.0128
    0.0147
    0.0152
    0.0151
    0.0164
    0.0166
    0.0162
    0.0157
    0.0163
    0.0149
    0.0163
    0.0158
    0.0154
    0.0157
    0.0163
    0.0163
    0.0157
    0.0170
    0.0168
    0.0174
    0.0178
    0.0174
    0.0184
    0.0171
    0.0174
    0.0173
    0.0172
    0.0167
    0.0186
    0.0181
    0.0179
    0.0167
    0.0174
    0.0171
    0.0166
    0.0157
    0.0167
    0.0164
    0.0158
    0.0157
    0.0156
    0.0158
    0.0160
    0.0159
    0.0150
    0.0148
    0.0156
    0.0158
    0.0152
    0.0156
    0.0151
    0.0150
    0.0160
    0.0155
    0.0157
    0.0159
    0.0164
    0.0162
    0.0162
    0.0169
    0.0173
    0.0168
    0.0178
    0.0171
    0.0170
    0.0178
    0.0177
    0.0184
    0.0180
    0.0180
    0.0185
    0.0185
    0.0188
    0.0187
    0.0191
    0.0183
    0.0185
    0.0193
    0.0193
    0.0196
    0.0196
    0.0196
    0.0194
    0.0198
    0.0200
    0.0198
    0.0205
    0.0204
    0.0203
    0.0209
    0.0212
    0.0217
    0.0215
    0.0218
    0.0217
    0.0222
    0.0222
    0.0226
    0.0231
    0.0234
    0.0239
    0.0241
    0.0243
    0.0247
    0.0243
    0.0249
    0.0247
    0.0249
    0.0253
    0.0252
    0.0255
    0.0256
    0.0257
    0.0252
    0.0260
    0.0257
    0.0257
    0.0262
    0.0263
    0.0266
    0.0269
    0.0272
    0.0270
    0.0278
    0.0275
    0.0277
    0.0276
    0.0278
    0.0278
    0.0278
    0.0277
    0.0276
    0.0271
    0.0269
    0.0270
    0.0266
    0.0262
    0.0261
    0.0260
    0.0257
    0.0257
    0.0253
    0.0255
    0.0256
    0.0255
    0.0254
    0.0256
    0.0257
    0.0257
    0.0258
    0.0257
    0.0259
    0.0258
    0.0259
    0.0257
    0.0257
    0.0259
    0.0256
    0.0257
    0.0253
    0.0253
    0.0254
    0.0250
    0.0249
    0.0245
    0.0245
    0.0241
    0.0239
    0.0237
    0.0235
    0.0231
    0.0231
    0.0226
    0.0225
    0.0224
    0.0222
    0.0222
    0.0221
    0.0217
    0.0217
    0.0214
    0.0211
    0.0209
    0.0207
    0.0205
    0.0203
    0.0201
    0.0197
    0.0196
    0.0194
    0.0188
    0.0188
    0.0185
    0.0183
    0.0179
    0.0176
    0.0173
    0.0170
    0.0168
    0.0164
    0.0164
    0.0161
    0.0158
    0.0154
    0.0154
    0.0151
    0.0150
    0.0147
    0.0143
    0.0140
    0.0138
    0.0138
    0.0137
    0.0135
    0.0132
    0.0129
    0.0130
    0.0126
    0.0127
    0.0125
    0.0124
    0.0124
    0.0122
    0.0122
    0.0119
    0.0120
    0.0117
    0.0116
    0.0116
    0.0114
    0.0112
    0.0112
    0.0108
    0.0110
    0.0108
    0.0104
    0.0101
    0.0102
    0.0101
    0.0099
    0.0096
    0.0092
    0.0092
    0.0088
    0.0086
    0.0083
    0.0080
    0.0078
    0.0074
    0.0075
    0.0073
    0.0070
    0.0068
    0.0067
    0.0066
    0.0062
    0.0063
    0.0062
    0.0060
    0.0060
    0.0059
    0.0060
    0.0059
    0.0058
    0.0056
    0.0057
    0.0056
    0.0054
    0.0056
    0.0054
    0.0055
    0.0053
    0.0053
    0.0054
    0.0054
    0.0055
    0.0053
    0.0053
    0.0053
    0.0053
    0.0054
    0.0052
    0.0051
    0.0051
    0.0050
    0.0050
    0.0050
    0.0049
    0.0049
    0.0048
    0.0047
    0.0046
    0.0048
    0.0048
    0.0047
    0.0047
    0.0049
    0.0049
    0.0049
    0.0049
    0.0052
    0.0052
    0.0052
    0.0053
    0.0054
    0.0054
    0.0055
    0.0055
    0.0056
    0.0059
    0.0057
    0.0057
    0.0059
    0.0061
    0.0059
    0.0057
    0.0061
    0.0059
    0.0061
    0.0063
    0.0063
    0.0066
    0.0064
    0.0066
    0.0065
    0.0066
    0.0066
    0.0065
    0.0065
    0.0066
    0.0066
    0.0065
    0.0067
    0.0066
    0.0066
    0.0068
    0.0066
    0.0066
    0.0067
    0.0065
    0.0068
    0.0067
    0.0068
    0.0068
    0.0071
    0.0074
    0.0077
    0.0080
    0.0085
    0.0090
    0.0094
    0.0103
    0.0108
    0.0115
    0.0118
    0.0129
    0.0137
    0.0146
    0.0149
    0.0159
    0.0164
    0.0170
    0.0174
    0.0177
    0.0179
    0.0181
    0.0180
    0.0181
    0.0176
    0.0173
    0.0169
    0.0161
    0.0156
    0.0147
    0.0138
    0.0125
    0.0115
    0.0104
    0.0096
    0.0087
    0.0075
    0.0067
    0.0061
    0.0053
    0.0049
    0.0043
    0.0040
    0.0037
    0.0033
    0.0032
    0.0030
    0.0028
    0.0026
    0.0023
    0.0023
    0.0021
    0.0020
    0.0021
    0.0019
    0.0018
    0.0018
    0.0017
    0.0017
    0.0014
    0.0014
    0.0016
    0.0011
    0.0013
    0.0011
    0.0013
    0.0014
    0.0011
    0.0014
    0.0010
    0.0011
    0.0011
    0.0011
    0.0007
    0.0010
    0.0008
    0.0005
    0.0005
    0.0008
    0.0007
    0.0003
    0.0010
    0.0007
    0.0007
    0.0001
    0.0006
    0.0010
    0.0008
    0.0003
    0.0005
    0.0002
    0.0001
    0.0004
    0.0005
    0.0007
    0.0004
    0.0002
    0.0003
   -0.0000
    0.0000
    0.0003
    0.0002
    0.0002
    0.0004
   -0.0001
    0.0003
   -0.0001
    0.0001
    0.0000
   -0.0001
    0.0003
   -0.0001
    0.0006
    0.0003
    0.0005
    0.0002
    0.0005
    0.0004
    0.0006
    0.0006
    0.0002
   -0.0000
    0.0003
    0.0002
   -0.0004
   -0.0002
   -0.0002
   -0.0001
   -0.0000
   -0.0001
   -0.0006
    0.0000
   -0.0002
    0.0002
    0.0005
    0.0004
   -0.0003
    0.0005
   -0.0004
    0.0001
   -0.0006
   -0.0000
    0.0001
    0.0006
   -0.0003
    0.0005
    0.0001
    0.0007
    0.0000
    0.0001
    0.0000
   -0.0003
   -0.0005
   -0.0001
    0.0003
   -0.0002
    0.0010
    0.0003
   -0.0001
   -0.0007
   -0.0008
    0.0009
    0.0004
   -0.0002
   -0.0005
   -0.0002
   -0.0009
   -0.0001
    0.0004
    0.0001
    0.0005
   -0.0000
    0.0002
   -0.0001
   -0.0011
   -0.0015
   -0.0014
   -0.0026
   -0.0052
   -0.0047
   -0.0042
   -0.0019
   -0.0021
   -0.0007
   -0.0005
   -0.0005
   -0.0003
   -0.0006
   -0.0015
   -0.0009
   -0.0013
   -0.0006
   -0.0010
   -0.0013
   -0.0012
   -0.0010];
a_phi=interp1(wl,a_f,wavelength,'linear')/1.25;